Mariner 10

Part of the Mariner program

Mariner 10 was the first mission to use the gravitational attraction of one planet to reach another, the first mission with two planetary objectives, and (to date) the only mission ever to perform up close imaging and science at Mercury. The vehicle's first planetary encounter was with Venus on November 3, 1973. Mariner 10 took some 4,000 photos of Venus, which revealed a nearly round planet enveloped in smooth cloud layers. After the Venus flyby, Mariner 10 was sent towards Mercury , which it flew past at 756 km altitude on March 29, 1974. Photographs taken during the pass revealed an intensely cratered, Moon-like surface and a faint atmosphere of mostly helium. After the first flyby, Mariner 10 entered solar orbit, which permitted two more rendezvous with Mercury. On September 21, 1974, the second Mercury rendezvous provided another opportuniy to photograph the sunlit side of the planet and the south polar region. The third and final Mercury encounter occured on March 16, 1975, and yielded primarily fields and particles data. The vehicle was turned off March 24, 1975 after its onboard fuel was depleted. Total mission cost was $100 million.

Spacecraft
Octagonal structure of magnesium and aluminum. 3-axis stabilized using cold gas thrusters. Solar panels produce 540 W max. NiCd batteries (20 AHr). Communications using S-Band and X-Band.

Payload
Cameras, magnetometer, plasma science experiment, charged particle telescope, ultraviolet spectrometer, and infrared radiometer.

Country of Origin	United States
Customer/User	NASA, JPL
Manufacturer(s)	Boeing
Orbit	Solar orbit - Venus flyby February 5, 1974 / Mercury flyby March 29, 1974 / 2nd Mercury flyby September 20, 1974 / 3rd Mercury flyby March 16, 1975
Related Sites	JPL Mariner 10 Summary Page

Launch Facts

Name	Int'l Desig.	Date	Site	Vehicle	Orbit	Mass(kg)
Notes
Mariner 10	1973-085A	11/3/73	ESMC	Atlas Centaur	Solar	526
Venus flyby 2/5/74; Mercury flybys on 3/29/74, 9/21/74, 3/16/75