Launch Pad 39A has been cleared of personnel today so oxidizers can be loaded into the orbital maneuvering system and reaction control system tanks on space shuttle Atlantis. The OMS and RCS are thruster systems used predominantly to steer the shuttle in space. The OMS engines are used to slow the shuttle down before it enters the atmosphere for landing.
Both of the units use hypergolic propellants, which are chemicals that burn on their own when they come in contact with each other. That is different from the oxygen and hydrogen mixture that fuels the shuttle’s three main engines at launch.
Atlantis is being prepared for a launch targeted for 2:28 p.m. EST Nov. 16 from NASA’s Kennedy Space Center in Florida.
The STS-129 astronauts continue practicing their launch routine, as well. They are rehearsing ascent procedures during part of the day in the motion base simulator at NASA’s Johnson Space Center in Houston.