Columbia's cockpit windows are protected by plastic and tape as it awaits its next mission in Orbiter Processing Facility bay 1. Photo: Steven Young/Spaceflight Now

On April 12, 1981, the space shuttle Columbia was at the center of worldwide attention, as years of development and planning came to fruition with the flight of the world's first reusable spacecraft.

Twenty years later, the venerable spaceplane quietly celebrated the anniversary of its maiden voyage in Orbiter Processing Facility (OPF) bay 1 at the Kennedy Space Center. Columbia's next journey into space is seven months or more away and little activity was scheduled in the hangar as workers concentrated on its three busier sisterships, engaged in the assembly of the International Space Station.

Columbia recently returned from a year-long overhaul in California, where it was fitted with upgraded systems and inspected from tip to tail.

Spaceflight Now and a handful of other news organizations toured OPF bay 1 as part of NASA's low-key commemoration of the anniversary. We captured the occasion in two virtual reality scenes on the floor on the building, beneath the orbiters belly and on the 13th level above the open payload bay. Click on the images below to see the VR scenes. You can download free QuickTime software to view these files.