Bags inflate once the released heat shield

The Europeans have missed the boat of the Moon, will also miss the March train Planned for a long time, the Ministerial Council of the European Space Agency (ESA) should confirm tomorrow in the Hague (see pages 12 and 25) the launch of the Exomars mission. Europe trépignait to finally embark on the conquest of the solar system. His suitcases were almost ready: a satellite was to take a capsule to the red planet, the drop to the ground, releasing a robotic rover that would start the tour of the owner.

Since then, the financial crisis came threaten the 1.2 billion euros promised to the program. The mission should have starting in 2013, its take-off is now postponed to early 2016 to spread the budgets and capture the next niche of March approaches. The Director General of ESA attempts to embark on the Russians and the Americans in the adventure to bring the invoice under EUR 1 billion. The Agency is even prepared to sacrifice a part of the scientific instrumentation on-board to lighten even the suitcases.

Going on to a new European space fiasco Twenty years after the abandonment of the shuttle Hermes, which was to compete with the American Shuttle, Europe moves again of his daring to compete with Nasa. Mid-2007, ESA had revised upward its Martian ambitions. His project was originally a small scientific payload of 8 kilos. Now the 25 kg, with 16.5 pounds on the rover to approach. This triple is heavy with consequence: the rover weighs 300 kg, the mass of the atterisseur rises to 1,200 kilos and bearer passes to 5 tons. The estimated budget doubled course in the meantime, and its launch can no longer simply the proposed Russian economic launcher at the beginning. The madness of the quantities, somehow.

Real skills

One year after the return to Earth is bitter. There is more money into the coffers of the States, but the temptation is strong among the members of the ESA to afford a bit of dream in the Hague. Europe dominates the commercial rocket industry, Kourou has one of the best space bases in the world, produces the most sharp satellites for science or industry. The Huygens capsule carried out in 2005 a spectacular landing on Titan, the satellite of Jupiter. Its Mars Express and Venus Express probes were able to impeccable put in orbit in the solar system. But that's it, play in the Court of the great, to touch March. All swear that it is the essential step for a place in the manned mission which will bring in the 21st century some cosmonauts to Earth cousin.

The abandonment of the Martian Dreams would be harder, that the project has already well matured. At the last ministerial meeting in 2005, ESA had received authorization to begin work. Since last April, developments have been signed with the Franco-Italian contractor Thales Alenia Space. Not to mention years of pre-study. "It is ten years hopefully go on Mars", said Patrick Mottey from Thales Alenia Space. "We studied more than 250 configurations," explains Don McCoy, head of programme at ESA. So far, ESA has committed only EUR 80 million, including a EUR 60 million contract for the industry. Thales Alenia Space said have already invested some EUR per year for the project.

A milestone in orbit

"We want the experience of landing on Mars," said Don McCoy. However, the ESA and its industry partners have no intention to reinvent the wheel. Exomars resumed the recipes that have worked in the American missions. A capsule inhibits the atmosphere with a shield and a parachute, strikes the ground and then releases a rover to explore. "We take some of the techniques in the public domain since Apollo, as atmospheric re-entry aerodynamics." "We also have international cooperation," explains Don McCoy. The ESA may also rely on the work carried out for the mission Huygens re-entry into the atmosphere of Titan. EADS had thus operated his experience of French ballistic missile designer to develop the shield for re-entry. But the surprises will not fail. March has a less dense than Titan atmosphere, it is more difficult to stop. At Thales Alenia Space, it takes seriously the risk that the parachutes kink or that they separate poorly from the lander.

As ESA decided in some areas to experiment with his own path. Unlike the other missions, Exomars is entered not directly the atmosphere in its approach to the red planet. The probe will remain in orbit about ten months before dropping a lander. "We want to avoid the period of dust storms which will take place in the Martian atmosphere at our arrival."

Innovations

The absorption of the shock on landing also appeal to a novel by dégonflables air cushion damping system. Engineers believe that it offers a better compromise of mass than the final braking by the only spacecraft as in the case of the US Phoenix mission. Bags inflate once the released heat shield. In contact with the ground, they host the shock immediately releasing the trapped air. This technology would provide greater security that cushions and previous missions rovers Americans so to touch more than 20 times. Industrialists have validated the relevance of this new system with many trials from a crane.

The European space also wants to innovate in the field of cold electronics. Engineers consider to locate the embedded electronics of the rover on the outside, which means temperatures of less 100 degrees Celsius.

Europeans must also prove their mastery of the rover. Here again, the American configuration 6 wheeled was taken over. Industrialists have already built a mock-up of the vehicle, but the most delicate remains to be done: the robot navigation software. The Martian terrain is rugged enough to disrupt the progress of such gear. The CNES is working for years on these technologies for robotics. Several European universities are also involved. It is certainly the latest technology of the mission that engineers decide, ensures Don McCoy. Previous calendar made these very strained choices. Engineers breathe better today... If the program is confirmed in the Hague.