The last big test before Starship SN9’s flight was conducted on Wednesday with the static fire of all three Raptor engines. While SpaceX fueedl up the rocket and briefly fired up the Raptor engines below SN9, some weird differences were noticed to suspect something didn’t go right.
SpaceX’s SN9 is due to attempt a high altitude test flight as soon as this weekend after it completed the static fire for its engines. Static fires are common nowadays for SpaceX. They conduct several of them on Falcon 9 rockets before they fly, and have done many already with the Starship vehicles.
This was the first static fire for SN9 and the first ignition of Raptor engines on their Mount B testing stand at the launch complex in Boca Chica, Texas. While SpaceX doesn’t publicly state what happens during these tests, we have been watching fueling operations and static fire tests for a while now and know what looks normal and what is either new or concerning.
A short and sweet static fire, a little too short
The two items that are of interest are the length of the static fire and some weird venting seen right before the ignition. On the vehicle, there are three vents that we believe correlate to each engine, and in the past we have seen a steady flow of vented oxygen come from them leading up to the ignition of the engines. The community refers to these vents as the “tri-vent”.
The tri-vent was performing as normal until within the last minutes of the test where it was seen intermittently stop venting, continue, then stop again before resuming just before the very large vent from them, which is normal, just before Raptor ignition.
What does this mean for the flight?
Now, this could all be explained away by a new process. Maybe the process has changed with what they have learned from the SN8 flight. All we know is that residents in the area received notices of another static fire attempt sometime today, which usually means something wasn’t right and they need to do it again or want to test another part of the vehicle before the flight.
After the static fire, SpaceX continued conducting tests on the vehicle until the end of the road closure time at 8 p.m. CST. It looked like they were going to attempt a second static fire but could have also been rehearsing fueling operations before the flight.
Currently, the temporary flight restrictions for the flight are for Friday, Saturday, and Sunday. If we see new ones for early next week, then we know there’s a good chance the flight will be pushed back. Also, we need to wait for residents in the area of Boca Chica to be evacuated prior to the start of flight testing operations.