Add a single scientist

The scientist heads directly for the base. When he (or she!) gets there, he
starts to repair it. After a short delay, the repairs are complete and the base
regains some health.
Air-drop the scientists in.

The scientists now arrive in little capsules dropped from above, much like the
shield recharges. You can't collect these yourself though - they fall to the
seafloor, then the scientist jumps out and heads for the base.

The scientists - and their capsules - show up on your radar now too.
Update the TODO