Wednesday, October 27, 2010

Dead Spacecraft Walking

Just when we had forgotten about the Moon.
Will it make the evening News?
- LRK -
NASA Science News for Oct. 27, 2010
A pair of NASA spacecraft that were supposed to be dead a year ago are instead flying to the Moon for a breakthrough mission in lunar orbit.
Oct. 27, 2010:  A pair of NASA spacecraft that were supposed to be dead last year are instead flying to the Moon for a breakthrough mission in lunar orbit. 

"Their real names are THEMIS P1 and P2, but I call them 'dead spacecraft walking,'" says Vassilis Angelopoulos of UCLA, principal investigator of the THEMIS mission. "Not long ago they appeared to be doomed, but now they are beginning an incredible new adventure."

The story begins in 2007 when NASA launched a fleet of five spacecraft into Earth's magnetosphere to study the physics of geomagnetic storms. Collectively, they were called THEMIS, short for "Time History of Events and Macroscale Interactions during Substorms." P1 and P2 were the outermost members of the quintet.

Working together, the probes quickly discovered a cornucopia of previously unknown phenomena such as colliding auroras, magnetic spacequakes, and plasma bullets shooting up and down Earth’s magnetic tail. This has allowed researchers to solve several longstanding mysteries of the Northern Lights.

The mission was going splendidly, except for one thing: Occasionally, P1 and P2 would pass through the shadow of Earth. The solar powered spacecraft were designed to go without sunlight for as much as three hours at a time, so a small amount of shadowing was no problem. But as the mission wore on, their orbits evolved and by 2009 the pair was spending as much as 8 hours a day in the dark.

"The two spacecraft were running out of power and freezing to death," says Angelopoulos. "We had to do something to save them."

The team brainstormed a solution. Because the mission had gone so well, the spacecraft still had an ample supply of fuel--enough to go to the Moon. "We could do some great science from lunar orbit," he says. NASA approved the trip and in late 2009, P1 and P2 headed away from the shadows of Earth.

With a new destination, the mission needed a new name. The team selected ARTEMIS, the Greek goddess of the Moon. It also stands for "Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon’s Interaction with the Sun."

The first big events of the ARTEMIS mission are underway now. On August 25, 2010, ARTEMIS-P1 reached the L2 Lagrange point on the far side of the Moon. Following close behind, ARTEMIS-P2 entered the opposite L1 Lagrange point on Oct. 22nd. Lagrange points are places where the gravity of Earth and Moon balance, creating a sort of gravitational parking spot for spacecraft.

Author: Dr. Tony Phillips | Credit: Science@NASA
[Check out the whole article and the graphics - LRK - ]
This should be an interesting mission extension and give us a better idea of what we would be in for if we were to set up camp at Lunar L1 and L2.
Wouldn't want a refueling station to get zapped by solar storms or magnetic fields a snapping.
- LRK -

. . .
"We are particularly hoping to catch some magnetic reconnection events," says Sibeck. "These are explosions in Earth's magnetotail that mimic solar flares--albeit on a much smaller scale." ARTEMIS might even see giant 'plasmoids' accelerated by the explosions hitting the Moon during magnetic storms.
. . .

My oh my, maybe we wouldn't be in Kansas.
- LRK -

Thanks for looking up with me.
- LRK -

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