A testing ground for fundamental physics: Gravity Probe B and other fundamental physics experiments in space

This presentation gives results from the Gravity Probe B Relativity Mission and some of the lessons learned on orbit. Space enables new fundamental physics experiments in General Relativity and other fields in 8 distinct ways. I shall illustrate the richness of opportunity by reviewing a number of existing and future missions with comments on the complications as well as the simplifications brought about by Space and the vital benefits of strong collaboration between physicists and engineers.