A Rotovator is is a spinning tether designed to take craft from a planetary surface to escape velocity in one easy step. This one is around Mars. There are plenty of arranged shuttle encounters and a few hair raising near-collisions. Three orbiting hanging tethers are included as well. V2.0 (February, 2011): contains additional features.
Mars from the Phobos Tether.
Mars from the Deimos Tether.
One of the shuttles on the Mars Station.
Two more shuttles from the center point on the Mars Station.
How to install add-ons? Find out here.