[meteorite-list] Mars Reconnaissance Orbiter Completes 40, 000 Mars Orbits

[Ron Baalke]

http://www.jpl.nasa.gov/news/news.php?feature=4478

NASA Spacecraft Completes 40,000 Mars Orbits
Jet Propulsion Laboratory
February 9, 2015

-- NASA's Mars Reconnaissance Orbiter, at Mars since 2006, has now orbited 
the Red Planet more than 40,000 times

-- The continuing mission studies the whole planet and has shown that 
Mars is diverse and dynamic

NASA's Mars Reconnaissance Orbiter passed a mission milestone of 40,000 
orbits on Feb. 7, 2015, in its ninth year of returning information about 
the atmosphere, surface and subsurface of Mars, from equatorial to polar 
latitudes.

The mission's potent science instruments and extended lifespan have revealed 
that Mars is a world more dynamic and diverse than was previously realized. 
Now in its fourth mission extension after a two-year prime mission, the 
orbiter is investigating seasonal and longer-term changes, including some 
warm-season flows that are the strongest evidence so far for liquid water 
on Mars today.

The orbiter has returned 247 terabits of data, which is more than the 
combined total from every other mission that has ever departed Earth to 
visit another planet.

It circles Mars at an altitude of about 186 miles (300 kilometers), on 
a near-polar pattern, about 12 times a day. In its 40,000 orbits, the 
spacecraft has flown nearly twice as far as the 310 million miles (500 
million kilometers) it flew during its 2006 journey from Earth to Mars.

The mission has illuminated three very different periods of Mars history. 
Its observations of the heavily cratered terrains of Mars, the oldest 
on the planet, show that different types of ancient watery environments 
formed water-related minerals. Some of these environments would have been 
more favorable for life than others.

In more recent times, water appears to have cycled as a gas between polar 
ice deposits and lower-latitude deposits of ice and snow. Extensive layering 
in ice or rock probably took at least hundreds of thousands, and possibly 
millions of years to form. Like ice ages on Earth, the layering is linked 
to cyclic changes in the tilt of the planet's rotation axis and the changing 
intensity of sunlight near the poles.

Mars' present climate is also dynamic, with volatile carbon dioxide and, 
just possibly, summertime liquid water modifying gullies and forming new 
streaks. With observations of new craters, avalanches and dust storms, 
the orbiter has shown a partially frozen world, but not frozen in time, 
as change continues today.

In addition to accomplishing its own science achievements, the Mars Reconnaissance 
Orbiter mission provides communication relay for missions on the surface 
of Mars and evaluates potential landing site candidates for surface missions.

Two other active NASA spacecraft are currently orbiting Mars -- Mars Odyssey 
since 2001, and MAVEN (Mars Atmosphere and Volatile Evolution) since last 
year. Two NASA rovers -- Opportunity and Curiosity -- are active on the 
surface. These robotic missions and others in development are paving the 
way for human-crew Mars missions in the 2030s and beyond as part of NASA's 
Journey to Mars strategy.

NASA's Jet Propulsion Laboratory, a division of the California Institute 
of Technology, Pasadena, manages the Mars Reconnaissance Orbiter for NASA's 
Science Mission Directorate, Washington. Lockheed Martin Space Systems, 
Denver, built the orbiter and collaborates with JPL to operate it. For 
more information about the Mars Reconnaissance Orbiter, visit:

http://www.nasa.gov/mro

http://mars.jpl.nasa.gov/mro/

Media Contact
Guy Webster
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-6278
guy.webster at jpl.nasa.gov

2015-054