ESA to risk Mars Express instrument deployment
The European Space Agency (ESA) has announced a date for deployment of the troubled MARSIS radar onboard its Mars Express spacecraft, following eight months of investigation into the possible consequences of the move. MARSIS, which is designed to search for subsurface water reservoirs and study the Martian ionosphere, had been scheduled for deployment in April 2004. However, shortly before its planned release, US manufacturers Astro Aerospace warned of the possibility of a damaging whiplash effect during deployment of the instruments' 20 metre booms. Now, after eight months of computer simulations and technical analysis to determine possible damage to the spacecraft and its instruments, an independent engineering review board has given the green light for the radar to be released. ESA has suggested the first week of May as the most likely date for deployment, though if preparations proceed faster than planned this could be brought forward by a week. The technical investigation included complex computer simulations, as well as theoretical studies and tests on similar instruments to assess the potential ageing of the boom material. This provided the review board with a complete analysis of possible impact scenarios, including the amount of energy involved, the nature of the materials and the physical conditions in space. According to ESA: 'The board concluded that the risk of an impact on the spacecraft could not be ruled out, but that the impact energy would be low and the probability of a severe failure was very small.' In the worst case scenario MARSIS itself might be partially or completely lost, but there is a minimal risk to the other instruments onboard Mars Express. An early deployment is desirable from a scientific perspective, as the orbital path of Mars Express will allow radar measurements of the most interesting regions of the Red Planet from May 2005 onwards.