WASHINGTON – Space Exploration Technologies (SpaceX) aborted the Falcon 9’s first static-fire test March 9 just as the rocket’s nine engines were about to ignite for a planned 3.5-second burn.
SpaceX officials said the test automatically aborted at T-minus 2 seconds when the rocket’s turbo machinery failed to commence spin start because a pressure valve that should have been commanded to open remained closed.
“The problem was pretty simple: Our autostart sequence didn’t issue the command to the normally closed ground side isolation valve,” SpaceX Chief Executive Elon Musk said in a March 11 statement. “We had tested everything on the vehicle side exhaustively in Texas, but didn’t have the [isolation] valve on our test stand there. Definitely a lesson learned to make sure that everything is the same between the test stand and launch pad on the ground side, not just on the vehicle side.”
Musk said that valve that should have been commanded to open releases ground-supplied high-pressure helium vital to starting the first-stage engine pumps spinning at several thousand rotations per minute. When that did not happen, the rocket’s systems triggered an abort.
While the engines never ignited during the March 9 static-fire attempt, video of the test shows a ball of flame followed by a cloud of black smoke erupting from the base of the 15-story-tall rocket.
Musk said the fire was generated from flushing the system of fuel and liquid oxygen. He said there was no damage to the vehicle or ground systems, and no other anomalies need to be addressed before SpaceX attempts the static fire again “in the next few days.”
SpaceX’s first attempt at the crucial prelaunch test came six days after completing what it described as a flawless countdown-and-propellant-loading exercise known in rocketry circles as a wet dress rehearsal. The company initially hoped to try again March 11, but was stymied by bad weather at Cape Canaveral, Fla., where the Falcon 9 has been standing erect since late February undergoing preparations for its maiden flight, a demonstration launch ordered in 2005 by an unnamed U.S. government customer.
Although the Falcon 9 will carry a prototype of SpaceX’s Dragon cargo capsule into space on the upcoming flight, the mission does not count as one of the three demonstrations the company plans to conduct for NASA under the U.S. space agency’s Commercial Orbital Transportation Services program.