apparatuses equipped with instruments for astronomical and geophysical observation conducted beyond the earth’s atmosphere or in its upper layers by means of balloons or artificial earth satellites and space probes in the form of geophysical rockets. The most prolonged and varied observations can be carried out by means of satellite (orbital) extraterrestrial observatories and extraterrestrial observatories established on the moon. Astronomical extraterrestrial observatories are useful for observing the celestial sphere as a whole, separate stars, and nebulas in regions of the spectrum inaccessible to terrestrial observation. Solar extraterrestrial observatories, which are designed for studying the sun in the shortwave region of the spectrum and in the radio-frequency region of emission, represent a special type of astronomical extraterrestrial observatory. Such are the orbital astronomical observatories devised in the USA for mapping the celestial sphere by means of television equipment on four spectral bands with a wavelength of less than 1,100 angstroms (Å) as well as by means of broad-band spectrophotometry of individual stars and nebulas within the range of 800-3,000 Å. The Soviet artificial earth satellite Cosmos 215 conducted astronomical observations using 10-cm telescopes equipped with narrow-band detectors with a band of approximately 100 Å operating in the range of 1,000-3,000 Å as well as using an X-ray telescope and a photometer sensitive to visible light. The Soviet satellites Cosmos 160 and Cosmos 230 were solar extraterrestrial observatories that studied the localization, dimensions, and structure of regions of X-ray flares on the sun and other phenomena. In the USA space apparatus of this type includes orbital solar observatories investigating such phenomena as solar activity and the sun’s corona and also the Solrad satellites, which record and transmit in the natural time scale data on variations in the sun’s shortwave radiation that are caused by the flares.
Geophysical extraterrestrial observatories conduct geophysical measurements in accordance with a broad, coordinated program—atmospheric, magnetic, ionospheric, and other measurements—along with measurements of parameters (for example, solar radiation) associated with the geophysical properties being measured. The third Soviet artificial earth satellite, the Soviet satellites of the Elektron series, the American orbital geophysical observatories, and polar geophysical observatories are examples of such satellites. Extraterrestrial observatories with scientific personnel on board are planned. New scientific prospects are opened up by the creation of lunar observatories. The first prolonged astronomical observations of the moon were carried out from the Soviet self-propelled laboratory Lunokhod 1, which began operating Nov. 18, 1970, equipped with an X-ray telescope for studying the intensity and structure of the extragalactic X-ray background and individual sources and a device for studying the flux of corpuscular radiation.
M. G. KROSHKIN