Friday, April 18, 2014
By ALICIA CHANG/The Associated Press
PASADENA, Calif. — A pair of NASA spacecraft crashed into a mountain near the moon's north pole on Monday, bringing a deliberate end to a mission that peered into the lunar interior.
This artist’s rendering shows the twin spacecraft Ebb and Flow orbiting the moon. The pair were crashed into the lunar surface Monday in a deliberate end to their mission.
The Associated Press/NASA
Engineers commanded the twin spacecraft, Ebb and Flow, to fire their engines and burn their remaining fuel. Ebb plunged first followed by Flow about 30 seconds later.
Afterward, NASA said it had dedicated the final resting spot in honor of mission team member Sally Ride, the first American woman in space, who died earlier this year. By design, the impact site was far away from the Apollo landings and other historical sites.
Ride's sister, who huddled in the NASA control room for the finale, said it might be time to dust off Ride's first telescope to view the newly named site.
"We can look at the moon with a new appreciation and a smile in the evening when we see it, knowing that a little corner of the moon is named after Sally," the Rev. Bear Ride said in an interview.
Since the back-to-back crashes occurred in the dark, they were not visible from Earth. The Lunar Reconnaissance Orbiter circling the moon will pass over the mountain and attempt to photograph the skid marks left by the washing machine-sized-spacecraft as they hit the surface at 3,800 mph.
After rocketing off the launch pad in September 2011, Ebb and Flow took a roundabout journey to the moon, arriving over the New Year's holiday on a gravity-mapping mission.
More than 100 missions have been flown to Earth's nearest neighbor since the dawn of the Space Age, including NASA's six Apollo landings that put 12 astronauts on the surface.
The loss of Ebb and Flow comes in the same month as the 40th launch anniversary of Apollo 17, the last manned mission to the moon.
Ebb and Flow focused exclusively on measuring the moon's lumpy gravity field in a bid to learn more about its interior and early history. After flying in formation for months, they produced the most detailed gravity maps of any body in the solar system.
Secrets long held by the moon are spilling out. Ebb and Flow discovered that the lunar crust is much thinner than scientists had imagined. And it was severely battered by asteroids and comets in the early years of the solar system -- more than previously realized.
Data so far also appeared to quash the theory that Earth once had two moons that collided and melded into the one we see today.
Besides a scientific return, the mission allowed students to take their own pictures of craters and other lunar features as part of collaboration with a science education company founded by Ride, who died in July of pancreatic cancer at age 61. Globally, about 3,600 classrooms participated, sending back 114,000 photos.
Scientists expect to sift through data from the $487 million mission for years.