One mustn't have radio waves flying about with a probe on.
The spring can be freed up by pushing on it with a probe.
Moonbase is going to do it again with a probe.
The information is gathered by "feeling" the surface with a mechanical probe.
With cameras and probes, data were collected from that planet.
They'll bring in an operator with a deep probe.
I can only get a true ground reading with a sonic probe.
With suitable probes, the method can be used on hot surfaces.
They feel a lot more can be done with robotic probes.