near_decision_010214 LAUREL, Md. -- The spacecraft that made history this week with the first-ever landing on an asteroid has a new lease on life -- the mission has been extended, officials announced Wednesday.
| Pictures of the Landing! |
| Browse through these stunning images of the NEAR spacecraft"s descent to Asteroid Eros. |
On the Rebound:
Does NEAR Shoemaker have enough fuel left to launch itself across the asteroid? Will the mission be extended? Scientists will announce today answers to these questions. SPACE.com will provide live coverage of the 1:00 p.m. EST (18:00 GMT) news conference. Read the story . |
On the same day that the
Near Earth Asteroid Rendezvous Shoemaker probe was slated for death, NASA announced it will fund a 10-day extension for the mission so the spacecraft can collect X-ray and gamma-ray data from asteroid Eros 433 and send data to the agency's network of radio antennae on Earth.Counter to indications earlier this week, NASA will not relaunch NEAR for a brief skim across the surface of the asteroid to collect bonus pictures. A fuel shortage and other science concerns led to this decision, said Robert Farquhar, NEAR mission director at the Applied Physics Laboratory. APL built the NEAR Shoemaker probe and manages the mission for NASA.
"We have no fuel on the spacecraft, plus or minus 8 kilograms," Farquhar said.
Ever since the 3:04 p.m. touchdown on Monday, NASA and the APL have debated whether to
extend the mission, as well as the relaunch option.During the extended mission, Applied Physics Laboratory will turn on the probe's X-ray/Gamma-ray Spectrometer to learn more about the surface and subsurface composition of the asteroid Eros.
The cost of the extension is unclear, said Jay Bergstralh, acting director of Solar System Exploration at NASA Headquarters. Tracking NEAR will require the use of NASA's largest, 70-meter radio antennae in its Deep Space Network.
"I think this is doable on an every other day or every third day basis," he said. "The project has some reserve. They haven't presented us with an estimate yet."
NEAR Shoemaker continued to send signals to the NEAR team two days after the touchdown.
Picture bounty
Scientists are baffled by
images relayed from NEAR Shoemaker as it descended to the rocky asteroid speeding through space 196 million miles (315 million kilometers) from Earth.The size of small car, the spacecraft hit the asteroid at 4 mph and bounced to a gentle rest stop on the asteroid. It had taken some four and a half hours to maneuver itself down to the landing after spending nearly a year orbiting the mega-space rock.
NEAR Shoemaker drifted sideways toward Eros. An outward-facing camera on the craft pointed down to the asteroid's terrain, clicking off about two photos a minute.
Giving Eros the soft touch
Roughly 60 surface images were taken during the controlled descent, with elated scientists oohing and ahhing over never-before-seen details of the asteroid. The actual
landing locale on Eros should be figured out shortly. This area appears to be close to the distinctive, targeted zone -- a saddle-shaped featured named Himeros, at the boundary of two major geologic provinces of Eros.
The final picture released on approach to Eros, taken at 131 yards (120 meters) from the surface. Note the data breakdown at the bottom of the image.
"I think we landed pretty soft," said Farquhar.
Contact with the spacecraft was lost, then regained, likely caused by the probe bouncing across Eros, then alighting to a dead stop.
"This is definitely a lander, not an impactor," Farquhar said. The craft is estimated to have struck Eros at about the same speed as a person taking a brisk walk.
Next page: Amazing detail in pictures
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Whooping and hollering
"I was lucky enough to see the images before anybody else. I don't know if we could be heard...but we were whooping and hollering and pretty excited," said Louise Prockter, member of the NEAR imaging team at APL.
"I'm just amazed at how much detail we can see, so close to the surface," Prockter told SPACE.com. Features as small as about a half-inch (1 centimeter) can be seen.
Prockter said small-scale details of boulders show some of them to be very flat and angular, much more than expected. The very last image taken includes an enormous boulder.
"We came down very near that boulder. We might have even hit it," Prockter said. "The surface there seemed to be littered with boulders," she said.
Surprisingly, no fresh craters can be seen in the close-up images. Everything on the surface appears to be covered in a kind of dirt that scientists call regolith. "We still don't understand how the regolith gets so well distributed across the surface. We'd like to know," Prockter said.
The end is NEAR
The $223 million NEAR Shoemaker mission is slated to officially end on Wednesday. Project funds are depleted. No additional radio link time between Earth and the craft is slated beyond that date, Farquhar said.
"The spacecraft has exceeded all of our expectations," Farquhar said.
The dozens of close-up asteroid images taken during the descent are astounding, said Joseph Veverka of Cornell University in Ithaca, New York. He is the NEAR science team leader for the probe's camera.
"We saw something which is clearly unexpected," Veverka said. An image was taken of a depression, caused by subsurface collapse.
"We're completely baffled, not only by flat areas we see, but the collapsed features," Veverka said. "This is one of the mysteries we're trying to solve." What causes such a collapse on the asteroid is sure to spur further research, he said.
Why so few craters is a head-scratcher for Clark Chapman, member of the NEAR Shoemaker science team from Southwest Research Institute in Boulder, Colorado.
"I am perplexed by the fact that there are so many boulders and so few craters. Small craters seemed to be pretty much absent. Even close-up, I still don't see any small craters at all. That really makes me wonder what's going on," Chapman said.
Mario Acuna, NEAR team leader for the magnetic field experiment, said that no magnetic field has been found at Eros.
The Shoemaker spirit
The Near Earth Asteroid Rendezvous spacecraft was renamed NEAR Shoemaker a month after the spacecraft entered Eros orbit on February 14, 2000.
The renaming honored the late Eugene M. Shoemaker, the legendary astrogeologist who tragically died in a car accident while carrying out research in central Australia in July 1997.
Among those gathered here at APL to watch first-hand the landing on Eros was Carolyn Shoemaker, Gene Shoemaker's widow.
"I'm sure, if Gene had been here, he would have been jumping up and down with excitement," said Carolyn Shoemaker. "This is one of the most successful missions that we've had for all time," she told SPACE.com.
"Gene would have been telling us why Eros looked like it did. He always had theories and he didn't hesitate to try them out on people," Shoemaker said. "Every time they changed spacecraft altitude, they learned new and different things...new and different questions. What could be more exciting than that?"
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