Studies ionosphere of the earth; version used for Intercosmos internationl launches. Design work began in April 1967. Adaptation of DS satellites by KB Yuzhnoye. For the Interkosmos modifications V F Chutkin was Chief Designer and First Assistant was V S Budnik. Investigation of the characteristics of the earth's ionosphere and of concentrations of electrons and positive ions.

Total Mass: 330 kg.

Central Committee of the Communist Party and Council of Soviet Ministers Decree 'On Co-operation of the USSR and Socialist Countries in the Sphere of Research and Use of Space-international co-operation' was issued.

For the Interkosmos modifications V F Chutkin was Chief Designer and First Assistant was V S Budnik. East European experiments studied protons, electrons, alpha particles.

East European ionospheric tests. Investigation of the characteristics of the earth's ionosphere and of concentrations of electrons and positive ions.

Continued joint investigation of the characteristics of the earth's ionosphere and recording of electron and proton fluxes.

• 2 - McDowell, Jonathan, The United Nations Registry of Space Objects, Harvard University, 1997. HTML when accessed: http://hea-www.harvard.edu/QEDT/jcm/space/un/un.html
• 6 - JPL Mission and Spacecraft Library, Jet Propulsion Laboratory, 1997. HTML when accessed: http://msl.jpl.nasa.gov/home.html
• 99 - Agapov, V, Novosti Kosmonavtiki, "K zapusku pervovo ISZ serii 'DS'", 1997, Issue 6.
• 116 - Novosti Kosmonavtiki, "AUOSi prodolzhayut rabotu", 1995, Issue 21, page 43.