Pioneer Programme

Key facts

Mission & specifications

Mission

The Pioneers were the United States' first probes beyond Earth orbit. The first five, launched for the Moon in 1958 and 1959, were flown by the US Air Force and by the Army's team with JPL; NASA ran the programme from then on, to the last launches in 1978. The early years were hard. Of the five Moon probes, Pioneer 0's rocket exploded, Pioneers 1 and 3 rose more than 100,000 km and fell back, Pioneer 2's third stage did not fire, and Pioneer 4 passed the Moon at about 60,000 km and went on to become the first US spacecraft to orbit the Sun. Three larger lunar orbiters followed on Atlas-Able rockets, and all three were lost: P-3's nose shroud broke away 45 seconds after launch on 26 November 1959, P-30's second stage failed on 25 September 1960, and P-31's rocket exploded just over a minute after launch on 15 December 1960 — at 68 seconds in NSSDCA's record, 74 in Beyond Earth. Another Atlas-Able had exploded during a ground test on 24 September 1959, without its payload. Then came the successes. Pioneer 5 in 1960 and Pioneers 6 to 9 in 1965–1968 studied the space between the planets from orbits around the Sun; Pioneer E was lost in 1969 when its rocket failed. Pioneer 10 became the first spacecraft to cross the asteroid belt and fly past Jupiter, in December 1973, and Pioneer 11 the first to fly past Saturn, in September 1979. Pioneer Venus 1 orbited Venus from 1978 to 1992, and Pioneer Venus 2 sent four probes into its atmosphere. The timeline lists every launch, with its date and what happened.

1. 1958Pioneer 0 (Able 1)Launch

   A Moon probe: its Thor first stage exploded 73.6 seconds after launch, about 15 km up (77 seconds and 16 km in NSSDCA's record).

2. 1958Pioneer 1Launch

   Fell short of the speed to reach the Moon; it rose to 113,800 km (114,750 km in Beyond Earth) and re-entered 43 hours after launch.

3. 1958Pioneer 2Launch

   Its third stage did not fire; it rose to about 1,550 km (1,530 km in Beyond Earth) and fell back.

4. 1958Pioneer 3Launch

   A Moon flyby attempt that rose to 102,360 km (102,322 km in Beyond Earth) and fell back.

5. 1959Pioneer 4Launch

   Passed the Moon at about 60,000 km and became the first US spacecraft to orbit the Sun.

6. 1959Pioneer P-3Launch

   A lunar orbiter on the first Atlas flown with an upper stage; its payload shroud broke away 45 seconds after launch, and the probe was lost.

7. 1960Pioneer 5Launch

   Into orbit around the Sun; it was last heard from 36.4 million km away, on 26 June 1960.

8. 1960Pioneer P-30Launch

   A lunar orbiter, lost when its rocket's second stage failed.

9. 1960Pioneer P-31Launch

   A lunar orbiter, lost when its rocket exploded just over a minute after launch.

10. 1965Pioneer 6Launch

    Into orbit around the Sun, between 0.81 and 0.98 AU from it.

11. 1966Pioneer 7Launch

    Into orbit around the Sun, between 1.01 and 1.12 AU from it.

12. 1967Pioneer 8Launch

    Into orbit around the Sun, between 0.99 and 1.09 AU from it.

13. 1968Pioneer 9Launch

    Into orbit around the Sun, between 0.75 and 0.99 AU from it; last heard from in 1983.

14. 1969Pioneer ELaunch

    Lost when its rocket's first-stage hydraulics failed; it was destroyed 484 seconds after launch.

15. 1972Pioneer 10Launch

    The first spacecraft to cross the asteroid belt and fly past Jupiter, on 4 December 1973.

16. 1973Pioneer 11Launch

    Flew past Jupiter in December 1974, then became the first spacecraft to fly past Saturn, on 1 September 1979.

17. 1978Pioneer Venus 1Launch

    Orbited Venus from 4 December 1978; its last signal came on 8 October 1992.

18. 1978Pioneer Venus 2Launch

    Its four probes and the craft that carried them entered Venus's atmosphere on 9 December 1978.

Images

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