(06/21/2001) -- Atop the mobile launcher platform, Space Shuttle Atlantis sits on Launch Pad 39B after rollout from the Vehicle Assembly Building. Seen on either side of the orbiter’s tail are the tail service masts. They support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft umbilicals. To the left of the orbiter is the white environmental chamber (white room) that mates with the orbiter and holds six persons. It provides access to the orbiter crew compartment. In the background is the Atlantic Ocean. The Shuttle is targeted for launch no earlier than July 12 on mission STS-104, the 10th flight to the International Space Station. The payload on the 11-day mission is the Joint Airlock Module, which will allow astronauts and cosmonauts in residence on the Station to perform future spacewalks without the presence of a Space Shuttle. The module, which comprises a crew lock and an equipment lock, will be connected to the starboard (right) side of Node 1 Unity. Atlantis will also carry oxygen and nitrogen storage tanks, vital to operation of the Joint Airlock, on a Spacelab Logistics Double Pallet in the payload bay. The tanks, to be installed on the perimeter of the Joint Module during the mission’s spacewalks, will support future spacewalk operations and experiments plus augment the resupply system for the Station’s Service Module