CAPE CANAVERAL, Fla. – NASA will begin the countdown for Space Shuttle Discovery’s STS-116 mission at 11 p.m. EST Monday, Dec. 4, at the T-43 hour point. During this mission, Discovery’s crew will rewire the International Space Station, bringing electrical power on line from solar arrays launched earlier this year.

The Kennedy Space Center, Florida, launch team will conduct the countdown from Firing Room 4 of the Launch Control Center. The countdown includes 27 hours, 36 minutes of built-in hold time leading to a preferred launch time at 9:35 p.m. on Thursday, Dec. 7. The launch window extends an additional five minutes.

A detailed list of launch countdown milestones and times is available at: http://www.nasa.gov/mission_pages/shuttle/news/index.html

This mission is the 117th space shuttle flight, the 33rd flight for Discovery and the 20th U.S. flight to the International Space Station. STS-116 is scheduled to last 12 days with landing at about 4:35 p.m. EST on Dec. 19 at Kennedy.

Discovery rolled into Kennedy’s Orbiter Processing Facility on July 17 after returning from its last mission, STS-121. The shuttle rolled out of the facility’s bay 3 and into the Vehicle Assembly Building on Oct. 31. While in the building’s high bay 3, Discovery was mated to its modified external fuel tank and solid rocket boosters. The entire space shuttle stack was transferred to Launch Pad 39B on Nov. 9.

The STS-116 crew consists of Commander Mark Polansky, Pilot Bill Oefelein and mission specialists Bob Curbeam, Joan Higginbotham, Nicholas Patrick, Christer Fuglesang of the European Space Agency and Sunita Williams. Williams will remain aboard the station to begin a six-month stay. European Space Agency astronaut Thomas Reiter, aboard the station since July, will return to Earth on Discovery.

During STS-116, Discovery’s astronauts will completely rewire and activate the station’s electrical and thermal control systems. The crew will deliver and install the P5 truss segment between the station’s existing P3/P4 and P6 truss segments during two of three planned spacewalks. Installation of the P5 truss will allow the solar arrays on the P3/P4 and P6 truss segments to operate and rotate without interfering with each other. The P5 truss will act as a conduit that will transmit power and data from the P6 segment to the other segments on the station.

For information about the STS-116 crew and the mission, visit: http://www.nasa.gov/shuttle

STS-116 LAUNCH COUNTDOWN MILESTONES (All times Eastern)

Launch-3 Days (Monday, Dec. 4)

  • Prepare for the start of the STS-116 launch countdown
  • Perform the call to stations (10:30 p.m.)
  • Countdown begins at the T-43 hour mark (11 p.m.)
  • Begin final vehicle and facility closeouts for launch
  • Check out backup flight systems

Launch-2 Days (Tuesday, Dec. 5)

  • Review flight software stored in mass memory units and display systems
  • Load backup flight system software into Discovery’s general purpose computers
  • Remove flight-deck platforms (7:30 a.m.)
  • Begin preparations to load power reactant storage and distribution system (9 a.m.)
  • Activate and test navigational systems (noon)
  • Flight deck preliminary inspections complete (3 p.m.)
  • Enter first built-in hold at T-27 hours for duration of 4 hours (3
  • p.m.)
  • Clear launch pad of all non-essential personnel
  • Perform test of the vehicle’s pyrotechnic initiator controllers

Resume countdown at T-27 hours (7 p.m.)

Launch-1 Day (Wednesday, Dec. 6)

  • Begin operations to load cryogenic reactants into Discovery’s fuel
  • cell storage tanks (3 a.m.)
  • Enter 4-hour built-in hold at T-19 hours (3 a.m.)
  • Demate orbiter mid-body umbilical unit (3:30 a.m.)
  • Resume orbiter and ground support equipment closeouts

Resume countdown at T-19 hours (7 a.m.)

  • Final preparations of the shuttle’s three main engines for main propellant tanking (7 a.m.)
  • Begin filling pad sound suppression system water tank (9 a.m.)
  • Pad sound suppression system water tank filling complete (noon)
  • Close out the tail service masts on the mobile launcher platform
  • Begin star tracker functional checks (2:50 p.m.)

Enter planned hold at T-11 hours for 13 hours, 40 minutes (3 p.m.)

  • Activate orbiter’s inertial measurement units
  • Activate the orbiter’s communications systems
  • Install film in numerous cameras on the launch pad (4:25 p.m.)
  • Flight crew equipment late stow (8:40 p.m.)

Launch Day (Thursday, Dec. 7)

  • Move Rotating Service Structure to the park position (12:27 a.m.)
  • Perform ascent switch list
  • Fuel cell flow-through purge complete

Resume countdown at T-11 hours (4:40 a.m.)

  • Activate the orbiter’s fuel cells (5:50 a.m.)
  • Clear the blast danger area of all non-essential personnel
  • Switch Discovery’s purge air to gaseous nitrogen (6:40 a.m.)

Enter planned 2-hour built-in hold at the T-6 hour mark (9:40 a.m.)

  • Launch team verifies no violations of launch commit criteria prior to cryogenic loading of the external tank
  • Clear pad of all personnel
  • Chilldown of propellant transfer lines (11:40 a.m.)

Resume countdown at T-6 hours (11:40 a.m.)

  • Begin loading the external tank with about 500,000 gallons of cryogenic propellants (about 11:50 a.m.)
  • Complete filling the external tank with its flight load of liquid
  • hydrogen and liquid oxygen propellants (about 2:40 p.m.)
  • Final Inspection Team proceeds to launch pad

Enter planned 3-hour built-in hold at T-3 hours (2:40 p.m.)

  • Perform inertial measurement unit preflight calibration
  • Align Merritt Island Launch Area tracking antennas
  • Perform open loop test with Eastern Range

Resume countdown at T-3 hours (5:40 p.m.)

  • Crew departs Operations and Checkout Building for the pad (5:45 p.m.)
  • Complete closeout preparations in the White Room
  • Check cockpit switch configurations
  • Flight crew begins entry into the orbiter (about 6:15 p.m.)
  • Astronauts perform air-to-ground voice checks with Launch and Mission Control
  • Begin to close Discovery’s crew hatch (7:30 p.m.)
  • Begin Eastern Range final network open loop command checks
  • Perform hatch seal and cabin leak checks
  • Complete White Room closeout
  • Closeout crew moves to fallback area
  • Primary ascent guidance data is transferred to the backup flight system

  • Enter planned 10-minute hold at T-20 minutes (8:20 p.m.)
  • NASA test director conducts final launch team briefings
  • Complete inertial measurement unit preflight alignments
  • Resume countdown at T-20 minutes (8:30 p.m.)
  • Transition the orbiter’s onboard computers to launch configuration
  • Start fuel cell thermal conditioning
  • Close orbiter cabin vent valves
  • Transition backup flight system to launch configuration
  • Enter estimated 46-minute hold at T-9 minutes (8:41 p.m.)
  • Launch director, Mission Management Team and NASA test director
  • conduct final polls for “go/no go” to launch
  • Resume countdown at T-9 minutes (about 9:27 p.m.)

  • Start automatic ground launch sequencer (T-9 minutes)
  • Retract orbiter crew access arm (T-7:30)
  • Start mission recorders (T-6:15)
  • Start auxiliary power units (T-5)
  • Arm solid rocket booster and external tank range safety safe and arm devices (T-5)
  • Start liquid oxygen drainback (T-4:55)
  • Start orbiter aerosurface profile test (T-3:55)
  • Start main engine gimbal profile test (T-3:30)
  • Pressurize liquid oxygen tank (T-2:55)
  • Begin retraction of the gaseous oxygen vent arm (T-2:55)
  • Fuel cells to internal reactants (T-2:35)
  • Pressurize liquid hydrogen tank (T-1:57)
  • Deactivate bi-pod heaters (T-1:52)
  • Deactivate solid rocket booster joint heaters (T-1)
  • Orbiter transfers from ground to internal power (T-0:50 seconds)
  • Ground launch sequencer go for auto sequence start (T-0:31 seconds)
  • Booster gimbal profile (T-0:21 seconds)
  • Ignition of three space shuttle main engines (T-6.6 seconds)
  • Booster ignition and liftoff (T-0)

CREW FOR MISSION STS-116

  • Commander: Mark Polansky
  • Pilot: Bill Oefelein
  • Mission Specialist (MS1): Nicholas Patrick
  • Mission Specialist (MS2): Bob Curbeam
  • Mission Specialist (MS3): Christer Fuglesang
  • Mission Specialist (MS4): Joan Higginbotham
  • Mission Specialist (MS5up): Sunita Williams
  • Mission Specialist (MS5down): Thomas Reiter