NASA was set to try launching its uncrewed Orion space vehicle on the morning of Dec. 5 after scrubbing the Dec. 4 launch due to mechanical issues, according to a post on the civil space agency’s blog.
The launch window was open at 7:05 a.m. EST and was to last roughly 2.5 hours, same as Dec. 4. Fill-and-drain valves on the United Launch Alliance (ULA) Delta IV Heavy launch vehicle were to be tested throughout Dec. 4 so the launch team can prevent a mechanical problem like the one that came up the morning of Dec. 4.
The valves that failed to close properly late in the countdown allow liquid hydrogen to flow into the three core boosters of the first stage. Normal operation calls for the valves to stay open during the fueling and shut tight a few minutes before liftoff to seal the fuel tank.
The weather for Dec. 5 was forecast to be a bit worse than Dec. 4, NASA said, though still favorable. Meteorologists were calling for a 60 percent change of acceptable conditions. Launch was to take place at Cape Canaveral Air Force Station, Fla.
During its 4.5-hour trip, formally known as Exploration Flight Test-1 (EFT-1), Orion was to orbit Earth twice and travel to an altitude of 3,600 miles into space. The flight test is designed to test many of the elements that pose the greatest risk to astronauts and was to provide critical data needed to improve Orion’s design and reduce risks to future mission crews. Mike Hawes, Orion program manager for prime contractor Lockheed Martin [LMT], said earlier in the week of Dec. 1 that the test flight is to evaluate critical technologies not just in the low-earth orbit (LEO), but farther out.
ULA’s Delta IV Heavy configuration features three RS-68 engine cores plus a RL-10B2 second stage, all developed by Aerojet Rocketdyne. ULA is a joint venture of Lockheed Martin and Boeing [BA]. Aerojet Rocketdyne is a division of GenCorp [GY].