NASA

NASA's Mars Science Laboratory rover, the most scientifically powerful robotic lander ever built, will use a suite of sophisticated instruments to search for carbon compounds and the geological markers that might indicate whether ancient, once-wet environments were ever habitable.

Scientists currently are assessing four potential landing sites for the rover's August 2012 arrival at the Red Planet that offer the best chance for a successful landing and the most scientifically promising terrain. (For the main story in this package, see "On Mars, satisfaction awaits Curiosity.")

"What we know going into this is every one of … Read more

Under the watchful eyes of anxious engineers, NASA's $2.4 billion Mars Science Laboratory rover has taken its first baby steps, rolling a few feet forward and back in an environmentally controlled clean room.

It was a seemingly modest test for an unfinished spacecraft that still faces technical challenges and months of assembly and testing. But with landing on the Red Planet now just two years away, the short drive on July 23 marked a major milestone for the men and women building the car-size rover.

"It's gone from designs on napkins to PowerPoint, to CAD drawings, … Read more

The International Space Station's coolant system is back up and running normally after a challenging three-spacewalk repair job, astronauts said Thursday.

The fix allows the crew to power up science equipment and other systems that had to be shut down when an ammonia pump shorted out July 31.

In an interview with CBS News, the station's three NASA astronauts--robot arm operator Shannon Walker and spacewalkers Douglas Wheelock and Tracy Caldwell Dyson--said the impromptu repair went well, despite unexpected problems.

"I think it was really NASA at its finest with all the teams on the ground and the … Read more

A new study shows that despite regular exercise, astronauts on long-duration spaceflights experience significant muscle wasting and a surprising loss of force, reducing their efficiency in space and their ability to respond to emergencies when returning to Earth.

The research suggests the reduction in the capacity for work after six months in space can exceed 40 percent, which would temporarily reduce the performance of a returning astronaut to that of an 80-year-old. The study suggests more effective exercise techniques are required to keep astronauts in shape during long missions.

Robert Fitts of Marquette University, lead author of a paper published … Read more

KENNEDY SPACE CENTER, Fla.--Astronauts Douglas Wheelock and Tracy Caldwell Dyson wrapped up a successful spacewalk Monday, installing a new ammonia pump to help flight controllers recover from a failure that shut down half the International Space Station's cooling systems.

"We had an extremely successful EVA today," Kirk Shireman, deputy manager of the space station program at the Johnson Space Center, said after the spacewalk. "We're very pleased with the results. We still have some more activities this afternoon and tomorrow to fully recover from the pump module failure, but things are certainly looking positive … Read more

KENNEDY SPACE CENTER, Fla.--Spacewalker Douglas Wheelock, given permission to "shake violently" a stuck ammonia connector, used a healthy dose of elbow grease to finally get a troublesome coolant system quick-disconnect fitting to release Wednesday on the International Space Station.

With the fourth and final ammonia line finally free, Wheelock and crewmate Tracy Caldwell Dyson removed a faulty coolant pump, clearing the way for installation of a replacement during a third spacewalk planned for Monday.

A fourth spacewalk likely will be required later to wrap up loose ends and move the old pump to a permanent stowage location.… Read more

KENNEDY SPACE CENTER, Fla.--Flight controllers are revising plans for a second spacewalk Wednesday to replace a coolant pump aboard the International Space Station, adding work to isolate an ammonia leak that should clear the way for installation of a new pump during a third spacewalk Sunday.

A formal decision on whether to proceed with the Wednesday spacewalk is expected after NASA's space station Mission Management Team reviews preparations during a meeting Tuesday at the Johnson Space Center in Houston.

The pump module, one of two in independent coolant loops, circulates ammonia through huge radiators to dissipate the heat … Read more

NASA is refining plans for two spacewalks by astronauts to replace a large ammonia pump module that shut down Saturday, knocking out one of the International Space Station's two cooling loops.

Astronauts Douglas Wheelock and Tracy Caldwell Dyson hope to carry out the first spacewalk Friday, starting at 6:55 a.m. EDT, and a second excursion August 9 to finish the job, one of the so-called "big 14" on a list of critical components that require spacewalk repair if problems crop up.

NASA managers initially targeted Thursday for the first spacewalk and Sunday for the second … Read more

Trouble with one of the International Space Station's external coolant loops (PDF), used to dissipate the heat generated by the lab's electronics systems, triggered an extensive powerdown late Saturday. NASA managers met Sunday and gave preliminary approval to a difficult two-spacewalk repair job, starting as early as Thursday, to restore the critical system to normal operation.

It is not yet clear what went wrong, but the ammonia pump module that is part of coolant loop A, mounted on the right side of the station's main power truss, failed around 8 p.m. EDT Saturday. A problem somewhere … Read more