Veteran satellite watcher Thierry Legault filmed the wayward Russian Phobos-Grunt probe, which was intended to collect soil samples from a Martian moon but is instead heading toward a destructive plunge back to earth.?
A veteran skywatcher has snapped an amazing video of Russia's failed Mars probe as the craft heads toward a destructive plunge into Earth's atmosphere this month.
Skip to next paragraphSatellite sleuth Thierry Legault captured the impressive?video of the Phobos-Grunt Mars probe?Jan. 1 from the Calern Plateau observatory above Nice in the French Riviera.
Russia's Federal Space Agency launched the Phobos-Grunt probe in November, only to see it fail to depart for Mars shortly after reaching Earth orbit. It has been stranded in orbit ever since.
Legault reported on his website that his new video shows no sign of the spacecraft tumbling.
"The unexpected thing that I realized when I looked carefully at the video is that Phobos-Grunt is moving backwards," Legault said, "with its solar panels deployed but at the opposite of the sun. It's not surprising that it had no energy to communicate!"
Spotting the Phobos-Grunt Mars probe
Legault's observation spurred Ted Molczan of Toronto, a leader in the amateur satellite- spotting network, to study the spacecraft's orientation.
"The orientation revealed in Thierry Legault's video ? propulsion module leading, solar arrays trailing ? may possibly be explained by analogy with the shuttlecock used in the sport of badminton," Molczan told SPACE.com. [Photos of the Phobos-Grunt mission]
Shuttlecocks are roughly conical, consisting of a heavy mass at the tip (called the cork) and trailing feathers forming the cone. This configuration results in highly stable flight through the air, with the heavy end leading, Molczan noted.
Molczan said that most of Phobos-Grunt's massive 14-ton bulk consists of fuel, located in tanks in the main propulsion module at one end of the spacecraft, similar to the heavy cork of a shuttlecock.
"Although Phobos-Grunt does not have feathers, it does have solar arrays, mounted on the end opposite the fuel tanks, which may produce a similar effect," Molczan said. ?"An essential requirement for shuttlecock flight is the presence of air, of which there is exceedingly little in space; however, at the very low altitude of Phobos-Grunt, the combination of atmospheric density and high orbital velocity is sufficient for aerodynamics to dominate the forces affecting the orientation of a spacecraft."
When will it fall?
Phobos-Grunt launched into space early Nov. 9 (Nov. 8 in the United States) and was intended to land on Phobos, one of two moons circling Mars. The spacecraft was designed to snare samples of Phobos' surface and rocket the specimens back to Earth in 2014.
But the Mars probe failed to boost itself out of Earth orbit on an interplanetary trajectory. Russian engineers have been unable to re-establish control of or contact with the spacecraft.
There is a convergence of tracking predictions that places?Phobos-Grunt's uncontrolled fall?into Earth's atmosphere in the Jan. 15-16 time period.
"That's about what we have as well ? but there are uncertainties of several days still," said Holger Krag, deputy head of the European Space Agency's Space Debris Office, at the European Space Operations Center in Darmstadt, Germany.
As for media reports of the disabled spacecraft crashing into any specific place, Krag said, "This is, of course, nonsense. It can come down at any place."
Krag told SPACE.com that because our planet is covered by about 73 percent water, "there is a rather small chance that there would be a land impact."
That being the case, the message from Krag for ground-dwellers is clear-cut.
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