August 15, 2022
A space observatory, also known as a space telescope, is an artificial satellite or space probe used to observe planets, stars, galaxies, and other celestial bodies in a similar way to a ground-based telescope. A significant number of space telescopes have been launched into orbit since Cosmos 215, considered the first space observatory, was launched on April 18, 1968, providing greater information and knowledge of the cosmos. There are several reasons why observing from space is desirable, since it avoids some of the problems that observatories on the ground have. The benefits of space observatories are: A telescope in space does not suffer from light pollution produced by nearby cities. In addition, it is not affected by the flickering caused by thermal turbulence in the air. Earth's atmosphere adds significant distortion to images, known as optical aberration. The resolving power of ground-based telescopes is greatly reduced. A space telescope does not observe through the atmosphere, so its capacity is always close to the theoretical maximum. This problem for ground-based telescopes has been partially solved by the use of adaptive optics, as in the Very Large Telescope, but they are complex and do not completely solve the problem. The atmosphere also absorbs a significant portion of the electromagnetic spectrum, making some observations practically impossible to make from the ground. X-ray astronomy is not carried out from Earth, but from space telescopes such as Chandra or XMM-Newton. Other portions of the electromagnetic spectrum, such as infrared or ultraviolet waves, are also filtered out by the atmosphere. Space telescopes, however, also suffer from some disadvantages that ground-based observatories do not: The high cost, mainly at launch. The costs to use a medium-sized rocket can be as high as $250 million, and using the space shuttle is twice that price. The impossibility of maintenance. Except for the Hubble Space Telescope, which has been serviced by space shuttle missions, if a space observatory fails it cannot be replaced. Short shelf life. Most space telescopes must be cooled and when the cooling liquids run out you cannot fill the reservoir with new liquid. However, space telescopes do not need periodic maintenance since they are not affected by conditions under the atmosphere. Space observatories can be divided into two general classes: those whose mission is to survey the entire sky, and telescopes that only make observations of parts of the sky. chosen from the firmament. Many of the space observatories have already completed their missions, while others are operational. Satellites and space probes for astronomical observation have been launched by NASA, ESA and JAXA.