yee@trident.arc.nasa.gov (Peter E. Yee) (05/29/90)
Kennedy Space Center Shuttle status - Sunday, May 27, 1990 11 am LAUNCH MINUS THREE DAYS STS-35 - COLUMBIA (OV 102) - LAUNCH PAD 39-A The STS-35 launch countdown began on time today at 1 a.m. EDT at the T minus 43 hour mark. The countdown will lead up to a planned liftoff of Columbia at 12:38 a.m. EDT on Wednesday, May 30. There are no problems with the vehicle or payload at this time in the countdown. Columbia's payload bay doors are scheduled to be closed for flight this evening. The Astro-1 broad band x-ray telescope is being serviced with argon today. Today, technicians are removing platforms from the crew cabin, removing engine covers and throat plugs from the orbital maneuvering system and activating Columbia's navigation system. The main engine controllers will be powered up for functional checks and to checkout the gaseous nitrogen and helium purge sys- tems. At the pad, workers will be performing final cleaning and wash down of the pad surface, flame trench and zero level of the mobile launcher platform. The countdown will enter the first of several built-in holds at the T minus 27 hour mark at 5 p.m. this evening. After the countdown clock resumes at 1 a.m. Monday, Columbia's fuel cell storage tanks will be loaded with liquid oxygen and liquid hydrogen reactants. For this countdown, Columbia's storage tanks will be filled from tankers on the pad surface instead of from the dewars at the Pad. This exercise will prove the capability to load reactants from tankers, the method that will be used for an extended duration orbiter flight. The capacity of the dewars at the pad is not sufficient to support an EDO flight. STS-35 flight crew members arrived at KSC's Shuttle Landing Facility today at 11 a.m. for final flight preparations. Today, the crew will be briefed on the status of the countdown and other pertinent events. Weather forecasts for the time of launch on Wednesday are favorable with an 80 percent chance of being within required con- ditions. Winds are forecast to be out of the southwest direction at 12 knots. The expected temperature at the time of launch is 75 degrees. Clouds are forecast to be scattered at low mid and upper levels.