Webb's orbit will place it out of reach of repair crews. The telescope will be located beyond the Moon, so far away even astronauts would be unable to access it. Ensuring perfect control of the telescope from the confines of Earth is vital.
At Northrop Grumman, engineers are testing the telescope's responses to its controllers and performing simulations of the conditions it would face in orbit. Making sure the telescope works on the ground is critical to guaranteeing it'll work in space.
NASA and Mary Estacion (STScI)
Publication: August 18, 2010