The only lander capable of actually measuring water on Mars since
Viking (1976), up in smoke! Yes, the competition was a good
thing. Hopefully, the Europeans will get another chance.
Gary
http://planetary.org/news/2004/beagle_reflections.html
Beagle 2 Scientists Reflect on Landers� Loss
by Amir Alexander
March 8, 2004:
Project scientists for the Beagle 2 lander mission speculated today that a thinner than expected upper Martian atmosphere may have doomed the spacecraft. Measurements taken by Beagle 2�s companion, the Mars Express orbiter, seem to show that Mars�s upper atmosphere is considerably less dense than previously expected. It is possible that due to the reduced atmospheric drag on the lander, its parachute failed to deploy causing the spacecraft to crash at high speed onto the planet�s surface.
The British Beagle 2 lander made the trip from Earth to Mars as part of the European Mars Express orbiter mission. The lander separated from Mars Express on December 19, 2003, as the mother-craft was beginning its orbit insertion maneuvers, which ultimately proved successful. Beagle 2 was due to land on the surface of Mars six days later, on December 25, and contact mission controllers on Earth. It never did, and the lander is now considered lost.
The thin atmosphere scenario is only one of many causes being currently considered for the loss of the spacecraft. Another possible culprit is atmospheric turbulence, which measurements by NASA�s Spirit rover show to be significant. Scientists also said that images of Beagle 2 taken from Mars Express as the two spacecrafts were separating on December 19 seem to show an unexplained bright spot on the lander�s dark surface. It is not clear what the bright patch is, but it may indicate a flaw or even a part breaking off the spacecraft.
Images taken in the past few weeks by the Mars Global Surveyor of Beagle 2�s projected landing area show a few tiny white specks standing out against Martian surface. While some scientists believe these may be the lander�s parachutes, others dismiss the specks as an artifact of the imaging process. The Beagle team has requested close-up images, which will be available in the next few days.
In a public event that took place at the Royal Society in London on Monday evening, Colin Pillinger, Beagle 2�s lead scientist, reflected on the causes of the spacecraft�s loss and on the lessons for the future that can be derived from it. Much of the problems with Beagle 2�s landing, he suggested, stem from the fact that the lander was a �hitch-hiker,� hitching a ride on the Mars Express orbiter. Priority was therefore always given to the orbiter, which was the main payload, over the lander. As a result Beagle 2 was �kicked off� the Mars Express much further away from the planet than would have been desirable, with six full days of travel still ahead of it. This, Pillinger argued, substantially increased the risk to the mission. Any future lander mission, he said, must be a dedicated one, with the lander as the primary payload.
Pillinger made several other suggestions that he said would increase the chances of a successful landing in future missions. The �bouncing� method, used to land NASA�s twin rovers as well as Beagle 2 on Mars, is too unpredictable to allow for safe landings he said. In this method the landing capsule is surrounded by inflated airbags, and bounces repeatedly on the surface before coming to rest. A more reliable method according to Pillinger would be to use �deadbeat airbags� that would absorb the shock of the landing and deflate without bouncing. Pillinger also suggested that a future mission should enter Mars orbit before landing, to allow time to make atmospheric measurements and choose the right timing and location for a landing.
Reflecting on the differences between Beagle 2 and NASA�s successful landers Spirit and Opportunity, Pillinger pointed out that the American rovers had �ten times the funding� that was available to him and his team. Even so, he said, he had no doubt that the competition provided by Beagle 2 pushed NASA engineers harder to accomplish their mission goals. �When NASA thought they were the only game in town, they had some well publicized failures.� With a rival on the scene, said Pillinger, NASA made an extra effort to ensure success.
