Who owns space probes

astronomical probes and satellites

astronomical probes and satellites, Astronomy satellites, devices launched into space used for astronomical research. One distinguishes between Satellitesorbiting the earth, and Space probes (sometimes called deep space probes) that are sent to other celestial bodies in the solar system. Another possible classification can be made with regard to their use in specific wavelength ranges, since satellites in particular are mostly designed for a specific spectral range. Satellites and space probes are astronomical instruments; they have a primary receiver that collects the radiation, and secondary receivers in the form of one or more detectors for converting the received radiation into electrical signals. In addition, they have telemetry facilities in order to recognize and change their own position in space, as well as transmission systems with which the data are transmitted to earth. The space probes in particular are multifunctional devices with optical detectors, spectrographs, magnetometers, etc., which should enable as many examinations of the planets and their satellites as possible.

The era of astronomical research in space began at the end of the 1950s with a wide variety of experiments that were brought into ballistic or narrow orbit and, as a rule, landed again on board rockets. For example, the cosmic radiation and the course of the terrestrial magnetic field were measured, but the first X-ray sources in the universe were discovered - rather by chance - on rocket flights.

The USA and the then USSR sent unmanned probes to the moon, which examined the surface and soil conditions, and which were followed as a highlight by the manned lunar flights of the Apollo program (1969-1975).

Probes to Venus and Mars followed. They provided the first images of the cloud cover and the surface of Venus as well as data on their chemical composition and surface temperature. Images of the crater-jagged surface of Mars and data on its extremely thin atmosphere provided further building blocks for the exploration of the planets. Planetary research reached a preliminary climax in 1976 with the successful landing of the Viking space probe on Mars, which, after several failures, was followed by the Pathfinder probe landing in 1997. The great swingby maneuver of the Voyager probes, which passed almost all outer planets, and the immersion of an atmosphere module of the Galileo probe into the gas envelope of the planet Jupiter are among the great successes in planetary exploration.

The deep space projects not only provided impressive images of the outer planets, but also data on temperatures, atmospheric compositions and the temporal and spatial course of the solar wind at the edge of the solar system. The era of the deep space probes is not over. Comets and asteroids were chosen as targets for future missions because they are believed to reflect the composition of the gas and dust clouds that made up the sun and planets. The Pluto-Kuiper-Express probe, which is also planned, is to reach Pluto and thus examine the bodies of the Kuiper Belt.

While most planetary probes provide data about the solar system, the observations made by the astronomical satellites from earth orbit aim further out into the cosmos. Since no more radiation is absorbed by the atmosphere in space, observations are possible in all wavelength ranges, from the radio range to gamma radiation. However, the satellites are mostly designed for a special spectral range, such as ROSAT for the X-ray range or ISO for infrared astronomy, since the devices and detectors can be better coordinated with one another. For example, infrared telescopes must be cooled to around 4K with liquid helium, as otherwise their own thermal radiation would dazzle the detectors. By observing bright objects, some helium repeatedly evaporates and is lost. The amount of helium carried with them limits the lifespan of infrared satellites to a period of a few months to about a year. The first pure infrared satellite was IRAS, which provided important results on the physics of stars, dust clouds, galaxies and galaxy clusters. Its successor ISO has been in use since the end of 1995 and can be expected to produce significantly better results.