Satelit ROSAT Jatuh Di Asia Tenggara

Satelit penyelidikan Jerman, ROSAT yang tidak lagi berfungsi terhempas di Asia Tenggara awal pagi tadi, menurut seorang saintis Amerika Syarikat, tetapi tiada seorang pun yang pasti di mana.

Menurut Pusat Aeroangkasa Jerman, kebanyakan bahagian satelit sebesar van mini itu dijangka hangus apabila memasuki atmosfera pada kelajuan sehingga 450 kilometer sejam tetapi kira-kira 30 serpihan seberat 1.7 tan metrik mungkin selamat dan terhempas.
Jonathan McDowell dari Harvard-Smithsonian Center for Astrophysics di Cambridge, Massachusetts, berkata satelit berkenaan mungkin jatuh di Asia Tenggara.

Katanya, dua bandaraya China dengan jutaan penduduk iaitu Chongqing dan Chengdu, berada di laluan satelit itu sewaktu kemasukan semula.

“Tetapi jika ia jatuh di kawasan berpenduduk, sudah tentu kita sudah memperoleh laporan sekarang," katanya.

Pengiraan berdasarkan data tentera AS menunjukkan serpihan satelit itu mungkin terhempas di Lautan Hindi di timur Sri Lanka atau di Laut Andaman di luar pantai Myanmar atau di pedalaman Myanmar atau China.

German satellite crashed in southeast Asia

A defunct German research satellite crashed into the Earth somewhere in southeast Asia on Sunday, a US scientist said – but no one is still quite sure where.

Most parts of the car-sized ROSAT research satellite were expected to burn up as they hit the atmosphere at speeds up to 280mph, but up to 30 fragments weighing a total of 1.87 tons, could have crashed, the German Aerospace Center said.

Jonathan McDowell of the Harvard-Smithsonian Centre for Astrophysics in Cambridge, Massachusetts, said the satellite appears to have gone down over southeast Asia. He said two Chinese cities with millions of inhabitants each, Chongqing and Chengdu, had been in the satellite's projected path during its re-entry time.

"But if it had come down over a populated area there probably would be reports by now," the astrophysicist, who tracks man-made space objects, said.

Calculations based on US military data indicate that satellite debris must have crashed somewhere east of Sri Lanka over the Indian Ocean, or over the Andaman Sea off the coast of Burma, or further inland in Burma or as far inland as China, he said.

The satellite entered the atmosphere between 0245 BST to 0315 BST and would have taken 15 minutes or less to hit the ground, the German Aerospace Centre said. Hours before the re-entry, the centre said the satellite was not expected to land in Europe, Africa or Australia.

There were no immediate reports from Asian governments or space agencies about the fallen satellite.

The satellite used to circle the planet in about 90 minutes, and it may have travelled several thousand miles during its re-entry, rendering exact predictions of where it crashed difficult.

German space agency spokesman Andreas Schuetz said a falling satellite also can change its flight pattern or even its direction once it sinks to within 90 miles above the Earth.

The 2.69-ton (2.4 metric ton) scientific ROSAT satellite was launched in Cape Canaveral, Florida, in 1990 and retired in 1999 after being used for research on black holes and neutron stars and performing the first all-sky survey of X-ray sources with an imaging telescope.

ROSAT's largest single fragment that could have hit is the telescope's heavy heat-resistant mirror.

"The impact would be similar to, say, an airliner having dropped an engine," said McDowell. "It would damage whatever it fell on, but it wouldn't have widespread consequences."

Since 1991, space agencies have adopted new procedures to lessen space junk and having satellites falling back to Earth. NASA says it has no more large satellites that will fall back to Earth uncontrolled in the next 25 years. -TheTelegraph