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Space Topics: Hubble Space TelescopeHistorical Timeline
1946 -- In a paper titled "Astronomical advantages of an extra-terrestrial observatory," Astronomer Lyman Spitzer argued that space telescopes would be better than ground-based ones because of their higher angular resolution and their increased ability to measure ultraviolet and infrared light. 1962 -- The United Kingdom launches the first space telescope, a solar telescope that was part of the Ariel program. 1966 -- The United States launches the Orbiting Astronomical Observatory, but its battery fails after only three days. 1968 -- The United States launches a second Orbiting Astronomical Observatory (OAO-2) which takes ultraviolet observations until 1972. NASA proposes plans for a Large Orbiting Telescope or a Large Space Telescope. 1974 -- Budget cuts end the Large Orbiting Telescope project. 1978 -- Design begins for a rejuvenated telescope project after a huge nationwide lobbying effort. The goal is for a 1983 launch. 1980s -- Optics company Perkin-Elmer begins construction of the space telescope's primary light-collecting mirror -- arguably its most important component -- but management and technical problems at Perkin-Elmer cause a postponement of the launch until 1985.
The developing space telescope mission is named for Edwin Hubble, the astronomer who discovered the expansion of the universe through measurements of the red-shifted spectra of distant stars. 1983 -- The Space Telescope Science Institute (STScI) is founded. STScI is operated by the Association of Universities for Research in Astronomy (AURA) and is located at Johns Hopkins University. STScI takes over the science management of the Hubble Space Telescope from NASA. 1985 -- Construction of the Hubble Space Telescope is completed. It carried five original science instruments: the Wide Field and Planetary Camera (WFPC); the Goddard High Resolution Spectrograph (GHRS); the Faint Object Camera (FOC); and the Faint Object Spectrograph (FOS). 1986 -- The space shuttle Challenger explodes upon liftoff. The disaster forces delays in all programs, including Hubble, that planned to launch from any future space shuttle. April 24, 1990 12:33:51 UTC -- The space shuttle Discovery lifts off on mission STS-31, carrying Hubble into orbit. April 27, 1990 19:38 UTC -- The Hubble Space Telescope is released into orbit by Discovery. It took very little time for its operators to discover that there was a flaw in Hubble's mirror that blurred its images. Although better than images achievable from the ground, the focus was 10 times worse than had been specified in its design because the mirror had been ground to the wrong shape.
December, 2 1993 -- The space shuttle Endeavour launches on Hubble Servicing Mission 1 (STS-61). A corrective optics package called COSTAR was installed to correct the effect of the misshapen mirror for three of Hubble's instruments, and the Wide Field and Planetary Camera 2 (WFPC2) replaced the original WFPC. WPFC2 contained internal devices that corrected for the mirror's flaw. June 1994 -- Hubble takes images of the Orion nebula that confirm the birth of planets around stars. November 1995 -- Images taken by Hubble of the Eagle nebula show the birth of stars. February 21, 1997 -- The space shuttle Discovery launches on Hubble Servicing Mission 2 (STS-82). Astronauts replace the GHRS and FOS with the Space Telescope Imaging Spectrograph (STIS) and the Near Infrared Camera and Multi-Object Spectrometer (NICMOS). In addition, a new Solid State Recorder replaces an Engineering and Science Tape Recorder, Hubble's insulation is replaced and its orbit is boosted. October 1997 -- Hubble's mission is extended to 2005-2010. November 13, 1999 -- A fourth gyroscope on the Hubble fails, so it can no longer aim itself. It is shut down. December 19, 1999: The space shuttle Discovery launches on Hubble Servicing Mission 3A (STS-103). All six gyroscopes are replaced, so the Hubble can keep running. In addition, a Voltage/temperature Improvement Kit (VIK) is installed to prevent battery overcharging, and the insulation is replaced for a second time. A computer with an Intel 486 Processor is installed.
March 1, 2002 -- The space shuttle Columbia launches on Hubble Servicing Mission 3B (STS-109). The Advanced Camera for Surveys (ACS) replaces the FOC and the Near Infrared Camera, and Multi-Object Spectrometer (NICMOS) is repaired. In addition, a new set of solar arrays with a new design provides the Hubble with more power and flexibility. This was Columbia's penultimate mission. 2003-2004 -- The ACS and NICMOS work together to image the Hubble Ultra Deep Field, the furthest and oldest part of the universe ever imaged. February 1, 2003 -- The space shuttle Columbia breaks up upon re-entry into Earth's atmosphere, killing all seven astronauts on board. The shuttle fleet is grounded, and any future Hubble servicing missions are deemed too risky for the aging shuttle fleet. 2004 -- The power system of the STIS fails, leaving it nonfunctional. Late 2004 -- The Laser Star Guide Adaptive Optics system comes online at the Keck II telescope at Mauna Kea. Using Laser Star Guide Adaptive Optics, ground-based telescopes can achieve images of comparable sharpness to Hubble's at a fraction of the cost. August 2005 -- Hubble is switched from using three gyroscopes to two. This reduces the amount of the sky accessible to Hubble and makes some observations more difficult but will extend the lifetime of the telescope by keeping one of the three gyroscopes as a backup. 2005 -- NASA's new director Mike Griffin states that it will consider the possibility of more manned or robotic missions to extend the lifetime of the Hubble after two successful shuttle missions. However, during the first shuttle mission following the Columbia disaster, problems recurred with foam falling off the shuttle's external tank. June 25, 2006 -- The first of several electronics failures on the Advanced Camera for Surveys. October 31, 2006 -- NASA announces plans for a fifth Hubble servicing mission, to take place in 2008. January 27, 2007 -- The Advanced Camera for Surveys fails due to a short circuit. One channel (the Solar Blind Channel) was successfully switched to an alternate set of electronics. September 27, 2008 -- Hubble's main Science Instrument Command and Data Handling (SI C&DH) unit fails just two weeks before Atlantis was planned to launch on Servicing Mission 4. The mission is delayed so that astronauts may prepare to replace the SI C&DH.
May 11, 2009 -- The space shuttle Atlantis launches on Hubble Servicing Mission 4 (STS-125). During five space walks, astronauts install two new instruments, the Wide Field Camera 3 (replacing the Wide Field and Planetary Camera 2) and the Cosmic Origins Spectrograph (which replaced the corrective optics -- with the installation of WFC 3, all instruments on Hubble have the correction built in). Astronauts also repaired the Advanced Camera for Surveys and the Space Telescope Imaging Spectrograph. They replaced all the gyroscopes, one of three Fine Guidance Sensors, the SI C&DH, all six of the batteries, and three new thermal insulation blankets. As a result of the servicing mission, Hubble should function into 2014 at least. 2014 -- Earliest possible launch date for the next-generation orbiting telescope, the James Webb Space Telescope. |
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