Key Dates:
- 08.12.05: Launch
- 03.10.06: Mars Orbit Insertion
- Jul 2008 - Feb 2010: Data Relay/Navigation
- Status: orbiting Mars
Mars Reconnaissance Orbiter Mission Information: The Mars Reconnaissance Orbiter (MRO) is designed to orbit Mars over a full martian year and gather data with six scientific instruments, including a high-resolution imager.
The science objectives of the mission are to: characterize the present climate of Mars & its physical mechanisms of seasonal and interannual climate change; determine the nature of complex layered terrain on Mars & identify water-related landforms; search for sites showing evidence of aqueous and/or hydrothermal activity; identify & characterize sites with the highest potential for landed science & sample return by future Mars missions; and return scientific data from Mars landed craft during a relay phase. MRO will return high resolution images, study surface composition, search for subsurface water, trace dust and water in the atmosphere, and monitor weather.
The Mars Reconnaissance Orbiter consists of a main bus, constructed of titanium, carbon composites, and aluminum honeycomb. Extending from the bus are two solar panel wings and a 3 meter high-gain antenna dish. The bus houses the propulsion system, telecommunications, command, guidance, and science instruments. The maximum spacecraft mass is 2180 kg, which includes 1149 kg of propellants.
MRO's science payload includes the High Resolution Imaging Science Experiment (HiRISE), a visible stereo imaging camera; the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), a visible/near-infrared spectrometer to study the surface composition; the Mars Climate Sounder (MCS), an infrared radiometer to study the atmosphere, a shallow subsurface sounding radar (SHARAD) provided by the Italian Space Agency to search for underground water; the Context Camera (CTX), to provide wide-area views; and the Mars Color Imager (MARCI), to monitor clouds and dust storms. In addition, there are three engineering instruments aboard MRO: the Electra UHF communications and navigation package, which will be used as a relay between the Earth and future Mars missions; the optical navigation camera, which will be tested for possible navigational use on future planetary spacecraft; and the Ka-band telecommunications experiment package, which will be testing high performance Ka-band communications. Engineering accelerometer data will be used to study the structure of the martian atmosphere and tracking of the orbiter will be used to study the gravity field of Mars.
Launch on an Atlas V-401 took place at 11:43 UT (7:43 a.m. EDT) on 12 August 2005 from Kennedy Space Center. The cruise to Mars will take about seven months and will include checkouts, calibrations, navigation, and five trajectory correction maneuvers. On 10 March 2006 MRO will reach Mars and perform a Mars orbit insertion maneuver, passing under the southern hemisphere of Mars and firing its main engines for about 27 minutes. Signals that the burn has started reached Earth at 21:24 UT (4:24 p.m. EST) on 10 March. With 6 minutes left in the burn MRO passed behind Mars as seen from Earth. Radio communication resumed when it re-emerged about 30 minutes later. The 1641 second burn slowed the spacecraft by about one km/sec, leaving it in a 400 x 35000 km polar capture orbit with a 35 hour period. Aerobraking will be used over the next six months to lower the orbit to the 255 x 320 km science orbit (with periapsis over the south pole and apoapsis over the north pole). There will be twelve sun-synchronous orbits per day so that the orbiter will always see the ground at 3:00 p.m. local time at the equator. Science operations will take place nominally from the end of solar conjunction in November 2006 to the start of the next solar conjunction in November 2008, roughly one martian year.
