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 1986–88 hiatus when the shuttle fleet was grounded following the loss of "Challenger", but retained its original wing markings until its last overhaul (after STS-93), and its unique black chines for the remainder of its operational life.