Since the end of the cold war and with it the associated desire for a space race it has become increasingly important to make sure that space exploration delivers good value for money. In the current economic climate this is particularly important, and has lead to agencies looking for mission types that go beyond the traditional approached of manned missions, satellites and soft landers. Missions such as the ill fated Beagle 2 and the much more successful Deep Impact and LCROSS spacecraft have demonstrated the potential of such efforts.
We have been working with Astrium, MSSL, QinetiQ and ESA over a number of years to develop a penetrator concept for exploring planetary bodies throughout the solar system. The idea is to pack scientific instruments into a hardened steel shell and embed them below the surface of the planet or moon of interest (the currently envisaged target is Europa). This is a very cost effective method of delivering instrumentation (as it doesn't have to be soft landed) and additionally allows for sub-surface science to be conducted (which is generally not possible by other methods).
In the laboratory the aim has been to investigate small scale survivability of the penetrator system. Specifically this has meant impacting a number of things in our gas gun facilities:
- Impacting the components for the mission in a representative way to ensure they are able to withstand the high acceleration loadings expected during planetary impact.
- The penetrator will have a dual skin design (to provide thermal isolation) with the inner shell held away from the outer by Torlon springs. The springs were shot in the gun to investigate their properties under high rate loading.
- In order to obtain samples from the planetary body it is necessary to have a hole in the outer steel shell. Various scaled penetrators were impacted to determine the level of deformation that could be expected.
Subsequent to the laboratory investigations the penetrator system was tested at a large scale at the Pendine Test Range in Wales. This facility (operated by QinetiQ) consists of a rocket sled which accelerates
The early concept for the penetrators is detailed in the following paper:
Specific details of the Europa penetrators are here:
R.A. Gowen, et al, Penetrators for in situ subsurface investigations of Europa, Advances in Space Research, Volume 48, Issue 4, 16 August 2011, Pages 725-742, ISSN 0273-1177, http://dx.doi.org/10.1016/j.asr.2010.06.026.
Various news articles have been generated, a selection of which are below: