Beagle 2's operation team has published the findings of its investigation into the fate of the European Mars lander, broadly supporting the theory that the craft got into trouble in the Martian atmosphere.
However, the inquiry found that the technology largely worked as planned, and was unable to identify a single obvious point of failure. The investigation then focused on the elements of the mission that could have contributed to the craft's failure to make contact, and highlights a number of places where things might have gone wrong.
Mission manager Dr Mark Sims of the University of Leicester said that the most likely scenario was some kind of failure during entry descent and landing. He reiterated the European Space Agency's suggestion that a thinner than expected Martian atmosphere caused the lander's parachutes to deploy either too early, or too late.
Professor Pillinger, also at the press conference, said that the mission "could have worked and should have worked, but it didn't, and we don't know why. All the failure modes we've identified are low likelihood, but something killed it".
The trigger for Beagle 2's parachutes was based on data input from an accelerometer. When the lander had decelerated by the appropriate amount, the chutes would be deployed. If models of the Martian atmosphere were incorrect, then the chutes would deploy at the wrong time, resulting in a crash landing for Beagle 2. Scientists have scanned the surface of the planet for the crater than this would have caused, but have found no conclusive evidence.
Both NASA's Mars rovers came into their landings faster than expected, Sims added, only just decelerating in time even with the benefit of braking thrusters. Pillinger said that although this evidence supported the theory of a too thin atmosphere, it was by no means the certain fate of Beagle 2.
Dr. Sims said that it was entirely possible that the craft made it safely to the surface and was just unable to broadcast a signal. "My nightmare scenario is that the antenna is damaged, and the craft is on the surface trying to talk to us," he told reporters. "It would be soul destroying if that is the case."
Beagle 2 had a "pocket watch" structure: that is, it had to unfold on landing for all the instruments to access the Martian surface. The designers also put the antenna on the inside of the casing, a move which was designed to protect it, but which in retrospect, both Professor Colin Pillinger and Sims suggest was a mistake.
Pillinger added that he would defend the management of the project to his dying breath, countering ESA criticisms by saying that Sims was the one of the most thorough men in the space business.
The charismatic scientist also refused to blame a lack of funding for the loss of the lander, but did acknowledge that having the money earlier in the process would have been helpful.
"Obviously more money means you can do more testing, but testing isn't everything, it still has to work on the day."
Both Sims and Pillinger remain convinced that another European mission to Mars is a possibility, saying that it is more important to look to the future than to continue the dissection of the Beagle 2 mission.
Pillinger says that the science Beagle 2 was designed to do is still ahead of anything planned by NASA in the next three years. He called on everyone involved in the European space effort to make a decision soon about a return to the Red Planet.
"I've written to NASA suggesting that the Beagle 2 science package should be considered as a standalone instrument package on the planned 2009 mission to Mars," said Pillinger. "I haven't had an answer yet, but if I don't hear from them soon, I'll ring them up and ask if they are taking me seriously." ®