NASA SpaceX Crew 6 Launch Aborted

On Monday, NASA's Crew-6 mission to the International Space Station aboard SpaceX's Falcon 9 rocket was postponed with T-2 minutes 12 seconds left on the clock due to an issue with the TEA-TEB igniter fluid.

The launch was scheduled to take place at 1:45 am ET from Kennedy Space Center's Launch Complex 39-A in Florida. The issue was first mentioned about five minutes before liftoff time during NASA's webcast, and despite efforts to resolve it, mission operators could not clear the technical issue before the instantaneous launch window opened.

The four astronauts, NASA astronauts Stephen Bowen and Warren “Woody” Hoburg, United Arab Emirates astronaut and Roscosmos cosmonaut, were safely onboard the Crew Dragon spacecraft. They are expected to egress later in the morning after the rocket's propellant is offloaded.

The Issue

After the scrub, SpaceX tweeted that the cause of the issue was a "TEA-TEB ground system issue."

Standing down from tonight's launch of Crew-6 due to a TEA-TEB ground system issue. Both Crew-6 and the vehicles are healthy and propellant offload has begun ahead of the crew disembarking Dragon

— SpaceX (@SpaceX) February 27, 2023

TEA-TEB">TEA-TEB is a combination of triethylaluminum (TEA) and triethylborane (TEB) used for igniting rocket engines, which can be tricky to control. Essentially, these are two different metal elements each linked to three hydrocarbon atoms. These molecules are held together by rather tenuous bonds that break easily. When it comes into contact with oxygen, therefore, TEA-TEB spontaneously combusts.

For the Merlin 1D engines inside the Falcon 9, oxygen is pumped into the engines' combustion chambers to meet up with TEA-TEB. After combustion begins, kerosene is injected into the chamber, and the flow of the TEA-TEB igniter fuel is turned off. Then, to increase thrust, the flow of oxygen and kerosene are increased.

Early in their development of the Falcon 1 and Falcon 9 rockets, SpaceX struggled mightily with safely handling TEA-TEB and getting the Merlin engines to ignite when desired. "The best thing about TEA-TEB is that it ignites on contact with air," SpaceX's original launch director, Tim Buzza, said. "The worst thing about TEA-TEB is that it ignites on contact with air."

Next Launch Opportunity

The mission has a backup launch opportunity on Tuesday, February 28 at 1:22am ET, but weather conditions could be less favorable than they were on Monday. NASA and SpaceX also have opportunities to launch the Crew Dragon mission on March 2, 3, and 4.

This is a developing story and will be updated as more details become available.