![]() ![]() Hubble has blanket of multilayered insulation, which protects the telescope from temperature extremes. One talks to the instruments, sends commands and other information, and transmits data the other handles pointing control, gyroscopes and other system-wide functions. ![]() Several computers and microprocessors reside in Hubble’s body and in each science instrument. Some of that electricity runs the telescope, some is stored in onboard batteries for the periods when Hubble is in Earth’s shadow. Each wing-like array has solar cells that convert the Sun’s energy into electricity. Four antennas receive and send information to a set of satellites, which in turn communicate with Earth. The antennas allow technicians to communicate with the telescope, telling it what to do and when to do it. Hubble performs in response to detailed instructions from people on the ground. Several spacecraft systems are in place to keep Hubble functioning smoothly. Hubble is operated by commands from the ground. The aft shroud houses the scientific instruments, gyroscopes, and star trackers. In the middle of the telescope are the reaction wheels and the bays that house the observatory's control electronics. The forward shell houses the telescope’s optical assembly. Spacecraft systems Hubble’s Control and Support Systems and Instruments Diagram The optics acted like eyeglasses to correct Hubble’s vision. During Servicing Mission 1 in December of 1993, astronauts added corrective optics to compensate for the flaw. The flaw was tiny, only about 1/50th the width of a human hair, but significant enough to distort Hubble’s vision. The telescope was designed to be visited periodically by astronauts, who brought new instruments and technology, and made repairs from December 1993 to May 2009.Īfter launch in April 1990, NASA discovered that the primary mirror was flawed. These are not the only instruments that have flown aboard Hubble. Hubble's current suite of instruments includes the Wide Field Camera 3 (WFC3), Cosmic Origins Spectrograph (COS), Advanced Camera for Surveys (ACS), Space Telescope Imaging Spectrograph (STIS) and Fine Guidance Sensors (FGS). Hubble holds two main varieties of instruments: cameras, which capture Hubble's famed images, and spectrographs, which break light into colors for analysis. Each instrument is designed to examine the universe in a different way. Hubble’s science instruments, the astronomer’s eyes to the universe, work together or individually to provide the observations. The reflecting surfaces are coated with a 3/1,000,000-inch layer of pure aluminum and protected by a 1/1000,000-inch layer of magnesium fluoride that also makes the mirror more reflective to ultraviolet light. Hubble’s mirrors are made of ultra-low expansion glass kept at a “room temperature” of about 70☏ (21☌) to avoid warping. There it is intercepted by pick-off mirrors that pass it into the scientific instruments. This secondary mirror then reflects the light through a hole in the primary mirror to form an image at the telescope’s focal plane. Hubble’s 1,825 pound, 7.8-foot (2.4-meter) diameter primary mirror collects light from its astronomical target and reflects it to a 12-inch (0.3-meter) diameter secondary mirror located in the optical tube. The light is focused on a small area called the focal plane, where it is picked up by its various science instruments. The secondary mirror bounces the light back to the primary mirror and through a hole in its center. Light from celestial objects travels down a tube, is collected by a bowl-like, inwardly curved primary mirror and reflected toward a smaller, dome-shaped, outwardly curved secondary mirror. Hubble is a Cassegrain reflector telescope. The telescope has beamed hundreds of thousands of celestial images back to Earth during its time in space. In addition to observing visible and near-infrared light, Hubble detects ultraviolet light, which is absorbed by the atmosphere and visible only from space. Orbiting high above the Earth, the Hubble Space Telescope has a clear view of the universe free from the blurring and absorbing effects of the atmosphere. Four Successful Women Behind the Hubble Space Telescope's Achievements.Characterizing Planets Around Other Stars.Measuring the Universe's Expansion Rate. ![]()
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