STS-68 was a human spaceflight mission using Space Shuttle Endeavour that launched from Kennedy Space Center, Florida on September 30, 1994.
Crew
Launch
Launch September 30, 1994, at 7:16:00.068 am EDT from Kennedy Space Center Launch Pad 39-A. The Launch window opened at 7:16 am EDT with a 2-hour-30-minute window. Orbiter mass at liftoff was 247,129 pounds (112,096 kg) including payload. Total vehicle mass was 2,045,879 kilograms (4,510,391 lb). Payload liftoff mass 12,511 kilograms (27,582 lb). Main Engine Cutoff (MECO) was at an apogee of 115 nautical miles (213 km; 132 mi) and a perigee of 28 nmi (52 km; 32 mi) at MET of 8 min 35 s with Endeavour traveling at 25,779 ft/s (7,857 m/s). No OMS-1 burn was required. OMS-2 burn was 1 min 42 s (164 ft/s or 50 m/s) at MET 33 min. The launch was originally scheduled August 18, 1994, but there was an RSLS abort at T−1.9 s, after all three main engines ignited – the fifth (and final) time in the shuttle program where an RSLS abort occurred after main engine ignition. Previous aborts occurred on STS-41-D, STS-51-F, STS-55 and STS-51. The automatic abort was initiated by the onboard General Purpose Computers (GPC) when the discharge temperature on MPS Main Engine #3 High Pressure Oxidizer Turbopump (HPOT) exceeded its redline value. The HPOT typically operates at 28,120 rpm and boosts the liquid oxygen pressure from 422 to 4,300 psi (2.91 to 29.6 MPa). There are 2 sensor channels measuring temperature on the HPOT. The B channel indicated a redline condition while the other was near redline conditions. The redline limit to initiate a shutdown is at 867 K. This limit increases to 980 K at T−1.3 s (5.3 s after Main Engine Start). Main Engine #3 (SN 2032) has been used on two previous flights with 2,412 seconds (40 min) of hot-fire time and a total of eight starts. This was the first flight for the HPOT on Main Engine (SSME) #3. Mission specialist Dan Bursch became the only astronaut to experience two RSLS aborts, having previously experienced one on STS-51. A new launch date was set for early October and then moved up to late September. The procedure that has been used on previous aborts treats an RSLS abort after SSME ignition as a launch and to require a complete engine reinspection. A rollback of Endeavour to the VAB was done on August 24, 1994. Afterwards, Endeavour's SSMEs were removed and inspected. Three flight certified SSMEs (removed from the Atlantis STS-66 mission) were installed on the orbiter and Endeavour was rolled back to the launch pad on September 13, 1994. SSME #3 was shipped to the Stennis Space Center in Mississippi for test stand firing over the Labor day weekend (September 5, 1994). The engine was later flown on STS-70 in 1995. Transatlantic Abort Landing (TAL) sites for the initial launch attempt were Zaragoza, Spain, Moron, Spain and Ben Guerir, Morocco. Abort Once Around landing site was White Sands Space Harbor, New Mexico, USA.
Landing Landing October 11, 1994, 1:02:09 pm EDT. Edwards Air Force Base concrete Runway 22. Endeavour did an OMS deorbit burn at 12:09 pm EDT about 4,600 miles (7,400 km) from the landing strip at Edwards Air Force Base. The burn lasted 2 min 17 s which lowered Endeavour's velocity 232 ft/s (71 m/s). Astronaut John Casper flew the shuttle training aircraft at Edwards and said the weather was clear with light winds. Approach was from the southwest with a right overhead turn of 280 degrees. Nose wheel touchdown at 13:02:21 EDT. Wheel stop at 13:03:08 EDT. Rollout was approximately 8,495 feet (2,589 m) down the runway. Landing speed at main touchdown was approximately 265 mph (426 km/h). Orbiter landing mass was 100,709 kilograms (222,025 lb). Payload landing mass was 12,511 kilograms (27,582 lb). Landing was originally scheduled for KSC, October 11, 1994, at 11:36 am EDT. The KSC landing attempts on that date were waved off due to cloud cover over the Shuttle Landing Facility.
Crew seat assignments
Mission highlights
September 30, 1994 (Flight Day 1) On Friday, September 30, 1994, at 9 am CST, STS-68 MCC Status Report #1 reported:
The Flight Control team in Houston gave the "Go for Orbit Operations" just before 8 am. The crew then began setting up the experiment and systems hardware aboard Endeavour. The primary payload on this flight is the Space Radar Laboratory (SRL-2), making its second flight to study the Earth's environment. Experiment operations will be conducted around the clock on this flight, with the astronauts divided into two teams. Commander Michael A. Baker, pilot Terrence W. Wilcutt and mission specialist Peter J. K. Wisoff are the "red team". Mission specialists Daniel W. Bursch, Thomas D. Jones and Steven L. Smith are the "blue team". On Friday, September 30, 1994, at 5 pm CDT, STS-68 MCC Status Report #2 reported:
Shortly after 4 pm that day, flight controllers reported that the on-orbit checkout of the Spaceborne Imaging Radar-C (SIR-C) and the Synthetic Aperture Radar (X-SAR) had been completed, and that the primary SRL-2 instruments were ready for operation. Throughout the checkout, data takes were recorded over a number of sites, including Raco, Michigan; Bermuda; Bebedouro, Brazil; the Northeast Pacific Ocean and the Juan de Fuca Strait, between the United States and Canada. In addition to the prime payload, Wilcutt also activated the Commercial Protein Crystal Growth Experiment, the Cosmic Radiation Effects and Activation Monitor, and checked on the mouse-ear cress seedlings growing in the CHROMEX-05 experiment. The crew successfully engineered an in-flight maintenance procedure to get additional cooling air to the CPCG apparatus after higher than desired temperatures were noted by crystal growth sensors.
October 1, 1994 (Flight Day 2) On Saturday, October 1, 1994, at 9 am CDT, STS-68 MCC Status Report #3 reported:
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