|Launch Date||Nov. 3, 1973|
|Launch Site||Cape Canaveral, Florida, USA|
|Alternate Names||1973-085A, Mariner-J, Mariner Venus/Mercury 73, 06919|
Mariner 10 was the first spacecraft sent to study Mercury. Mariner 10 also studied Venus while using the planet's gravity to modify its speed and trajectory, enabling it to reach Mercury.
Mariner 10 was the only mission to Mercury until NASA's MESSENGER mission more than 30 years later. On its way to Mercury, Mariner 10 became the first spacecraft to use the gravity of one planet (in this case, Venus) to reach another. This has become an extremely important technique. While flying by Venus, the spacecraft took ultraviolet pictures that revealed great bands of clouds, providing data on atmospheric circulation which included upper-atmosphere wind speeds of 300 km/hr.
During three flybys of Mercury, Mariner 10 photographed half the planet's moonlike surface and transmitted data indicating a surprising magnetic field, a metallic core comprising about 80 percent of the planet's mass, and temperatures ranging from 187 degrees Celsius on the dayside to -183 degrees Celsius on the nightside.
Nov. 3, 1973: Launch
Feb. 5. 1974: Venus Encounter
Mar. 29, 1974: Mercury Flyby 1
Sept. 21, 1974: Mercury Flyby 2
Mar. 16, 1975: Mercury Flyby 3
Launch Vehicle: Atlas-Centaur
Spacecraft Mass: 474 kilograms
- imaging system
- infrared radiometer
- ultraviolet airglow spectrometer
- ultraviolet occultation spectrometer
- two magnetometers
- charged-particle telescope
- plasma analyzer
Siddiqi, Asif A. Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000, NASA, 2002.