Falcon fires its 9 engines to simulate first stage flight
BY STEPHEN CLARK
Posted: November 24, 2008
Intense orange light and a booming roar cut through the Central Texas countryside for three minutes Saturday night, signaling the end of a year-long series of ground tests on the core of SpaceX's new Falcon 9 rocket.
The test was designed to simulate the entire first stage burn of the booster. The 90-foot-long prototype stage was secured to a 135-foot-tall concrete tripod designed to withstand the 855,000 pounds of thrust produced by the engines.
"The full mission-length test firing clears the highest hurdle for the Falcon 9 first stage before launch," said Elon Musk, founder, CEO and chief technology officer of Space Exploration Technologies Corp.
Engineers are studying data from the test, but early results indicate everything was successful, according to Diane Murphy, vice president of communications at SpaceX.
Two engines shut down 18 seconds early to imitate the rocket's staggered cutoff sequence designed to limit acceleration late in the first stage burn. The seven remaining engines continued to fire for a total duration of two minutes and 58 seconds, according to SpaceX.
The early shutdown also demonstrated the rocket's ability to recover from engine failures during launch.
The engines consumed more than 500,000 pounds of propellant during the burn, according to SpaceX.
The test was postponed late into the night due to technical delays. The rocket's deafening sound and bright orange flames were observed dozens of miles away, local officials said.
SpaceX's test facility is located near McGregor, a Central Texas town of less than 5,000 people.
Emergency calls in the hour between 10 p.m. and 11 p.m. were about eight times more frequent than normal, according to Robert Leathers, program manager at the McLennan County 911 District.
"We were flooded with phone calls," said McGregor Assistance Police Chief James Burson. "They tried to get the word out, but a lot of people didn't know what was going on."
"SpaceX strives to be a good corporate neighbor, bring high technology jobs to the Central Texas area, and stimulate the local economy," the company said in a written statement. "We have contacted those concerned individuals personally. Any disturbance was unanticipated as we had conducted five previous nine-engine tests for approximately 80 seconds in duration with no complaints or concern."
Murphy said the company informed local police and fire departments and published a notice in the McGregor newspaper to warn the public.
"During these previous tests, we followed the same notification procedures used for Saturday's test and several previous tests were conducted at similar times in the evening," the statement said.
Cloudy and cool weather conditions could have amplified the sound caused the light to glow brighter, officials said.
Saturday's engine firing wrapped up a step-by-step testing program to prove the Falcon 9 rocket's first stage propulsion system is ready for flight. The regimen began with single-engine tests and gradually added more Merlin powerplants and increased the duration of the firings.
Engineers at Boeing Co. followed a similar testing program to qualify the Delta 4 rocket's first stage for flight in 2001.
Boeing tested the Delta 4 Common Booster Core first stage and the RS-68 engine at NASA's Stennis Space Center in Mississippi.
Testing continues on the Falcon 9's second stage, which will be powered by a single vacuum-rated Merlin 1C engine.
SpaceX is busy readying hardware for the first Falcon 9 launch at the company's headquarters in Hawthorne, Calif.
Company officials hope to ship the flight vehicle to Cape Canaveral by the end of the year, but managers are currently reviewing that schedule.
"There are a lot of things that have to be accomplished and go right for that to occur," Murphy said.
Regardless of whether flight equipment arrives in Florida by the end of 2008, the first launch remains on track for the second quarter of next year.
"We're on our own schedule," Murphy said. "We are under no contractual obligations to launch by a certain date."
The Falcon 9 is a key part of SpaceX's proposal to supply the international space station with cargo after the space shuttle is retired in 2010. The heavy-lift rocket will haul the company's own Dragon spacecraft into orbit before docking to the complex.
SpaceX and Orbital Sciences Corp. are receiving federal money to help fund the development of new transporation systems for cargo delivery. The funding is unlocked as the companies meet schedule milestones.
The rocket will also compete for satellite contracts with Atlas and Delta rockets in the U.S. fleet, plus boosters from Europe, Russia and China.