Wednesday - December 12, 2007
Friday - August 31, 2007
They are alive...
This is cool:
LOS ANGELES — They're old and dirty, but NASA's Mars rovers are back in the exploration business after enduring a lengthy Red Planet dust bowl that blocked most of the sunlight they need for power.
With skies gradually brightening, the solar-powered rovers Spirit and Opportunity recently resumed driving and other operations that had been suspended during the dust storm.
"The rovers are in good health and in good shape," said John Callas, the rover project manager at NASA's Jet Propulsion Laboratory in Pasadena. "Things have improved from the more dire conditions that were existing previously due to the dust storm on Mars."
During the storm, each of the rovers spent a couple of weeks sleeping most of the time.
"They were in sort of a hibernation state where we were only communicating with them every few days," Callas said Friday. "The rovers would only be awake a very short amount of time each day to save power."
The major concern was whether the rovers would have enough energy to keep sensitive electronics at proper temperatures on the frigid planet.
"At the darkest part of the storm, Opportunity had only 128 watt-hours of energy. Today, it has about 350 watt-hours of energy, so almost three times as much now," Callas said. "The most energy that the rovers have ever seen in their 3 1/2 years on Mars is about 900 watt-hours of energy."
The biggest problem left by the storm is dust on the instruments at the end of the rovers' robotic arms, he said. Some has fallen off or been blown off, and there are ways to measure how dust contamination is affecting an instrument, he said.
The longer-term concern is how the rovers, particularly Spirit, will deal with the next Martian winter, when the sun is low and less energy reaches their solar panels.
"The solar arrays are dusty on both rovers, but dustier on Spirit, and they are dustier now than they were exactly one Martian year ago. So if they don't get cleaner and they continue to accumulate dust at the same rate they saw last year, it will be a tough Martian winter for Spirit," Callas said...
Saturday - August 18, 2007
Friday - August 17, 2007
Mystery Image of the Day...
What is it?
Credit & Copyright: Malin Space Science Systems, MOC, MGS, JPL, NASA
Explanation: What causes the black dots on dunes on Mars? As spring dawned on the Northern Hemisphere of Mars in 2004, dunes of sand near the poles begin to defrost. Thinner regions of ice typically thaw first revealing sand whose darkness soaks in sunlight and accelerates the thaw. The process might involve sandy jets exploding through the thinning ice. By summer, the spots expanded to encompass the entire dunes that were then completely thawed and dark. The carbon dioxide and water ice actually sublime in the thin atmosphere directly to gas. Taken in mid-July, the above image shows a field of spotted polar dunes spanning about 3 kilometers near the Martian North Pole. Today, the future of Mars rovers Spirit andOpportunity remains unknown windy dust storms continue to starve them of needed sunlight.
Monday - August 13, 2007
Friday - July 20, 2007
Could it be the end...
The little Robots that could may be about done:
A raging dust storm on Mars has cut power to NASA's twin rovers to dangerously low levels, threatening an end to the mission.
The rovers were slated to operate for only 3 months but have been on Mars more than 3 years, so mission officials have had ample time to ponder their eventual silencing.
The storm presents perhaps the rover team's biggest challenge, NASA said in a statement today. Scientists said the storm, which has been brewing for nearly a month, is blocking around 85 to 90 percent of all sunlight to the surface.
The rovers, Opportunity and Spirit, rely on sunlight to charge their solar panels, and one or both rovers could be damaged permanently or even disabled by the limited solar power, officials said.
SPACE.com reported the storm's fresh severity earlier today.
Scientists fear the storms might continue for several days or weeks. If the sunlight is further slashed for an extended period, the rovers will not be able to generate enough power to keep warm and operate at all, even in a near-dormant state, the statement said.
The rovers use electric heaters to keep vital core electronics from becoming too cold.
"We're rooting for our rovers to survive these storms, but they were never designed for conditions this intense," said Alan Stern, associate administrator of NASA's Science Mission Directorate.
Steve Squyres of Cornell University, who is the lead scientist of the Mars Exploration Rover Project, said the direct sunlight to the rovers is at an all-time low.
Tuesday - June 12, 2007
Interesting...
This will be fun to watch:
HOUSTON -- NASA engineers are conducting a series of tests to determine how best to repair a torn heat-resistant blanket on the space shuttle Atlantis.
John Shannon, NASA's deputy shuttle program manager, said astronauts and engineers on Earth are testing repair options that range from using a medical stapler to what amounts to a spacesuit darning needle to secure the blanket swatch, which ripped free of its mount at the aft end of Atlantis during the orbiter's June 8 launch.
"They have several different solutions to put the blanket down and keep it down," Shannon told reporters here at NASA's Johnson Space Center during a mission briefing.
Wire ties and tools to pin the 4-inch by 6-inch (10-centimeter by 15-centimeter) triangular blanket flap into heat-resistant tiles nearby its location on Atlantis' left Orbital Maneuvering System (OMS) pod are also among the options, said Shannon. Duct tape, it turns out, won't work in the vacuum of space, he added.
The front runner is the spacesuit needle using a stainless steel wire as thread. But a final decision is expected sometime in the next two days, during which time mission managers will also decide whether to perform the repair during the third STS-117 spacewalk set for Friday or wait until the newly added fourth excursion on Sunday, Shannon said.
While not a threat to the safe return of Atlantis' STS-117 astronaut crew, there is a risk that heat of reentering the Earth's atmosphere could damage honeycomb-like graphite-epoxy material beneath the torn blanket and require a repair after landing that could be avoided, mission managers have said.
Later this week, NASA engineers will conduct a series of wind tunnel tests and heating studies on mockups of the damaged blanket to evaluate the repair techniques...
Sunday - June 10, 2007
Wednesday - March 21, 2007
The Sun...
March 21, 2007: It's enough to make you leap out of your seat: A magnetic vortex almost as big as Earth races across your computer screen,twisting, turning, finally erupting in a powerful solar flare. Japan's Hinode spacecraft recorded just such a blast on Jan. 12, 2007.
"I managed to stay in my seat," says solar physicist John Davis of the Marshall Space Flight Center, "but just barely."
Davis is NASA's project scientist for Hinode, Japanese for Sunrise. The spacecraft was launched in Sept. 2006 from the Uchinoura Space Center in Japan on a mission to study sunspots and solar flares. Hinode's Solar Optical Telescope, which some astronomers liken to "a Hubble for the Sun," produces crystal-clear images with 0.2 arc-second resolution. (Comparison: 0.2 arc-second is a tiny angle approximately equal to the width of a human hair held about 100 meters away.) "We're getting movies like these all the time now," he says...
Sunday - March 04, 2007
Friday - March 02, 2007
Tuesday - February 27, 2007
Sunday - February 11, 2007
Friday - January 05, 2007
Saturday - December 30, 2006
Thursday - December 14, 2006
Comets Different than Thought...
SAN FRANCISCO (AP) - Detailed observations from the first comet samples returned to Earth are debunking some of science's long-held beliefs on how the icy, celestial bodies form.Scientists expected the minute grains retrieved from a comet Wild 2 to be made up mostly of interstellar dust - tiny particles that flow through the solar system thought to be from ancient stars that exploded and died.
Instead, they found an unusual mix of primordial material as if the solar system had turned itself inside out. Hot particles from the inner solar system migrated out to the cold, outer fringes beyond Pluto where they intermingled and congealed to form a comet.
"People imagine that comets form in total isolation, which is definitely not true," said Don Brownlee, a University of Washington astronomer who is the principal scientist for the $212 million Stardust mission.
Brownlee estimated that up to 10 percent of materials in comets may come from the inner solar system.
A series of papers detailing the first scientific results from the Stardust mission were to be published Friday in the journal Science and presented at an American Geophysical Union meeting Thursday.
A capsule carrying thousands of minuscule samples from comet Wild 2 returned to Earth last January after looping around the sun to capture the interstellar and comet debris and swooping past Wild 2 to scoop up dust...
Previous posts here, here, here and here.
Monday - October 30, 2006
Thursday - October 26, 2006
Headline of the Day...
I want to type "well yeah" or "duh" but I won't.
I will instead show you the dark spot:
(Yeah, I know. I am mentally stuck in Junior High.)
