Hubble Space Telescope
(Hubble Space Telescope, abbreviated as HST), named after the astronomer Hubble, is a telescope that orbits the earth. His position is above the earth’s atmosphere, so it has the benefits that ground-based telescopes do not have-the image will not be disturbed by atmospheric turbulence, the viewing angle is excellent and there is no background light caused by atmospheric scattering, and it can be observed that it will be absorbed by the ozone layer. Of ultraviolet rays. After being launched in 1990, it has become the most important instrument in the history of astronomy. He has filled in the gaps in ground observations, helped astronomers solve many fundamental problems, and have a better understanding of astrophysics. Hubble’s Hubble ultra-deep space field of view is the deepest (sharpest) optical image ever obtained by astronomers.
From his original idea in 1946 until launch, the plan to build a space telescope was constantly delayed and troubled by budgetary issues. After his launch, he immediately found that the primary mirror had spherical aberration, which severely reduced the telescope’s observation ability. Fortunately, after a maintenance mission in 1993, the telescope restored its planned quality and became the most important tool for astronomical research and public relations. The Hubble Space Telescope and Compton Gamma-ray Observatory, Chandra X-ray Observatory, and Spitzer Space Telescope are all part of NASA’s Large Orbital Observatory Program. The Hubble Space Telescope is jointly managed by NASA and ESO.
Hubble’s future depends on the success of subsequent maintenance tasks. Several gyroscopes that maintain stability have been damaged. At present (2007), even the spare ones have been exhausted, and the function of another telescope for pointing is also declining. . The gyroscope must be repaired manually. On January 30, 2007, the main Advanced Sky Survey Camera (ACS) also stopped working. Before manual repairs were performed, only the ultra-ultraviolet channel could be used. On the other hand, if there is no further elevation to increase the orbital height, drag will force the telescope to return to the atmosphere in 2010. Since the unfortunate incident of the Space Shuttle Columbia in 2003, because the International Space Station and Hubble are not at the same altitude, astronauts lack a safe refuge in emergency situations, so NASA believes that manned space missions to repair the Hubble telescope are Unreasonably dangerous tasks. After NASA’s new review, CEO McGriffin decided on October 31, 2006 to conduct the last Hubble maintenance mission in Atlanta. The mission was scheduled for September 11, 2008. Based on safety considerations, at that time Discovery will be on standby on the LC-39B launch pad to provide rescue in an emergency. The planned repairs will allow the Hubble Space Telescope to continue working until 2013. If it succeeds, the successor James Webb Space Telescope (JWST) should have been launched into space and can be connected to the mission. The Webb Space Telescope has far more functions than Hubble in many research projects, but it will only observe infrared rays, so it cannot replace Hubble’s functions in the visible and ultraviolet fields of the spectrum.
Hubble (1889～1953)
The American astronomer Edwin P. Hubble is one of the most famous figures in the study of modern cosmological theory, and the founder of astronomy outside the river. He discovered the existence of extragalactic galaxies and the continuous expansion of the universe. He was the founder of extragalactic astronomy and the first person to provide evidence of the expansion of the universe.
Spitzer Space Telescope
Launched into space on August 25, 2003, it is the largest infrared band space telescope in human history, replacing the original IRAS telescope. Spitzer’s predecessor was called SIRTF (Space Infrared Telescope Facility).
Its observation band is 3 microns to 180 microns. As the earth’s atmosphere absorbs part of the infrared rays, and the earth itself emits infrared rays due to black body radiation, astronomical data in the infrared band cannot be obtained on the surface of the earth.
It has a total length of about 4 meters and a total weight of about 865 kg. It has a 0.85 meter primary mirror and three extremely low temperature observation instruments. In order to prevent the telescope itself from emitting infrared rays due to black body radiation to interfere with the observation results, the temperature of the observation instrument It must be lowered to close to absolute zero. In addition to avoiding interference from solar thermal energy and infrared rays emitted by the earth itself, the telescope itself also includes a protective cover, and the location of the telescope in space is deliberately arranged on the earth’s orbit around the sun. Follow the earth to move far behind the earth.
Since infrared rays can penetrate dense dust clouds, it allows us to observe many astronomical phenomena that cannot be observed with visible light. For example, its observations can help astronomers to further clarify the formation of stars, galaxy cores and planetary systems.
The Spitzer Space Telescope is the last space telescope planned by the Great Observatories Program of NASA.
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