An important box checked on the engineers’ roadmap, but several variables still make it impossible to predict the launch date.
NASA announced that its engineers had replaced two of the failed seals that had led to hydrogen leaks on the Space Launch System, NASA’s launch vehicle which was due to take off on August 29 for the first of three Artemis program missions.
The launch has already been postponed twice. Each time, the cause was a malfunction identified at the level of a hydrogen pipe. Over the course of its investigations, the agency ended up going back to the source of the problem, namely two circular joints which were not perfectly sealed.
NASA did not say if it was an assembly problem, or if the parts had been damaged at another time. Today, however, it announced that these two elements could be replaced without concern on September 9th. In theory, the leaks should therefore finally be plugged.
A new filling test on September 17
From now on, we will have to make sure that these interventions have indeed made it possible to plug the leaks. NASA will carry out a new filling test of its enormous 98-meter high rocket, capable of carrying more than 3 million liters of hydrogen and liquid oxygen. This demonstration will allow the engineers to check the integrity of the new seals under conditions almost identical to those of the launch.
This test is scheduled for September 17. If the SLS passes this stage, the technical teams will finally be able to tackle a test that leaks have made impossible until now. The objective will be to cool the engines of the machine to a temperature of around -250°C. This will make it possible to condition the structure to prepare for the arrival of the fuel, which is also kept at an extremely low temperature.
If these tests go as planned, engineers will finally be able to tick this very important box on their roadmap. But they will not be at the end of their sentences for all that.
The US Space Force must still deliberate
Last I heard, the agency was still awaiting a response from the US Space Force (USSF). NASA sent him a request for an extension of the Flight Termination System (FTS) certification. It is an emergency system that must spray the machine in the air in the event of a catastrophic accident. The goal is to prevent it from causing major damage by crashing into Earth.
It must be tested regularly (every 25 days), otherwise the vehicle is simply not allowed to take off. However, this certification is soon to expire. And it turns out that the testing procedure is quite long; if it had to do so again, NASA would be forced to sacrifice several interesting firing windows. The agency therefore remains suspended on the USSF’s verdict. It will be decisive when choosing the next launch date.
We therefore give you an appointment on September 17 to check if the SLS piping will finally be watertight. Until then, NASA may know more about the extension of the FTS certification. If all the stars align, the agency may be looking at a September 23 or 27 launch, as its officials recently suggested. Otherwise, we will have to wait until October to see the SLS soar towards the Moon.