On this day in 1990, the Space telescope Hubble was released from the space shuttle Discovery beginning a new era in Astronomy.
The origins of the Hubble project can be traced back to Astronomer Lyman Spitzer who wrote a paper in 1946 titled “Astronomical advantages of an extraterrestrial observatory.” In it he discussed the two main advantages a space-based observatory would have over ground-based telescopes.
One being the absence of atmospheric turbulence which is what makes stars “twinkle” when observed from the ground. The other being the ability to view the cosmos with the full infrared and ultraviolet components intact. These are mostly removed by Earth’s atmosphere and skews the visual data from land based systems.
In 1962 the National Academy of Science recommended a project be undertaken to study the feasibility of placing a telescope platform in space. In 1965 Spitzer was made chairman of a committee tasked with defining the scientific objectives for a large space telescope.
The space telescope design and fabrication project took shape in 1968 when NASA developed plans for a space telescope with a mirror size of three meters. With the project ready to move forward NASA only needed to clear one more hurdle — funding.
The project came under close scrutiny by the U.S. Congress in 1972 as proposals were flying around Washington faster than the Concorde. The scope and financial requirements of the telescope project were massive and politicians were already sliding into cost savings mode. In 1974, the project was shelved under President Gerald Ford’s spending cuts. This move prompted thousands of astronomers and scientists from around the country to initiate a letter writing campaign aimed at all levels of government, asking the project to continue due to its importance in the exploration of space.
Congress responded by agreeing to fund the project at a level one half the original budget. NASA cut corners in many places including the size of the mirror design, now reduced to 2.4 meters. Many aspects of the project were trimmed to meet the new budget constraints. Congress increased the funding in 1978 and the project moved forward with scientists eying a launch window of sometime in 1983.
In 1983 the telescope was named after famed astronomer Edwin Hubble.
Engineering and fabrication delays plagued the project from day one and the planned 1983 launch slipped past 1984 to late 1985 when the project team assured NASA they would be ready for an October 1986 launch. That date fell by the wayside on the heels of the Challenger tragedy in January of 1986.
Hubble patiently sat in the wings as NASA got their house in order after the process failures of the Challenger launch. Eventually the shuttles returned to space in 1988 and the Hubble Mission was scheduled for April of 1990 aboard Discovery.
Within weeks of the Discovery mission it was determined there had been a serious design flaw in Hubble’s optical system. Images being received had a slight out of focus condition. The only viable solution would be a repair mission to replace the flawed mirror.
In December of 1993, Shuttle Endeavor launched on STS-61 with an aggressive ten-day repair of the Hubble as their mission. Over the next several days they replaced the primary mirrors and several other instruments. At the time is was the most intensive shuttle mission ever undertaken by NASA and included five lengthy extra-vehicular processes to repair the scope. Endeavor also boosted the flight altitude of Hubble by taking it to a much higher orbit than before.
In January of 1994, NASA announced the mission had been a resounding success and they now had a usable telescope in space. Over the years following NASA would return to Hubble four more times, as recently as 2009, to upgrade and repair the instrument. Following the retirement of the shuttle fleet, one of the concerns is the maintenance of the Hubble.
If NASA is unable to return and boost Hubble to a higher atmosphere its orbit will continue to decay until it falls from the sky sometime between 2019 and 2032.
For more about the Hubble Telescope visit: http://hubblesite.org/