SpaceX test fires Falcon 9 first-stage engines in key pre-launch milestone (UPDATED)

CBS News

02:30 PM, 12/04/10: Falcon 9 test fired

After a last-second abort Friday and another Saturday, a SpaceX Falcon 9 rocket's first stage engines were test fired, setting the stage for launch next week on a NASA-sponsored fight to demonstrate the booster's ability to deliver cargo to the International Space Station.

The nine main engines of a SpaceX Falcon 9 rocket were ignited Saturday in a brief, apparently successful test firing, setting the stage for launch next week on a critical space station demonstration flight. (Photo: SpaceX)

An initial attempt to "hot fire" the nine Merlin first-stage engines was aborted Friday because of high pressure in the combustion chamber of engine No. 6. A second attempt Saturday was aborted at 9:30 a.m. EST (GMT-5) because of low pressure in a gas generator. Again, the culprit was engine No. 6.

After assessing the issue, SpaceX engineers recycled the countdown to the T-minus 13-minute mark and successfully fired up all nine engines at 10:50 a.m. In keeping with normal SpaceX policy, no details were immediately available beyond a Twitter update saying "we will continue to review data but today's static fire appears to be a success!"

06:06 PM, 12/03/10: Falcon 9 first stage test firing aborted

KENNEDY SPACE CENTER, FL--SpaceX attempted a brief "hot firing" of its unmanned Falcon 9 cargo rocket Friday, planning to ignite the booster's nine first-stage engines to test critical systems before launch next week on a long-awaited space station resupply demonstration flight. But the test was aborted at the last second because of high pressure in an engine combustion chamber, the company said in a Twitter posting. No other details were immediately available.

A planned test firing of SpaceX's Falcon 9 cargo rocket was aborted Friday because of problems with one of nine first-stage engines. (Photo: SpaceX)
The "hot fire" was only intended to last 3.5 seconds, including two seconds at full power, before a computer-commanded shutdown. Ignition was scheduled for 1 p.m. and a rush of brilliant orange flame and a billowing cloud of exhaust could be briefly seen at the base of the rocket. But the sequence of events was difficult to determine. SpaceX provided a webcast of the firing, but it was marred by intermittent audio and video and no results were mentioned.

Sources said an abort had been ordered just after ignition because of high chamber pressure in one of the main engines. But a company tweet received just after 5 p.m. EST -- the company's first statement about the test -- said only that the "1st static fire attempt aborted at T-1.1 sec due to high engine chamber pressure. Reviewing data & will make a 2nd attempt tomorrow (Saturday)." Calls and email to a company spokeswoman were not answered and it was unclear whether the engines actually ignited or whether the observed flame was the result of a pre-ignition abort.

SpaceX hopes to make an actual launch attempt Tuesday between 9:03 a.m. and 12:22 p.m. Additional launch opportunities are available Wednesday and Thursday.

It will be the first "demonstration" flight in NASA's Commercial Orbital Transportation Services -- COTS -- program, an initiative intended to encourage development of private sector rockets to deliver cargo to the International Space Station after the space shuttle is retired next year.

SpaceX has a $1.6 billion contract with NASA to provide 12 cargo flights to the station for delivery of more than 44,000 pounds of equipment and supplies. The contract may be expanded to cover additional flights, boosting its value to some $3.1 billion.

The first test flight of a Falcon 9 rocket was conducted last June when a dummy payload was lofted into orbit. The rocket met its major test objectives, although an unexpected roll developed that caught engineers by surprise, the apparent result of heating on a second-stage motor steering actuator. Additional insulation was added to correct the problem.

The rocket scheduled for launch next week is carrying the first SpaceX Dragon cargo capsule that eventually will be used to ferry supplies to the space station and return trash and other cargo to Earth. For the inaugural COTS demonstration flight, the Dragon capsule is expected to be launched into a 186-mile-high orbit tilted 34 degrees to the equator. It will not approach the space station. After a few orbits, the Dragon capsule will re-enter the atmosphere and splash down in the Pacific Ocean off the West Coast of California.

SpaceX also hopes to recover the first stage of the booster. The company is renting a space shuttle booster recovery ship that will be standing by off Cape Canaveral next week to haul it back to shore.