Home
News
In Focus
Business
Metro
Nation
World
Sports
Feature
Opinion
View more 禄Opinion Columns
Wan LixinOpinion deputy editor of Shanghai Daily
City-born architect lists inspiration behind his designs in a new book
Digitization helps preserve, disseminate intangible cultural heritage
Sunday
- Subscribe
German satellite set to crash at weekend
Source: Agencies |
October 21, 2011, Friday
|
Print Edition
Print Edition
PIECES of a retired German satellite may crash to earth this weekend, the German Aerospace Center said yesterday.
Scientists have now honed their initial estimate of when the satellite would hit from a span of four days to either Saturday or Sunday. As it nears, they will be able to estimate impact to within about 10 hours.
Parts of the satellite, which is the size of a minivan, will burn up during re-entry but up to 30 fragments weighing a total of 1.7 tons could crash to earth at a speed of up to 450 kilometers per hour.
The satellite orbits the Earth every 90 minutes and scientists can say only that it could hit the surface anywhere along its path, between 53 degrees north and 53 degrees south, a huge area.
Scientists are no longer able to communicate with the dead German satellite Rosat, which was launched in 1990. It was used to research black holes and neutron stars and performed the first all-sky survey of X-ray sources with an imaging telescope.
It was initially intended to be active for only 18 months, but due to its scientific success it was retired more than eight years later, in 1999, when communications were lost.
Even if the control center still had contact with the satellite, it has no engines with which to change its trajectory.
Scientists are now working on developing new technology that would allow for a controlled destruction of satellites in space, or the capture of satellites to prevent them from crashing to earth. But it will take many years for that technology to be implemented, the German Aerospace Center said.
As it stands, satellite debris hits the atmosphere almost every week, but most burns up on re-entry and pieces rarely reach the surface. The largest single fragment of Rosat that could reach the surface is the telescope's heat-resistant mirror.
Scientists have now honed their initial estimate of when the satellite would hit from a span of four days to either Saturday or Sunday. As it nears, they will be able to estimate impact to within about 10 hours.
Parts of the satellite, which is the size of a minivan, will burn up during re-entry but up to 30 fragments weighing a total of 1.7 tons could crash to earth at a speed of up to 450 kilometers per hour.
The satellite orbits the Earth every 90 minutes and scientists can say only that it could hit the surface anywhere along its path, between 53 degrees north and 53 degrees south, a huge area.
Scientists are no longer able to communicate with the dead German satellite Rosat, which was launched in 1990. It was used to research black holes and neutron stars and performed the first all-sky survey of X-ray sources with an imaging telescope.
It was initially intended to be active for only 18 months, but due to its scientific success it was retired more than eight years later, in 1999, when communications were lost.
Even if the control center still had contact with the satellite, it has no engines with which to change its trajectory.
Scientists are now working on developing new technology that would allow for a controlled destruction of satellites in space, or the capture of satellites to prevent them from crashing to earth. But it will take many years for that technology to be implemented, the German Aerospace Center said.
As it stands, satellite debris hits the atmosphere almost every week, but most burns up on re-entry and pieces rarely reach the surface. The largest single fragment of Rosat that could reach the surface is the telescope's heat-resistant mirror.
- About Us
- |
- Terms of Use
- |
-
RSS - |
- Privacy Policy
- |
- Contact Us
- |
- Shanghai Call Center: 962288
- |
- Tip-off hotline: 52920043
- 娌狪CP璇侊細娌狪CP澶05050403鍙-1
- |
- 浜掕仈缃戞柊闂讳俊鎭湇鍔¤鍙瘉锛31120180004
- |
- 缃戠粶瑙嗗惉璁稿彲璇侊細0909346
- |
- 骞挎挱鐢佃鑺傜洰鍒朵綔璁稿彲璇侊細娌瓧绗354鍙
- |
- 澧炲肩數淇′笟鍔＄粡钀ヨ鍙瘉锛氭勃B2-20120012
Copyright 漏 1999- Shanghai Daily. All rights reserved.Preferably viewed with Internet Explorer 8 or newer browsers.
