Space Shuttle Components Shuttle components included the Orbiter Vehicle (OV), a pair of recoverable solid rocket boosters (SRBs), and the expendable external tank (ET) containing liquid hydrogen and liquid oxygen. The Shuttle was launched vertically, like a conventional rocket, with the two SRBs operating in parallel with the OV's three main engines, which were fueled from the ET. The SRBs were jettisoned before the vehicle reached orbit, and the ET was jettisoned just before orbit insertion, which used the orbiter's two Orbital Maneuvering System (OMS) engines. At the conclusion of the mission, the orbiter fired its OMS to de- orbit and re-enter the atmosphere. The orbiter glided to a runway landing on Rogers Dry Lake at Edwards Air Force Base in California or at the Shuttle Landing Facility at the KSC. After the landings at Edwards, the orbiter was flown back to KSC on the Shuttle Carrier Aircraft, a specially modified Boeing 747.
Shuttle Mission History The first orbiter, Enterprise, was built for Approach and Landing Tests and had no orbital capability. Four fully operational orbiters were initially built: Columbia, Challenger, Discovery, and Atlantis. Of these, Challenger and Columbia were destroyed in mission accidents in 1986 and 2003 respectively, in which a total of fourteen astronauts were killed. A fifth operational orbiter, Endeavour, was built in 1991 to replace Challenger. The Space Shuttle was retired from service upon the conclusion of Atlantis ' s final flight on July 21, 2011.
Shuttle Politics VP Agnew suggested 3 possibilities Mars landing was too ambitious Nixon selected least costly: STS & ISS NASA agreed to cut cost in half by not being fully re-usable STS must meet both defense and NASA needs Later, all space launches were required to use STS to reduce cost of expendable vehicles
Shuttle retirement NASA retired the Space Shuttle in 2011, after 30 years of service. The Shuttle was originally conceived of and presented to the public as a "Space Truck", which would, among other things, be used to build a United States space station in low earth orbit in the early 1990s. When the US space station evolved into the International Space Station project, which suffered from long delays and design changes before it could be completed, the service life of the Space Shuttle was extended several times until 2011, serving at least 15 years longer than it was originally designed to do. Discovery was the first of NASA's three remaining operational Space Shuttles to be retired.
Shuttle Disasters On January 28, 1986, Challenger disintegrated 73 seconds after launch due to the failure of the right SRB, killing all seven astronauts on board. The disaster was caused by low-temperature impairment of an O-ring, a mission critical seal used between segments of the SRB casing. The failure of a lower O-ring seal allowed hot combustion gases to escape from between the booster sections and burn through the adjacent external tank, causing it to explode. Repeated warnings from design engineers voicing concerns about the lack of evidence of the O-rings' safety when the temperature was below 53 °F (12 °C) had been ignored by NASA managers.  On February 1, 2003, Columbia disintegrated during re-entry, killing its crew of seven, because of damage to the carbon-carbon leading edge of the wing caused during launch. Ground control engineers had made three separate requests for high-resolution images taken by the Department of Defense that would have provided an understanding of the extent of the damage NASA managers intervened to stop the Department of Defense's assistance and refused the request for the spacewalk,.
Space Station The International Space Station (ISS) is a space station, or a habitable artificial satellite, in low Earth orbit. It is a modular structure whose first component was launched in 1998. Now the largest artificial body in orbit, it can often be seen with the naked eye from Earth. The ISS consists of pressurised modules, external trusses, solar arrays and other components. ISS components have been launched by American Space Shuttles as well as Russian Proton and Soyuz rockets.
Space Station History NASA megaproject: A complex of orbital modules to sustain astronauts in low earth orbit Von Braun suggested it in 1952 Reagan approved it in 1984, with Canada, Japan and 9 European nations; Russia joined in 1998: Space Station Freedom. First modules Each nation constructs it own modules
The ISS serves as a microgravity and space environment research laboratory in which crew members conduct experiments in biology, human biology, physics, astronomy, meteorology and other fields. The station is suited for the testing of spacecraft systems and equipment required for missions to the Moon and Mars. [ The ISS maintains an orbit with an altitude of between 330 and 435 km (205 and 270 mi) by means of reboost manoeuvres using the engines of the Zvezda module or visiting spacecraft. It completes 15.54 orbits per day. [
More history Pressure to control budget over-runs led to lost scientific capability: more about jobs and international politics Do dangers outweigh returns? Bush 2004 directed space to Moon, Mars, reducing ISS role. STS end causes ISS to depend on Russian re- supply
ISS Policy Issues Enormously complex, who are the partners? What role should science play? Does international cooperation foster efficiency or just diplomacy? Wouldn’t many smaller programs be better? Technology development versus science?