Kosmos 1 (Russian: Космос 1 meaning Cosmos 1), also known as DS-2 No.1 and occasionally in the West as Sputnik 11 was a technology demonstration and ionospheric research satellite launched by the Soviet Union in 1962.

It was the first satellite to be designated under the Kosmos system, and the first spacecraft launched as part of the Dnepropetrovsk Sputnik programme to successfully reach orbit.

The DS-2 was a scaled-down version of the earlier DS-1 satellite, without the cylindrical section for avionics, which was built after the first two DS-1 spacecraft failed, DS-1 No.1 on 27 October 1961, and DS-1 No.2 on 21 December 1961, to reach orbit.

[2][3] Its primary missions were to measure the performance of its launch vehicle, and to conduct research into the ionosphere.

It was also the first Kosmos launch vehicle of any type to successfully place a satellite into orbit.