A Falcon 9 rocket got to within 2 seconds of launching Friday night in Florida. [credit: Trevor Mahlmann for Ars Technica ]
The countdown clock ticked steadily on Friday night for a Falcon 9 rocket and reached T-2 seconds before the launch of a valuable Global Positioning System satellite was aborted. That was the second consecutive time, in just two days, that a Falcon 9 launch was called off with mere seconds left in the countdown.
An "unexpected ground-sensor reading" triggered an automatic abort of a Starlink launch on Thursday at T-18 seconds. And on Friday evening, according to SpaceX founder Elon Musk, "an unexpected pressure rise in the turbomachinery gas generator" caused the scrub. The turbomachinery in this instance pressurizes gas entering the "gas generator," which in turn is a small engine that powers the larger Merlin rocket engine.
So what is going on? SpaceX has now launched its Falcon 9 rocket more than 90 times, and before this week, recent delays have almost exclusively been due to weather rather than technical problems with the rocket or its ground systems.