The public has seen four rovers scratching the surface of Mars, and two orbiters peering at the red planet. Now with dazzling precision, NASA has put an expedition in orbit with more power to probe the secrets of Mars than all the previous orbiters and landers combined. The Mars Reconnaissance Orbiter has arrived at the red planet.

The Reconnaissance Orbiter is a unique package of six instruments to help identify landing locations for future Mars Explorers. The six mission objectives for the Mars Reconnaissance Orbiter (MRO) in plain English:

1. Characterize the present climate and seasonal adjustments of Mars.

2. Determine the nature of complex layered terrain and identify water-related landforms.

3. Search for sites and pinpoint where any water is (to inform future studies asking if there was ever life on Mars, because, water is essential for life.)

4. Identify sites with the highest potential for landing and roving in the future.

5. Return scientific data from Mars.

NASA intends to fulfill all these goals while in orbit!

One instrument will analyze the chemical composition of the Martian surface, including water ice, a second instrument, the Shallow Subsurface Radar will detect and map sub-surface ice, rather than guessing at its presence.

The MRO will also be carrying the highest resolution cameras ever flown to another planet by NASA. Unlike previous orbital cameras that could see mountains and canyons, HiRISE (High Resolution Imaging Science Experiment) will be able to see details as small as a card-table, while another instument, the Context Imager, maps those observations against the surrounding geography.

Other instuments will learn the weather patterns of Mars, from dust storms to water vapor, and from cloud formations to surface temperatures.

Equally astonishing was the act of inserting the MRO into orbit around Mars. In a process that has failed twice before — destroying the orbiter completely — NASA slowed the MRO by passing it so close to Mars that the friction of Mars’ outer atmosphere acted as a brake on the MRO, in a maneuver known as “aerobraking”. When the MRO slowed down
it was successfully captured by the planet’s gravity. This is a delicate maneuver. If you go too deep, your components overheat.

As the MRO swung behind Mars on its first orbit, mission planners waited white-knuckled to hear if the orbiter would emerge from behind the red planet successfully. If no signal came, it would mean that the MRO had burned-up in the Martian atmosphere. For nearly 30 minutes, the NASA team at the Jet Propulsion Lab in Pasadena, California seemed to hold its breath.

At 2:13 Pacific Standard Time, elation erupted among the team as the signal was received. MRO had emerged from behind Mars unscathed. The initial pass through Mars’ atmosphere brought the ship so close to the Martian surface (within 423 km), that Rob Lock, the lead mission planner quipped it was “awesomely good shooting… better than Robin Hood.”

NASA will cautiously test their instruments as the ship is slowed further, and will be ready to begin intensive observations in November. Mysteries of the red planet will soon be revealed.

(photo by NASA, composite of 102 Viking 1 Orbiter images of Mars taken on 22 Feb. 1980)

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