Artist's concept of the Odyssey spacecraft. Credit: NASA/JPL-Caltech
Astronautics (Denver) and JPL
Mass at launch
725 kg (349 kg of propellant)
Still in Mars orbit
The 2001 Mars Odyssey probe was launched on Apr 7, 2001 into solar orbit.
Formerly the Mars Surveyor 2001 Orbiter, this is the first spacecraft in
the revamped NASA Mars Exploration Program; the satellite is similar to Mars Climate
Orbiter. It carries a 6-meter boom with a gamma ray spectrometer for
remote sensing of Martian surface mineralogy, as well as an infrared
imager and a radiation environment monitor. Mars Odyssey (the "2001"
seems to be dropped in informal use) will reach Mars orbit in October.
2001 Mars Odyssey was launched by a Boeing Delta 7925 from Cape Canaveral and entered a 195 x 215 km x 52 (?) deg parking orbit 10 min
after launch. After a 12 minute coast the Delta second stage fired again and separated from the third stage, which placed the probe on an Earth
escape trajectory. The second stage's final orbit was 177 x 1805 km x 40.0 deg, the lowered inclination probably the result of the depletion burn.
Mars Odyssey is in a 0.982 x 1.384 AU x 3.05 deg solar orbit. It
escaped Earth's nominal gravitational sphere of influence at around 1900 UTC on Apr 10, 2001 and will enter Mars orbit on Oct 24.
The Mars Odyssey probe entered Mars orbit on Oct 24, 2001. The orbit
insertion burn with the main 640N bipropellant hydrazine/N2O4 engine
began at 02:18 UTC and ended at 02:38 UTC after a 20 min 19 sec burn with a
300 km periapsis at 02:31 UTC. Mass of the spacecraft is now about 456 kg
(including 79 kg of fuel left) compared with 725 kg at launch.
The Odyssey team has kindly provided the orbital data at first apoapsis:
relative to a 3397.5km radius for Mars, the orbit was 272 x 26818 km x
93.42 deg with a period of 18hr 36min. Longitude of node is 278.4 deg
and argument of periapsis is 112.5 deg, putting closest approach near the
Martian north pole. The choice of a 93.4 deg orbit, the same as for MGS,
makes the spacecraft sun-synchronous. Apoapsis was reached at 1147 UTC on
Oct 24 and the next periapsis was at 2105 UTC (by which time orbital
mechanics reduced the apoapsis slightly to 26400 km). Aerobraking was due
to begin on Oct 26; the solar panels will reach almost 180 deg C when
Odyssey dips through the Martian atmosphere.
On Dec 28, 2001 Mars Odyssey was in a 99 x 2951 km x 93 deg orbit around
Mars, continuing to aerobrake.
Odyssey provided real-time bent-pipe communications from
Phoenix lander when it touched down on the northern polar plains of Mars in 2008.
On Jan 1, 2010 Mars Odyssey remain operating in Mars orbit; Mars Odyssey is in a 387 x 450 km x 93 deg orbit.
March 2012: Engineers are shifting the orbits of the Mars Reconnaissance Orbiter and Odyssey probes, ensuring they have line-of-sight
communications with Curiosity as it lands at Gale crater, a 96-mile-wide impact site adorned with
rugged rock formations and a colossal central peak. Landing is scheduled for early Aug. 6, 2012.
The Odyssey spacecraft, which has orbited Mars since late 2001, will be the primary means of monitoring Curiosity's progress during
landing. Odyssey will be in view of both Curiosity and Earth, so the orbiter will offer bent-pipe communications, receiving transmissions
from the rover and relaying them directly to Earth.
Without MRO and Odyssey, controllers would lose crucial information on how the $2.5 billion mission performs as it plunges through the
Martian atmosphere at hypersonic speeds, deploys parachutes, fires a rocket back and lowers the six-wheeled rover to the surface on a
bridle. NASA has never tried such a landing system before, and if it works, it will allow the space agency to place much larger, and heavier, payloads on Mars.