STEVE INSKEEP, host:
A new space probe is expected to arrive today at Mars. As its name suggests, the Mars Reconnaissance Orbiter will not land on the surface. It's designed to view the planet from an altitude of about 200 miles. First it has to arrive safely, and that's been no easy task for missions to Mars. NPR's Richard Harris has the story.
RICHARD HARRIS reporting:
This will be a thrilling day for Fuk Li at NASA's Jet Propulsion Laboratory. After a 300 million mile journey, Mars Reconnaissance Orbiter is finally reaching its destination.
Mr. FUK LI (NASA Jet Propulsion Laboratory): At least for me, my heart rate is also going up for a different reason.
HARRIS: His heart is pounding because Mars is often cruel to spacecraft.
Mr. LI: If you look back at history of exploration of Mars and all the missions that were sent by all the nations since the dawning of space age to Mars, only about a third of them succeeded. If you look at these kinds of numbers, they may be great if you're considering them as batting averages for when you play baseball. But for us, those are very sobering numbers.
HARRIS: Mars Reconnaissance Orbiter has been in perfect health since its launch last August. But its biggest test comes later today. Project manager Jim Graff says in order to get into orbit the breaking rocket needs to burn at precise rate for 27 minutes.
Mr. JIM GRAFF (Project Manager, NASA): We will be able to watch that burn for the first 21 minutes. At that point the spacecraft actually goes behind the planet and we no longer get a signal from it. And so for the last six minutes, we are essentially in white knuckle time, wondering if we're going to actually complete the burn and go into orbit.
HARRIS: It will remain behind Mars for half an hour, so there's plenty of time for the suspense to build. Even assuming that it peaks out again as expected, the adventure doesn't stop there. The initial orbit is a huge oblong. To make it nice and round, controllers will put the orbiter through some fancy paces.
Mr. GRAFF: And we do that by slowly grazing the atmosphere with the spacecraft and allow the atmosphere, the friction with the molecules in the atmosphere, to slow ourselves down. We do that over 500 hundred times.
HARRIS: In six or seven months, Mars Reconnaissance Orbiter will finally be in a circular orbit and ready to get down to business. It has six instruments to photograph the surface and even to peer through the first half mile of the dusty red planet.
Scientist Rich Zurek says as always they are especially interested in looking for signs of water to get a better idea about whether Mars could ever have sustained life. Zurek says the orbiter can also prospect for minerals for high above the surface.
Mr. RICH ZUREK, (Scientist, NASA): The ones we're most interested in, of course, are about aqueous minerals, things that would have formed in water, standing bodies of water in particular on the planet, or in hot springs like Yellowstone and as such. And when we find those interesting regions, then we zoom in with our big telescope, which will increase the resolution that we're presenting able to get by a factor of five or so.
HARRIS: In fact, assuming it survives its critical moments today, the Mars Reconnaissance Orbiter could ultimately send back 10 times as much data about Mars as been gathered by all previous missions. The orbiter can ultimately serve as a relay station for future unmanned mission to Mars, and it will also help scout locations for a possible human trip some decades from now.
Richard Harris, NPR News.
INSKEEP: You can read about past missions to Mars, both successes and failures, at NPR.org.
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