Brussels, 01 Sep 2004
Following a six-month internal investigation, the project team behind Beagle 2 has produced a report detailing the possible causes of the disappearance of the Mars lander, and a second document outlining the lessons learned as a guide for future missions.
Beagle 2 formed part of Europe's Mars Express mission to the Red Planet, but following its successful ejection from the orbiter on 19 December 2003, the lander failed to establish communications with mission control on 25 December and has not been heard from since.
The first report notes that following the comprehensive internal review of the mission, no definitive cause for its failure could be identified due to a paucity of data. 'However, a review of pre-launch assembly, integration and test data and post launch cruise telemetry data, and some post mission theoretical studies, allows the team to assign likelihood to a particular failure mode irrespective of whether there is any absolute evidence for or against it.'
The report stresses that analysis of the ejection images show that Beagle 2 was ejected at the correct velocity and spin rate. Despite the successful ejection, however, it is apparent that the lander could have failed at any number of subsequent stages in its journey to the planet's surface.
For example, observations from Mars Express, backed up by data from NASA's Spirit and Opportunity rovers, showed evidence of unusually low atmospheric density at 20 to 40 kilometres above the planet in early January. 'If such a condition existed over the Beagle 2 landing site [on 19 December], it may have prevented successful landing.' Therefore improved characterisation of the Martian atmosphere if critical to the success of future missions, according to the Beagle 2 team.
Furthermore, break up of the thermal protection tiles or failure of the front heat shield during entry cannot be ruled out, and similarly, malfunction of the electronics system during the various high shock environments encountered by the craft is also a possibility.
Other possible explanations for the lack of contact from Beagle 2 include damage to the lander's antenna, and the failure of the craft's folded components to deploy properly due to damage sustained during landing, although the team stress that all stages of the deployment were tested on numerous occasions.
Before moving onto the second report and the lessons that can be drawn from the mission, the team points out that Beagle 2 achieved a number of important results, including: an innovative and integrated lander design; advancement of planetary lander technology in Europe; pioneering industry-academia collaboration; and unprecedented levels of public interest and support for planetary science.
However, Mars Express and Beagle 2 did not comprise a single integrated project of two spacecraft, according to the mission team. 'The Beagle 2 programmatic planning was consistently forced to meet the needs of Mars Express at the expense of its own requirements. It is therefore strongly recommended that that any future combined orbiter and lander mission is managed and defined as a cohesive programme, with no part given less than equal priority,' states the second report, indicating the first of its 'lessons learned'.
The team also believes that more testing would have been valuable, and those involved would be keen to carry out such a future test programme with appropriate hardware to eliminate uncertainties in developing future lander systems. For example, the report notes that the airbag/gasbag test programme was limited by access to and the cost of US test facilities, as none were available in Europe.
The full list of lessons learned runs to many pages, but the report stresses that: 'This long list does not imply however that the design was inadequate but rather highlights the routes and ways to improve and make a small lander most robust and to ease the load on any future lander teams of designers, integration and test teams and operations staff. Beagle 2 was severely constrained by mass, volume and schedule and given adequate margins, time and resources many of these lessons would have been implemented on Beagle 2.'
Its authors hope that the report will serve as a permanent record of the of the Beagle 2 mission, and will be of use in similar projects in the future. They argue that the Beagle 2 payload would have made significant contributions to understanding Mars, and conclude that: 'Consequently, it is a desire of the consortium to re-fly the payload as soon as possible using an improved and evolved design of the low mass, innovative and integrated lander.'
To download the two reports, please consult the following web address: