The Hubble Space Telescope (H.S.T.) By Jason Hunyar

The Beginning In 1923. The idea of a telescope in space, or at least outside Earth’s atmosphere was proposed officially by a man named Hermann Oberth. A man named Lyman Spitzer Jr. helped encourage NASA to approve the Large Space Telescope project in 1969. In 1974, the group working on the project suggested that the telescope should have interchangeable instruments. The Space Shuttle would be used to get the telescope in orbit and possibly return it to Earth for repairs and replacement instruments, or they would just service it in space. In 1975, the European Space Agency began to work together with NASA on a plan that would eventually become the Hubble Space Telescope. In 1977, Congress approved funding for the telescope.

Why? The Hubble Space Telescope is the direct solution to a problem that telescopes have faced since the very earliest days of their invention: the atmosphere. There are two problems. The first problem that ground telescopes face are shifting air pockets in the Earth's atmosphere. They make the the view of telescopes on the ground blurry and distorted, no matter how large or scientifically advanced those telescopes are. The second problem ground telescopes encounter is that the atmosphere also partially blocks or absorbs certain wavelengths of radiation, like ultraviolet, gamma and X-rays, before they can reach Earth. This is not good for astronomers because scientists can best examine an object like a star by studying it in all the types of wavelengths that it emits. Newer ground-based telescopes are using technological advances to try to correct atmospheric distortion, but there's no way to see the wavelengths the atmosphere prevents from even reaching the planet. The most effective way to avoid the problems of the atmosphere is to place your telescope beyond it. Or, in Hubble's case, 353 miles (569 km) above the surface of Earth. *Cool Fact: This "atmospheric distortion" is the reason that the stars seem to twinkle when you look up at the sky.

The On-Board Tools The Wide Field Camera 3 (WFC3) sees three different kinds of light: near-ultraviolet, visible and near-infrared, though not simultaneously. Its resolution and field of view are much greater than that of Hubble's other instruments. WFC3 is one of Hubble's two newest instruments, and will be used to study dark energy and dark matter, the formation of individual stars and the discovery of extremely remote galaxies previously beyond Hubble's vision. The Cosmic Origins Spectrograph (COS), Hubble's other new instrument, is a spectrograph that sees only in ultraviolet light. Spectrographs acts something like prisms, separating light from the cosmos into its component colors. This provides a wavelength "fingerprint" of the object being observed, which tells us about its temperature, chemical composition, density, and motion. COS will improve Hubble's ultraviolet sensitivity at least 10 times, and up to 70 times when observing extremely faint objects. The Advanced Camera for Surveys (ACS) sees visible light, and is designed to study some of the earliest activity in the universe. ACS helps map the distribution of dark matter, detects the most distant objects in the universe, searches for massive planets, and studies the evolution of clusters of galaxies. ACS partially stopped working in 2007 due to an electrical short, but was repaired during Servicing Mission 4 in May 2009.

The On-Board Tools (2) The Space Telescope Imaging Spectrograph (STIS) is a spectrograph that sees ultraviolet, visible and near-infrared light, and is known for its ability to hunt black holes. While COS works best with small sources of light, such as stars or quasars, STIS can map out larger objects like galaxies. STIS stopped working due to a technical failure on August 3, 2004, but was also repaired during Servicing Mission 4. The Near Infrared Camera and Multi-Object Spectrometer (NICMOS) is Hubble's heat sensor. Its sensitivity to infrared light — perceived by humans as heat — lets it observe objects hidden by interstellar dust, like stellar birth sites, and gaze into deepest space. Finally, the Fine Guidance Sensors (FGS) are devices that lock onto "guide stars" and keep Hubble pointed in the right direction. They can be used to precisely measure the distance between stars, and their relative motions. All of Hubble's functions are powered by sunlight. Hubble sports solar arrays that convert sunlight directly into electricity. Some of that electricity is stored in batteries that keep the telescope running when it's in Earth's shadow, blocked from the Sun's rays.

Where Most people think of where the actual telescope is in space when they think of the HST, but the real information is on the ground. The Goddard Space Flight Center in Greenbelt, MD, is the true base of the Hubble Space Telescope. This is where the images from the telescope itself are relayed down from multiple satellites to (as shown in the diagram). As soon as the Goddard Space Flight Center receives data from the telescope, they send it to Space Telescope Science Institute (STScI) where the staff translate the data into meaningful units. Then the data goes into archives and is enabled to be downloaded by astronomers anywhere in the world. The HST usually brings in about 18 DVDs worth of information every week.

Non-Visible Light (Why this is important to us) Using the advanced instrumentation of the Hubble Space Telescope, astronomers have been able to see different types of light, such as ultra violet, that come through space dust, to find out more about the universe. After analyzing these images through the COS, we have been able to find out the composition of stars, galaxies, etc. But while the Hubble Space Telescope looks out through space, it is also looking through time. As the telescopes looks at light that was created x number of light years away, it can see what happened at that place x number of light years ago. For example, if the HST was looking at the light of a star 30,000 light years away, it would be looking at the same light that was created at that star 30,000 light years ago.

Why we should care As students and citizens, everyone around the world should care about the Hubble Space Telescope. This telescope can unlock answers about science that today, is beyond our wildest imaginations. This telescope and future telescopes, should be able to help us find out huge questions in the minds of scientists today; what happened at the beginning of the universe. With all of these new discoveries, we will definitely by able to make huge advances in science technology and future advances in the world of astronomy. As Neil Armstrong once said, “That’s one small step for man, one giant leap for mankind.”

Source Citations National Aeronautics and Space Administration (N.A.S.A.). World Book At N.A.S.A.: Hubble Space Telescope. Retrieved October 29, 2009 from: http://www.nasa.gov/worldbook/hubble_telescope_worldbook.html HubbleSite. The Telescope: Hubble Essentials. Retrieved November 2, 2009 from: http://hubblesite.org/the_telescope/hubble_essentials/