The Interdisciplinary Evolution of the Hubble Space Telescope

The Interdisciplinary Evolution of the Hubble Space Telescope
An Historical Examination of Key Interdisciplinary Interactions Team Hubble Huddle is pleased to present our investigation of the Hubble Space Telescope. Our team reviewed numerous documents and conducted oral interviews with a number of key participants in the program. Greg Carras, Jerry Cordaro, Andrew Daga, Sean Decker, Jack Kennedy, Susan Raizer University of North Dakota, Department of Space Studies 24 April 2006

The Hubble Space Telescope: An Overview
An orbiting telescope that collects light from celestial objects in visible, ultraviolet, and near-infrared wavelengths Launched 24 April 1990 aboard the Space Shuttle Discovery Dimensions: Cylindrical 24,500 lb (11,110-kg), 43 ft long (13.1 m ) and 14.1 ft (4.3m) wide Orbital period: 96 minutes Primarily powered by the sunlight collected by its two solar arrays The telescope’s primary mirror is 2.4 m (8 ft) in diameter Was created by NASA with substantial and continuing participation by ESA Operated by the Space Telescope Science Institute (STSI) in Baltimore, MD Named for Edwin Powell Hubble The Hubble space telescope is basically a large reflector telescope (similar to Newton’s original concept), whereby two parabolic mirrors act to concentrate light. The size and need for near-perfection in the shaping of the large primary mirror was a long-standing concern for the developers. Original concepts were based on a 3-meter mirror, but the implications for this on overall vehicle size were prohibitive, and so Hubble was eventually designed with a 2.4-meter primary mirror. The amazing feature of the HST is its ability to remain pointed where astronomers want it to focus. Imagine dividing a circle into 60 minutes, and then each minute into a second, and then divide one second into a thousand segments – Hubble can remain focused on 7/1000’s of a second, and it can maintain this for long periods of time while moving on a circular path at 17,500 mph. "The Hubble Space Telescope is the most productive telescope since Galileo's" - Robert Kirshner, President of the American Astronomical Society Reference: Image and data: STSI (

The evolution of HST may be best approached by understanding the interaction of four factors:
The Social and Political Conditions The Historical Context (and the post WWII trend toward “Big Science”) Hubble is a marvel of engineering, and its scientific accomplishments have exceeded expectations – but there is much more to Hubble than technology and beautiful astronomical imagery. The four sides of Hubble’s evolution include: Historical context, people and agencies, technology, and social and economic conditions. Other divisions are possible, but this is one useful way to analyze the program. We shall see how these four sides of Hubble are sewn together by the following disciplines: History Technology Science Funding and economics Policy, law, and international cooperation Management and operations The Technological Dimension The Participants (People and Agencies)

Hubble’s Historical Context
At the beginning of the 20th Century, scientists had a remarkably limited view of the physical universe – many believed that our galaxy was the only galaxy. Before WWII most astronomy was conducted by individuals or small groups, and astronomical observatories were funded by private philanthropists (example: Carnegie) or by an individual astronomer (example: Percival Lowell). By the 1920’s this view was being rapidly revised, in part due to the observations of Edwin Hubble and Milton Humason in the 20’s and 30’s who saw many other galaxies, and that these galaxies were moving away from each other (which leads to the concept of an expanding universe and the Hubble Constant). During WWII, the federal government teamed up with industry and the scientific community to form working partnerships. People learned how to develop transformational projects quickly and “Big Science” is born. Some scientists learn how to play the game and extend themselves to be activists for important programs. One of these, an astronomer, is Lyman Spitzer, Jr. To understand Hubble’s evolution, it is useful to begin with an appreciation for the condition of science in the post-WWII years, how it was changing, and how science and industry were teaming up with the federal government for common purposes. The idea of “Big Science” emerges as the new paradigm after WWII, showing the pathway to large transformational programs. (The government focuses the money, industry supplies the engineering and technology, and the academic science community supplies expert insight and inspiration – to oversimplify). Moreover, some scientists have learned to become politically savvy during this time, and they become the crucial advocacy for Hubble sustenance.

Hubble’s Historical Context (continued)
In 1946 Spitzer publishes “Astronomical Advantages of an Extra-Terrestrial Observatory,” for RAND. It lays out in detail for the first time the enormous advantages of a space-based telescope. This report remains classified for years. The US Army has been experimenting with captured V2 rockets, some of which have been equipped with scientific payloads. In 1950, at a dinner party in his home, physicist James Van Allen and several scientists consider the idea for a third International Polar Year – this will become the IGY. An increasing number of scientists are looking at the space environment and new space age technologies to further scientific exploration. Other scientists and engineers are also speculating about the new realm of possibilities for science, including Wernher von Braun, who describes a manned orbital telescope in 1952. 1955: In response to growing pressure from scientists, the US National Academy of Sciences and National Science Foundation jointly agree to seek approval to orbit a scientific satellite during the upcoming IGY (to be ). During this period, many scientists remain unconvinced of the idea to take science into space. Nevertheless a scientific advocacy emerges, and it learns to become politically savvy. The paradigm has shifted to Big Science. With the scientists providing the impetus, the concept for a space telescope emerges in the mid-1940’s, and grows in the 50’s in the heat of Cold War tensions. As the Apollo program concludes, NASA is seeking new missions, but Congress is averse to any new program start. The US is engaged in the Cold War, and high-technology public demonstrations run apace with the deployment of secret spy satellites in the 1950’s and 1960’s. The DoD is careful to control secrecy, and NASA is looking beyond Apollo for new programs to demonstrate its capabilities. The federal government wants to stimulate scientific involvement and progress through these programs, but by the early 1970’s the US economy is stagnant. As we shall see, most presidential administrations after Ford concur with the astronomer advocates of a large telescope, as does NASA management (Fletcher), but NASA is unwilling to ask for the money that Marshall Space Flight Center believes is necessary, fearing Congress will balk.

Hubble’s Historical Context (continued)
In 1958 (and following Sputnik), the Space Science Board of National Academy of Sciences calls for and receives hundreds of suggestions for follow-on projects to IGY. These are forwarded to NASA's Space Science Working Group on "Orbital Astronomical Observatories (OAOs)" President Eisenhower enthusiastically supports. In the Cold War climate, NASA is interested in demonstrating what it can do. In it issues first RFP’s for OAO series. The contentious relationship between NASA and the science community takes form with the OAO project. Scientists who have been used to taking complete charge of their science projects will now have to contend with a loss of control to NASA. On the positive side: With OAO, the idea of a Guest Observer is introduced – breaking from the idea of strict control by a single Principal Investigator. This will have later implications as key scientists will insist that the new Large Telescope be a National Facility (open to all) On the negative side: 2 of 4 OAO missions fail – in large part because NASA did not communicate well with the scientists and the technology was too complicated. Before HST, there were precursor space telescopes, notably NASA’s OAO program. OAO telescopes were smaller than Hubble. The first mission OAO-1 in 1966 had a much smaller primary mirror and a pointing accuracy of 0.1 arcsec (compared to Hubble’s .007 arcsec), but it was more technically complex than scientists had actually wanted – it failed due to an electrical malfunction 7 minutes after achieving orbit. Of the four OAO missions, two failed, but these successful flights were enough to validate the case for space-based astronomy, and NASA looked for ways to bridge from OAO to the LST that Sptizer and Von Braun and others had been promoting. At the time, it was not clear that the 120”-class mirror was technically feasible, and Von Braun’s team envisioned it as part of a pressurized manned laboratory which could be serviced by astronauts. At this time, the technical means to capture imagery was uncertain. Film was considered (as used in some spy sats), but conventional film is not optimal for astronomy (it is too sensitive to some wavelengths). Versions of the Vidicon system were seriously considered, but in the end, the development of CCD’s would prove ideal. CCD’s had been invented in 1970, and companies were working rapidly to develop them for the commercial market. The LST would have to be quite different than OAO and use unproven technologies. OAO also evidenced the trend where these expensive space assets would come to seen as long-lived national facilities. This broke with the convention of a space experiment designed and operated by a single Principal Investigator. On Hubble, any scientist could propose to do work. Reference: Smith, Robert W, et al. The Space Telescope: A Study of NASA, Science, Technology, and Politics. New York: Cambridge Univ. Press, 1989

Social and Political Conditions
As NASA begins to seriously contemplate a Large Space Telescope, the financial and budgetary condition of the nation weighs heavily. This factor, and how the various participants perceive it, will prove to be critical in defining Hubble’s scientific potential, management, ultimate cost, and schedule. By the mid-1970’s the federal budget has been overstressed by the expenses of war and the Great Society programs, and the economy is stagnating. NASA senior management is concentrating on the new Space Shuttle and the political climate for new expensive projects is hostile. NASA continues to pursue an LST by using available funds (not needing congressional approval) to fund “Phase A” studies, forcing Marshall Space Flight Center to compete with Goddard Space Flight Center to become the lead center. NASA Administrator Fletcher finds the Phase A cost estimates politically untenable – and orders MSFC to limit the program cost to $300M. Finally, throughout the 1960’s and 70’s, the DoD has been building a series of increasingly sophisticated reconnaissance satellites, and it forces controls on NASA that severely limit NASA’s access to the technology to protect secrecy. Ironically, the same companies that know how to build the recon satellites are ultimately selected to build Hubble. The overarching problem that cut through all disciplinary areas in HST’s evolution was money. NASA’s principal critic is asking for money was not so much the various presidents and their OMB’s, but congress. In fact, shortly after President Ford came into office, he asked for extraordinary fiscal frugality by the congress. Despite this (and just as LST was being proposed for a new program start), his director of OMB recommended that NASA get more money. Most other federal programs were to be cut across the board, but OMB director Lynn was a supporter of Big Science. Nevertheless, NASA would initially ask Congress for too little money. Marshall’s Phase A estimates came in so high that they were untenable, according to NASA Administrator Fletcher – he believed that $300M was a more reasonable amount, and the most NASA could ask congress for. Marshall goes back and essentially tries to fit their LST concept into a $300M box. The estimate by MSFC emerged from their Phase A study. NASA HQ had asked MSFC and GSFC to compete against each other to see which would be the lead center. There were legitimate pros and cons for each center, but the ultimate decision to choose Marshall put the two centers on a collision course which would lead to hostile relations and confused management authority. As a peer field center, Goddard assumed the subordinate roll, which was problematic since they were, justifiably, the lead astronomy center. The decision to select Marshall was also colored by intangibles – one being that Marshall was threatened with closure at the time, and LST would, it was believed, save it. Reference: Smith, Robert W, et al. The Space Telescope: A Study of NASA, Science, Technology, and Politics. New York: Cambridge Univ. Press, 1989

Hubble’s Participants – Key People and Agencies
The four key participants in the development lifecycle of Hubble: Space Agencies NASA Headquarters – the Office of Space Science believes the LST is a major priority, but senior management were reluctant to propose any new program. MSFC – it had no astronomy expertise and was threatened with closure at the time of the LST Phase A competition; it wanted the LST badly and said so. GSFC – it had the experienced people and know-how to build astronomical sats (it was lead for OAO), but was overburdened with project work; it’s Director was ambivalent about the project. JSC, KSC and JPL would play important roles in the program too. JSC’s astronauts would prove essential. JPL designed and built the WF/PC (and the $60M spare). Astronomers and other scientists within NASA would play a pivotal role in coordinating with the science community, of these Dr Robert O’Dell (Chief Project Scientist at MSFC) and Dr Nancy Roman of NASA HQ were crucial. ESA – It wanted a substantial space science program but could not do it on its own, and NASA needed to satisfy Congress while reassuring domestic scientists that they would not sacrifice control as a price for ESA’s involvement Executive and Legislative Branches of Government Executive Branch – despite budget constraints imposed by the Ford administration, the OMB and President Ford were generally supportive, as were officials in the Carter and Reagan administrations. Congress – Hubble will face stiff opposition from key congressional committees forcing major delays and economic limits. Congress will ultimately mandate international cooperation. The most prominent opponents of Hubble were Representative Edward P. Boland (D-MA) and Senator William Proxmire (D-WI). We can categorize four principal participant agencies. Two are branches of government, the others balance the Big Science triad. The slide shows the key space agencies, including NASA and ESA. It is important to understand that NASA did not act as a coordinate agency, but as independent groups. Within NASA HQ, for instance there was for a time a schism between the technology and science offices. The schism between MSFC and GSFC was openly angry. The lines of communication, particularly prior to 1983, were poor and sometimes suppressed. Interesting, it was frequently the case that a single individual could break through the lines to open an independent line of communication. Sometimes this was within NASA, sometimes between NASA and a contractor, sometimes with key politicians, but most often a scientist/astronomer was involved. At NASA, several key scientists acted in this role, including MSFC’s chief scientist (O’Dell) and HQ’s chief of astronomy (Roman). In the period prior to 1983, however, NASA HQ deferred to MSFC to run the program, and very few people at HQ were involved. This lack of authority would haunt the program. As we have said, presidential science advisors, OMB directors, and presidents from key administrations were generally supportive, but congressional appropriations committees were actively hostile. Much of NASA HQ’s time was spent in dealing with congress, usually with a mood of fear of program cancellation. Reference: Smith, Robert W, et al. The Space Telescope: A Study of NASA, Science, Technology, and Politics. New York: Cambridge Univ. Press, 1989

Key People and Agencies (continued)
Scientists and Advocates Individual scientists will come to save the telescope by rallying their community and aggressively lobbying congress. Of these, the most influential will be Lyman Spitzer and John Bahcall, both of Princeton. Their collaboration with Robert O’Dell (at MSFC) in lobbying Congress will come to be called the “Princeton-Huntsville Axis.” O’Dell actively promotes the project in scientific journals and presentations. Industry Many companies contributed to LST/HST, including all major aerospace firms, most in subcontractor roles to Lockheed Missiles and Space Company (CA) for the SSM, and to Perkin-Elmer (CT) for the OTA. Lockheed and P-E had substantial experience working on highly classified PHOTOINT satellites. Other firms were contracted by the universities to build elements of the Scientific Instruments. At various times, corporate competitors worked together and with NASA and outside scientists to lobby congress at critical junctures. Importantly, since both Lockheed and P-E were operating as “associate contractors” – no company was fully charged with systems engineering authority, and NASA was unable to perform this role adequately. There were many heroes in Hubble’s history, skilled technicians and ingenious engineers, but the role of scientist advocates has been extraordinary. This has been true from the inception to the present day. It is also true that, from inception, there have been scientist detractors. Among scientists, clearly, astronomers and astrophysicists have been the most obvious apologists. But some in the planetary science field were slower to come around (which is one reason why the WF/PC is named as it is (PC stands for “planetary camera”). In order to widen the advocacy coalition, changes were planned into Hubble to make it more useful to the wider group. These sorts of changes (and trade-offs) tended to add to the cost and complexity. The role of scientists was not merely to guide the planning of the telescope, but to make the case for it. Key scientists would address groups of other scientists, and would make media presentations. The most vocal worked congress. Within NASA, O’Dell and others coordinated quietly with the university community. HST is a magnificent technological accomplishment, and the geniuses who designed and built it were enabled by companies like Lockheed, Boeing, Bendix, and Perkin-Elmer. However, there were major problems with some of these contractors. Much of the blame for this can be directed at NASA’s decision to use associate contractors (as opposed to a prime), thereby leaving no agency or company in an effective systems management role. More of it can be attributed to inadequate funds to manage the program, and to underestimates of cost and schedule and complexity. A lot can be attributed to poor communication, by both NASA and some of the contractors. And, the effect of the demand for compartmentalization of the contractors by DoD (to protect secrecy of PHOTOINT technology) was clearly deleterious. Reference: Smith, Robert W, et al. The Space Telescope: A Study of NASA, Science, Technology, and Politics. New York: Cambridge Univ. Press, 1989

Hubble’s Evolution – Consolidated Summary
In the context of big science and Cold War tensions and technology advancements, NASA and the scientific community find common purpose in proposing a large (3m) reflecting telescope in Earth orbit. Astronomers know it will be revolutionary; NASA and several presidents agree. As Apollo concludes, NASA is under fire and fighting to keep field centers open. It develops an LST program but forces GSFC to compete with MSFC to lead the program. The compromise sets up antagonism between the centers. With Marshall in the lead, the program is believed to be untenable politically – an artificial limit of $300M is imposed, and the DoD demands limits on contractor penetration of the two key defense contractors. With constant cost overages, NASA management demands reductions, forcing trade-off studies of capability versus cost. In this process the 3m primary mirror will be reduced to 2.4m. The scientists are always pushing back. When the program is proposed to Congress, the House appropriations subcommittee rejects it, forcing NASA to appeal to the Senate in hopes of effectuating a resolution, and NASA considers holding off on the program. It is at this point that university scientists, key NASA staffers and scientists, and contractors, begin to collaborate to lobby congress. From this emerges a partial victory, leading to the restoration of some funding and the mandate that NASA collaborate with ESA. NASA begins talks with ESA. To put it simply, the space telescope began with the ideas of a few visionaries. The case for such a telescope came about when it was realized that Earth-based visible light telescopes were essentially limited; atmospheric distortion could not be corrected further. As scientists began to form a new cosmological vision, it was clear that the glimpses we had just showed that there was a lot more yet to be seen – and science would be starved of the information it needed to build its understanding of the universe. The visionary astronomers make their case to NASA, the US agency able build a space telescope. But as the 60’s unfold, NASA itself is starved for funding. The OAO program and others whet the appetite for more. But the science community is wary of ceding control to NASA. Persistence will pay off as NASA and scientists build the case. Despite the weight of national economic pressures, the argument for LST is sufficiently good that the program proceeds, but with so much caution that it is crippled from its start.

As the program moves into the design and development phase (C/D), a manpower cap and the limited budget restrain Marshall’s ability to manage the program. NASA depends on two associate contractors to do their own systems engineering. MSFC saw itself in this role, but was not able to do it. During this period the relationship between MSFC and GSFC is antagonistic and even hostile. Goddard is charged with developing the scientific instruments and eventually operating the telescope, but only reluctantly takes direction from MSFC. Marshall objects to Goddard’s interference, and Marshall’s project scientist (O’Dell) takes the initiative away from GSFC. As the project moves ahead, even with ESA’s 15% contribution, the LST runs out of money. Faced with the prospect of severely reducing the scientific capability and delaying the launch, NASA management concedes to extend the launch date and returns to congress for more money. Status 1980: From it’s inception, LST has been underfunded and consequently, its capabilities were oversold (Smith, 1989). In 1980, the program is in crisis but still at a design stage where NASA considers cutting back on certain technologies to save money. During this time, scientists are working to create the methodologies that will be needed to operate HST at the STSI. A entire new star reference system is created to help guide the telescope. In 1983, the program hits another crisis – NASA finally recognizes that changes need to be made, the launch date extended, and NASA HQ demands new managers and appoints its own project manager. NASA works with OMB and Congress begins to infuse much more money. Things begin to change. It took nine years (1977 to 1986) to design and build Hubble, much longer than expected. Though it is an unfair comparison, the Apollo program executed the manned lunar landing in less time. During this time it faced multiple crises and was incalculably over budget. The reasons for this were primarily social and political rather than technological.

Between 1983 and 1986, the program is disciplined and turned around. New managers at NASA do not feel tied to the unrealistic promises that the program has made. Launch is scheduled for 1986. In 1986, just as the program is being readied for its final round of thermal-vacuum chamber testing, the Shuttle fleet is grounded with the Challenger disaster. NASA is afraid to lose the technical skills it needs to finish the program, so work continues to fix lingering problems and complete the thermal-vacuum testing. HST goes into protected storage. In 1990, HST is launched and very quickly put into service. Soon, it will be discovered that there is a flaw in the optics, which will be traced to a manufacturing error at P-E (which P-E knew about for 10 years). In 1993, in a dramatic series of EVA’s during the first servicing mission (SM), HST’s optics are corrected and a new era of space astronomy finally begins. Since 1993, there have been 3 additional SM’s, each one replacing and upgrading HST to state-of-the-art technology. Hubble has generated data of unprecedented quality in vast quantities since – and continues to do so. With more demand for observing time than can be filled, and the ability to be extended indefinitely, Hubble has turned out to be everything and more than its supporters ever claimed. It is important to stress some points: Someone has to be truly responsible for a project’s systems engineering. This must be an agency or company empowered to make decisions, not a nominal function. Lockheed lacked the power from NASA to perform this function. It was only when NASA HQ appointed a tough program manager in HQ that the program turned around. High management turnover also contributed to HST’s problems. This was probably a manifestation of inadequate funding for such a complex program. Hubble is not a reconnaissance satellite simply turned to view space. The design of PHOTOINT satellites and space telescopes are necessarily very different. Hubble did benefit from the intrinsic knowledge that resided in certain key contractors, but it also suffered because walls were erected to prevent dissemination of this knowledge. Perkin-Elmer was under-qualified to accept the responsibility for the OTA. It was an optical house trying to act like a major aerospace company. It is apparent that the psychology of the budget process was a key factor. NASA management was afraid to ask for what it really needed (it is also true that it probably would not have gotten the money had it asked for it). It is also ironic that congress, in its effort to limit spending, probably influenced the budget for HST to go up by restricting funding. References: Smith, Robert W, et al. The Space Telescope: A Study of NASA, Science, Technology, and Politics. New York: Cambridge Univ. Press, 1989, and personal interview, Dr David Leckrone, Goddard Space Flight Center, 10 April 2006.

Hubble’s Technological Dimension Index to Technology Slides
The Hubble Space Telescope was designed with many constraints – both technical and cost. This technology section will cover the technology components of Hubble and the rationale that drove decisions on its design. Index to Technology Slides Hubble Components - Overall Components - Power Systems - Spacecraft Systems - Mirrors and Baffles – Mirror Problem - Sensors - Actuators - Scientific Instruments Most Difficult Technical Challenge – Pointing Control System “Get the Cost Down” Initial Deployment Components and Servicing Missions The Hubble Space Telescope was constrained by cost and technology. Team leader Downey said the Agency wanted “to procure the lowest cost system that will provide acceptable performance” and would “be willing to trade performance for cost.” By December 1974 the Program Development task team had downsized the telescope. As before the team had to balance cost and performance and devise a design pleasing to Congress and the astronomers. This section will cover the components of Hubble, discuss servicing missions to fix and upgrade Hubble, and will also discuss some of the challenges of the program.

Overall Components – Exploded View
Hubble Technology Overall Components – Exploded View This slide shows an exploded view of Hubble. Note specifically the mirror location in this diagram as we will discuss this later in the presentation.

Hubble Technology Power Systems Solar Arrays:
(2) 40-foot (12-meter) panels that convert sunlight into 2400 watts of electricity in order to power the telescope. Batteries: - 6 nickel-hydrogen (NiH) batteries - Power storage capacity is equal to 20 car batteries - Power usage: 2,800 watts This slide shows the power systems. Hubble solar arrays power the telescope and re-charges the batteries. Also, on this slide, note the aperture door which protects the mirror. Initially Marshall had the most difficulties with vibrations in the solar panel booms. Dr. Gerald Nurre, Marshall’s chief scientist for pointing control systems, recalled noticing the problem almost immediately. As the telescope traveled in and out of Earth’s shadow, temperature changes bent materials in the booms. Project engineers had anticipated minor deformations, but ESA had predicted no serious problems would result. What they had not expected was the array’s deployment and orientation mechanisms to magnify the deformations and bounce the whole telescope. The vibrations were severe enough to prevent the guidance system from locking on guide stars and to cause “jitter” in the optical images. The booms only stabilized in the last few minutes of daylight, and so the pointing system initially met its design specifications in about 10 percent of its orbit. Nurre’s team in Marshall’s Structures and Dynamics Lab worked with Lockheed to change the control program in the telescope’s computer, directing the pointing and control system to counteract the vibrations. The new program brought the pointing system within the telescope’s stringent specifications in 95 percent of the orbit.

Hubble Technology Power Systems
This slide shows the wing detail of the solar array.

Hubble Technology Spacecraft Systems Communications antennae (2)
Transmit Hubble's information to communications satellites called the Tracking & Data Relay Satellite System (TDRSS) for relay to ground controllers at the Space Telescope Operations Control Center (STOCC) in Greenbelt, Maryland. Computer support systems modules Contains devices and systems needed to operate the Hubble Telescope. Serves as the master control system for communications, navigation, power management, etc. Electronic boxes Houses much of the electronics including computer equipment and rechargeable batteries. Aperture door Protects Hubble's optics in the same way a camera's lens cap shields the lens. It closes when Hubble is not in operation to prevent bright light from hitting the mirrors and instruments. Light shield Light passes through this shaft before entering the optics system. It blocks surrounding light from entering Hubble. Pointing control system This system aligns the spacecraft to point to and remain locked on any target. The telescope is able to lock onto a target without deviating more than 7/1000th of an arcsecond, or about the width of a human hair seen at a distance of 1 mile. Hubble sends data to the STOCC in Greenbelt, MD via satellite and ground relays. The computer support systems modules provide overall control for the systems of Hubble. As said on the previous slide, the aperture door protects the optics. The light shield helps the optics by preventing surrounding light from negatively impacting the optics system. The pointing control system aligns the spacecraft and locks on target. This is the most difficult technical challenge on the Hubble. Note the accuracy in the slide – it is amazing!

Hubble Technology Spacecraft Systems
This slide shows the optical telescope assembly components. Note the orientation of the mirrors, fine guidance sensors, baffles, star tracker and science instruments.

This slide depicts the support systems module. Note the location of the reaction wheel assembly with respect to the body of the module.

This slide depicts the structural components of the support systems module.

The diagram on the left depicts the aperture door and light shield. These are primarily for protection of the optics. The diagram on the right depicts the forward shell of the support systems module. Note the stowed position of the solar arrays and antenna mast.

Hubble’s Spacecraft Systems – the OTA
This chart depicts the launch and deployment of Hubble. It provides a better graphic than the previous slides.

Hubble Technology Communications
As mentioned in an earlier slide, this depicts the path of data from Hubble to Goddard Space Flight Center. Note that Hubble first transmits to the Tracking and Data relay satellite before sending to the ground station. The ground station then transmits to Goddard. Hubble data path to the Goddard Space Flight Center.

Pointing Control System
Hubble Technology Pointing Control System Probably the greatest challenge was the pointing and control system. The telescope would be the largest astronomical instrument in space; the size of a semi truck, it would measure 43 feet long and 14 feet in diameter, and weigh over 12 tons. Yet this huge spacecraft would have pointing requirements more stringent than any previous satellite. To make images from faint objects, the scientific instruments needed long exposures, demanding a pointing accuracy of 0.01 arc second and holding onto a target within accuracy of arc second. In other words if the telescope were in Washington, DC, it could focus on a dime in Boston and not stray from the width of the coin The Pointing Control System (PCS) aligns Hubble so that the telescope points to and remains locked on a target. The PCS is designed for pointing to within .01 arcsec and is capable of holding a target for up to 24 hours while Hubble continues to orbit the Earth at 17,500 mph. If the telescope were in Los Angeles, it could hold a beam of light on a dime in San Francisco without the beam straying from the coin's diameter.

Hubble Technology Mirror and Baffles Primary Mirror Secondary Mirror
Primary Mirror Diameter: 94.5 in (2.4 m), Weight: 1,825 lb (828 kg). Hubble's two mirrors were ground so that they do not deviate from a perfect curve by more than 1/800,000ths of an inch. If Hubble’s primary mirror were scaled up to the diameter of the Earth, the biggest bump would be only six inches tall. Secondary Mirror Secondary Mirror Diameter: 12 in (0.3 m), Weight: 27.4 lb (12.3 kg). Focal Plane Mirrors focus starlight on the Focal Plane. Baffles: Keep out stray light. Main baffle Central baffle Secondary mirror baffle This slide shows the technical specification of the mirrors. The focal plane and baffles provide protection for the mirror. The telescope's primary mirror (2.4 m diameter) being hoisted up

Hubble Technology Mirror and Baffles Hubble Main Mirror
Note the size of the mirror in relation to the size of the people. Now think about the polishing tolerances that Perkin-Elmer had to meet. 1/50 of a human hair was the out of tolerance condition after polishing. Workers study Hubble’s main, eight-foot (2.4 m) mirror. Hubble, like all telescopes, plays a kind of pinball game with light to force it to go where scientists need it to go. When light enters Hubble, it reflects off the main mirror and strikes a second, smaller mirror. The light bounces back again, this time through a two-foot (0.6 m) hole in the center of the main mirror, beyond which Hubble’s science instruments wait to capture it. In this photo, the hole is covered up.

Hubble Technology Mirror and Baffles
This slide depicts the light path to the mirrors.

The diagram on the left depicts the focal plane structure which contains science instrumentation. The diagram on the right depicts the secondary mirror assembly.

This chart depicts the primary mirror assembly.

Hubble Technology Mirror and Baffles Mirror Problem
The mission controllers made progress and by 21 May began receiving the first optical images from the telescope. These views of a double star in the Carina system, scientists believed, were much clearer than those from ground-based telescopes. Such success left project officials surprised on the weekend of 23–24 June when the telescope failed a focus test. The controllers had moved the telescope’s secondary mirror to focus the light, but a hazy ring or “halo” encircled the best images. Subsequent tests determined that the blurry images resulted from the “spherical aberration” of the primary mirror; spherical aberration reflected light to several focal points rather than to one. It occurred because Perkin-Elmer had removed too much glass, polishing it too flat by 1/50th of the width of a human hair. This seemingly slight mistake, however, prevented the telescope from making sharp images. The problem was caused by polishing the mirror too flat by removing an extra 1/50th of the width of a human hair. This resulted in unclear images.

Corrective Optics Space Telescope Axial Replacement
Hubble Technology Mirror and Baffles COSTAR Corrective Optics Space Telescope Axial Replacement Although the primary mirror was not one of the replaceable units, its aberration could be corrected, much like the way an eye doctor corrects poor vision with spectacles, by modifications to “second generation” scientific instruments. COSTAR, the corrective optics Space Telescope axial replacement, would replace the high speed photometer and use relay mirrors mounted on movable arms to focus the scattered light. COSTAR is the Corrective Optics Space Telescope Axial Replacement. It replaced the high speed photometer and uses relay mirrors mounted on movable arms to focus the scattered light. This is the same principle as correcting your vision with a pair of glasses.

Optical Camera Channel and Baffles
Hubble Technology Optical Camera Channel and Baffles This is a picture of the Optical Camera Channel and Baffle assemblies. Four Optical Camera Channel and Baffle assemblies from the Wide Field and Planetary Camera (WF/PC) 1 recovered from the Hubble Space Telescope during HST Service Mission

Optical Camera Channel and Baffles
Hubble Technology Optical Camera Channel and Baffles Faint Object Camera (FOC) M1 Field Mirror Mechanism that was ultimately installed as part of the COSTAR (Corrective Optics Space Telescope Axial Replacement) payload during Space Shuttle Mission STS-61 (Hubble Service Mission 1) to correct errors in the primary mirror onboard the Hubble Space Telescope. The error was the result of a residual aberration polished into the primary due to a mis-assembled nulling apparatus; the error resulted in the Hubble's primary mirror being ground about 2 micrometers too flat (1/40 the thickness of a human hair). Scientists and engineers devised COSTAR with four small mirrors, about the size of dimes and quarters. The small mirrors were intentionally produced with a flaw identical to and opposite the flaw on the primary Hubble mirror. This is the Faint Object Camera (FOC) M1 Field Mirror Mechanism that was ultimately installed as part of the COSTAR (Corrective Optics Space Telescope Axial Replacement).

Hubble Technology Sensors Fine Guidance Sensors (3)
These sensors are locked onto two guide stars to keep Hubble in the same relative position of these stars. Coarse Sun Sensors (2) Measure Hubble's orientation to the sun. Also assist in deciding when to open and close the aperture door. Magnetic Sensing System Measure Hubble position relative to Earth's magnetic field. Rate Sensor Unit Two rate sensing gyroscopes measure the attitude rate motion about its sensitive axis. Fixed Head Star trackers An electro-optical detector that locates and tracks a specific star within its field of view. The fine guidance sensors orient the Hubble position. The coarse sun sensors measure orientation of the Hubble to the sun and assist in determination of actuation of the aperture door. Magnetic sensing system measures the Hubble’s position relative to the Earths magnetic field. Rate sensor unit gyroscopes measure attitude rate motion. Fixed Head Star trackers locates, locks on and tracks a specific star in its field of view.

Hubble Technology Actuators Reaction Wheel Actuators (4)
The reaction wheels work by rotating a large flywheel up to 3000 rpm or braking it to exchange momentum with the spacecraft which will make Hubble turn. Magnetic Torquers (4) The torquers are used primarily to manage reaction wheel speed. Reacting against Earth's magnetic field, the torquers reduce the reaction wheel speed, thus managing angular momentum. The Reaction Wheel Actuators and Magnetic Torquers make Hubble turn and orient to the appropriate stars.

Hubble Technology Actuators
This diagram depicts the location of pointing control subsystem equipment.

Scientific Instruments
Hubble Technology Scientific Instruments Axial bays (4) Four instruments are aligned with the main optical axis and are mounted just behind the primary mirror. As of the year 2000 they consisted of: ACS (Advanced Camera for Surveys) The newest camera (2002) with a wider field of view, and better light sensitivity. It effectively increases Hubble's discovery power by 10x. NICMOS (Near Infrared Camera and Multi-Object Spectrometer) Infrared instrument that is able to see through interstellar gas and dust. STIS (Space Telescope Imaging Spectrograph) Separates light into component wavelengths, much like a prism. COSTAR Contains corrective optics for spherical aberration in the primary mirror. Radial bay (1) Wide Field/Planetary Camera 2 (WFPC2) is housed here. Taking images that most resemble human visual information, WFPC2 is responsible for taking nearly all of Hubble's famous pictures. Fine guidance sensors (3) The sensors lock onto guide stars and measure relative positions, providing data to the spacecraft's targeting system and gathering knowledge on the distance and motions of stars. The ACS enables Hubble to see more in the field and increases discovery power by 10%. NICMOS is an infrared instrument that enables observation through interstellar dust and gas. STIS is a spectrograph that separates light into its component parts. COSTAR as was mentioned earlier, corrected the spherical aberration in the primary mirror. Fine Guidance Sensors lock onto guide stars which enables targeting.

Hubble Technology Scientific Instruments This diagram depicts the optical path of light in the Fine Guidance Sensor.

Hubble Technology Scientific Instruments Space Telescope Imaging Spectrograph (STIS) This is a picture of the STIS which was mentioned earlier. Engineers in a clean room at Ball Aerospace in Boulder, Colo., work on one of Hubble’s instruments, the Space Telescope Imaging Spectrograph (STIS), in The instrument, installed in Hubble in 1997, breaks light into colors, giving scientists an important analytical tool for studying the cosmos. STIS has been used to study such objects as black holes, new stars, and massive planets forming outside our solar system.

The Most Difficult Technical Challenge – Pointing Control System
Hubble Technology The Most Difficult Technical Challenge – Pointing Control System The Problem: A major problem for NASA and its contractors was the means to guide and stabilize the telescope. If the completed telescope was to perform to the negotiated requirements, it would have to be capable of being aimed at an astronomical target with a pointing stability of seconds of arc, an angle on the sky about 360,000 times smaller than the angle that is subtended by the diameter of the full moon. So taxing was this requirement that it was widely viewed in NASA and outside as the most difficult technical challenge the designers and builders had to overcome. The telescope not only had to be pointed extremely accurately, means also had to be devised to keep it locked on its astronomical targets. This task was crucial because there would inevitably be tiny disturbances that would act to move the spacecraft away from its targets, disturbances known as "jitter". Jitter might arise from the motions of the gyroscopes in pointing, for example. Should the entire spacecraft be moved if small corrections in its position were needed (a method known as body pointing)? Or should the secondary mirror of the Large Space Telescope be shifted to compensate for the spacecraft's minor motions (a method known as image motion compensation)? As you can see from the description of the problem in the chart, the accuracy and stability requirements were very stringent.

The Most Difficult Technical Challenge – Pointing Control System
Hubble Technology The Most Difficult Technical Challenge – Pointing Control System The Answer: During Phase A, Bendix had performed studies for Marshall that argued that body pointing alone was sufficient. Marshall, however, was not convinced. Hence the center's Phase A design concept also incorporated a movable secondary mirror. But more studies persuaded Marshall that control moment gyroscopes could point and stabilize the telescope. If so, a moving secondary would not be essential, even though Perkin-Elmer argued that it promised to give the best performance. Marshall's basic engineering approach was to use the simplest available systems where possible, and for pointing and control that would mean using either control moment gyroscopes or reaction wheels alone, but preferably not the two in combination. The solution to the problem was driven by technology and cost.

$300 million as a cost target.
Hubble Technology “Get the Cost Down” The Problem: Financial pressure pushed the Center’s design activities and often forced it to relinquish conservative engineering principles. The Center’s March 1972 project plan called for three telescopes, an engineering model, a “precursor” flight unit, and the final LST. Design and development would cost between $570 and $715 million. Headquarters believed this was too expensive. In a December 1972 meeting, NASA Administrator Fletcher “emphasized that the current NASA fiscal climate was not conducive to initiation of large projects” and suggested $300 million as a cost target. Cost issues drove the engineering approach of the program to go from three telescopes to one for test and flight.

Hubble Technology “Get the Cost Down”
A “proto-flight” approach would eliminate the engineering and precursor units; a single spacecraft would serve as test model and flight unit. The proto-flight approach had been successfully tried for Department of Defense projects, and the Center expected it to reduce costs—which would please Congress—and speed progress to operations—which would please the astronomers. The telescope maintenance strategy also changed. Rather than designing for extensive repair in orbit inside a pressurized cabin, Marshall suggested a design that would eliminate the cabin and minimize repairs in orbit. The new design assumed the Space Shuttle could return the telescope to Earth for major repairs. These changes simplified the overall LST design and development scheme. The “proto-flight” approach was successfully tried in DOD projects. The maintenance approach was changed from using a pressurized cabin in orbit to repairs on Earth. As you will see later, EVA was the ultimate solution for Hubble repairs and upgrades.

Hubble Technology “Get the Cost Down”
By December 1974 the Program Development task team had downsized the telescope. As before the team had to balance cost and performance and devise a design pleasing to Congress and the astronomers. Team leader Downey said the Agency wanted “to procure the lowest cost system that will provide acceptable performance” and would “be willing to trade performance for cost.” Working with the LST science groups and contractors, the team reduced the telescope’s primary mirror from a 3-meter aperture to 2.4 meters. This major change mainly resulted from new NASA estimates of the Space Shuttle’s payload delivery capability; the Shuttle could not lift a 3-meter telescope to the required orbit. In addition, changing to a 2.4-meter mirror would lessen fabrication costs by using manufacturing technologies developed for military spy satellites. The smaller mirror would also abbreviate polishing time from 3.5 years to 2.5 years. The redesign also reduced the mass of the support systems module from 24,000 pounds to 17,000 pounds; the SSM moved from the aft of the spacecraft to one-third of the way forward and became a doughnut around the primary mirror. These changes diminished inertia and facilitated steering of the spacecraft, thus permitting a smaller pointing control system. The astronomers chose to reduce the number of scientific instruments from seven to four. Finally, the Marshall team believed that designing for repair would allow for lower quality standards. The Agency was willing to trade performance for cost. This led to reduction in mirror diameter from three meters to 2.4 meters. This was in part due to the limitations of the Shuttle. This reduction of mirror size reduced fabrication costs. This lower weight enabled a smaller pointing control system. And finally, the number of scientific instruments was reduced from seven to four.

Initial Deployment Components and Servicing Missions
Hubble Technology Initial Deployment Components and Servicing Missions 1990 Initial Complement at Deployment: WFPC (1) - Wide Field/Planetary Camera - First-generation imaging camera. WFPC (1) operated in either Wide Field mode, capturing the largest images, or Planetary mode with higher resolution. GHRS - Goddard High Resolution Spectrograph - First-generation spectrograph. GHRS was used to obtain high resolution spectra of bright targets. FOS - Faint Object Spectrometer - First-generation spectrometer. FOS was used to obtain spectra of very faint or faraway sources. FOS also had a polarimeter for the study of the polarized light from these sources. FOC - Faint Object Camera - First-generation imaging camera. FOC is used to image very small field of view, very faint targets. This is the final, first-generation instrument still on Hubble. HSP - High Speed Photometer - First-generation photometer. This instrument was used to measure very fast brightness changes in diverse objects, such as pulsars. FGS - Fine Guidance Sensors - Science/guidance instruments. The FGS's are used in a "dual-purpose" mode serving to lock on to "guide stars" which help the telescope obtain the exceedingly accurate pointing necessary for observation of astronomical targets. These instruments can also be used to obtain highly accurate measurements of stellar positions. This is a list of the equipment on the initial deployment.

Hubble Technology Initial Deployment Components and Servicing Missions 1993 Servicing Mission 1: WFPC2 - Wide Field Planetary Camera 2 - Second-generation imaging camera. WFPC2 is an upgraded version of WF/PC (1) which includes corrective optics and improved detectors. COSTAR - Corrective Optics Space Telescope Axial Replacement - Second-generation corrective optics. COSTAR is not an actual instrument. It consists of mirrors which refocus the abbreviated light from Hubble's optical system for first-generation instruments. Only FOC utilizes its services today. Restoring Hubble's Vision As the first in a series of planned visits to the orbiting Hubble Space Telescope, the First Servicing Mission (STS-61) in December 1993 had a lot to prove and a lot to do. The mission's most important objective was to install two devices to fix Hubble's vision problem. Because Hubble's primary mirror was incorrectly shaped, the telescope could not focus all the light from an object to a single sharp point. Instead, it saw a fuzzy halo around objects it observed. Once astronauts from the space shuttle Endeavour caught up with the orbiting telescope, they hauled it into the shuttle's cargo bay and spent five days tuning it up. They installed two new devices—the Wide Field and Planetary Camera 2 (WFPC2) and the Corrective Optics Space Telescope Axial Replacement (COSTAR). Both WFPC2 and the COSTAR apparatus were designed to compensate for the primary mirror's incorrect shape. Also installed during the First Servicing Mission were: New solar arrays to reduce the "jitter" caused by excessive flexing of the solar panels during the telescope's orbital transition from cold darkness into warm daylight New gyroscopes to help point and track the telescope, along with fuse plugs and electronic units. This successful mission not only improved Hubble's vision — which led to a string of remarkable discoveries in a very short time — but it also validated the effectiveness of on-orbit servicing. This is a description of what was accomplished on Servicing Mission 1.

Hubble Technology Initial Deployment Components and Servicing Missions Servicing Mission 2: STIS - Space Telescope Imaging Spectrograph - Second-generation imager/spectrograph. STIS is used to obtain high resolution spectra of resolved objects. STIS has the special ability to simultaneously obtain spectra from many different points along a target. NICMOS - Near Infrared Camera/Multi-Object Spectrometer - Second-generation imager/spectrograph. NICMOS is Hubble's only near-infrared (NIR) instrument. To be sensitive in the NIR, NICMOS must operate at a very low temperature, requiring sophisticated coolers. Problems with the solid nitrogen refrigerant have necessitated the installation of the NICMOS Cryocooler (NCC) on SM3B to continue its operation. The light from the most distant galaxies is shifted to infrared wavelengths by the expanding universe. To see these galaxies, Hubble needed to be fitted with an instrument that could observe infrared light. During the 10-day Second Servicing Mission (STS-82) in February 1997, the seven astronauts aboard the space shuttle Discovery installed two technologically advanced instruments. The Near Infrared Camera and Multi-Object Spectrometer (NICMOS) would be able to observe the universe in the infrared wavelengths. The second instrument—the versatile Space Telescope Imaging Spectrograph (STIS)—would be used to take detailed pictures of celestial objects and to hunt for black holes. Both instruments had optics that corrected for the flawed primary mirror. In addition, they featured technology that wasn't available when scientists designed and built the original Hubble instruments in the late 1970s—and opened up a broader viewing window for Hubble. The new instruments replaced the Goddard High Resolution Spectrograph and the Faint Object Spectrograph. Also installed during the Second Servicing Mission were: • A refurbished Fine Guidance Sensor—one of three essential instruments used to provide pointing information for the spacecraft, to keep it pointing on target, and to calculate celestial distances • A Solid State Recorder (SSR) to replace one of Hubble's data recorders (An SSR is more flexible and can store 10 times more data) • A refurbished, spare Reaction Wheel Assembly—part of the Pointing Control Subsystem. This is a description of what was accomplished on Servicing Mission 2.

Hubble Technology Initial Deployment Components and Servicing Missions Servicing Mission 3a: On December 19, 1999, seven astronauts boarded the space shuttle Discovery to pay the Hubble Space Telescope a special holiday visit. After a successful launch and several trips around Earth, the crew caught up with Hubble and hauled it into the shuttle's cargo bay. Six days and three 6-hour spacewalks later, the crew had successfully completed Part A of the two-part Third Servicing Mission, which had them replacing worn or outdated equipment and performing several critical maintenance upgrades. Servicing Mission 3A (STS-103) was a busy one. The most pressing task was the replacement of gyroscopes, which accurately point the telescope at celestial targets. The crew, two of whom were Hubble repair veterans, replaced all six gyroscopes-as well as one of Hubble's three fine guidance sensors (which allow fine pointing and keep Hubble stable during observations) and a transmitter. The astronauts also installed an advanced central computer, a digital data recorder, an electronics enhancement kit, battery improvement kits, and new outer layers of thermal protection. Hubble was as good as new. This is a description of what was accomplished on Servicing Mission 3a.

Hubble Technology Initial Deployment Components and Servicing Missions Servicing Mission 3b: On March 1, 2002, NASA launched the space shuttle Columbia into an orbit 360 miles above Earth, where its seven-member crew met with the Hubble Space Telescope to perform a series of upgrades. Servicing Mission 3B, also known as STS-109, was the fourth visit to Hubble. NASA split the original Servicing Mission 3 into two parts and conducted the first part – Servicing Mission 3A – in December 1999. The highly-trained astronauts performed five spacewalks. Their principal task was to install a new science instrument called the Advanced Camera for Surveys, or ACS. The first new instrument to be installed in Hubble since 1997, ACS brought the nearly 12-year-old telescope into the 21st century. With its wide field of view, sharp image quality, and enhanced sensitivity, ACS doubled Hubble’s field of view and collects data ten times faster than the Wide Field and Planetary Camera 2, the telescope’s earlier surveying instrument. Hubble gets its power from four large flexible solar array panels. The 8-year-old panels were replaced with smaller rigid ones that produce 30 percent more power. Astronauts also replaced the outdated Power Control Unit, which distributes electricity from the solar arrays and batteries to other parts of the telescope. Replacing the original unit, which has been on the job for nearly 12 years, required the telescope to be completely powered down for the first time since its launch in 1990. Reaction Wheel Assembly: Four Reaction Wheel Assemblies like this one are needed to point the telescope. Astronauts will replace one of them. During the last spacewalk astronauts installed a new cooling system for the Near Infrared Camera and Multi-Object Spectrometer, or NICMOS, which became inactive in 1999 when it depleted the 230-pound block of nitrogen ice that had cooled it since The new refrigeration system, which works much like a household refrigerator, chills NICMOS’s infrared detectors to below –315° F (–193° C). NICMOS Cooling System: An experimental refrigeration technology will make it possible to restore Hubble's infrared vision. New Steering Equipment: Astronauts replaced one of the four reaction wheel assemblies that make up Hubble's pointing control system. Flight software commands the reaction wheels to “steer” the telescope by spinning in one direction, which causes Hubble to spin in the other direction. This is a description of what was accomplished on Servicing Mission 3b.

The Science of Hubble It is not even remotely possible to cover all the science that Hubble has done in a single presentation. Tens of thousands of papers and hundreds of books have been written based on HST data, and every day generates 20 GB of data. Astronomers will be mining this resource for generations to come. At its heart, Hubble is a science machine, and has done unprecedented work. Even in the early days after the mirror problems were discovered, it gathered much valuable data, and has opened up the universe in ways never before dreamed.

Exceeding Expectations
“It should be emphasized, however, that the chief contribution of such a radically new and more powerful instrument would be, not to supplement our present ideas of the universe we live in, but rather to uncover new phenomena not yet imagined, and perhaps modify profoundly our basic concepts of space and time.” - Lyman Spitzer, Jr. “[T]his mechanism …has succeeded in opening the universe to us in ways never dreamed possible.” Ever since the invention of the telescope in the 1600s, astronomers have been frustrated by the atmosphere. Twinkling may inspire poets, but it is the bane of good observations; this is why observatories are built on mountaintops. The best situation, of course, would be a telescope in vacuum, but this would be rather hard on the astronomers who might wish to use it. Lyman Spitzer was not the first to suggest a space-based telescope – that distinction belongs to Hermann Oberth – but Spitzer laid out a plan in 1946 that eventually led to the Hubble Space Telescope, as well as the observatory that bears his name. Petersen, Carolyn C. and Brandt, John C. Hubble Vision: Further Adventures with the Hubble Space Telescope, 2nd ed., Cambridge University Press, Cambridge UK Petersen, Carolyn C. and Brandt, John C. Hubble Vision: Further Adventures with the Hubble Space Telescope, 2nd ed., Cambridge University Press, Cambridge UK

The Science of Hubble Even before Hubble was launched, it had changed the science of astronomy. Because of its exacting pointing requirements, the Guide Star Catalog had to be created to allow its fine guidance sensors to be used to their full capacity. The GSC now contains almost a billion objects and is a valuable resource for astronomers worldwide. The GSC and its expansion, the GSC II surveys, have themselves become research tools. Popular astronomy software such as TheSky as well as automated telescope control software such as ACP use the catalogs as references. UND’s own observatory uses ACP software so distance students can carry out astronomical research without ever setting foot in the observatory.

First Light “First light” images from Hubble showed that, even with the spherical aberration of the main mirror, good science could still be done. The image on the left is from a ground-based telescope; the right is from Hubble. According to Eric Chaisson’s book The Hubble Wars, this picture almost didn’t take place – NASA was resisting the Space Telescope Science Institute’s urging to release “first light” images because of the problems with the mirror. Releasing the pictures meant admitting that the crown jewel of astronomy was flawed. Oddly enough, this particular star has not been imaged since, so a side-by-side comparison after SM1 is not possible.

A Busy Ten Years In its first decade of operation, Hubble refined and reshaped our knowledge of Mars, Jupiter, star formation, globular clusters, black holes, and the age of the universe. After only five years of “20/20 vision,” Hubble had studied the atmosphere of Mars, imaged Venus, studied the weather of Jupiter, discovered new moons, studied comets and asteroids, mapped Pluto, and forever changed our picture of the Solar System. It has now been 16 years since Hubble was launched, and in this time it has validated Oberth and Spitzer’s claims. More than half of Hubble’s discoveries have been unexpected (Leckrone, 2006), and there is more work for it than can be scheduled. It is not running out of things to do. The proposed JWST is not intended to replace Hubble, as it is designed to view the cosmos in different wavelengths, but Hubble can coordinate and become JWST’s “spotter”. This would be more efficient as it is easier to slew HST to new targets, and since JWST will not be serviceable by astronauts, it will have a limited lifetime. Livio M. et al, eds, A Decade of Hubble Space Telescope Science, Cambridge University Press, Cambridge UK 2003. Petersen, Carolyn C. and Brandt, John C. Hubble Vision: Further Adventures with the Hubble Space Telescope, 2nd ed., Cambridge University Press, Cambridge UK

Hubble’s Top 10 Scientific Discoveries
Hubble’s studies of supernovas helped to show the existence of dark energy Determining the age of the universe Snapshots of the early universe via the Hubble Deep Field Surveys (image seen here) First direct measurement of an extrasolar planet’s atmosphere (further work is halted due to STIS failure) Discovering black holes in the hearts of galaxies Sources of gamma ray bursts – the collapse of massive stars in distant galaxies Showing that quasars are the hearts of distant galaxies Showing that protoplanetary disks are common The 1994 impacts of comet Shoemaker-Levy 9 on Jupiter Studies of planetary nebulae yielded more information on how stars die. There are ten to twelve areas that had high success; half of which were not expected prior to launch in 1990. People thought that Hubble did not have the right capability to see distant galaxies. According to Dr. David Leckrone: “People were really wrong!” Hubble sees very structured proto galaxies-small clumps of stars and dust-that collide with each other. Hubble was first able to detect these objects, using the Hubble Deep Field and Hubble Ultra Wide Field camera, back in the universe’s history 5-6 billion years. Hubble can see approximately 13.8 billion years (13.7 +/- 2 from the Big Bang). WMAP mapped faint CMB that described the universe. We are now able to see smudges of red; the JWST will be able to look in the distant past and tell what these smudges are (probably very first stars and proto galaxies. In 1997, there was a discovery that the universe was expanding (as per the Hubble Constant). Prior to that, it was thought that the universe was slowing down, but there was no idea of how fast the slowing was occurring. Since 1997, it is believed that the universe will expand forever. The universe is expanding and accelerating and there is another force besides gravity that is causing this-dark energy (first named in 1997). About 4 billion years ago, the universe slowed down, and then it started to accelerate again, probably caused by the dark energy. Handwerk, Brian, “Hubble Space Telescope Turns 15,” National Geographic, April 25, 2005, viewed at Interview with Dr. David Leckrone, Goddard Space Flight Center, April 10,2006.

The Future? HST Service Mission 4 is currently being studied; if carried out, it will install batteries, gyros, one fine guidance sensor, and two new science instruments, repair STIS, and extend the telescope’s lifespan by at least five years. One instrument, WFC3, would allow astronomers to measure the universe’s rate of expansion over time with unprecedented accuracy. If SM4 is not carried out, Hubble is expected to shut down by 2008. James Webb Space Telescope (JWST) is slated for launch in It is expected to have finer resolution and concentrate more on IR than HST. Hubble can detect faint IR smudges at the very edge of resolution; JWST should be able to reveal what those smudges are (probably some of the very first stars and proto-galaxies to form.) The possible cancellation of SM4 is obviously of great concern to scientists. Even though Hubble generates massive amounts of data, there is no way to know what could be missed if the observatory becomes inoperative; serendipity is always a factor in the world of science. The best of all possible worlds is to have HST and JWST operational at the same time in order to conduct simultaneous studies of objects; this has already been done with Hubble and Chandra. On the next mission, the Wide Field Camera 3 will measure the dark energy. By observing a Type 1a supernova, it will be possible to study the brightness that comes from these supernovae, as they make a very good standard candle. By looking at a Type 1a, astronomers can measure the rate of expansion over time. There is a need to study as many of these supernovae as possible to “beat down the error bars.” Hubble will be the means to do this. It will also provide an explanation to Einstein’s cosmological constant-is it really a constant or did it change over time? Dark energy is the most important concept in the last twenty five years. Observations will become more efficient with the new camera. Interview with Dr. David Leckrone, Goddard Space Flight Center, April 10, 2006 Interview with Dr. David Leckrone, Goddard Space Flight Center, April 10, 2006

Hubble: Large Space Telescope, Astronomical Price Tag
Funding and Economics The common thread that ties together nearly every aspect of the Hubble struggle is money. In the period after WWII the US, still flushed with victory, had atomic weapons as well as rocket technology. America was also in the beginning of a Cold War with the USSR. A third element was the establishment over the course of the war of a substantial industrial complex with strong ties to the government and geared for large scale projects. In 1946 the US government had some money that it wanted to invest in space, and asked the RAND Corporation to put together some ideas that would net maximum return, both scientifically and politically. One of those ideas was put forward by a young scientist named Lyman Spitzer, and involved putting a relatively large telescope in orbit for scientific research. In the 1960s, Lyman Spitzer and others began lobbying for the creation of an orbital observatory. Over the course of the decade, they continued to try to gather support for the creation of a large space telescope. Meanwhile the smaller OAOs were designed and launched. Despite the fifty percent failure rate, these satellites did demonstrate the technical feasibility and scientific advantages of space telescopes. By the end of the 1960s and into the 1970s, there is increasing support, both at NASA and amongst the scientific community. However, between the international difficulties and a sluggish economy at home, it was hard to pitch a new, purely scientific project with such a high cost (the initial estimate was $ million). Only after extensive cuts and compromises, and the addition of international partners, was the LST approved in 1977. Hubble: Large Space Telescope, Astronomical Price Tag

Overview of an Overrun Original budget: $475 million
OTA: $69.4 million Actual cost: In 1986, when it was first assembled for launch, it cost $1.6 billion, and had several technical problems. Four years of tinkering and improvements later, it is finally launched – at $2.2 billion (not counting the $0.5 billion for the launch!) Percentage overrun: 463% The original budget approved by Congress in 1977 was for a total expense of $475 million. This did not include the additional pledge of support by the European Space Agency of 15% of the costs, which were to arrive in the form of the FOC and solar panels, and ground scientific and technical support. As part of an effort to bring down costs, NASA decided not to use a primary contractor, but rather associate contractors under the lead of MSFC. The contractor for the SSM was Lockheed, and they were also charged with final assembly of all components. The contractor for the OTA, optical telescope assembly, was Perkin-Elmer. Perkin-Elmer had previous experience with this type of job because they had been one of the primary contractors working on the DOD Keyhole reconnaissance satellites. They were able to put in the low bid because of their proposal to use a new technique, reflective null error polishing. MSFC expressed some misgivings on the capability and management of P-E, which grew as cost and schedule overruns mounted. Their initial contract was for $69.4 million, to have it ready, approved, and installed in time for a 1983 launch. By the time the OTA was delivered, they were over three years behind schedule (during one period, they fell behind another day for every day of work), and the cost was $440 million. They were also eligible for an $11 million dollar bonus, under their cost-plus-fee contract, for keeping it on budget, on schedule, and within technical specifications.

Players NASA MSFC: engineering and construction
GSFC: scientific instruments and mission operations JSC: launch and astronaut training Science Interests -STScI: created to oversee the interests of the outside scientific community -AURA: international group of 31 educational and nonprofit entities Contractors Lockheed: SSM Perkin-Elmer: OTA Secondary contractors: almost two dozen companies throughout the aerospace industry The distributed management of the Hubble program was part of an effort to bring the cost of the HST down. Under the associated contractor plan, MSFC was the lead center for engineering and construction, overseeing the associated and sub contractors. They had engineering management experience, and with the drawing to a close of Apollo, several thousand people highly motivated to find a new mission. GSFC was in charge of the scientific instruments and mission operations after launch. Although GSFC was the home of NASA space science, they were overworked already, and only lukewarm about pursuing a major new project. Lockheed was responsible for constructing the SSM, the satellite bus essentially, as well as integrating all of the components together. Perkins-Elmer was the company responsible for the OTA and fine guidance sensors. Although the idea looked good on paper, it broke down fairly quickly and severely in practice. MSFC and GFSC engaged in a power struggle, confusing the issue of who had authority to contractors. The contractors had problems keeping to budget and schedule, and required increasing oversight. The scientific community was convinced that their issues were not being addressed, and essentially forced the creation of the Space Telescope Science Institute.

Costs Plus Mirror discovered to have spherical aberration – only seeing about 21% of the light it is supposed to. SM-1: repaired faulty optics, replaced gyros, solar panels, and memory banks. SM-2, SM3A, SM3B: $0.5 billion plus Proposed fifth mission: $ million (not counting $2.2 billion for Shuttle rehab) Two months after the launch of HST, NASA announced a critical flaw in the OTA, a spherical aberration. According to the report of the Allen Board, the flaw occurred in , when MSFC was bringing enormous pressure onto Perkin-Elmer to get back on schedule and budget. The report goes on to explain that allow P-E obviously made the original error, it should have been caught by NASA. This was an enormous embarrassment to NASA, and they struggled to find a way to recover. HST was designed in a modular fashion, to facilitate on-orbit servicing by the shuttle. NASA scientists and engineers came up with a way to correct the problem, COSTAR and WFPC-2. In 1993 STS-61 performed the first servicing mission. The cost of the mission was $674 million, $100 million of which was the optics (P-E was never convicted of gross negligence, and so only a fraction of that cost was recouped). This was followed by three other missions. Hubble has now been in orbit for 16 years, and, depending on sources and methods of calculation, has cost between $7-11 billion. It has also proven the existence of dark matter, given us a much better gauge of the age and size of the universe, and produced more data for more scientific papers than any scientific instrument in history. It currently badly needs another servicing mission, or it will probably fail by the end of the decade. The mission itself is estimated at $ billion, after approximately $2.2 billion is spent to refurbish the shuttle fleet.

and International Ramifications: Lessons Learned
Hubble’s Policy, Legal, and International Ramifications: Lessons Learned Political incrementalism is reflected in studies on congressional decision-making as it relates to Big Science (large-scale) NASA projects like the Hubble Space Telescope. The policy evolution of the now $2-billion plus project illustrates the complex technical nature of the space project leading to incremental decision-making. As clearly evidenced in the late 1970’s funding decisions of the President and Congress relating to the Large Space Telescope, incrementalism occurs when Congressional decision-makers lack the information and knowledge to put forward policy with confidence of near-term success. The policy of incrementalism enhanced the role of the Congress in formulating and overseeing the implementation of the space-based telescope project for well in excess of a decade. Nonetheless, the incremental policy-making relating to the Hubble Space Telescope resulted in pressure to down-size, readjust costs, and underestimate the technical challenges associated with its decade long development. Costs and technology constraint have been watch words throughout the project’s history. Even today, incremental policy-making remains very viable with regard to the ongoing operations of the Hubble Space Telescope as witnessed by the failure of President Bush to include in his budget proposals monies for a servicing mission yet the Congress reversing the policy with inclusion of monies for a fifth orbital repair mission. Political incrementalism is reflected in studies on congressional decision-making as it relates to Big Science (large-scale) NASA programs like the Hubble Space Telescope.

Astronomers in the mid-to-late 1970s were very effective in using the growing pluralistic political interest group, single-issue oriented politics, to advance the development of the Space Telescope. Political interest group, one-issue oriented politics became entrenched in American political culture in the 1970’s. American astronomers and scientists supporting the development of a Large Space Telescope became policy activists as incremental policy making was leading to a decision of postponement or cancellation of the space-based telescope. The convergence of astronomer grassroots activists in contacting key members of Congress, in part aided by contractor-lobbyists who wanted the multi-million dollar contracts to build a Large Space Telescope, happened at the right time in the late 1970’s to sustain the a pro-space telescope policy. In fact, astronomers lobbying on Capitol Hill were such an oddity at the time that members of Congress were taken-aback by having such high-level experts at their disposal and offering counsel on the space telescope. Congressional confusion and the lack of technical skills by the Congress generally enabled, in some ways, for the incremental policy of the space-based telescope to evolve. Several members of the Congress tended to favorably view the early development of the space telescope as an ancillary outgrowth of military orbital photoreconnaissance. In fact, the commingled policy of a space-based telescope and military photoreconnaissance both helped and hurt the development of the Hubble Space Telescope over its developmental and operational life. In more contemporary terms of political scientists, the network that has emerged with the Hubble Space Telescope is known as an “Iron Triangle” of American politics. The triangle is recognition of common interest among government bureaucrats, congressional members on key committees, and advocacy coalition interest groups and the associated private sector contractors. The construction decision of the space telescope benefited from the so-call Iron Triangle. Today the Hubble Space Telescope has forged a populist-backing among millions of Americans purely on the visualization of the cosmos that has enabled the Iron Triangle advocates of the telescope to advance Congressional policies to keep the Hubble Space Telescope alive in the wake of the loss of the Space Shuttle Columbia. In fact, should the space shuttle continues to fly up to a dozen missions or more in 2006 and beyond, the sheer weight of popular support may enable a fifth servicing mission to the Hubble Space Telescope as evidenced by recent pronouncements of NASA Administrator Michael D. Griffin.

Civil space officials formulate international agreements with foreign officials, in part to expand their base of support. An international agreement with a foreign government provides a layer of extra protection not afforded a pure domestic program. Civilian space officials in the United States commonly formulate international space agreements with foreign governments, in part to broaden their base of support to sustain a project. The Hubble Space Telescope is a classic case-in-point of such an international agreement providing an extra layer of political policy protection not afforded a purely domestic science program. In the case of the space-based telescope, the incremental Congressional policy urged formation of a European partnership to reduce the cost burden associated with the telescope’s construction and operation. Following the forging of international agreements on space policy, the Congress tends to defer to the President because of the foreign policy and international obligation concerns. The policy of international cooperation on space projects with Europe emerged in the late 1950’s and early 1960’s with the European Launch and Development Organization and with it some technology transfer. Yet in the 1970’s the issues associated with national security policy and technology transfer slowed the pace. International cooperation was stalled, regulated, and controlled. But the space spectacular of the US-Soviet détente-in-space of the Apollo-Soyuz mission resulted in some members of the Congress calling for both European and Soviet participation in the Large Space Telescope development. The growth of international cooperation with Europe in space affairs in the late 1970’s resulted in active European participation in the Hubble Space Telescope technology and operational funding. In fact, it is noted, that the European junior space partnership with the United States advanced to full partnership with the European Space Agency (ESA) in the 1990’s with the Hubble Space Telescope leading the way on a multitude of joint efforts including a host of other astronomical investigation satellites, the International Space Station, and a number of interplanetary unmanned missions to Mars and Saturn and its moon Titan. International cooperation forged with the Hubble Space Telescope is today serving as the model for even greater cooperation in space-based astronomy with the James Webb Telescope. The new space-based telescope will be launched aboard a European Ariane-5 booster in 2011 or thereafter.

Some of the technology of the Hubble Space Telescope was developed initially for satellite reconnaissance programs of the DoD. It has been suggested that the initial telescope problems could have been mitigated had the DoD been more forthcoming with NASA Marshall. Eric J. Chaisson, a former scientist at the Space Telescope Science Institute, makes the case in his book The Hubble Wars: Astrophysics in the Two-Billion-Dollar Struggle over the Hubble Space Telescope that the NASA Marshall Space Flight Center engineers and scientists were inhibited from perfecting the Hubble Space Telescope by the lack of cooperation and transparency by the Department of Defense. Chaisson avers that the problems with the space telescope would have been mitigated had DoD been more forthright in assisting NASA. In fact, the Hubble Space Telescope optics was technology developed in part for military orbital photoreconnaissance. Nonetheless, the size of the Marshall team assigned the Hubble Space Telescope was limited in part because of budget constraints but moreover the desire to limit the number of people penetrating the veil of secrecy associated with DoD contractors working various military optical photoreconnaissance technologies. The legal and policy concerns associated with the optics of the Hubble Space Telescope’s early developmental period demonstrates the level of national security concern with the dual-use nature of space-based assets. Issues of technology transfer and national security has permeated the Hubble Space Telescope from its onset to this very day.

Technology transfer issues remain a vexing political and legal issue.
Today International Traffic in Arms Regulation (ITAR) limits international cooperation through exclusion or added burden of bureaucratic waiver paperwork upon scientists working with international space telescope projects. Technology transfer issues remain a vexing political and legal issue. The International Traffic in Arms Regulations (ITAR) was promulgated from the Arms Export Control Act adopted by the Congress in 1994 applies to the Hubble Space Telescope. Dr. David Leckrone related that several European scientists have not been allowed to attend workshops and conferences related to the space telescope over the past decade because of ITAR. He noted that while there are waivers to permit attendance and technology transfer, the waivers must go through a significant and time-consuming review process at the U.S. State Department. Under the ITAR regulatory regime, space technology and their components are treated the same as military weapons because of the possibility of dual-use. The export license process has caused a strain in international cooperation on scientific endeavors as a shift from Department of Commerce to Department of State implementation of the ITAR regulations changed policy motivations. The Hubble Space Telescope will serve as the ITAR model for future cooperation with European scientists and astronomers as the launch campaign of the James Webb telescope continues into the next decade. In fact, as Dr. Leckrone noted, the James Webb Telescope will be placed into orbit on a foreign European booster, (not the space shuttle). In addition thereto, the European role in the James Webb Telescope will be of much more significant scope than that of the Hubble Space Telescope requiring more ITAR review of technology transfer issues.

The Hubble Space Telescope
Management & Operations Now, let’s look at the management and operations component of HST.

Early Years of the Program
After Apollo, NASA considered both MSFC & GSFC to manage its proposed Large Telescope program. GSFC had the scientific expertise & MSFC more experience in managing a large program and had a large idle staff. In 1971, NASA divides the program between the two centers causing rivalry and animosity that lasted for most of the program NASA gave lead to Marshall in 1972, as well as too many responsibilities, making it, in effect a prime contractor (without the experience to be one), that led to serious management and technical problems. By 1976, this rivalry threatened program, with Goddard’s role viewed as that of a sub-contractor. Rivalry abated when NASA threatened to give entire program to Marshall. The Space Telescope program was a departure from NASA’s normal mode of operation in that the Agency divided responsibility for a major program between two of its centers. This caused friction and rivalry between Marshall and Goddard Space Flight Centers that threatened to kill the telescope before it was even launched. Part of the problem was that NASA used the Centers as contractors, each with their own agenda, budgets, supporters and management.

Marshall and the Associate Contractors
In 1977, Marshall chose Lockheed Martin to build the support craft and Lockheed in turn chose Perkin-Elmer for the mirror. Marshall was wary of Perkin-Elmer because their low bid did not include proper testing of the mirror polishing computer program. This concern proved to be prophetic. European Space Agency becomes partner in program to provide camera a solar panels in exchange for 15% of observation time. MSFC also prevented from sufficient staff and management penetration at PE due to its DoD work. Once NASA removed personnel cap in 1979, Marshall took more active role at PE, it was too late to make changes. Marshall had to step in to help finish the mirror’s shaping as PE was over budget & behind schedule. MSFC felt that PE was ‘good at testing … but nothing else’. By 1982, Marshall was increasingly dissatisfied with PE & had to increase its own staff in Danbury because Perkin-Elmer lacked competent management and inadequate operating procedures. Once Marshall Space Flight Center (Huntsville, AL) was secure in its role as lead center, it could concentrate on taking a managerial role at the contractors chosen to build the support craft and mirror. By this time, inefficient management practices and the lack of an effective operational plan at Perkin-Elmer, and at Lockheed Martin, were too firmly entrenched for Marshall to correct. Even with a larger staff presence at the contractors, Marshall was too late to reverse the downward spiral. Had Marshall be able to penetrate PE earlier and insisted that testing be done on the mirror, the aberration of the mirror would have been found before launch.

More Problems and New Solution
Marshall fully managing at PE, better progress was made. Management, scheduling and cost problems at Lockheed that Marshall had to rectify Marshall finally informed NASA of the worsening situation at PE and NASA reports it to Congress. Communications breakdown caused by NASA’s lack of experience at managing multiple centers for same project and Marshall’s naiveté in hoping problems would correct themselves. Science community had lobbied for independent institute to operate telescope; finally got their wish in 1981, with the establishment of the Space Telescope Science Institute, located on the campus of Johns Hopkins University. With cost overruns and management issues still a factor, Marshall took over the management at the contractors, resulting in better cost and operations management. Marshall finally let NASA know about the problems, after realizing that the situation would not improve on its own. The problems stemmed from multiple factors: lack of communication at various levels of management; NASA’s inexperience in overseeing multiple centers; too many players, each with their own agendas; rivalry and distrust when there should have been cooperation. NASA HQ resolved the problem by taking control of the project and appointing a Program Manager who would report directly to the DAA. And, acting upon the scientific community’s call, it created an independent institute to manage and operate the program. (the Space Telescope Science Institute at Johns Hopkins University in Baltimore, MD). With these changes the program progressed much more efficiently (post 1983).

Program Management Prior to Launch
This chart is taken from Robert W. Smith’s “The Space Telescope”, an excellent source for the program from its inception to launch. As you will note, there are too many players involved in the Space Telescope program to have cohesive and effective management practices.

Management and Operations Today
Hubble is operated on behalf of NASA by AURA (the Association of Universities for Research in Astronomy, Inc.), Goddard Space Flight Center and the European Space Agency. Operations are monitored by staffers (including 15 from the ESA) at both GSFC and STSI STSI operates 24/7; it is manned in rotating shifts (3-4 at a time) Operations are divided into Engineering and Science foci Engineering responsibility is spacecraft performance. By communicating in real time, engineers are able to tell HST what to do and how to focus. Science Operations encompass observation scheduling, science hardware, interpreting the raw data, as well as maintaining the data and disseminate the data to end users. Dr. David Leckrone (lead STSI Hubble scientist) explained that there is an oversubscription of proposals (5:1 at present; 8:1 before STIS failed) with no sign of lessening. To date HST viewings have generated over 5,000 science papers. Today, the Hubble Space Telescope is jointly operated primarily by the scientific community in conjunction with Goddard Space Flight Center and the European Space Agency. Computer Science Corporation supplies the technical personnel. (NOTE: this slide will be revised subsequent to a visit to the STSI this week).

Operations (continued)
Once images are taken, the data (more than several million bits daily are taken by HST’s high gain antennas) is returned to Earth several times a day. The data is then sent as digital signal to White Sands, NM, the HST ground station via a TDRSS satellite. The data then goes to GSFC for accuracy determinations either immediately or are stored on tapes for later review. STSI gets the data next for processing and distribution to the requesting astronomer who has exclusive rights to the data for one year. Each orbit lasts about 95 minutes, with scheduled downtime to allow for maintenance, repositioning, target acquisition, etc. Please study the picture above. It describes the operation of the HST in a concise format. At Goddard’s STOCC, a detailed operations schedule is created to accommodate the observations. Computer commands are then sent to Hubble at intervals during the day, via the Tracking and Data Relay Satellite System (satellites in geosynchronous orbit). Scientists who have a project on the current HST schedule are given a computer to use at STSI so that they can monitor their observations in real time. This is an efficient operation converting the raw data on its journey from observation by HST to pictures that are truly astounding.

Conclusions and Lessons Learned
What does this investigation of Hubble’s integrated evolution teach us? Having examined the interaction of disciplines which combined to create Hubble, let’s look at the lessons we might draw from the experience.

Hubble has been a stunning scientific and technological success. The LST/HST history can be described as an example of how not to conduct a large national science program. The contributing detrimental factors in its development can be summarized as follows: The sources of trouble were multiple, but the overarching problem was money. The promise of the program was great, but NASA did not believe it could ask Congress for the money MSFC had estimated the project would cost. Competition was misplaced. In the case of NASA’s management, the forced competition between two co-equal NASA centers was detrimental. NASA was faced with the threat of having one or more centers closed – this was one factor in the selection of MSFC as the lead. The decision to use two associate contractors (not a prime with real authority to do systems management) was a critical error since MSFC did not have the resources to perform this function. NASA HQ had too few people to watch over the program and left it to the field centers to manage until By then, the program was faced with intractable problems. Congress was opposed to the project and key legislators fought it. We can learn from this that efforts to unrealistically limit a program’s budget by forcing limits can, over time, force a program to cost more, not less. An overestimation of the Space Shuttle’s capabilities was a factor. The influence of the DoD in limiting NASA penetration of key contractors was a major factor which exacerbated the problem. Perkin-Elmer was unqualified to handle the OTA. NASA did a poor job of communicating not just within the program, but in effectively describing the potential value of the project. In future programs, we might try to apply the following lessons from Hubble: Reliable cost estimates should be considered which are truly representative of the proposed technology, rather than trying to force the technology to match an artificial budget. The competition between GSFC and MSFC may have been done to spur these two agencies to develop strong proposals, but it also led to persistent conflict between peer agencies. In the case of Hubble, HQ leadership was absent, as was a means of dispute resolution. The conflict within government also existed between NASA and the DoD. While the need for security was clear, the means was unreasonable. This issue could have been anticipated and a means of permitting NASA penetration of secure contractors could have been arranged. The goal of cost control and efficiency is desirable, necessary, but also complex. In some cases, as in Hubble, the desire to control costs can paradoxically lead to higher costs and more waste. It can be argued that if Hubble had been clearly defined from the beginning, the full and proper amount of funds honestly estimated and the funds appropriated, and the management structure in place, it could have been delivered sooner and for several hundred million dollars less. Divided command must be avoided. Systems engineering requires authority, and with Hubble, this authority did not exist (until after 1983). It requires more than inspiration to execute a politically vulnerable project like Hubble. The project survived because a grassroots movement of scientists moved a skeptical congress – NASA’s inability to do this may have been a failure of imagination.

On the positive side, we have also learned the following; Large national space science programs do work, and can lead to enormous gains for the nation. More should be done to explain the accomplishments effectively. Hubble demonstrated the idea of a National Facility, breaking from the paradigm of a single Principal Investigator. The scientific community was a hero in the story of the HST HST demonstrated that multiple countries can cooperate effectively on a major science program in space. The role of astronaut servicing on orbit was validated by Hubble – without it, we would not have this program. With it, we have an orbital observatory that can be upgraded and extended for decades. (On this point, we have good reason to see concordance between the advocates of both manned and unmanned space exploration.) One is tempted to look at Hubble’s evolution and simply conclude that, in the future, all we need to do is spend lavishly on such science programs. But in fairness, the people who made the decisions that guided the LST/HST program were molded by the social, political, economic, and technological forces effective in their day. Nevertheless, HST provides an object lesson in how not to run a major science program. Despite its troubled design and development period, the Hubble Space Telescope has lived up to its promise of being a transformational science project. In its 16 years of service it has produced a quantity of high quality astronomical and physical data that is unprecedented for any observatory, and more than half of its discoveries have been unanticipated. It validated the idea of Big Science in a way that allowed individual scientists to access a national facility and maintain control over their work. It showed how scientists can present their ideas affirmatively to win consensus. It validated the idea of how manned operations can support space science (and need not be its antithesis). For the investment of treasure and resources by the US and the Europeans, humanity has been returned a treasure that will revolutionize our view of ourselves and of the universe. This value is inestimable. Finally, perhaps the lasting lesson that we can learn from Hubble is that we should not be afraid to challenge ourselves with these potentially transformational projects. Doing so may require us to suspend our disbelief – as the Hubble builders did when they allowed themselves to dream of a telescope in space that would be operated by multiple nations and tended by astronauts, and that they did not know how to build. Perhaps the lasting lesson of Hubble is that we should allow ourselves to be challenged by potentially transformational projects. At the height of the Cold War, Hubble’s builders allowed themselves to dream of a telescope in space that they did not know how to build. It would be able to point at galaxies while flying through space; it would be operated by multiple nations; tended by astronauts; and for all this, its results were unpredictable.

Team Hubble Huddle Professor Shan de Silva PhD
Team and Component Research Areas: Greg Carras (Technology) Jerry Cordaro (Science) Andrew Daga (Evolution and History) Sean Decker (Funding and Economics) Jack Kennedy (Policy, Law, and International Cooperation) Susan Raizer (Management and Operations) With appreciation to the Space Telescope Science Institute in Baltimore, MD; Dr David Leckrone and the staff and personnel of NASA Goddard Space Flight Center, Greenbelt, MD; and to the Boeing Company, Seattle, WA Submitted in partial fulfillment of the requirements of Space Studies 502 (with associated Evolutionary Chart and References) Department of Space Studies, University of North Dakota, April For more information, we would like to recommend the following: The Space Telescope, by Robert W. Smith, with contributions by Paul A Hanle, Robert H. Kargon, and Joseph N. Tatarewicz. New York: Cambridge University Press, ISBN: NASA’s history office: "The Hubble Space Telescope", in Power to Explore: A History of Marshall Space Flight Center, by Andrew J. Dunar and Stephen P. Waring , NASA History Office, pp. 723, NASA SP-4313, Chapter 12, Internet:

The Interdisciplinary Evolution of the Hubble Space Telescope

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