MOSCOW (AP) _ A Russian space probe designed to boost the nation's pride on a bold mission to a moon of Mars came down in flames Sunday, showering fragments into the south Pacific west of Chile's coast, officials said.
Pieces from the Phobos-Ground, which had become stuck in Earth's orbit, landed in water 1,250 kilometers (775 miles) west of Wellington Island in Chile's south, the Russian military Air and Space Defense Forces said in a statement carried by the country's news agencies.
The military space tracking facilities were monitoring the probe's crash, its spokesman Col. Alexei Zolotukhin said. Zolotukhin said the deserted ocean area is where Russia guides its discarded space cargo ships serving the International Space Station.
RIA Novosti news agency, however, cited Russian ballistic experts who said the fragments fell over a broader patch of Earth's surface, spreading from the Atlantic and including the territory of Brazil. It said the midpoint of the crash zone was located in the Brazilian state of Goias.
The $170 million craft was one of the heaviest and most toxic pieces of space junk ever to crash to Earth, but space officials and experts said the risks posed by its crash were minimal because the toxic rocket fuel on board and most of the craft's structure would burn up in the atmosphere high above the ground anyway.
The Phobos-Ground was designed to travel to one of Mars' twin moons, Phobos, land on it, collect soil samples and fly them back to Earth in 2014 in one of the most daunting interplanetary missions ever. It got stranded in Earth's orbit after its Nov. 9 launch, and efforts by Russian and European Space Agency experts to bring it back to life failed.
Prof. Heiner Klinkrad, Head of The European Space Agency's Space Debris Office that was monitoring the probe's descent, said the craft didn't pose any significant risks.
``This one is way, way down in the ranking,'' he said in a telephone interview from his office in Berlin, adding that booster rockets contain more solid segments that may survive fiery re-entries.
Thousands of pieces of derelict space vehicles orbit Earth, occasionally posing danger to astronauts and satellites in orbit, but as far as is known, no one has ever been hurt by falling space debris.
Russia's space agency Roscosmos predicted that only between 20 and 30 fragments of the Phobos probe with a total weight of up to 200 kilograms (440 pounds) would survive the re-entry and plummet to Earth.
Klinkrad agreed with that assessment, adding that about 100 metric tons of space junk fall on Earth every year. ``This is 200 kilograms out of these 100 tons,'' he said.
The Phobos-Ground weighed 13.5 metric tons (14.9 tons), and that included a load of 11 metric tons (12 tons) of highly toxic rocket fuel intended for the long journey to the Martian moon of Phobos and left unused as the probe got stranded in orbit around Earth.
Roscosmos said that all of the fuel will burn up on re-entry, a forecast Klinkrad said was supported by calculations done by NASA and the ESA. He said the craft's tanks are made of aluminum alloy that has a very low melting temperature, and they will burst at an altitude of more than 100 kilometers (60 miles).
The space era has seen far larger spacecraft crash. NASA's Skylab space station that went down in 1979 weighed 77 metric tons (85 tons) and Russia's Mir space station that de-orbited in 2001 weighed about 130 metric tons (143 tons). Their descent fueled fears around the world, but the wreckage of both fell far away from populated areas.
The Phobos-Ground was Russia's most expensive and the most ambitious space mission since Soviet times. Its mission to the crater-dented, potato-shaped Martian moon was to give scientists precious materials that could shed more light on the genesis of the solar system.
Russia's space chief has acknowledged the Phobos-Ground mission was ill-prepared, but said that Roscosmos had to give it the go-ahead so as not to miss the limited Earth-to-Mars launch window.
Its predecessor, Mars-96, which was built by the same Moscow-based NPO Lavochkin company, experienced an engine failure and crashed shortly after its launch in 1996. Its crash drew strong international fears because of around 200 grams of plutonium onboard. The craft eventually showered its fragments over the Chile-Bolivia border in the Andes Mountains, and the pieces were never recovered.
The worst ever radiation spill from a derelict space vehicle came in January 1978 when the nuclear-powered Cosmos 954 satellite crashed over northwestern Canada. The Soviets claimed the craft completely burned up on re-entry, but a massive recovery effort by Canadian authorities recovered a dozen fragments, most of which were radioactive.
The Phobos-Ground also contained a tiny quantity of the radioactive metal Cobalt-57 in one of its instruments, but Roscosmos said it poses no threat of radioactive contamination.
The spacecraft also carried a small cylinder with a collection of microbes as part of an experiment by the Pasadena, California-based Planetary Society that designed to explore whether they can survive interplanetary travel. The cylinder is attached to a capsule that was supposed to deliver Phobos ground samples back to Earth.
Igor Marinin, the editor of Russia's Novosti Kosmonavtiki magazine, said on Russia's NTV television that it would likely be destroyed.
<한글 기사>
"러' 화성 위성 탐사선 태평양에 추락"
러' 우주방어군 "칠레군도 서쪽 1천250km 해역"
일부 전문가들은 "브라질 동쪽 대서양 추락" 주장도
러시아 화성 위성 탐사선 '포보스-그룬트 '호의 잔해가 모스크바 시간 15일 오후 9시 45분(한국시간 16일 오전 2시 45분) 태 평양 해상에 추락했다고 러시아 공중-우주방어군 공보실이 밝혔다.
이타르타스 통신에 따르면 러시아 공중-우주방어군 공보실장 알렉세이 졸로투힌 대령은 이날 "공중-우주방어군 우주상황정찰센터 자료에 따르면 포보스-그룬트호 추 락 지점이 태평양 해역으로 확인됐다"고 밝혔다.
정확한 추락지점은 남미 칠레군도의 웰링턴섬에서 서쪽으로 약 1천250km 떨어진 태평양 해상으로, 보통 임무를 끝낸 러시아 우주화물선 '프로그레스'가 수장되는 곳 이라고 졸로투힌 실장은 덧붙였다.
하지만 현지 리아노보스티 통신은 포보스-그룬트호가 대서양 해상에 떨어졌다고 보도해 정확한 추락 지점에 대한 정보가 엇갈리고 있다.
이 통신은 로켓-우주분야 소식통을 인용해 "포보스-그룬트 잔해가 오후 9시 59 분(모스크바 시간) 대기권에 진입한 뒤 브라질 동쪽 해안에서 멀지않은 동경 310.7 도 남위 18.2도의 대서양 해상에 추락했다"고 보도했다.
지난해 11월 9일 카자흐스탄 바이코누르 우주기지에서 로켓 운반체 '제니트-2SB '에 실려 발사된 포보스-그룬트호는 로켓 운반체와 성공적으로 분리됐으나, 이후 자 체 엔진장치가 켜지지 않아 화성으로 향하는 정상궤도에 진입하지 못하고 중력에 이 끌려 지상으로 내려오다 이날 추락했다.
포보스-그룬트 발사는 러시아가 15년 만에 시도한 야심찬 화성 탐사 프로젝트였 다. 탐사선은 지구에서 3억 3천만 km 떨어진 화성 위성 포보스까지 11개월을 날아가 포보스의 토양을 채취한 뒤 지구로 귀환하는 임무를 맡았다. 전체 임무 수행 기간은 34개월로 책정됐다.
학계는 포보스 탐사를 통해 태양계의 역사와 화성의 생명체 존재 가능성 등에 대한 중요한 정보를 제공받을 수 있을 것으로 기대했었다. 포보스-그룬트 프로젝트 에는 약 50억 루블(약 1천850억원)이 든 것으로 알려졌다. 하지만 러시아의 원대한 시도는 또다시 실패로 끝나고 말았다.
러시아는 지난 1996년에도 화성 탐사선 '마르스-96'을 발사했으나 정상궤도에 진입시키는 데 실패한 바 있다. 탐사선을 궤도에 진입시키는 역할을 하는 가속블록 이 제대로 작동하지 않아 결국 태평양 상에 추락하고 말았다. 옛 소련 시절 러시아 가 발사한 16개의 화성탐사선 가운데 목적지에 도달한 것은 고작 5개였다.
서방의 화성 탐사 시도도 실패로 끝난 경우가 많았다. 1999년 미국 항공우주국( NASA)이 쏘아 올린 화성 탐사선 '마스 폴라 랜더(Mars Polar Lander)'는 착륙 도중 부서지고 말았다. 2003년 발사된 영국의 화성 착륙선 '비글 2(Beagle 2)' 탐사선은 화성 대기권으로 진입하는 과정에서 지상과 교신이 끊겨 실종됐다.
이처럼 인류의 화성 탐사 시도가 수많은 좌절을 경험하자 일부에선 '화성의 저주' 때문이란 속설까지 제기됐다.
