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Rogue black holes skulk Milky Way perimeter

...Hundreds of rogue black holes left over from the galaxy building days of the early Universe could be wandering loose in the Milky Way...

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Postcards from MESSENGER

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Fermi explores high energy "space invaders"

...New details of high energy particles detected by NASA's Fermi Gamma-ray Space Telescope were at the American Physical Society meeting held...

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Video archive

STS-120 day 2 highlights

Flight Day 2 of Discovery's mission focused on heat shield inspections. This movie shows the day's highlights.


STS-120 day 1 highlights

The highlights from shuttle Discovery's launch day are packaged into this movie.


STS-118: Highlights

The STS-118 crew, including Barbara Morgan, narrates its mission highlights film and answers questions in this post-flight presentation.

 Full presentation
 Mission film

STS-120: Rollout to pad

Space shuttle Discovery rolls out of the Vehicle Assembly Building and travels to launch pad 39A for its STS-120 mission.


Dawn leaves Earth

NASA's Dawn space probe launches aboard a Delta 2-Heavy rocket from Cape Canaveral to explore two worlds in the asteroid belt.

 Full coverage

Dawn: Launch preview

These briefings preview the launch and science objectives of NASA's Dawn asteroid orbiter.

 Launch | Science

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More video

Spirit struggles with soft soil



Posted: 12 May, 2009

NASA’s Mars Exploration Rover Spirit is facing one of its biggest challenges yet with a patch of soft soil that is currently holding the rover hostage.

During recent attempts to drive around the Home Plate area of Mars, Spirit’s wheels have sunk about halfway into the ground. Concerns have been raised that Spirit may sink so low that its body may make contact with rocks on the surface, making the escape from this situation even more of a challenge. Engineers and scientists have temporarily suspended all driving while they simulate driving options with a test rover back on Earth.

Spirit took this image with its front hazard-avoidance camera on Sol 1899. With Spirit in the position shown here, the rover team temporarily suspended driving attempts while studying the ground around Spirit and planning simulation tests of driving options with a test rover at NASA's Jet Propulsion Laboratory in Pasadena. Image: NASA/JPL-Caltech.

“Spirit is in a very difficult situation,” says JPL’s John Callas, project manager for Spirit and its twin rover, Opportunity. “We are proceeding methodically and cautiously. It may be weeks before we try moving Spirit again. Meanwhile, we are using Spirit’s scientific instruments to learn more about the physical properties of the soil that is giving us trouble.”

Both Spirit and Opportunity have exceeded all expectations, operating more than five years longer than anticipated, and the rover team is becoming adept at developing workarounds for the aging rovers, such as the loss of use in one of Spirit’s six wheels three years ago.

At least the Martian weather is being kind – three times in the last month wind has removed some of the dust building up on the solar panels, increasing the rover’s capability for generating electricity. “The improved power situation buys us time,” says Callas. “We will use that time to plan the next steps carefully. We know that dust storms could return at any time, although the skies are currently clear.”

Behavioral problems that Spirit exhibited in early April – episodes of amnesia, computer resets and failure to wake for communications sessions – have not recurred in the past three weeks, though investigations have yet to diagnose the root causes.