A series of US space probes. The first Pioneers, launched in 1958–9, were intended as Moon probes, but none succeeded. Pioneers 5–9, in 1960–8, were put into orbit around the Sun, monitoring solar activity and conditions in interplanetary space. Pioneers 10 and 11, the last and best-known of the series, were the first probes to reach Jupiter, photographing the planet and studying its environment. Pioneer 10, launched in 1972 March, flew past Jupiter in 1973 December. Pioneer 11, launched 1973 April passed Jupiter in 1974 December and then became the first probe to reach Saturn, in 1979 September. Both Pioneers are currently on their way out of the Solar System. Pioneer 10 crossed the orbit of Pluto in 1983 June, the first spacecraft to do so. Contact with it was finally lost in 2003 January at a distance of 82 au. Contact with Pioneer 11 was lost in 1995 November at a distance of 44 au.
http://nssdc.gsfc.nasa.gov/nmc/spacecraftDisplay.do?id=1972-012A NASA information page for Pioneer 10.
http://nssdc.gsfc.nasa.gov/nmc/spacecraftDisplay.do?id=1973-019A NASA information page for Pioneer 11.
Any of a series of US Solar System space probes launched 1958–78. The probes Pioneer 1–3, all launched in 1958, were intended Moon probes, but the launch of Pioneer 1A and Pioneer 2 failed, and Pioneer 1B and Pioneer 3 failed to reach their target, although they did fly deep enough into space to measure the Van Allen radiation belts. Pioneer 4 began to orbit the Sun after passing the Moon. Pioneer 5 (1960) was the first of a series to study the solar wind between the planets. Pioneer 6 (1965), Pioneer 7 (1966), Pioneer 8 (1967), and Pioneer 9 (1968) went into orbit around the Sun and monitored solar activity. Pioneer 10 (March 1972) was the first probe to reach Jupiter (December 1973) and to leave the Solar System (1983). Pioneer 11 (April 1973) passed Jupiter (December 1974) and was the first probe to reach Saturn (September 1979), before also leaving the Solar System. NASA ceased to operate Pioneer 10 in April 1997, but re-established contact in March 2002, when the probe had reached a distance of 11.9 billion km from the Earth. Pioneer 11 ceased to function in 1995.
Pioneer 10 and 11 carry plaques containing messages from Earth in case they are found by other civilizations among the stars. Pioneer Venus probes were launched May and August 1978. One orbited Venus, and the other dropped three probes onto the surface. The orbiter finally burned up in the atmosphere of Venus in 1992.
The design etched into the gold-anodized plate carried by Pioneer 10 and Pioneer 11, and which might—in millions of years—be found by other intelligent spacefaring beings. The symbols are designed to identify the Solar System, show the position of Earth, the time the spacecraft was launched, and the type of creatures who built it. The man is shown making a gesture of goodwill.
Credit: NASA
A series of NASA spacecraft that conducted explorations of the solar system. Pioneer 10, launched on 2 March 1972, was the first spacecraft to reach the edge of the solar system, in 1987; its last signal was received on 23 January 2003, following the decay of its radioisotope power source. Pioneer 11 was launched on 5 April 1973, for Saturn; the last communication with it was in November 1995. Pioneer Venus, launched in 1978 to Venus, comprised an orbiter and probes sent to the surface.
http://www.nasa.gov/centers/ames/missions/archive/pioneer.html A NASA programme of unmanned space probes launched for planetary exploration.
- outlier
- out-of-bag sample
- out of office reply
- out of phase
- out-of-phase component
- output
- output area
- output device
- output effect
- output gap
- output impedance
- output-limited process
- output method
- output per hour worked
- output signal
- output transformer
- Outremer
- outside money
- outsourcing
- outwash
- outwash (outwash sands) and gravels
- outwash plain
- outwelling
- outworker
- oval window