UPDATE – The launch of Orion’s flight test has been scrubbed for today because of an issue related to fill and drain valves on the Delta IV Heavy rocket that teams could not troubleshoot by the time the launch window expired. The next launch window opens at 7:05 a.m. Eastern on Friday, Dec. 5.
The Mobile Service Tower at Space Launch Complex 37 has been moved away from the launch stand where a United Launch Alliance Delta IV Heavy and Orion spacecraft stand pointed skyward for launch Thursday morning.. Meteorologists upgraded their outlook for Orion’s launch to give it a 70 percent chance of acceptable conditions. The forecast says drier conditions are expected and the chance of coastal showers has diminished during the 2-hour, 39-minute launch window.
With less than 7 hours remaining before Orion begins its first flight test with a launch on a Delta IV Heavy rocket, everything remains on track for liftoff at 7:05 a.m. EST. The Mobile Service Tower enclosing the rocket and spacecraft will be rolled back to its launch position late tonight, revealing the Orion stack on the launch stand at Space Launch Complex 37.
NASA TV launch commentary of the flight, designated Exploration Flight Test-1, begins at 4:30 a.m. and will continue through splashdown in the Pacific Ocean approximately 600 miles southwest of San Diego.
This will be a short flight and is deigned to test the Orion systems and simulate a high speed orbital re-entry. The spacecraft will orbit Earth twice and travel to an altitude of 3,600 miles into space. This flight will test many of the elements that pose the greatest risk to astronauts and will provide critical data needed to improve Orion’s design and reduce risks to future mission crews.