Gravity Gradiometry For Lunar Surface Exploration

The first (Apollo) phase of Lunar surface exploration primarily employed geological surveying techniques (collecting rocks, taking photographs) to characterize the surface properties of the Moon near the landing sites. Future Lunar exploration will include activities which involve excavating the surface for various reasons, such as:

    • Drilling to extract core samples.
    • Collecting material for processing to extract resources such as oxygen.
    • Digging pits into which crew modules can be emplaced which will provide thermal and radiation shielding.
    • Collecting material for building berms to shield equipment and crew from rocks/dust entrained in the exhaust from landers.

It will be important to know the subsurface distribution of rock types and sizes within volumes of Lunar regolith that are being considered for such excavations, to avoid encountering rocks too large to excavate, or large enough/hard enough to damage excavation equipment. Geophysical surveying techniques may be used to collect this type of information.

One such well-know geophysical exploration technique uses a gravity gradiometer to measure one or more component of the tensor which characterizes the spatial gradient of gravitational force. Gedex is a Canadian leader in developing gravity gradiometers for terrestrial airborne surveying applications. This paper describes a concept for a gravity gradiometer suitable for mounting on a Lunar rover, suitable for collecting this type of information via geophysical traverses. This type of survey will also have considerable geoscientific value.