The successful completion of the first development phase, which confirmed the good prospects of remote sensing techniques for solving scientific and application problems, made it necessary to expand the field of research and design work. OKB-586 established a special division incorporating design-theoretical departments, but the range of problems was so extensive that a single company was not capable to deal with them properly. Therefore, it was decided to transfer several projects to other space enterprises.

To reduce time and cost of spacecraft development and manufacture, it was decided to create the world’s first series of satellite buses comprised of the DS-U1, non-oriented with storage batteries; DS-U2, non-oriented with solar panels; and the Sun-oriented DS-U3.

Forty-nine spacecraft were developed, manufactured, and delivered into orbit in 1963-1976.

The small unified satellite buses became the instrumental basis for establishment of international cooperation in space under the Interkosmos program.

Results of scientific studies into problems of space physics, obtained using the small unified spacecraft, received wide international acclaim.

DS-U1 based spacecraft

The first spacecraft designed by OKB-586 to lay the foundation for further development of spacecraft design field.

DS-U1-G geophysical

Mass, kg

291
Active life, days 24
Launch vehicle 11К63
Main experimental results Valuable information on correlation between solar activity and condition of the atmosphere. A middle-atmosphere model was built.
Orbited on

12 February 1966

DS-U1-A astronomical

Mass, kg

302
Active life, days 30
Launch vehicle 11К63
Main experimental results Valuable information on energy distribution in spectra of various stars. Photometric studies of stellar radiation in ultraviolet and X-ray spectral regions.
Orbited on

19 April 1968

DS-U1-Ya nuclear

Mass, kg

316
Active life, days 14
Launch vehicle 11К63
Main experimental results Valuable information on the level of natural radiation background and radiations in a wide range of energies and intensities in near-Earth space.
Orbited on

12 June 1968

DS-U1-P

Mass, kg

315
Active life, days 30
Launch vehicle 11К63
Main experimental results Data on discrete X-radiation sources, on energy distribution in spectra of various stars, and on isotropic X-ray background.
Orbited on

24 April 1970

DS-U1-IK-1

Mass, kg

288
Active life, days 30
Launch vehicle 11К63
Main experimental results

Data on global distribution of electron temperature and ion concentration.

A night equatorial ionospheric anomaly was discovered at an altitude of 1000 km.

Orbited on

25 December 1969

DS-U1-IK-2

Mass, kg

287
Active life, days 30
Launch vehicle 11К63
Main experimental results

Data on subauroral ionosphere of the northern and southern hemispheres; on ionospheric electron concentration and temperature and ion concentration; on mechanism of the predawn effect.

Orbited on

14 October 1970

DS-U2 based spacecraft

The satellite instrumentation helped to discover and determine a range of large-scale heterogeneous formations in the ionosphere; radio refraction angles were determined.

DS-U2-V vibration

Mass, kg

240
Active life, days 20
Launch vehicle 11К63
Main experimental results

Electron concentration in the vicinity of the spacecraft was defined, as well as properties of the ionosphere in the path of coherent-wave propagation from the spacecraft to an observation point.

Orbited on

19 October 1965

DS-U2-М molecular

Mass, kg

230
Active life, days 90
Launch vehicle 11К63
Main experimental results

Spacecraft missions experimentally confirmed that quantum frequency standards can work in vacuum, zero gravity, and other space flight environments. The data allowed continuing engineering development of onboard molecular oscillators in order to produce generic designs.

Orbited on

26 November 1965

 

DS-U2-I ionospheric

Mass, kg

286
Active life, days 90
Launch vehicle 11К63
Main experimental results

The desired signal was received at all working frequencies: for the first time ever, the passage of 31.8 kHz and 44.9 kHz radio-waves through the ionosphere was confirmed. The hypothesis of the ultralow frequency electromagnetic waves passage through the ionosphere was confirmed. The data allowed estimating charged-particle concentration in lower ionosphere versus time and other factors.

Orbited on

24 May 1966

DS-U2-D dosimetric

Mass, kg

237
Active life, days 70
Launch vehicle 11К63
Main experimental results

Data on charged particles in Earth natural and artificial radiation belts; data on primary cosmic rays

Orbited on

21 December 1966

 

DS-U2-MP meteorite

Mass, kg

280
Active life, days 90
Launch vehicle 11К63
Main experimental results

Data did not confirm a dust belt around Earth and allowed determining the nature of trace elements in a majority of principal meteor showers. A nuclear explosion in China was recorded.

Orbited on

12 December 1966

DS-U2-GK geophysical integrated

Mass, kg

335
Active life, days 40
Launch vehicle 11К63
Main experimental results

Data on ionospheric plasma motion

Orbited on

20 December 1968

DS-U2-GF heliophysical

Mass, kg

283
Active life, days 90
Launch vehicle 11К63
Main experimental results

This spacecraft was a small optical observatory with instrumentation for simultaneous recording of solar, stellar, nebula, and Earth upper atmosphere radiation. Instrumentation recordings enabled tracing radiation bursts and decays due to active processes in outer sheaths of the Sun (solar flares).

Orbited on

26 December 1968

DS-U2-MG magnetic

Mass, kg

265
Active life, days 40
Launch vehicle 11К63
Main experimental results

Data on Earth’s magnetic field behavior. The equatorial electrojet effect was measured for the first time. These data are used for studying the globe conductivity.

Experiments in space allowed determining the degree of conformity of a true picture with theoretical models created on the basis of observations conducted for centuries from the Earth surface.

Orbited on

20 January 1970

 

DS-U2-IP ionospheric

Mass, kg

281
Active life, days 90
Launch vehicle 11K65М
Main experimental results

The spacecraft studied ion and electron concentrations, ion chemical composition, and absorption of solar ultraviolet radiation in the atmosphere. Energetic-particle fluxes, related to the outer radiation belt and the “soft”-electron flow, were measured.

Orbited on

17 November 1970

 

DS-U2-K geophysical

Mass, kg

298
Active life, days 90
Launch vehicle 11K65М
Main experimental results

Regular observations of geoactive corpuscles and survey of anisotropic distribution of Earth’s magnetic field were carried out; upper atmosphere structure parameters were measured; global distribution of corpuscular fluxes was studied, and a relationship between the corpuscular flux intensity and the aurora luminosity was established.

Orbited on

4 June 1971

DS-U2-MT meteorite

Mass, kg

330
Active life, days 40
Launch vehicle 11K63
Main experimental results

Low-energy and high-energy component intensity variations of charged-particle flows were measured; radiation intensity and spectral composition were studied over a wide range, from X-ray to hard gamma radiation; radiation variations and a correlation with the activity of principal meteor showers was studied.

Orbited on

2 December 1971

DS-U2-GKA Aureole

Mass, kg

348
Active life, days 40
Launch vehicle

11K65М

Main experimental results

New data were obtained about a particular phenomenon, which is hardly visible to the human eye but very important for researchers: the hydrogenous aurora caused by precipitation of energetic protons into the atmosphere. Some characteristics of the precipitation, in particular on the dayside auroral oval, were studied.

Orbited on

27 December 1971

DS-U2-IK-1

Mass, kg

222
Active life, days 60
Launch vehicle

11K63

Main experimental results

Research into natural low-frequency radio waves was conducted. Many and various signals generated by lightning discharges were recorded during the experiment. The interaction of radio waves and ionospheric plasma, which was the source of peculiar space "noises", was observed. The ionospheric plasma "self-excitation" effect was also observed; it was manifested by the plasma emitting natural noise waves of higher intensity.

Orbited on

7 August 1970

DS-U2-IK-2

Mass, kg

296
Active life, days 60
Launch vehicle

11K63

Main experimental results

Studying of charged-particle flows gave additional data on the structure of radiation belts in geomagnetic calm; allowed monitoring the charged particle dynamics under magnetic agitation, and, with data on low frequency electromagnetic radiation, allowed proposing possible mechanisms of charged-particle loss in radiation belts.

It was found experimentally that electrons leave ionosphere as a result of cyclotron resonance of particles and low-frequency noise.

Orbited on

2 December 1971

DS-U2-IK-3

Mass, kg

329
Active life, days 60
Launch vehicle

11K65M

Main experimental results

The experimental gear gave simultaneous information on ionospheric, magnetic, and electrical field parameter values; on electromagnetic low-frequency radiations and charged-particle flows. Data on electrical field oscillations and low-frequency radiation spectrum, on electron temperature and concentration in ionospheric plasma

Orbited on

30 October 1973

DS-U2-IK-4

Mass, kg

317
Active life, days 60
Launch vehicle

11K65M

Main experimental results

Data on electron and positive-ion density, electron temperature and ionic composition of Earth’s ionosphere; on space density, energy characteristics, spectra, mass and destructive effects of sporadic meteoric particles of meteor showers

Orbited on

31 October 1974

DS-U2-IK-5

Mass, kg

320
Active life, days 60
Launch vehicle

11K65M

Main experimental results

Data on interaction between charged particles and low-frequency electromagnetic radiation in Earth’s magnetosphere

Orbited on

12 March 1975

DS-U2-IK-6

Mass, kg

312
Active life, days 60
Launch vehicle

11K65M

Main experimental results

Data on electrical and magnetic components of low-frequency electromagnetic radiation; allocation of charged-particle concentration and temperature distribution; integrated electron content in ionospheric plasma

Orbited on

11 December 1975

DS-U2-IK-8 Interkosmos-Kopernik-500

Mass, kg

256
Active life, days 60
Launch vehicle

11K63

Main experimental results

Data on sporadic solar radio emission. Irregularity was detected in the structure of solar radio bursts in the 3 to 6 MHz frequency range. Measurement data helped discover a new type of radio noise in ionosphere: Bernstein waves that occur spontaneously in high-temperature magnetic plasma.

The most interesting solar observation was the discovery of significant polarization of type III bursts in the 2 to 4 MHz frequency range.

Orbited on

19 April 1973

DS-U3 based spacecraft

The DS-U3 spacecraft family specialized in research into short-wave solar radiation that can be observed only above the atmosphere. Solar observations using space technologies allow gaining new knowledge about physical processes inside the Sun.

DS-U3-S

Mass, kg

285
Active life, days 75
Launch vehicle

11K63

Main experimental results

Data on the hottest areas of the solar corona in X-ray and ultra-violet spectral regions were used to assess the quantity of short-wave solar radiation absorbed by Earth's atmosphere.

Orbited on

16 June 1967

DS-U3-IK-1 (the first spacecraft built with direct participation of scientists and experts from socialist countries under the Interkosmos program)

Mass, kg

303
Active life, days 60
Launch vehicle

11K63

Main experimental results

Discovery of X-ray polarization during solar flares. When the spacecraft was in eclipse, optical and Lyman-alpha photometers determined a "reserve" of molecular oxygen and aerosols in upper atmosphere.

Orbited on

14 October 1969

DS-U3-IK-2

Mass, kg

303
Active life, days 60
Launch vehicle

11K63

Main experimental results

A vast store of data on physical processes on the Sun; research into fine X-ray spectra of ions in solar flares.

Orbited on

14 October 1970

DS-U3-IK-3

Mass, kg

301
Active life, days 60
Launch vehicle

11K63

Main experimental results

Data on dynamics and X-ray spectrum of energetic proton flares; one-dimensional monochrome X-ray patterns; research into absorption of visible solar radiation by the high-altitude aerosol. Studies of soft and hard solar X-rays.

Orbited on

30 June 1972

DS-U3-IK-4

Mass, kg

335
Active life, days 60
Launch vehicle

11K65М

Main experimental results

Study of general properties of quiet Sun X-rays. Measurement of absolute radiant flux and its variations in various levels of solar activity; definition of radiation spectral composition; location of active X-ray regions in the solar corona.

Orbited on

17 May 1974

DS-U3-IK-5

Mass, kg

305
Active life, days 60
Launch vehicle

11K65М

Main experimental results

Data on X-ray and ultraviolet spectra in solar minimum periods. The data are very valuable for studying the mechanism of solar-terrestrial relationship and developing new methods of diagnostics of hot astrophysical and laboratory plasma.

Orbited on

27 July 1976

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