(04/03/2002) -- Space Shuttle Atlantis is revealed as the Rotating Service Structure rolls back into launch position. The RSS provides protected access to the orbiter for changeout and servicing of payloads at the pad. The structure has access platforms at five levels to provide access to the payload bay. The Shuttle rests on the Mobile Launcher Platform (MLP), which straddles the flame trench below. The flame trench is part of the Flame Deflector System that insulates pad structures from the intense heat of the launch. Above the golden external tank is the vent hood (known as the 'beanie cap') at the end of the gaseous oxygen vent arm. Vapors are created as the liquid oxygen in the external tank boil off. The hood vents the gaseous oxygen vapors away from the Space Shuttle vehicle. Mission STS-110 is scheduled to launch April 4 on its 11-day mission to the International Space Station