Woude, Jurrie van der, 1935-

The Hubble Space Telescope (HST) was named after Edwin Powell Hubble, (1884-1953), eminent astronomer of the twentieth century. By his inspired use of the largest telescope of his time, the 100-inch Hooker Telescope reflector at the Mount Wilson Observatory, Pasadena, California, he revolutionized ideas of the size, structure, and basic properties of the universe. Hubble's observations proved that galaxies are "island universes".

Hubble also outlined the current classification system for galaxies. His greatest discovery was the linear relationship between a galaxy's distance and the speed with which it is moving relative to Earth, known as the Hubble Constant.

HST is a cooperative program of the European Space Agency (ESA) and the National Aeronautics and Space Administration (NASA) to operate a long-lived space-based observatory for the benefit of the international astronomical community. The HST was the flagship mission of NASA's Great Observatories program. The HST Program is managed by the NASA/Goddard Space Flight Center (GSFC) for the Office of Space Science (OSS) at NASA Headquarters.

The Program falls under the Search for Origins and Planetary Systems scientific theme. Within GSFC, the Program is in the Flight Projects Directorate (Code 400), under the supervision of the Associate Director of Flight Projects for the HST (Code 440). The HST Program is organized as two flight projects, the HST Operations and Ground Systems Project (O&GS, Code 441) and the HST Flight Systems and Servicing Project (FS&S, Code 442). Responsibility for conducting and coordinating the science operations of the HST rests with the Space Telescope Science Institute (STScI) on the John Hopkins University Homewood Campus in Baltimore, Maryland. The Association of Universities for Research in Astronomy, Inc. (AURA) operates STScI for NASA.

Princeton astronomer Lyman Spitzer first dreamt of a telescope like the HST in the 1940's. The HST was designed and built in the 1970s and 1980s, completed in 1989 and operational finally in the 1990s. When originally planned in 1979, the Large Space Telescope program called for it to be returned to Earth for refurbishment, and re-launch every 5 years, with on-orbit servicing every 2.5 year.

Hardware lifetime and reliability requirements were based on that 2.5-year interval between servicing missions. In 1985, contamination and structural loading concerns associated with return to Earth aboard the Shuttle eliminated the concept of ground return from the program. NASA decided to adopt on-orbit servicing. On April 5, 1990, Shuttle flight STS-31 soared to 600 km, the highest Shuttle altitude to date. This altitude permitted the crew to photograph Earth's large-scale geographic features not apparent from lower orbits. This was the tenth launch of the shuttle Discovery. The main purpose of this mission was to deploy the $1.6 billion 2.4-meter Hubble Space Telescope.

It was designed with 8 Orbital Replacement Units, equipped with 225 linear feet of handrails and 31 pins of attaching portable foot restraints. It operates from a vantage-point of 620 km above the Earth's turbulent and obscuring atmosphere, particularly at ultraviolet wavelengths. The mission was troubled soon after launch by the discovery that the 96-inch wide primary mirror, made by Perkin-Elmer Corp. of Danbury, Conn., was spherically aberrated (slightly too flat). It blurred objects and obscured distant galaxies.

In addition, flexing of the solar panels as the spacecraft passed from the Earth's shadow into sunlight caused problems with HST's pointing stability. Various steps were taken by NASA to correct these problems. First, a replacement camera would be needed to correct the spherical aberration, and second, an on-orbiting successful servicing mission was also required for the HST to work as planned.

After NASA conducted a three-year investigation of the troubled mission, the Federal Government disclosed the details publicly after Bill D. Colvin, Inspector General of NASA, testified detailing a total of six irregularities that doomed the mirror to blurred vision. The Justice Department worked out a deal to drop all potential lawsuits against Perkin-Elmer Corporation when they agreed to pay $25 million in damages, for making the faulty mirror. Prior to the discovery of the flawed Hubble in 1990, the engineers and scientists at the Jet Propulsion Laboratory had gained optical experience supplying optics for Voyager spacecraft and mirrors for the Keck telescope in Hawaii.

JPL was given the challenge to develop the $101 million Wide Field/Planetary Camera-2 to correct the HST flaw. JPL's optical scientist, Arthur Vaughan and planetary scientist, David Crisp, were part of the team that figured out the prescription that would correct the Hubble Space Telescope's blurred vision. Vaughan was involved with the creation of the first Wide Field Planetary Camera, by designing the camera's optics in 1977-78 using a hand calculator. NASA also contacted Tinsley Laboratories, after Kodak, Hughes and United Technologies, three of the nation's largest high technology firms, declined to manufacture the needed optics and meet the agency's strict specifications. Tinsley Laboratories, just outside San Francisco, mostly made custom lenses for the electronics industry. They were given the assignment to meet NASA's strict schedule and billionths-of-an-inch specifications.

NASA decided the mirrors must be ground to a tolerance of 10 Angstrom units (an Angstrom is four-billionths of an inch). Tinsley's mirrors, about the size of a 10-cent coin in a payload of 8 ounces, exceeded those requirements. Their work was better than tolerance, on time and within NASA's stringent budget. Using proprietary computer-controlled grinding and polishing machines, Tensley turned out all 36 mirrors fully tested in 11 months for less than $1.6 million, to within six Angstroms. Hubble's enormous telescopic power now was set to reach its designed potential.

On December 2, 1993, Shuttle flight STS-61 was launched to repair, replace, and/or update the instruments on the Hubble Space Telescope. Astronauts Story Musgrave and Jeff Hoffman's space walk would include replacing the telescope's two 12- meter (30-foot) solar panels; and replacing the Wide Field/Planetary Camera. Also they installed the $50 million Corrective Optics Space Telescope Axial Replacement, known as COSTAR, roughly the size of a telephone booth. The astronauts earned their pay for the day after they managed to accomplish their planned tasks successfully despite delays on their third space walk. David Crisp, Karl Stapelfeldt, Arthur Vaughan and Larry Simmons, members of the camera science team at JPL, stated, "We feel that we've participated in a tremendous success here, which we believe NASA definitely needed."

But it would take several weeks of tweaking, aligning and calibrating before the Hubble and its new camera started taking pictures by mid-January of 1994. In 1999, a second successful service mission took place and a future service mission is tentatively planned for mid- 2002. The HST is to be serviced for 20 years, giving it a much longer service active life than anticipated when it was originally planned. Engineering and scientific data from the HST, as well as up-linked operational commands, are transmitted through the Tracking Data Relay Satellite (TDRS) system and its companion ground station at White Sands, New Mexico. Up to 24 hours of commands can be stored in the onboard computers.

Since the 1993 installation of the Wide Field/Planetary Camera-2, developed by JPL, the Hubble Space Telescope has been sending back unprecedented images of galaxies far and beyond our expectations, complementing Edwin P. Hubble's observations that galaxies are truly "island universes."

From the description of Hubble Space Telescope Wide Field / Planetary Cameras 1 and 2 Photograph Collection, 1990-1998. (Jet Propulsion Laboratory Library and Archives). WorldCat record id: 733100858