S89-41093 (9 Aug 1989) --- STS-28 Columbia, Orbiter Vehicle (OV) 102, mission specialist David C. Leestma relaxes in chair after donning launch and entry suit (LES) and launch and entry helmet (LEH). Technician in the background monitors LES systems. Leestma, along with fellow crewmembers, is participating in the terminal countdown demonstration test (TCDT) at the Kennedy Space Center (KSC) Operations and Checkout (O&C) Building. View provided by KSC with alternate number KSC-89PC-673.