Digging For Who Knows What in the Solar System

The University of Arkansas just got funding to make a giant probe. This article announces that NASA has funded a project to try and build a ground probe for the next rover mission. This probe would be of indeterminate length, but at least a foot. What is interesting about it is that all along the probe's length will be quartz windows and fiber optic cable. This will allow all of the spectroscopy to occur on the rover itself. This is good both, because the rover will already have a mass spectroscoper, and because it prevents the probe from somehow altering the readings. The probe's heat, if it did its own processing, could actually distort the readings when the ground is really cold (which it wil be in any part of the solar system a rover could survive in). All in all this is a very good project to fund, and it will presumably someday confirm that there really is water trapped under the surface of Mars. The only problem as I see it, is that they have no idea how much force it will take to drive this probe into any sort of ground. Given that the ground in question will be frozen this would seem to be a big issue. After all, last time I checked the rovers were not that strong. I can just see them needing to use small rockets to drive this thing into the ground, and then we would never get it out again.