The Interkosmos DS-U1-IK series consisted of two missions in to investigate the ionosphere. They were conducted by Interkosmos, an international cooperation of socialist countries.
The satellites were based on Yuzhnoye's DS-U1 bus. The satellites were battery powered. These satellites carried a suite of east European experiments to study the characteristics of the earth's ionosphere and of concentrations of electrons and positive ions.
Interkosmos 2 was launched on 25 December 1969 on a Kosmos-2 rocket from the Kapustin Yar cosmodrome.
Interkosmos 8 was launched on 30 November 1972 on a Kosmos-2 rocket from the Plesetsk cosmodrome.