 Artist's impression of the ASTP docking | |
| Orbital launches | |
|---|---|
| First | 10 January |
| Last | 27 December |
| Total | 132 |
| Catalogued | 125 |
| National firsts | |
| Satellite |  India |
| Rockets | |
| Maiden flights | Atlas SLV-3D Centaur-D1AR Delta 3000 Diamant-BP4 Long March 2C N-I Scout F-1 Titan III(34)B |
| Retirements | Atlas SLV-3D Centaur-D1A Delta 1000 Diamant-BP4 Saturn IB Scout F-1 |
| Crewed flights | |
| Orbital | 4 |
| Suborbital | 1 |
| Total travellers | 9 |
 |
In 1975, several notable events occurred in spaceflight, including the launches of Venera 9 and 10 and their Venus arrivals, the launches of the Viking Mars missions, the joint American-Soviet Apollo–Soyuz Test Project (ASTP), the failure of Soyuz 7K-T 39, and the launch of Aryabhatta, India's first satellite.
- The Venera 9 mission was launched 8 June 1975 and on 20 October 1975 became the first spacecraft to orbit Venus; two days later its lander returned the first images from the surface of any planet (other than Earth).
- Venera 10 was launched on 14 June 1975; it entered orbit of Venus on 23 October 1975 and its lander arrived on the surface of Venus on 25 October 1975. Both Venera 9 and Venera 10 returned various scientific observations of Venus and black-and-white television pictures from the planet's surface.
- Viking 1 was launched on 20 August 1975 and Viking 2 was launched 9 September 1975. This orbiter/lander mission was to photograph the surface of Mars in 1976.
- The Apollo-Soyuz Test Project was a collaboration between the United States and the Soviet Union that saw an end to the space race. The mission was launched on 15 July 1975, with the Soyuz returning on 21 July and Apollo on 24 July.
- On 5 April, Soyuz 7K-T 39 aborted after the second and third stages failed to separate, with the crew pulling over 21 g on a ballistic reentry.
- On 19 April, the first Indian satellite, Aryabhatta, was launched on a Soviet Kosmos-3M.