Boeing’s uncrewed Starliner spacecraft arrives at the ISS. Photo: NASA

NASA, Boeing, and ULA will try, once again, to launch the Starliner Crew Flight Test (CFT) this Wednesday after scrubbing their latest attempt just 3 minutes and 50 seconds before liftoff on Sunday. The group has two more windows this week – June 5 at 10:52 a.m. and June 6 at 10:29 a.m. (EST) – before they would be forced to service the rocket, which would take at least 10 days to complete.

NASA said that there is a 90% chance that weather conditions will be favorable for a June 5 launch.

Following the aborted attempt on Sunday, ULA CEO Tory Bruno said that a hardware or networking malfunction in the launch sequencer, caused by an issue in the power supply unit, caused ground control computers to initiate a hold on the launch on the Atlas 5 rocket carrying NASA Astronauts Butch Wilmore and Suni Williams.

This was the just the latest in a series of delays that has plagued Starliner since NASA awarded Boeing a $4.2 billion to develop the spacecraft 10 years ago. Starliner was previously scheduled to launch May 6 and then May 25, but problems with an oxygen valve on the rocket and a small helium leak on the service module pushed the launch back to June.

Once launched, Starliner will take Wilmore and Williams on an approximately 24-hour trip to the International Space Station, where they will spend one week before returning to Earth. NASA hopes Starliner will serve as an second option to SpaceX in sending astronauts to space.