Stock Photo - 05/03/1998 ___ The orbiter Columbia approaches touchdown on Runway 33 of KSC´s Shuttle Landing Facility to complete the nearly 16_day STS_90 mission. Main gear touchdown was at 12:08:59 p.m. EDT on May 3, 1998, landing on orbit 256 of the mission. The wheels stopped at 12:09:58 EDT, completing a total mission time of 15 days, 21 hours, 50 minutes and 58 seconds. The 90th Shuttle mission was Columbia´s 13th landing at the space center and the 43rd KSC landing in the history of the Space Shuttle program. During the mission, the crew conducted research to contribute to a better understanding of the human nervous system. The crew of the STS_90 Neurolab mission include Commander Richard Searfoss, Pilot Scott Altman, Mission Specialists Richard Linnehan, D.V.M., Dafydd Dave Williams, M.D., with the Canadian Space Agency, and Kathryn Kay Hire, and Payload Specialists Jay Buckey, M.D., and James Pawelczyk, Ph.D