日批在线视频_内射毛片内射国产夫妻_亚洲三级小视频_在线观看亚洲大片短视频_女性向h片资源在线观看_亚洲最大网

Remains of satellite may never be found, NASA says

Updated: 2011-09-25 11:25

(Agencies)

  Comments() Print Mail Large Medium  Small 分享按鈕 0

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

The US 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.

Remains of satellite may never be found, NASA says

NASA conceptual image shows the Upper Atmosphere Research Satellite (UARS), launched on September 15, 1991, by the space shuttle Discovery. [Photo/Agencies]

The Upper Atmosphere Research Satellite, or UARS, ended 20 years in orbit with a suicidal plunge into the atmosphere sometime between 11:23 pm on Friday and 1:09 am 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.

As it fell to Earth, UARS passed from the east coast of Africa over the Indian Ocean, then the Pacific Ocean, across northern Canada and the northern Atlantic Ocean to a point over West Africa. Most of the transit was over water, with some flight over northern Canada and West Africa, NASA said.

"Because we don't know where the re-entry point actually was, we don't know where the debris field might be," said Nicholas Johnson, chief orbital debris scientist at NASA's Johnson Space Center in Houston. "We may never know."

Stretching 35 feet (10.7 meters) long and 15 feet (4.6 meters) in diameter, UARS was among the largest spacecraft to plummet uncontrollably through the atmosphere, although it is a slim cousin to NASA's 75-tonne (68,000 kilogram) Skylab station, which crashed to Earth in 1979.

Russia's last space station, the 135-tonne (122,000 kilogram) Mir, crashed into the Pacific Ocean in 2001, but it was a guided descent.

NASA now plans for the controlled re-entry of large spacecraft, but it did not when UARS was designed.

The 13,000-pound (5,897 kg) satellite was dispatched into orbit by a space shuttle crew in 1991 to study ozone and other chemicals in Earth's atmosphere.

It completed its mission in 2005 and has been slowly losing altitude ever since.

With most of the planet covered in water and vast uninhabited deserts and other land directly beneath the satellite's flight path, the chance that someone would be hit by falling debris was 1-in-3,200, NASA said.

"The risk to public safety is very remote," it said.

The satellite flew over most of the planet, traveling between 57 degrees north and 57 degrees south of the equator.

UARS was one of about 20,000 pieces of space debris in orbit around Earth. Something the size of UARS falls back into the atmosphere about once a year.  

   Previous Page 1 2 3 Next Page  

Related Stories

Lifeless satellite falls back to Earth 2011-09-24 07:53
Tumbling satellite to miss North America 2011-09-23 15:27
主站蜘蛛池模板: 久久人久久| 久久免费久久 | 日韩三级国产 | 欧美精品xx | 99视频热 | 黄色一大片 | 久久久福利视频 | 日本五十路女优 | 一区二区三区亚洲 | 涩涩一区| av在线免费观看网址 | 欧美成年人 | 免费网站91 | 久久影院国产 | 亚洲欧美另类在线观看 | 亚洲欧美日本在线 | 欧美激情成人 | 不卡的毛片 | 男人的天堂va | 女人十八毛片嫩草av | 亚洲一区在线免费 | 天天干夜夜操 | 日韩av一区二区三区在线观看 | 91精品国产成人 | 欧美一级爽aaaaa大片 | 亚洲一区和二区 | 国产又爽又黄又嫩又猛又粗 | 深夜视频在线免费观看 | theporn玉足脚交91 | 欧美精品久 | 香蕉视频成人 | 密桃成人av | 97精品国产97久久久久久免费 | 久久精品天堂 | 国产福利在线免费观看 | 在线观看欧美一区 | 久草视频免费在线观看 | 精品国产一区二区在线观看 | 成人一区二区三区四区 | a√天堂网 | av中文天堂在线 |