Boeing, NASA, and the United Launch Alliance (ULA) scrubbed today’s launch of Starliner less than 4 minutes before liftoff. The setback comes after a string of disappointments, but as with its early May delay, the issue wasn’t with Boeing’s crew vehicle.

NASA says the ULA is currently investigating why a computer, called a ground launch sequencer, didn’t enter “the correct operational configuration,” triggering an automatic hold. During a press conference afterward, ULA CEO Tory Bruno said the issue was that one of three redundant launch sequencers, which are used to control things like releasing connections to the rocket prior to launch, was slow to respond.

The three organizations had hoped to try again tomorrow around noon, but that won’t happen, either. NASA now says the teams have opted to punt the launch a few more days (the next two chances are June 5th and 6th) to give the team more troubleshooting time with the faulty equipment.

The flight was meant to take two US astronauts — Butch Wilmore and Suni Williams — up to the International Space Station (ISS), where they will dock. Wilmore and Williams had planned to stay on the station for a week to carry out testing of Starliner and its subsystems prior to NASA’s final certification of the craft for rotational missions to ISS.

Boeing’s Starliner scrubbed its May 6th launch after the United Launch Alliance discovered an issue with a pressure regulation valve in its Atlas V rocket. Starliner also has a helium leak, which NASA has decided not to repair because it doesn’t believe it endangers the mission, and fixing it would involve another lengthy delay. Prior to that, Boeing’s Starliner faced repeated delays and setbacks, including a failed 2019 mission, but finally successfully docked its capsule, unmanned, with the ISS in 2022.

Starliner is part of NASA’s Commercial Crew Program, which involves the agency working with private companies to develop novel spacecraft. SpaceX is also part of this program and has launched NASA astronauts since 2020.

Update June 1st, 2024, 3:16PM ET: Updated to reflect that the launch was scrubbed and that there is a new launch target date.

Update June 1st, 2024, 6:14PM ET: The launch is delayed until at least June 5th.