That’s how long the flight of LauncherOne lasted from being dropped from the Boeing 747 to its engine crapping out.
Virgin Orbit explained on its website:
For about 9 seconds after drop, the flight went perfectly. Through some of the most challenging portions of our flight — release, the controlled drop, the rocket’s ignition sequence, and the initial portion of guided, powered flight — every part of our system did exactly as we designed it to do. We have solid data from hundreds of channels and sensors — and in looking at those, we see performance that is well-matched to our predictions and to the extensive data we have from our models and ground tests. This means that we have proved out via flight the foundational principles of our air-launch operations, which is the key thing that separates us from our peers in the industry.
About 9 seconds after drop, something malfunctioned, causing the booster stage engine to extinguish, which in turn ended the mission. We cannot yet say conclusively what the malfunction was or what caused it, but we feel confident we have sufficient data to determine that as we continue through the rigorous investigation we’ve already begun. With the engine extinguished, the vehicle was no longer able to maintain controlled flight — but the rocket did not explode. It stayed within the predicted downrange corridors of our projections and our Federal Aviation Administration (FAA) launch license as the vehicle fell to the ocean, posing no risk to public safety, no danger our aircrew or aircraft, and no significant environmental impact.
There’s more on the website about what the company achieved despite the failure on Monday. There’s lots of data to go over before the next launch attempt.