Confirmed by NASA in 1983 as the first industrial payload specialist, Mr. Walker accompanied the McDonnell Douglas CFES equipment as a crew member on Space Shuttle missions 41-D, 51-D, and 61-B, accumulating 20 days of experience in space and traveling 8.2 million miles. Aboard these Space Shuttle missions Mr. Walker also performed early protein crystal growth experiments and participated as a test subject in numerous medical studies. Since 1986 Mr. Walker has served in various NASA study and review team capacities including as a member of the NASA Microgravity Material Science Assessment Task Force, the NASA Space Station Office Quick-is-Beautiful/Rapid Response Research Study Group, and the NASA Space Station Operations Task Force. He has served on the national panels of the NASA/Industry Manned Flight Awareness Program and the NASA/Industry Education Initiative.