Posts Tagged ‘UARS

Final Update: NASA’s UARS Re-enters Earth’s Atmosphere

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NASA’s decommissioned Upper Atmosphere Research Satellite fell back to Earth at 12:01 a.m. EDT (0401 GMT) on Saturday, Sept. 24. The Joint Space Operations Center at Vandenberg Air Force Base in California has determined the satellite entered the atmosphere over the Pacific Ocean at 14.1 degrees south latitude and 189.8 degrees east longitude. This location is over a broad, remote ocean area in the Southern Hemisphere, far from any major land mass. The debris field is located between 300 miles and 800 miles downrange, or generally northeast of the re-entry point. NASA is not aware of any possible debris sightings from this geographic area.

This is your source for official information on the re-entry of UARS. All information posted here has been verified with a government or law enforcement agency. This is NASA’s final status report on the re-entry of UARS

This map shows the ground track for UARS beginning in the Indian Ocean off the coast of Africa at 0330 GMT and ending at atmospheric interface over the Pacific Ocean at 0401 GMT.

Six years after the end of its productive scientific life, UARS broke into pieces during re-entry, and most of it up burned in the atmosphere. Twenty-six satellite components, weighing a total of about 1,200 pounds, could have survived the fiery re-entry and reach the surface of Earth….. Read the rest of this entry »

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September 27, 2011 at 6:31 pm

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Remains of satellite may never be found, NASA says

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A six-ton NASA science satellite crashed to Earth on Saturday, leaving a mystery about where a ton of space debris may have landed.

The U.S. space agency said it believes the debris ended up in the Pacific Ocean, but the precise time of the bus-sized satellite’s re-entry and the location of its debris field have not been determined.

The Upper Atmosphere Research Satellite, or UARS, ended 20 years in orbit with a suicidal plunge into the atmosphere sometime between 11:23 p.m. on Friday and 1:09 a.m. EDT on Saturday (0323 to 0509 GMT Saturday), NASA said.

The satellite would have been torn apart during the fiery re-entry, but about 26 pieces, the largest of which was estimated to have weighed 330 pounds (150 kg), likely survived the fall, officials said………… Read the rest of this entry »

Written by physicsgg

September 26, 2011 at 1:03 pm

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UARS falling

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UARS Updates

NASA’s UARS Re-enters Earth’s Atmosphere

NASA’s decommissioned Upper Atmosphere Research Satellite (UARS) fell back to Earth between 11:23 p.m. EDT Friday, Sept. 23 and 1:09 a.m. Sept. 24, 20 years and nine days after its launch on a 14-year mission that produced some of the first long-term records of chemicals in the atmosphere.

The precise re-entry time and location of debris impacts have not been determined. During the re-entry period, the satellite passed from the east coast of Africa over the Indian Ocean, then the Pacific Ocean, then across northern Canada, then across the northern Atlantic Ocean, to a point over West Africa. The vast majority of the orbital transit was over water, with some flight over northern Canada and West Africa.

Six years after the end of its productive scientific life, UARS broke into pieces during re-entry, and most of it up burned in the atmosphere. Data indicates the satellite likely broke apart and landed in the Pacific Ocean far off the U.S. coast. Twenty-six satellite components, weighing a total of about 1,200 pounds, could have survived the fiery re-entry and reach the surface of Earth. However, NASA is not aware of any reports of injury or property damage.

The Operations Center for JFCC-Space, the Joint Functional Component Command at Vandenberg Air Force Base, Calif., which works around the clock detecting, identifying and tracking all man-made objects in Earth orbit, tracked the movements of UARS through the satellite’s final orbits and provided confirmation of re-entry.

“We extend our appreciation to the Joint Space Operations Center for monitoring UARS not only this past week but also throughout its entire 20 years on orbit,” said Nick Johnson, NASA’s chief scientist for orbital debris, at NASA’s Johnson Space Center in Houston. “This was not an easy re-entry to predict because of the natural forces acting on the satellite as its orbit decayed. Space-faring nations around the world also were monitoring the satellite’s descent in the last two hours and all the predictions were well within the range estimated by JSpOC.”

UARS was launched Sept. 12, 1991, aboard space shuttle mission STS-48 and deployed on Sept. 15, 1991. It was the first multi-instrumented satellite to observe numerous chemical components of the atmosphere for better understanding of photochemistry. UARS data marked the beginning of many long-term records for key chemicals in the atmosphere. The satellite also provided key data on the amount of light that comes from the sun at ultraviolet and visible wavelengths. UARS ceased its scientific life in 2005.

Because of the satellite’s orbit, any surviving components of UARS should have landed within a zone between 57 degrees north latitude and 57 degrees south latitude. It is impossible to pinpoint just where in that zone the debris landed, but NASA estimates the debris footprint to be about 500 miles long.

Nasa satellite has fallen to Earth

Scientists don’t yet know where exactly six-tonne UARS satellite has landed, but say danger to people is remote
The six-tonne Nasa satellite falling back to earth landed overnight, according to the space agency, but it has yet to determine the precise location of re-entry.
Although it admits it doesn’t know where it has landed, Nasa said: “The risk to public safety is very remote.”
According to the Nasa website, the 3.5-metre, bus-sized satellite re-entered the earth’s atmosphere as it was travelling “eastward over Canada and Africa as well as portions of the Pacific, Atlantic and Indian Oceans”.
Most of the old research spacecraft was expected to burn up during re-entry.
The upper atmosphere research satellite, or UARS, will be the biggest Nasa spacecraft to crash back to Earth, uncontrolled, since the post-Apollo 75-tonne Skylab space station and the more than 10-tonne Pegasus 2 satellite, both in 1979.
Russia’s 135-tonne Mir space station slammed through the atmosphere in 2001, but it was a controlled dive into the Pacific.
Some 26 pieces of the UARS satellite – representing 1,200lbs (544kg) of heavy metal – are expected to rain down. The biggest surviving chunk should be no more than 300lbs.
Earthlings can take comfort in the fact that no one has ever been hurt by falling space junk – to anyone’s knowledge – and there has never been serious property damage.
Nasa put the chances that somebody somewhere on Earth would get hurt at one in 3,200. But any one person’s odds of being struck were estimated at one in 22tn, given that there are 7 billion people on the planet.

Written by physicsgg

September 24, 2011 at 8:28 am

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UARS Will Hit the South Pacific Today

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Orbital scientists say that the falling Upper Atmosphere Research Satellite (UARS) will not impact the ground over US territory. According to the latest predictions, it will splash in the South Pacific Ocean, a little to the north of New Guinea.

Over the past few days, experts have been hard at work in analyzing the trajectory the UARS took when it began its descent, as well as all the other factors that may be involved in altering this course.

This is very complex task, especially when considering that even solar activity can influence the rate at which a spacecraft is influenced and pulled by the atmosphere. However, researchers from NASA and the US Air Force (USAF) managed to understand UARS’ path in more detail.
In addition, amateur astronomers and skywatchers have also been keeping an eye on the satellite, working with NASA to centralize the data. In the end, this proved to be useful for narrowing down the possible time windows when the satellite was expected.

A post published on the NASA website on Thursday, September 22, indicates that the UARS has entered a 115-by-120 mile (185-by-195 kilometer) orbit around the planet, and that reentry is therefore expected to occur sometimes during Friday afternoon (EDT).

Experts also said that there will be night at the location where the impact is expected to occur, giving people an early warning about the incoming spacecraft. “The satellite will not be passing over North America during that time period,” the NASA post said yesterday.

“It is still too early to predict the time and location of re-entry with any more certainty, but predictions will become more refined in the next 24 to 36 hours,” the agency announced. The Joint Space Operations Center of US Strategic Command contributed to tracking the satellite as well.

Expert Ted Molczan, who is using United States Strategic Command (USSTRATCOM) orbital elements to determine where the 6.5-ton spacecraft will impact the ground, says that scientists will not be able to determine exactly where UARS will impact until it does.

“I am making these estimates to maintain awareness of the approximate decay time, to maximize my chances of seeing the event,” Molczan explains, as quoted by Space. He says that the satellite’s debris trail will cover almost 500 kilometers (310 miles) in length.

“If, within a few hours of the decay, it appears that it will occur on a revolution that spends some time above my horizon, then, weather permitting, I will go out and watch for it during the several minutes in which it might pass,” he concludes.

Written by physicsgg

September 23, 2011 at 12:15 pm

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