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curiousuburb
Antimatter Man
 
Join Date: May 2004
Location: that interweb thing
 
2006-03-02, 08:40

MRO expected to arrive at Mars on March 10th...
plans to take almost six months to adjust orbit via aerobraking, but initial orbital success should be known in the early hours of next saturday.

Quote:
However, before Mars Reconnaissance Orbiter can begin its main assignments, it will spend half a year adjusting its orbit with an adventurous process called aerobraking. The initial capture by Mars' gravity on March 10 will put the spacecraft into a very elongated, 35-hour orbit. The planned orbit for science observations is a low-altitude, nearly circular, two-hour loop. To go directly into an orbit like that when arriving at Mars would have required carrying much more fuel for the main thrusters, requiring a larger and more expensive launch vehicle and leaving less payload weight for science instruments. Aerobraking will use hundreds of carefully calculated dips into the upper atmosphere -- deep enough to slow the spacecraft by atmospheric drag, but not deep enough to overheat the orbiter.

"Aerobraking is like a high-wire act in open air," Graf said. "Mars' atmosphere can swell rapidly, so we need to monitor it closely to keep the orbiter at an altitude that is effective but safe." Current orbiters at Mars will provide a daily watch of the lower atmosphere, an important example of the cooperative activities between missions at Mars.
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