Last but not least there were the long-awaited first two launch attempts of NASA’s Space Launch System.

The rocket’s first official launch attempt was on August 29 after it had finally reached the pad after several Wet Dress Rehearsal attempts. During the countdown, the team ran into an anticipated issue because not everything could be tested during the rehearsals. The engine itself is fine — it turns out that there was a faulty sensor in the tank. In case you didn’t know, the inside of the rocket has not been inspected since it left the factory… three years ago.

That didn’t stop the Internet from making loads of memes about it though.

The next launch attempt on September 3 didn’t go well either, with the teams calling a scrub hours before launch due to yet more propellant loading issues. The next possible launch date is September 19, but that could slip to October 17 or even later depending on how and where the issue is fixed — as well as the schedules of the other rockets waiting to launch, including the need to send astronauts to the ISS and national security satellites to orbit from Florida as well.

There are several things NASA needs to do to get the SLS rocket ready for another attempt.

Engineers need to replace a seal on the pipe that brings liquid hydrogen from the ground to the rocket. This seal is right at that interface, and its failure was the cause of the September 3 scrub.

There are two ways this can be done: replace the seal while the rocket is on the pad or push SLS back to the VAB and do it there. Doing the work on the pad prevents any potential stresses on the rocket and mobile launcher that might happen during pushback. The seal could also be tested since the cryo-temperature propellant loading system is right there. However, access to the rocket at the pad is limited, and this work can probably be done more easily in the VAB. But once SLS is in the VAB, the ability to test the seal is lost. This may mean another wet dress rehearsal before the next launch attempt.

That decision might be made for them. There’s another pesky issue: the batteries in the rocket’s flight termination system. They are only certified for a certain number of days, a condition which NASA has already waived once through September 6. Without an additional waiver, the SLS has to be rolled back to the VAB to replace the batteries.

It is important to note that this is a brand new rocket, and all of these systems are seeing their first issues. Teething issues are expected, and it’s better to not launch rather than launch and explode.

Space is hard, and watching these folks fight to keep hydrogen contained… well, on days like this I’m glad I’m an astronomer and not a rocket scientist.

More Information

NASA to Stand Down on Artemis I Launch Attempts in Early September, Reviewing Options (NASA)