Story Continues BelowThe rocket was supposed to fire for a total of 3.5 seconds to test the ground systems and rocket during the critical final seconds of the launch countdown and ignition prior to releasing the vehicle for flight. However, during today's exercise, the countdown experienced an automatic cutoff just as the rocket was preparing to light the engines.

"We counted down to T-2 seconds and aborted on Spin Start," according to a statement released by SpaceX a few hours after today's aborted test. "Given that this was our first abort event on this pad, we decided to scrub for the day to get a good look at the rocket before trying again. Everything looks great at first glance."


(Image above credit: SpaceX)

Since SpaceX didn't provide any real-time commentary or updates, some people were startled by the sight of the rocket seeming to come to life only to shutdown immediately after. On remote cameras, it appeared as though the engines ignited and then cutoff, which was not the case.

"The problem was pretty simple: our autostart sequence didn't issue the command to actuate (trigger) the ground side isolation valve to open," said the statement from SpaceX. The ground side isolation valve releases ground-supplied high pressure helium to start the first stage engine turbopumps spinning at several thousand rpm. That generates enough pressure to start the gas generator, which is a small rocket engine that powers the turbopump. There are no vehicle side valves actuated for spin start (just check valves), so it is an all engines or none situation."

"Ignition fluid (TEA-TEB) flowed nominally to all engines creating the green flame and the main valves opened, but no engines actually started and the system automatically aborted on lack of spin," said SpaceX. "The fire generated was from flushing the system of fuel and LOX from the open mains. No damage to the vehicle or ground systems and no other anomalies that need to be addressed.

The cause of the cutoff was due to the failure of the ground system to open a helium isolation valve, which releases the high-pressure gas from tanks at the launch pad and start the propellant turbopumps spinning at a very high rate to force fuel and oxidizer to the engines.

The automatic sequencer detected the anomaly and correctly issued the command to cutoff the test and isolated the engines from the rest of the propulsion system as part of normal safing procedures.

"We tested everything on the vehicle side exhaustively in Texas, but didn't have this iso valve on our test stand there," said SpaceX. "Definitely a lesson learned to make sure that *everything* is the same between test stand and launch pad on the ground side, not just on the vehicle side."


(Image above credit: SpaceX)

Up to the point of the cutoff, all ground support equipment as well as vehicle systems operated nominally, according to SpaceX.

"Despite the abort, we completed pad preps on time and with good execution. The integrated countdown with the range included holdfire checks, S- band telemetry, C-band, and Flight Termination System (FTS) simulated checks," said the statement regarding today's countdown. "We completed helium, liquid oxygen (LOX), and fuel loads to within tenths of a percent of T-zero conditions. Tanks pressed nominally and we passed all Terminal count, flight software, and ground software abort checks right down to T-2 seconds."

SpaceX's inaugural Falcon 9 launch vehicle has been at Cape Canaveral undergoing preparations for launch this spring on a demonstration flight carrying a mockup of the company's Dragon cargo-carrying spacecraft. For the last two weeks, the rocket has been erected on the launch pad, lowered and erected again while the launch team put the entire launch system through exhaustive testing prior to today's attempted static test.

Prelaunch testing included a wet dress rehearsal February 26 when the rocket was raised to vertical and filled with kerosene and liquid oxygen propellants as part of a full-scale countdown rehearsal.

So far SpaceX has declined to release a specific target launch date. Although SpaceX has the Eastern Range booked for March 22, people close to the company state that sometime in April is more likely. Presumably, launch would be sometime in the second half of the month since NASA already has use of range assets in support of the launch of space shuttle Discovery, currently targeted for April 5.

The 154 foot tall rocket, its nine Merlin 1C engines generating nearly 900,000 pounds of thrust at liftoff, will orbit a test mockup of the Dragon spacecraft the company is developing to deliver cargo to the International Space Station as part of a $1.6 billion dollar contract SpaceX has with NASA to support the station after the space shuttle is retired at the end of the year.

Under the terms of the contract, SpaceX will conduct a minimum of twelve operational flights to the space station. Dragon is slated to make fly the first of those missions in 2011, with one or two test flights before that.

Below is the text of SpaceX's statement issued after today's aborted static test fire, including a later update with more details:

"On Tuesday, March 9th, SpaceX performed our first Static Fire for the Falcon 9 launch vehicle. We counted down to T-2 seconds and aborted on Spin Start (the process that fires the engines). Given that this was our first abort event on this pad, we decided to scrub for the day get a good look at the rocket before trying again.

"The problem was pretty simple: our autostart sequence didn't issue the command to actuate (trigger) the ground side isolation valve to open. The ground side isolation valve releases ground-supplied high pressure helium to start the first stage engine turbopumps spinning at several thousand rpm. That generates enough pressure to start the gas generator, which is a small rocket engine that powers the turbopump. There are no vehicle side valves actuated for spin start (just check valves), so it is an all engines or none situation.

"Ignition fluid (TEA-TEB) flowed nominally to all engines creating the green flame and the main valves opened, but no engines actually started and the system automatically aborted on lack of spin. The fire generated was from flushing the system of fuel and LOX from the open mains. No damage to the vehicle or ground systems and no other anomalies that need to be addressed.

"We tested everything on the vehicle side exhaustively in Texas, but didn't have this iso valve on our test stand there. Definitely a lesson learned to make sure that *everything* is the same between test stand and launch pad on the ground side, not just on the vehicle side.

"Despite the abort, we completed pad preps on time and with good execution. The integrated countdown with the range included holdfire checks, S- band telemetry, C-band, and Flight Termination System (FTS) simulated checks. We completed helium, liquid oxygen (LOX), and fuel loads to within tenths of a percent of T-zero conditions. Tanks pressed nominally and we passed all Terminal count, flight software, and ground software abort checks right down to T-2 seconds.

"We detanked and safed the vehicle and launch pad. Preliminary review shows all other systems required to reach full ignition were within specification. All other pad systems worked nominally.

"It is important to appreciate that what we are going through right now is the equivalent of "beta testing". Problems are expected to occur, as they have throughout the development phase. The beta phase only ends when a rocket has done at least one, but arguably two or three consecutive flights to orbit.

"Right now, we are holding due to extreme weather. It is raining sideways at 46 mph and tornados have been spotted just north of the Cape. If all goes well, we will try the static fire again in the next few days."

(The Spacearium / SpaceflightNews.net)