Concept evaluation of Mars drilling and sampling instrument

Abstract

The search for possible extinct or existing life is the goal of the exobiology investigations to be undertaken during future Mars missions. As it has been learnt from the NASA Viking, Pathfinder and Mars Exploration Rover mission, sampling of surface soil and rocks can gain only limited scientific information. In fact, possible organic signatures tend to be erased by surface processes (weathering, oxidation and exposure to UV radiation from the Sun).

The challenge of the missions have mostly been getting there; only roughly one third of all Mars missions have reached their goal, either an orbit around the planet, or landing to the surface. The two Viking landers in the 1970's were the first to touch down the soil of Mars in working order and performing scientific studies there. After that there was a long gap, until 1997 the Pathfinder landed safely on the surface and released a little rover, the Sojourner. In 2004 other rovers came: the Mars Exploration Rover Spirit and a while after that, the sister rover Opportunity. These five successful landings are less than half of all attempts to land on Mars. Russia, Europe and the United States have all had their landers, but Mars is challenging. Even Mars orbit has been tough to reach by many nation's orbiters. It is then understandable that of these five successful landings, performed by National Aeronautics and Space Administration (NASA), there have not yet been very complicated mechanical deep-drilling instruments onboard. The risks to get there are great, and the risk of malfunctioning of a complicated instrument there is also high. Another reason to avoid a deep-driller from the lander payload is simply the mass constrains. A drill is a heavy piece of payload, and the mass allocations for scientific instruments are small.

In the launch window of 2009, both European Space Agency (ESA) and NASA have their plans to send a rover to Mars. Both of them will include some means to analyse the subsurface material. ESA's rover, called the ExoMars rover, will carry a deep-driller onboard in its Pasteur payload. At the time of writing this thesis, an exact definition of the Pasteur drill has not yet been defined.

The author of this thesis has studied the driller instruments in his past work projects and in his doctoral studies. The main focus of this thesis is to analyse the feasibility of different drill configurations to fit to the requirements of the ExoMars' Pasteur payload drill by using the information gathered from the past projects. In this thesis, the author introduces a new concept of a robotic driller, called the MASA drill. The MASA drill fulfils the needs for the drill instrument onboard the Pasteur payload. The main study in this thesis concentrates on design work of the MASA drill, as well as analysis of its operation and performance capabilities in the difficult task of drilling and sampling.