On Monday, Astra came within 53 seconds of launching its Rocket 3.0 from a spaceport in southern Alaska. With less than a minute to go in the countdown, a sensor delivered some data about the rocket that Astra’s chief executive, Chris Kemp, said “really concerned us.”

Despite the prospect of losing out on a $2 million check from the US Defense Advanced Research Projects Agency, and potentially $10 million more later this month, Astra engineers halted the launch attempt. They thought the problem may lie with a faulty sensor, as bad data was intermittent, but they weren’t sure.

“By making the decision to not fly today, we’ll have the opportunity to fly this rocket safely at a later date,” Kemp said. He said the company is likely “weeks” away from trying again, rather than months.