IDENTIFICATION OF THE FORCES BETWEEN REGOLITH AND A RECIPROCATING DRILL-HEAD: PERSPECTIVES FOR THE EXPLORATION OF MARTIAN REGOLITH
Gouache, T, Gao, Y, Frame, T, Coste, P and Gourinat, Y IDENTIFICATION OF THE FORCES BETWEEN REGOLITH AND A RECIPROCATING DRILL-HEAD: PERSPECTIVES FOR THE EXPLORATION OF MARTIAN REGOLITH In: 62nd International Astronautical Congress, 2011-10-03 - 2011-10-07, Cape Town, South Africa.
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Official URL: http://www.iafastro.org/
The large success of Mars exploration missions, such as the NASA Mars Exploration Rovers, Pathfinder and Viking I and II, have allowed a widespread access to the top layer of Martian regolith. However, no exploration deeper than the few centimetres allowed by the scoop of Phoenix has been conducted on Mars. The potential discoveries that will follow from access to the Martian sub-surface (for example, the presence or absence of extinct life forms and of resources for future human exploration; a better understanding of Martian and Solar System history) require the development of new tools and a better understanding of their interaction with regolith to increase their performance and reliability. A promising new drilling methodology, dual reciprocating drilling (DRD), was tested in regolith and showed higher penetration than static penetration. DRD is conducted by two half-cone drillheads, with back-ward facing teeth, moved back and forth in opposition one to another (no rotation). To gain a better understanding of the forces acting on each half-drill-bit and the influence of slippage on drilling performance, a mono-block drill-head, with the same shape as the DRD drill-head, was tested in static and alternating penetration in two different regolith simulants. The forces acting on it were measured. These novel experimental observations allowed to revise the penetration model of DRD in regoliths and to illustrate the importance of lateral forces in the drilling process. To complement the experimental campaign and to gain a better insight on the regolith kinematics around the reciprocating drill-head, numerical simulations were developed. The discrete element method was chosen to simulate the complex behaviour of regolith. It was implemented within the commercial software Impetus-AFEA. The advantage of using this platform is its ability to use the power of graphical processing units (GPU) to cope with a very large number of elements within reasonable computation times. These numerical simulations allowed to confirm the importance of the lateral forces in DRD. They are also one of the first DEM simulations with more than one million particles on a single desktop computer and pave the way to highly efficient numerical simulations.
|Item Type:||Conference or Workshop Item (Paper)|
|Additional Information:||Paper presented at the 62nd International Astronautical Congress, 3-7 October, Cape Town, South Africa. Copyright ©2011 by the International Astronautical Federation. All rights reserved.|
|Divisions:||Faculty of Engineering and Physical Sciences > Electronic Engineering > Surrey Space Centre|
|Deposited By:||Symplectic Elements|
|Deposited On:||17 May 2012 11:37|
|Last Modified:||24 Apr 2013 02:34|
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