MESSENGER
MESSENGER was a NASA robotic space probe that orbited the planet Mercury between 2011 and 2015, studying Mercury's chemical composition, geology, and magnetic field. The name is a backronym for "Mercury Surface, Space Environment, Geochemistry, and Ranging", and a reference to the messenger god Mercury from Roman mythology.
Artist's rendering of MESSENGER orbiting Mercury. | |
| Mission type | Mercury probe |
|---|---|
| Operator | NASA |
| COSPAR ID | 2004-030A |
| SATCAT no. | 28391 |
| Website | messenger |
| Mission duration | Total: 10 years, 8 months and 27 days At Mercury: 4 years, 1 month and 14 days En route: 7 years Primary mission: 1 year First extension: 1 year Second extension: 2 years |
| Spacecraft properties | |
| Manufacturer | Applied Physics Laboratory |
| Launch mass | 1,107.9 kg (2,443 lb) |
| Power | 450 watts |
| Start of mission | |
| Launch date | August 3, 2004, 06:15:56 UTC |
| Rocket | Delta II 7925H-9.5 |
| Launch site | Cape Canaveral SLC-17B |
| Entered service | April 4, 2011 |
| End of mission | |
| Disposal | Crashed into Mercury |
| Destroyed | April 30, 2015 at 19:26 UT |
| Orbital parameters | |
| Reference system | Hermiocentric |
| Perihermion altitude | 200 kilometers (120 mi) |
| Apohermion altitude | 10,300 kilometers (6,400 mi) |
| Inclination | 80 degrees |
| Period | 12 hours |
| Epoch | January 1, 2000 |
| Flyby of Earth (gravity assist) | |
| Closest approach | August 2, 2005 |
| Distance | 2,347 kilometers (1,458 mi) |
| Flyby of Venus (gravity assist) | |
| Closest approach | October 24, 2006 |
| Distance | 2,990 kilometers (1,860 mi) |
| Flyby of Venus (gravity assist) | |
| Closest approach | June 5, 2007 |
| Distance | 337 kilometers (209 mi) |
| Flyby of Mercury | |
| Closest approach | January 14, 2008 |
| Distance | 200 kilometers (120 mi) |
| Flyby of Mercury | |
| Closest approach | October 6, 2008 |
| Distance | 200 kilometers (120 mi) |
| Flyby of Mercury | |
| Closest approach | September 29, 2009 |
| Distance | 228 kilometers (142 mi) |
| Mercury orbiter | |
| Orbital insertion | March 18, 2011, 01:00 UTC |
MESSENGER was launched aboard a Delta II rocket in August 2004. Its path involved a complex series of flybys – the spacecraft flew by Earth once, Venus twice, and Mercury itself three times, allowing it to decelerate relative to Mercury using minimal fuel. During its first flyby of Mercury in January 2008, MESSENGER became the second mission, after Mariner 10 in 1975, to reach Mercury.
MESSENGER entered orbit around Mercury on March 18, 2011, becoming the first spacecraft to do so. It successfully completed its primary mission in 2012. Following two mission extensions, the spacecraft used the last of its maneuvering propellant to deorbit, impacting the surface of Mercury on April 30, 2015.