InSight-MPS

The problem addressed in this proposal is to understand the penetration behaviour of a mole-type penetrator in a planetary soil. Such an instrument has been developed over the recent years in the frame of the HP3 project and will now form a part of the payload of the NASA InSight mission to Mars, which will be launched in 2016.

The key activity of the project will be the development of several models to describe and predict the motion of the mole from the planetary surface down to a depth of several metres. To reach this goal, three different approaches will be studied:

1. A so-called Pile Driving method, where existing algorithms used in geotechnical engineering will be modified and adapted to the geometry and size of the HP3/InSight mole. This type is model is easy to implement in a numerical algorithm because it demands low computational resources. For the investigation of dynamical processes a competitive comparison will be made early in the project and one of the following methods will be selected for further use.
2. A Discrete Element Method (DEM), which should be able to study the influence of different particle size distributions in the planetary soil on the penetration performance of the mole. This method is numerically most demanding, but can be used to parameterise dynamical processes needed in other models.
3. A Material Point Method, which demands less computational resources than a DEM method, but still may be able to describe the behaviour of a soil in response to a hammer stroke in enough detail to allow reasonable predictions.

The results of the model calculations will be compared to measurement results being performed by other partners in the InSight/HP3 team.

Based on this comparison a Program Package allowing a "best guess" prediction of the penetration behaviour of the mole during its movement into the subsurface of Mars will be provided.

Such a numerical tool is of importance for the InSight mission both during the development phase (from now to launch) and after a successful landing and mole deployment, where it can be used to evaluate the soil parameters of the Mars regolith.

Coordinator

Austrian Academy of Sciences

Austrian Academy of Sciences
Dr. Ignaz Seipel-Platz 2
A-1010 Vienna
Web: www.oeaw.ac.at