A HIGH-ENERGY SAMPLE RETURN EARTH RE-ENTRY DEMONSTRATOR TO ADDRESS PLANETARY PROTECTION ISSUES

摘要

For many of the proposed planetary exploration missions, robotically collected sample materials must be returned to Earth for more detailed analysis. For the more interesting locations in the solar system, full planetary protection guidelines must be taken into account to prevent cross contamination. So far, few missions have demonstrated re-entry from interplanetary space, which requires a considerably greater velocity change than the more common Earth orbit re-entry missions, and so far none have dealt with the planetary protection issues. Missions such as the proposed Mars Sample Return mission must depend on reliable systems to carry out a sample return. Such a complex safety critical system can of course not be used for the first time on a real mission, nor can it be tested under Earth laboratory conditions. This paper proposes a design concept for a European Space Agency testbed to help validate the necessary technology. The spacecraft will carry scientific instruments to help characterise the environment, so that subsequent missions can rely on this. The proposed mission is launched into Earth orbit, and it carries an upper stage to propel it to interplanetary speeds, before being re-entered into the Earth's atmosphere. The proposed re-entry probe weighs just 45kg, and carries a sealed container with up to 1kg sample material. Design trades related to the probe design and the recovery operation is discussed. The paper concludes that the demonstration mission will allow many issues and risks in sample return missions to be rehearsed and retired.