Russian space craft crash

MOSCOW — A Russian space probe designed to boost the nation’s pride on a bold mission to a moon of Mars has come down in flames, 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 Sunday 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).