Soviet experiments on manned spacecraft have found that this type of spacecraft is not suitable for astronomical observations. Human activity inside a ship or orbital station creates vibrations that make observations unusable.
The actual goal of the experiment was the antenna itself. It was the prototype of future modular structures - lightweight, compact, which could unfold from a small initial volume into impressive structures. These experiments continue now on the ISS - the use of inflatable and thin-film structures, as well as mechanical structures deployed directly in space.
Large radio antennas will be needed on board future space stations, for example, for higher-quality relaying of signals to Earth from spacecraft exploring distant regions of the solar system. When studying distant objects of the solar system (planets, their satellites, comets) in the immediate vicinity of spacecraft, the problem of high-speed transmission of telemetric information to the Earth becomes important, and this is also associated with the use of sufficiently large onboard radio antennas.
Various areas of space research require the equipping of spacecraft with various kinds of devices that receive electromagnetic radiation. The efficiency of these instruments (mainly sensitivity and angular resolution) increases with an increase in the area of the receiving elements.
In addition to antennas, such designs will find application in space power plants, both in the classic solar panels or in solar concentrators in powerful power plants of large space stations or solar ovens.
As well as grandiose projects, like launching giant mirrors into orbit to directly reflect the energy of solar radiation to Earth.
Almost all auto-deployable reflector antennas already used in space were of the umbrella type. The disadvantages of space antennas of this type include the relatively low rigidity of the mirror and large deviations of the real surface from the theoretical one.
The new compact antenna design was tested in space in 1979 оn the Salyut-6 orbital station. The 10-meter space radio telescope (KRT-10) was delivered to the station in July 1979 using the Progress-7 cargo transport vehicle. The mass of the mirror was 65 kg, and when folded it was a hexagonal prism with a maximum size at the base of 0.5 m and a total length of 0.9 m. The total mass of the KRT-10 was 300 kg. Soviet cosmonauts V. A. Lyakhov and V. V. Ryumin docked and assembled all the KRT-10 units, reinforced it on the station's access hatch, and also pre-checked the interactions of its elements. On July 18, 1979, the Progress-7 cargo transport vehicle departed from the station, after which the KRT-10 radio telescope was automatically extended and opened. After putting it into operation, the alignment was carried out (alignment of the antenna beams to the axes of the Salyut-6 station) and the determination of the directional patterns.
These measurements were carried out during the turns of the entire orbital station. They were carried out during the registration of radio emission from the Crab Nebula (source Cassiopeia A), the Sun and a terrestrial radio source. The measurement results turned out to be close to the calculated ones. During the operation of the KPT-10, astrophysical and geophysical studies were carried out. The operation of the KRT-10 equipment continued until August 9, when the space radio telescope was separated from the Salyut-6 station. In the process of separation, four cables caught on the protruding part of the orbital station, and the cosmonauts had to go out into open space and cut them. This event is depicted in a painting by the artist A. Sokolov.
Theoretical and experimental studies of space antennas, which have a structure of the type of space-rod trusses, have shown that they are quite reliable and meet all operational requirements. Such designs of space antennas have sufficient rigidity and can ensure the accuracy of keeping the shape of the reflecting surface required for operation in the centimeter range. Calculations show that the ratio of the mass of the space antenna to the area of the mirror aperture for structures of space-rod trusses, depending on the operating conditions, varies from 0.2 to 1.0 kg/m2.
Thus, the radio telescope KRT-10 at the manned orbital station was a unique experiment, the purpose of which was to test new technologies for the construction of large mirrors in space, which in the future could be used for communications and power engineering.
