Fijilive
Russia Mars probe spirals back to Earth
January 16, 2012 12:00:00 AM
Russia's doomed probe for Mars on Sunday spiralled ever closer to the Earth before it plunges back into the atmosphere in a fiery end which reportedly could see parts crashing into South America.

The Phobos-Grunt spacecraft should have been on an expedition to Mars' largest moon but instead became stuck in an Earth orbit which has become lower and lower as it becomes increasingly tugged by the Earth's gravity.

Russian space agency Roscosmos said that as of 1430 GMT Phobos-Grunt was in an maximum orbit of just 142.9 kilometres (89 miles) above the Earth and was now whizzing round the planet once every 87 minutes as it moved closer.

The probe will crash back to Earth between 1730 GMT and 1912 GMT, Roscosmos said, without predicting where in the world the fragments were expected to land.

The Interfax news agency however quoted a space industry source as saying that fragments of Phobos-Grunt will hit Earth 120 kilometres (75 miles) west of the Argentinian city of Rosario, northwest of the capital Buenos Aires.

Previous forecasts have predicted that debris would hit the Pacific off the western coast of Chile or the Chinese portion of the Gobi Desert. Earlier updates had the fragments falling into the Indian and Atlantic oceans.

The unmanned $165 million vessel -- stuck in a low Earth orbit since its November 9 launch -- will be one of the largest objects to re-enter the atmosphere since Russia brought down the Soviet-era Mir space station in 2001.

Sky gazers report the gold-coloured vessel emitting a bright orange glow as it traverses the globe in an eastward direction between London to the north and New Zealand to the south.

The Soviet-designed system is loaded with 11,000 tonnes of toxic fuel -- enough to take it to Phobos -- and a Chinese satellite it had been due to put in orbit around the Red Planet under a landmark deal with Beijing.

Roscosmos predicts that only 20 or 30 segments weighing no more than 200 kilogrammes (440 pounds) in total will survive the explosive re-entry and actually hit the Earth's surface.

Russian and NASA scientists have downplayed the risks posed by the fuel, predicting that it should burn up in the atmosphere before reaching the Earth's surface.

The fuel is stored in tanks of light aluminium -- not the sturdy titanium used by the now-retired US space shuttle -- with a relatively low melting point.

"The explosion of such a vast amount of fuel will completely destroy the station," said Russian Academy of Sciences expert Igor Marinin. "But you will get pretty fireworks," Marinin told NTV television.

The inglorious ending provides a bitter reminder for Russia of the prowess it has lost in the half-century since Yuri Gagarin's historic first space flight in 1961.

The ambitious project had initially aimed to revive Russia's interplanetary programme and prepare the way for a manned mission to Mars.

But Russia lost sight of the probe almost immediately after its launch and then spent weeks trying to send commands that would either nudge it on its way to Mars or at least enable its controlled return to Earth.

Neither proved successful and Roscosmos now admits that the impact location will depend on varying circumstances such as atmospheric density and even solar activity.

The November accident represents one of the more high-profile mishaps in a year littered with unprecedented setbacks for the once-vaunted programme.

It struck less than three months after an unmanned Progress supply ship bound for the International Space Station crashed into Siberia.

Russia also lost three navigation satellites as well as an advanced military satellite and a telecommunications satellite in the past year.

AFP