Pioneer 8 Mission Mission Overview ================ The Pioneer missions set the stage for U.S. space exploration. Pioneer 1 was the first manmade object to escape the gravitation field of the Earth. Later Pioneer 4 was the first spacecraft to fly to the moon, Pioneer 10 was the first to Jupiter, Pioneer 11 was the first to Saturn and Pioneer 12 was the first U.S. spacecraft to orbit another planet, Venus. Pioneers 6, 7, 8 and 9 were first solar monitoring networks. Both Pioneer 10 and 11 left the solar system. Originally designed to operate for at least 6 months, most Pioneers lasted for decades. The following table summarizes the Pioneer spacecraft and scientific objectives of the Pioneer missions. Name Launch Mission Status (as of 1998) ------------------------------------------------------------------------------------- Pioneer 1 1958-10-11 Moon Reached altitude of 72765 miles Pioneer 2 1958-11-08 Moon Reached altitude of 963 miles Pioneer 3 1958-12-02 Moon Reached altitude of 63580 miles Pioneer 4 1959-03-03 Moon Passed by moon into solar orbit Pioneer 5 1960-03-11 Solar Orbit Entered solar orbit Pioneer 6 1965-12-16 Solar Orbit Contacted in 2000; Still believed to be operating Pioneer 7 1966-08-17 Solar Orbit Tracked in 1995; Still believed to be operating Pioneer 8 1967-12-13 Solar Orbit Contacted in 1996; Still believed to be operating Pioneer 9 1967-11-08 Solar Orbit Signal lost in 1983 Pioneer E 1969-08-07 Solar Orbit Launch failure Pioneer10 1972-03-02 Jupiter Communication terminated 1998 Pioneer11 1973-04-05 Jupiter/Saturn Communication terminated 1997 Pioneer12 1978-05-20 Venus Entered Venus atmos. 1992-10-08 Pioneer 8, also known as Pioneer C, was launched on 13 December 1967 into a heliocentric orbit to study interplanetary space with a primary focus to collection data on magnetic fields, plasma, and cosmic rays. During tracking on 23 July 1995, NASA was unable to switch on the transmitter on Pioneer 8 probably because the spacecraft was too far away from the Sun to charge the solar panels. On 22 August 1996, contact was re-acquired via a backup transmitter. The electric-field detector remains functional as of June 2001, nearly 36 years after launch. References ========== Siddiqi, A.A., Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000, Monographs in Aerospace History No. 24, NASA, SP-2002-4524, Washington, D.C, 2002.