Today I had two spaceships for flying to Mun but in the Orbit I noticed that my fuel was way to less, unfortunatley I could build a full orbit with the ships. So how to rescue them and bring them back to Kerbin, so they are not stranded in space? EVA from the spaceship and stand behind your spaceship and use the force of the Jetpack to lower your orbit as you want. If your jetpack fuel goes near zero, reenter your spaceship and let your Kerb' fill the jetpack and do the same again. This tactics rescued to of my finest astronauts!