Space Shuttle Discovery. Image credit: NASA/KSC. Click to enlarge
NASA will begin the countdown for the second Return to Flight launch attempt of Space Shuttle Discovery at noon EDT, July 23, 70 hours before liftoff. On mission STS-114, Discovery’s seven-member crew will test new equipment and procedures to increase the safety of the Shuttle and deliver spare parts, water and supplies to the International Space Station.
The Kennedy Space Center launch team will conduct the countdown from Firing Room 3 of the Launch Control Center. The countdown includes nearly 28 hours of built-in hold time, leading to a preferred launch time at about 10:39 a.m. July 26 with a launch window extending about five minutes.
This historic mission is the 114th Space Shuttle flight and the 17th U.S. flight to the International Space Station. STS-114 is scheduled to last about 12 days, with a planned KSC landing at about 5:46 a.m. EDT Aug. 7.
Discovery’s first launch attempt was July 13 and was postponed at 1:30 p.m. EDT. During countdown activities, a low-level fuel cut-off sensor located inside the External Tank failed a routine prelaunch check. The sensor protects a Shuttle’s main engines by triggering their shut- down in the event that fuel runs unexpectedly low. The sensor is one of four inside the liquid hydrogen section of the External Tank.
Discovery rolled into KSC’s Orbiter Processing Facility (OPF) on Aug. 22, 2001, after returning from its last mission STS-105 in August 2001 and undergoing an Orbiter Major Modification period. The Shuttle rolled out of OPF bay 3 and into the Vehicle Assembly Building (VAB) on March 29 this year. While in VAB high bay 1, Discovery was mated to its redesigned External Tank and Solid Rocket Boosters. The entire Space Shuttle stack was transferred to Launch Pad 39B on April 7.
In order to allow for the addition of a new heater to the External Tank, Space Shuttle Discovery was rolled back to the VAB on May 26 for that modification to be performed. Discovery was removed from its External Tank and attached to a new tank originally scheduled to fly with orbiter Atlantis on mission STS-121, the second Return to Flight mission.
Discovery was rolled back out to Launch Pad 39B on June 15 in preparation for the July launch window.
On mission STS-114, the crew will perform inspections on orbit for the first time of all of the Reinforced Carbon-Carbon (RCC) panels on the leading edge of the wings and the Thermal Protection System tiles using the new Canadian-built Orbiter Boom Sensor System and the data from 176 impact and temperature sensors. Mission specialists will also practice repair techniques on RCC and tile samples during a spacewalk in the payload bay.
In the payload bay, the Multi-Purpose Logistics Module Raffaello, built by the Italian Space Agency, will carry 11 racks with supplies, hardware, equipment and the Human Research Facility-2.
During two additional spacewalks, the crew will install the External Stowage Platform-2, equipped with spare part assemblies, and a replacement Control Moment Gyroscope contained in the Lightweight Multi-Purpose Experiment Support Structure. The STS-114 crew includes Commander Eileen Collins, Pilot James Kelly, and Mission Specialists Soichi Noguchi, Stephen Robinson, Andrew Thomas, Wendy Lawrence and Charles Camarda.
For the latest information on NASA’s Return to Flight efforts, visit: http://www.nasa.gov/returntoflight
Original Source: NASA News Release