Hitting the random article button at Wikipedia can often yield very interesting results.
A launch loop or Lofstrom loop is a design for a belt based maglev orbital launch system that would be around 2,000 km (1,240 mi) long and maintained at an altitude of up to 80 km (50 mi). A launch loop would be held up at this altitude by momentum of the belt as it circulates around the structure, in effect it transfers the weight of the structure onto magnetic bearings at each end which support it.