The 7.5-cm-diameter cryo-drill has successfully drilled 47 meters beneath the surface in Greenland.

Shown during its descent into the Greenland surface, the cryo-drill tether supplies power, carries data, and removes meltwater for surface instruments.

The main goal of subsurface access is to develop technologies to explore the Martian subsurface. This includes ground-based subsurface mapping techniques such as ground penetrating radar devices; methods of physical access to subsurface samples such as coring and sampling drills; and subsurface instrumentation such as borehole spectrometers.

Some of these systems involve the development of science instruments that can be brought to a subsurface sample. Others bring samples from the subsurface to elements on the surface. Drilling depths of interest may be roughly classified as shallow (less than one meter), moderate (greater than one meter and less than 50 meters) and deep (greater than 50 meters). All of these technologies must function in the unique environment of the Martian subsurface. This drives the development of rugged, low-mass, low-power designs that must be highly autonomous.

Given the increased uncertainties associated with operating such systems, these tasks aim to bring enabling technologies to high Technology Readiness Levels (TRLs) so that they may be readily utilized by future missions. In most cases, achieving this high level of maturity will necessitate field testing as well as other relevant environmental tests.