NASA's Lunar Atmosphere Dust Environment Explorer will soon end its mission — but not before swooping close to the lunar surface and enduring the frigid darkness of a total lunar eclipse.
|Update: Ground controllers at NASA's Ames Research Center have confirmed that the Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft impacted the farside of the Moon, as planned, sometime between 9:30 and 10:22 p.m. PDT on April 17th. For more details see NASA's press release.
On or about April 21st, NASA's Lunar Atmosphere Dust Environment Explorer (LADEE) will crash into the far side of the Moon. Good thing LADEE's flight team is doing it on purpose.
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An artist's concept of NASA's Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft orbiting the Moon.[/caption]
LADEE was launched last year on September 6th on the first-ever use of the Minotaur rocket (full specs here), and the mission was never intended to last a long time. After settling into lunar orbit in mid-October and completing its checkout, the spacecraft started its observations of gas and dust hovering over the Moon.
An artist's concept of NASA's Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft seen orbiting near the surface of the moon.
NASA Ames / Dana Berry
The craft's orbit was relatively snug, ranging from as close as 20 to 50 km at low point to as high as 75 to 150 km. Science observations were only expected to last 100 days, ending early in March. But flight controllers have been so frugal with fuel reserves that the mission got a month-long extension
— and, with that, a chance to do some daring low-level passes over the lunar landscape.
"LADEE's science cup really overfloweth," said project scientist Rick Elphic (NASA Ames Research Center) during a teleconference with reporters on April 3rd. One discovery is that a veil of micron-size dust particles continually encases the Moon (created by a constant rain of meteoritic matter onto its surface). The spacecraft picked up the presence of helium, neon, and argon right away in the Moon's ultra-tenuous transient atmosphere (technically called an exosphere), and it's detected atoms of magnesium, aluminum, titanium, and oxygen — the remnants of rocky minerals blasted upward from the lunar surface.
Curiously, the spacecraft didn't detect any change in the exosphere's composition following the arrival of China's Chang'e 3 lander on December 14th. There was a spike in exospheric dust about that time, but mission scientists attribute that to surface impacts during mid-December's Geminid meteor shower.
Elphic says more research on LADEE's findings will be published in the coming months, but its science team already presented many preliminary results at the Lunar and Planetary Science Conference a few weeks ago.
the orbit of NASA's LADEE spacecraft brought it within 15 miles (25 km) of the lunar surface, close enough to sample the tenuous gas and ultrafine dust particles known to hover above the Moon. This portrayal shows the spacecraft backlit by sunlight scattered off dust particles during a lunar sunset. Click on the image for a larger version.
NASA Ames / Dana Berry
Every time LADEE has flown lower, Elphic says, it has discovered something new — a statement echoed by Butler Hine (NASA Ames Research Center), LADEE's project manager. So, given a perfectly functioning spacecraft, its primary science goals completed, and fortuitous timing, the mission team gets to pursue some bonus (and very daring) science objectives.
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