 | This timeline of spaceflight may require cleanup to ensure consistency with other timeline of spaceflight articles. See Wikipedia:WikiProject Spaceflight/Timeline of spaceflight working group for guidelines on how to improve the article. Details Concerns have been raised that:
|  |
 The Pioneer Venus Orbiter atop an Atlas-Centaur before launch | |
| Orbital launches | |
|---|---|
| First | 6 January |
| Last | 28 December |
| Total | 128 |
| Catalogued | 124 |
| National firsts | |
| Space traveller |  Czechoslovakia Poland East Germany DDR |
| Rockets | |
| Retirements | Atlas-Agena Mu-3H |
| Crewed flights | |
| Orbital | 5 |
| Total travellers | 10 |
1978 saw the launch of the Pioneer Venus missions launched by the United States, on 20 May and 8 August. The Pioneer Venus Multiprobe landed four spacecraft on the planet, one of which transmitted data for 67 minutes before being destroyed by atmospheric pressure. ISEE-C, which was launched on 8 December, flew past comet 21P/Giacobini–Zinner in 1985, and Halley's Comet in 1986.[1]
- ^ Hughes, J (1996) Larousse Desk Reference Encloypedia London RD Press