Yeah, that doesn’t sound quite right to me either. It’s not like these engines weren’t previously test fired. Apparently it’s a sensor issue that they and they were going to proceed with the launch anyways- I have to imagine they have more than one sensor thus the apparent limited amount of concern expressed. The engines are cooled with the cryogenic fuels, so maybe the cooling systems cannot be truly and fully tested without fueling the rocket- which of course is a major (and inherently dangerous) process.
It’s disappointing to see that the launch will be delayed for at least a month due to problems with the quick disconnect fueling system. I would think this would be very similar if not the same as the shuttle system so it’s a little surprising this would be the issue preventing a launch. That said, it’s my understanding the SLS fuel tank is completely redesigned from the shuttle’s. Plus hydrogen is a notoriously difficult product to deal with given its molecular size and launch delays and rockets are not uncommon, especially when it’s the first launch of a new design.
I’m still not quite sure how this program is considered to be remotely sustainable, at the very least for using refurbished shuttle engines that will not be recovered. The RS-25’s haven’t been made in ages and I question what the plan is when they run out. It probably wouldn’t make sense to restart production. I guess we’ll be lucky if we get past Artemis 2 in my book.
The ULA Vulcan rocket (still in development, Atlas successor) allegedly may eventually have engines that are jettisoned with parachutes and recovered in-air with helicopters. This actually makes a lot of sense considering the amount of fuel aka extra weight required for propulsive landings like SpaceX uses. And helicopters catching items out of the air is nothing new, this is how spy satellite film was recovered back in the day. That said, catching multiple engines presumably with multiple helicopters in likely a very close vicinity sounds extremely dangerous. This would have been an interesting feature for SLS to have explored.
If we are to have a remotely “sustainable” moon program, SLS is clearly not the rocket to do it. And I have some doubts about the practicality of using starship, especially in the near term, as the lunar lander. While starship, if successful, will be a game changer on so many levels, for early moon missions it seems to me unnecessarily large and overly complicated for the task at hand- and quite risky. Sierra Nevada had a very interesting lunar lander concept but evidently got their math wrong- their proposed lander was in fact too heavy to get off the moon.
While I’m thrilled to see us going back to the moon, it’s just very disappointing how much money was spent on a rocket that really doesn’t seem to be the ideally what is needed.
Ultimately, I think commercial customers is the only way to get a remotely efficient moon program in action. Otherwise the design process is beholden to politics, bureaucracy, vastly inflated costs.
