 Complete the following phrase:  In 1983, Enterprise had its wing markings changed to match Challenger, and the NASA worm logotype on the aft end of the payload bay doors was changed from gray to black. Some black markings were added to the nose, cockpit windows and vertical tail to more closely resemble the flight vehicles, but the name Enterprise remained on the payload bay doors as there was never any need to open them. Columbia had its name moved to the forward fuselage to match the other flight vehicles after STS-61-C, during the 198688 hiatus when the shuttle fleet was grounded following the 