(04/17/1998) --- STS-90 Mission Specialist Richard Linnehan, D.V.M., is assisted by NASA and USA closeout crew members immediately preceding launch for the nearly 17-day Neurolab mission. Investigations during the Neurolab mission will focus on the effects of microgravity on the nervous system. Linnehan and six fellow crew members will shortly enter the orbiter at KSC's Launch Pad 39B, where the Space Shuttle Columbia will lift off during a launch window that opens at 2:19 p.m. EDT, April 17