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25 Years of Challenges and Triumphs

On April 24, 1990, something happened that forever altered mankind’s view of the universe. It was on that day that the Hubble Space Telescope (HST) was launched into space aboard the Space Shuttle Discovery.

The Hubble Space Telescope is named for Edwin Hubble, a pioneering American astronomer who used the giant 100-inch Hooker Telescope atop Southern California’s Mount Wilson in 1924 to observe numerous galaxies beyond our Milky Way, all of which appeared to be moving away from each other. Those observations led him to conclude that the universe is expanding.

The problem with Earth-based telescopes is that they must peer through Earth’s atmosphere, which introduces a tremendous amount of distortion and absorbs certain wavelengths of light, making it difficult to observe and analyze them. This led forward-thinkers like German rocket scientist Hermann Oberth and Princeton astrophysicist Lyman Spitzer to propose putting a telescope into space, well above Earth’s atmosphere.

The feasibility of this concept was tested by NASA with the launch of four instruments called Orbiting Astronomical Observatories (OAO) between 1966 and 1972.

Meanwhile, Lyman Spitzer continued his efforts to rally support among the world’s astronomers for the design and construction of a large, orbiting space telescope. His efforts received a major boost in 1969 when the National Academy of Sciences endorsed NASA’s plans for a Large Space Telescope (LST) project that would feature a mirror 3 meters (9.9 ft) in diameter.

The first servicing mission corrected the telescope’s flawed optics. (NASA)
When Congress cut all funding for it in 1974, public outcry and a massive lobbying effort from the scientific community prompted the Senate to restore half the funds. Less money meant the project had to be reduced in size and scope. The size of the mirror, for example, was changed from 3m to 2.4m (7.9 ft.) and an even smaller (1.5m) prototype telescope for system validation purposes was scrapped altogether. A partnership was formed in 1975 with the European Space Agency (ESA), which agreed to absorb fifteen 15 percent of the project’s cost by providing one of the instruments, known as a Faint Object Camera (FOC), the solar panels needed to power the telescope, and manpower to support the project. In return, the European science community was guaranteed 15 percent of the telescope’s operational time.

In 1977, Congress agreed to provide $36 million for the project in their 1978 budget and work finally got underway. The anticipated launch date was 1983.

With funding in place, NASA set about structuring the project. They designated Marshall Space Flight Center (MSFC) in Huntsville, AL to design and build the newly renamed Space Telescope (ST), and Goddard Space Flight Center in Greenbelt, MD to manage the scientific instruments and handle ground control duties once the telescope was launched. MSFC, in turn, hired the Perkin-Elmer Corporation to manufacture the optical telescope assembly, including the mirror, and the system’s fine guidance sensors. A contract to build the telescope’s airframe and assemble the instrument was awarded to the Lockheed Missiles and Space Company (now Lockheed Martin).

On the instrumentation front, Goddard solicited proposals from the scientific community, and from those proposals selected five instruments for inclusion: a Faint Object Camera (FOC); a Wide Field/Planetary Camera (WFPC); a Faint Object Spectrograph (FOS); a High Resolution Spectrograph (HRS); and a High Speed Photometer (HSP).

The Original Instruments

The iconic Pillars of Creation image captured by Hubble. (NASA)
Faint Object Camera (FOC): The FOC, built by the European Space Agency, was an optical and ultraviolet instrument capable of capturing images over a broad spectrum from ultraviolet to near infrared. The FOC was equipped with two separate detector systems. Incoming light was filtered to isolate specific wavelengths, which would then be passed on to a detector for processing and recording. This data would then be digitized for transmission to Earth where it could be processed and analyzed. It operated in the 122 nm to 550 nm wavelength range.

Wide Field and Planetary Camera (WFPC1): This instrument, which was proposed by California Institute of Technology professor James Westphal and built by NASA’s Jet Propulsion Laboratory, was made up of two separate cameras, each using four 800 × 800 pixel CCDs manufactured by Texas Instruments. The Wide Field Camera was designed to capture panoramic views of distant light sources, while the Planetary Camera was designed to capture higher resolution images. It operated in the 115 nm to 1000 nm wavelength range.

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