A space-walking astronaut has become detached from her spaceship. She is floating in space with her handy tool that attached to her waist. Her toolbelt contains a big wrench. she is thinking about how she my get back to the ship which she can see 50 m from her current location.

Question

royalranger · Answer

Newtons 3rd law.

osprey · Answer

poor thing ... take careful aim with the wrench so that she's chucking it on the line of her and the spacecraft, and then fling it on that line. If she's lucky and hasn't panicked too much, the recoil momentum - see @royalranger - should shove her back to safety, and the medical centre for recovery from the shock.
Might help if she hadn't got detached in the first place, though .. years ago there was a US tv show called "lost in space" ... hmmm