NASA's Latest Mission To The Moon Is On Track
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RENEE MONTAGNE, HOST:
NASA's latest mission to the moon is stuck in orbit around the Earth. And that sounds bad. But as NPR Science Correspondent Joe Palca explains, it's actually normal.
JOE PALCA, BYLINE: The Lunar Atmosphere and Dust Environment Explorer, or LADEE as the folks at NASA refer to it, is supposed to spend the next three weeks or so in orbit around the Earth. Each time around, LADEE will fire its engines, extending its orbit further and further from the Earth. Eventually, it will be so far out that the moon's gravity can take over. All told it will take about 30 days to reach the moon.
LADEE lifted off right on time this past Friday night from NASA's Wallops Flight Facility on the Virginia coast.
LADEE was essentially asleep as it rode into space aboard a Minotaur V rocket. When the rocket dropped away, LADEE woke up and sent a status report back to Earth. Right away, mission controllers noticed that there was a problem. The spacecraft's four reaction wheels weren't working.
BUTLER HINE: A reaction wheel is a spinning disc, and you can turn a spacecraft by commanding the disc to spin faster.
PALCA: Butler Hine is LADEE project manager.
Without the reaction wheels, it would be hard to control the spacecraft. But as it turns out the reaction wheels were just fine, an overprotective software setting had shut them down. Hine said all they had to do was change the setting.
HINE: It actually only took us two hours to resolve the issue and then safely bring the reaction wheels back online.
PALCA: LADEE doesn't have any science to do until it reaches the moon, so Mission controllers will use the time while its looping the Earth to make sure all its hardware is working properly.
HINE: You look at the temperatures you're getting.You look at the voltages and currents your getting and then you tweak things. So we're in the tweaking phase but everything's looking really good right now.
PALCA: Once it gets to the moon, it has another 30 to 40 day check-out period, and then it can start its scientific mission of studying the tenuous lunar atmosphere and taking samples of lunar dust float above the Moon's surface.
Joe Palca, NPR News.
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发表于 2016-8-2 13:36:04