Pioneer 11

Pioneer 11

An artist's impression of Pioneer 11 on its way to interstellar space.
Mission type	Planetary / Heliosphere exploration
Operator	NASA / Ames
COSPAR ID	1973-019A
SATCAT no.	6421
Website	science.nasa.gov
Mission duration	22 years, 7 months and 19 days
Spacecraft properties
Manufacturer	TRW
Launch mass	258.5 kg[1]
Power	155 watts (at launch)
Start of mission
Launch date	April 6, 1973, 02:11:00 (1973-04-06UTC02:11Z) UTC[1]
Rocket	Atlas SLV-3D Centaur-D1A Star-37E
Launch site	Cape Canaveral LC-36B
End of mission
Disposal	Decommissioned
Last contact	November 24, 1995 (1995-11-25)
Flyby of Jupiter
Closest approach	December 3, 1974
Distance	43,000 kilometers (27,000 miles)
Flyby of Saturn
Closest approach	September 1, 1979
Distance	21,000 kilometers (13,000 miles)
Pioneer program ← Pioneer 10 Pioneer 12 →

Pioneer 11 (also known as Pioneer G) is a NASA robotic space probe launched on April 5, 1973, to study the asteroid belt, the environment around Jupiter and Saturn, the solar wind, and cosmic rays.^[2] It was the first probe to encounter Saturn, the second to fly through the asteroid belt, and the second to fly by Jupiter. Later, Pioneer 11 became the second of five artificial objects to achieve an escape velocity allowing it to leave the Solar System. Due to power constraints and the vast distance to the probe, the last routine contact with the spacecraft was on September 30, 1995, and the last good engineering data was received on November 24, 1995.^[3]