NASA and SpaceX were preparing to launch the next quartet of astronauts to the International Space Station on Tuesday, but the launch was scrubbed at the last minute due to a technical issue.

The Falcon 9 rocket and Crew Dragon capsule, carrying four astronauts, were set to launch at 6:11 p.m. ET from the Kennedy Space Center in Florida. However, the launch was aborted at the 11th hour due to an issue with the rocket’s first-stage igniter fluid.

NASA and SpaceX teams worked to troubleshoot the issue, but ultimately decided to scrub the launch for the day.

The launch was expected to be the first of three missions to the International Space Station this year. The mission, dubbed Crew-2, would have sent astronauts Shane Kimbrough, Megan McArthur, Akihiko Hoshide, and Thomas Pesquet to the space station for a six-month stay.

The launch was originally scheduled for March 30, but was pushed back due to unfavorable weather conditions.

The next launch attempt is scheduled for Wednesday at 5:49 p.m. ET. If all goes well, the astronauts could reach the space station as early as Friday.

This would be the second crewed mission to the International Space Station launched by SpaceX. The first, Crew-1, launched in November and is still in orbit.

NASA and SpaceX are hoping to have a successful launch this time around, as it would be a major milestone in their mission to make space exploration more accessible.