* Astronomy

Blobrana · L

RE: Phobos-Grunt Mission

Blobrana · L

Cosmic Rays unlikely to have caused Mars mission failure

Even though top Russian officials previously offered well-publicised speculations about interference from American radar, that hypothesis was rejected. Instead the investigation suggested that cosmic rays had knocked out two non-radiation-hardened microchips at exactly the wrong moment. This event led the probe's computer to default to "safe mode" and await remedial commands from Earth. Although American experts in radiation hardening found the conclusion unlikely, they admitted it was not impossible.
Now that finding is in serious doubt because it is so statistically unlikely and because reports of more likely fatal flaws have appeared.
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Blobrana · L

Phobos-Grunt Failure Report Released

The spacecraft computer failed when two of the chips in the electronics suffered radiation damage. (The Russians say that radiation damage is the most likely cause, but the spacecraft was still in low Earth orbit beneath the radiation belts.) Whatever triggered the chip failure, the ultimate cause was the use of non-space-qualified electronic components. When the chips failed, the on-board computer program crashed.
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Ed ~ Re: South Atlantic Anomaly.

Blobrana · L

Russia blames Mars probe failure on space radiation

Russia blamed radiation on Tuesday for a computer glitch that doomed its Mars moon mission, but space industry experts cast doubt on the findings of an investigation into the crash of what was to be Moscow's first deep space mission in two decades.
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Blobrana · L

Space debris experts confirm estimate for Phobos-Grunt reentry

Before the reentry of Russia's Phobos-Grunt Mars probe on 15 January, ESA established a final prediction for reentry of 17:45 GMT, referring to an altitude of 10 km. Within the expected uncertainties, the prediction has been largely confirmed by observations.
Following the 15 January Phobos-Grunt reentry, the US Strategic Command confirmed a reentry time of 17:46 GMT, referring to an altitude of 80 km at 46°S and 87°W, near the South American coastline. This corresponds to a pass at 10 km altitude about seven minutes later - very close to ESA's prediction.
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Blobrana · L

Update:
New US 'official' Phobos-Grunt re-entery time at 17:46 UT ± 1 minute.

Inclination: 51.4°
Revolution Number: 1097
Predicted Location: 46°S, 273°E

Blobrana · L

Russia asks if US radar ruined space probe

Russian media say space experts will look into the possibility that a U.S. radar station may have inadvertently interfered with the failed Mars moon probe that later plummeted to Earth.
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Ed ~ it seems very unlikely. The satellite electronics should have been radiation hardened. See South Atlantic Anomaly.

Blobrana · L

Russia's elusive Mars probe crashes into Pacific - or Brazil?

Blobrana · L

Phobos-Grunt is thought to have landed in the Pacific Ocean.

The Phobos-Grunt spacecraft, which was meant to travel to a moon of Mars and back, has crashed back to Earth. The ambitious but doomed probe almost certainly splashed into the southern Pacific Ocean on 15 January, between 16:59 and 17:47 gmt.
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Blobrana · L

According to the Main Intelligence Space environment Space Command of the Air Forces Space Defence Centre the spacecraft had ceased to exist in the Pacific Ocean at 21 hours 45 minutes Moscow time, which is consistent with projections data Roscosmos.
Read more (Russian)