Mariner 10 spacecraft

Mariner 10 spacecraft

Courtesy of NASA

http://nssdc.gsfc.nasa.gov/nmc/spacecraftDisplay.do?id=1973-085A



Overview
Mariner 10 was the first spacecraft to use the gravitational pull of one planet (Venus) to reach another (Mercury), and the first spacecraft mission to visit two planets.

The Mariner program consisted of a series of 10 unmanned flyby missions launched by NASA between 1962 and 1973. These missions were designed to be the first to travel to other planets, specifically Venus, Mars, and Mercury. Seven were successful; three were lost. In summary:


Spacecraft

Destination

Launch year

Status

Mariner 1

Venus

1962

destroyed

Mariner 2

Venus

1962

flyby

Mariner 3

Mars

1964

lost

Mariner 4

Mars

1964

flyby

Mariner 5

Venus

1967

flyby

Mariner 6

Mars

1969

flyby

Mariner 7

Mars

1969

flyby

Mariner 8

Mars

1971

lost

Mariner 9

Mars

1971

flyby

Mariner 10

Venus, Mercury

1973

flyby


Launch
November 3, 1973


Arrival
February 5, 1974 (Venus flyby); March 29, 1974 (first Mercury flyby), September 21, 1974 (second Mercury flyby), March 16, 1975 (third Mercury flyby)


End of Mission
March 24, 1975


Goals
Fly by Venus and Mercury. At Mercury, measure the environment, atmosphere, surface, and body characteristics. Make similar investigations of Venus. Perform experiments in the interplanetary medium and obtain experience with a dual-planet, gravity-assist mission.


Findings
On its flyby of Venus, Mariner 10 discovered rotating clouds and a very weak magnetic field, and sent back the first ever close-up images of Venus. The three flybys of Mercury revealed a moon-like surface, which scientists had not been able to detect previously with telescopes. About 40% of Mercury’s surface was mapped in detail using close-up images. Mariner 10 found that Mercury has an atmosphere consisting primarily of helium, as well as a magnetic field and a large iron-rich core. Radiometer readings suggested that Mercury has a nighttime minimum temperature of −183°C (−297°F) and maximum daytime temperature of 187°C (369°F). Mariner 10 also made ultraviolet observations of Comet Kohoutek in January 1974.