Launch Teams Hustle To Place Orion In Orbit Early Friday After Scrub

NASA and its contractor partners assessed the readiness of the Orion crew exploration vehicle and its Delta IV Heavy launch vehicle late Thursday as they prepared for another attempt to launch the capsule on its two orbit, 4.5-hr. space debut early Friday.

Stiff winds and a pair of sticky first-stage rocket propellant valves prevented a liftoff from Cape Canaveral Air Force Station, Florida, early Thursday.

Mission managers from Lockheed Martin and United Launch Alliance as well as NASA were expected to regroup early Friday for a launch attempt at 7:05 a.m. EST, the opening of a 2 hr., 39 min. launch window.

As Thursday waned, ULA engineers assessed the performance of liquid hydrogen fill and drain valves in the propellant tanks within the center and left cores of the Delta IV's three part first stage. The reluctance of the ball valves to close fully during the final minutes of Thursday’s countdown prompted a scrub for the day.

Meanwhile, NASA examined the health of four batteries that power Orion vehicle systems and data recorders. The recorders cycled a dozen times during three launch attempts on Thursday. Their readiness was another factor in whether mission managers were to push ahead early Friday, or perhaps wait until Saturday for a 7:10 a.m. EST launch attempt.

"I'll make it short and sweet," Mark Geyer, NASA's Orion program manager, told a post-scrub news briefing. "The team made a great attempt to get off today, and in the end made the right choice based on the data we had to not fly today. We will attempt tomorrow. There is still some open work to confirm that. But our plan is to fly tomorrow."

Friday’s weather outlook, which included a 60% chance of unfavorable conditions for the start of the unpiloted Exploration Flight Test-1, was a factor as well. Forecasters pointed to northerly winds that could shove the rocket into the structure of Launch Complex 37 as it took flight as well as the prospects for isolated rain showers and thick clouds as potential show stoppers.

The $370 million test mission was to vault Orion to an altitude of 3,630 mi. on its second and final orbit for a plunge back into the Earth's atmospheres at 20,000 miles per hour -- speeds near those of a lunar trajectory return, and fast enough to challenge the capsule's critical heat shield with temperatures of 4,000F.  Eleven carefully sequenced parachute deployments are to slow the spacecraft -- that may one day usher U.S. astronauts to the lunar environs, the asteroids and Mars -- to a 20 mph splashdown 600 mi. southwest of San Diego, California.

The USS Anchorage and USNS Salvor, which set sail from the U. S. Navy base in San Diego prior to the opening of Thursday's launch window, are remaining in the recovery zone for launch attempts Friday and, if necessary, Saturday. They'll be joined in  the recovery operation by P-3 Orion aircraft, helicopters assigned to the Anchorage and the NASA's Ikhana, a Predator B drone, to spot and track the descending capsule as well as document its return to Earth with video.

Orion's journey also will be documented by more than 1,200 sensors placed throughout the capsule to measure structural stresses, pressures and temperatures as the flight unfolds. Cameras were to capture the shedding of 17 capsule components, including the towering inert Launch Abort System fitted atop the rocket.

Efforts to launch the Delta IV on Thursday were called off at 9:34 a.m., EST, 10 min. before the day's launch period closed, while ULA engineers assessed the two sticky Delta IV fill-and-drain valves.

Earlier efforts to lift off were thwarted first by a ship that appeared to stray into an Atlantic Ocean hazard zone established by the U.S. Air Force Eastern Range. Range personnel are responsible for tracking the launch vehicle on its easterly trajectory to make sure it does not stray off course into a populated area.

Northerly surface winds twice automatically prompted countdown holds, when they exceeded  a 24 mph constraint.