I took it as a challenge, so I built a probe with a downward facing grabber unit and two sets of landing struts, one higher than the other. I landed near the flag, scooted over it with rcs, and retracted the lower set of legs to drop the grabber down. It actually worked, I just had to use rcs to push the ship down to get it to grab the flag. Lifted off and brought it home to the space center as a souvenir!