SpaceX conducted a successful full mission-length firing of its Falcon 9 launch vehicle’s first stage at its McGregor Test Facility in Texas, late Saturday evening, November 22. But the big news wasn’t the success of the firing, but the brouhaha it created with the neighboring communities. The test occurred at 10:30 pm local time, and the light and noise created by the test was unprecedented, causing a bit of panic. People said it sounded like a bomb exploding, that their house and windows shook the entire time, and one woman said her son was scared the sun was exploding. Television news reports convey the panic, and some online newspaper articles have an incredible amount of comments posted. But SpaceX has conducted over 2,000 previous engine tests and this one is the only test that prompted such a commotion … why?
SpaceX spokesperson Lauren Dryer said the weather conditions at the time of the test contributed to sound and light traveling further. “A combination of low clouds and cool temperatures drastically affected the distance the sound and light traveled,” Dryer said, making the test easier to see and hear from much farther away. She said the company has never had any previous calls or concerns with test firings, even though SpaceX has conducted more than 2,000 tests since operations began in 2003, including 10 multiple-engine tests similar to Saturday’s. SpaceX said they notified local police and fire departments about the test, put a notice in the local newspaper and even put it on the marquee of the area high school, but obviously many residents had no clue the test was going to occur. SpaceX said they will try to put out more notices about future tests as well as invite the media to cover them.
For the static test firing, the first stage remained firmly secured to a huge vertical test stand, where it fired for 178 seconds or nearly three minutes, which simulates the climb the rocket will take to Earth orbit. At full power, the rocket generated 855,000 pounds of force at sea level. In vacuum, the thrust increases to approximately one million pounds or four times the maximum thrust of a 747 aircraft. The test consumed over half a million pounds of propellant.
All nine engines fired for 160 seconds, then two engines were shut down to limit the acceleration and the remaining seven engines continued firing for 18 more seconds, as would occur in a typical climb to orbit. The test firing validated the design of SpaceX’s use of nine engines on the first stage, as well as the ability to shut down engines without affecting the functioning of the remaining engines. This demonstrates the ability of Falcon 9 to lose engines in flight and still complete its mission successfully, much as a commercial airliner is designed to be safe in the event of an engine loss. The Falcon 9 will be the first vehicle since the Saturn V and Saturn 1 to have the ability to lose any engine/motor and still be able to complete its mission without loss of crew or spacecraft.