Posted on 01/06/2004 10:30:13 AM PST by blam
Mothership is last chance for Beagle 2
13:17 06 January 04
NewScientist.com news service
Europe's Mars Express spacecraft is gearing up for a last-ditch attempt to make contact with the missing Beagle 2 lander.
Beagle 2 has been completely silent since it entered the Martian atmosphere on Christmas Day. Several attempts by NASA's Mars Odyssey orbiter and the 76-metre Jodrell Bank radio dish in the UK have failed to pick up any signals from the British lander.
Scientists say their best hope is that Mars Express, Beagle 2's mothership, will pick up transmissions from the lander when it flies over the landing site on Wednesday at around 1215 GMT. They will announce the result at around 1500 GMT.
If Mars Express does not hear signals, the mission is almost certainly dead. However, the Beagle 2 team is adamant that they will not give up until mid-February, when Mars Express will have had several chances to make contact.
Solar panels
Beagle 2 might have crash-landed on the Martian surface and shattered into pieces. Or the solar panels that charge its battery may have failed to unfold following the landing. Another remote possibility is that it fell into a kilometre-wide crater in the centre of its target area.
Alternatively, a software glitch may have confused the lander's onboard clock, which tells Beagle 2 when to transmit signals to Mars Odyssey or Mars Express.
Mission manager Mark Sims says he wishes Beagle 2 had been programmed to transmit signals more continuously following touchdown, a mode which was supposed to begin after about 10 days without contact. "With hindsight, which is always beautiful 20-20 vision, we all might have paid a bit more attention to failure modes earlier on," he says.
Black box
Experts at Leicester University have ruled out some of the possible reasons for Beagle 2's silence, for instance that bad weather disrupted the lander's descent and landing, or that its communications antenna is at the wrong angle.
But they admit they might never know what happened. "That's the worst thing - Beagle could be sat quite happily working on the surface of Mars, but for some reason we don't understand, it's not talking to us," Sims told New Scientist.
Other experts suspect the worst. "My bet is that during the landing phase, one of the steps did not go as planned," says Max Meerman, an engineer with UK company Surrey Satellites, currently on sabbatical at the US Air Force Academy in Colorado Springs. The lander could have burned up in the Martian atmosphere. Or the parachutes and airbags designed to give Beagle 2 a soft landing could have failed.
Sims says some kind of black-box recorder that transmitted information about the lander's fate would have been ideal, but weight and cost constraints prevented this.
Yes. MGS is equipped to handle such tasks. But that won't do much good. MGS has too low of a resolution. A few groups out there think MGS may have photographed the polar lander crash site and debris, but its only a few pixels of data. Beagle is much smaller than the polar lander, so you're not going to find anything.
Odyssey might also be able to pick something out in other bands, but it probably has too low a resolution also.
Mars Express has a 10-meter resolution camera, and can zoom to 2-meter, but if Beagle's in pieces, 2 meters is low.
I can't tell you the resolution of MGS or Odyssey because JPL's mars missions page is down for everthing other than the rovers.
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