by Meleagris on 12/3/23, 3:54 PM with 59 comments
by dmillar on 12/3/23, 5:54 PM
Some longer takeaways:
- Simplify. We went to the moon 50+ years ago, but we are reinventing the wheel in some significant ways in Artemis. Why? We are supposedly going to the moon in two years, but we have never attempted a cryogenic refuel in orbit (this seems like a biggie).
- Communicate a lot. Why aren't people talking about the seemingly giant increase in complexity to accomplish the same mission we had in the 60s (land on the moon)? People need to have safe/comfortable way to raise questions and concerns.
- Have many layers of redundancy. Apollo had 6-7 backup procedures for what to do if they couldn't launch the lander off the moon.
- Test. small tests, big tests, real tests, skin-in-the-game tests. Some tests can be eliminated by simplifying or, in the case of big systems/tests, doing small tests on the riskiest components.
- Humans have ingrained biases. Will be situations astronauts haven't experienced where their instincts may be wrong.
by Meleagris on 12/3/23, 3:56 PM
"What made Apollo A Success?"
https://ntrs.nasa.gov/api/citations/19720005243/downloads/19...
by unsupp0rted on 12/3/23, 5:02 PM
I wonder if NASA people are more prickly, less, or the same in terms of taking negative feedback as compared to programmers and hackers.
I suspect since we spend all day with compilers telling us we made silly errors, we're a bit more inured to criticism than the general public.
by protastus on 12/3/23, 10:05 PM
The complexity and safety concerns have been pointed out multiple times. I stopped paying attention because this program appears to be on bureaucratic autopilot. Government contractors deliver parts, without control or accountability about the performance of the entire system. The complexity indicates that Artemis will get cancelled once it fails to achieve goals. I hope nobody dies.
The top engineering talent of the U.S. is not in this program. Poor engineering leadership is inevitable. Artemis looks like a jobs program.
by ulrashida on 12/3/23, 7:20 PM
by nabla9 on 12/3/23, 4:21 PM
15 rockets!
by avmich on 12/3/23, 10:09 PM
"Focus on the mission"
What's the mission? We're "returning to the Moon" - what does it mean? Boots on the regolith? I somehow doubt that. USA did that half a century ago, we're supposed to go farther. What's the mission this time?
We're going to the Moon for a more serious, longer exploration this time, right? That's the mission, right? So, we want more people at the same time on the Moon, we want more payloads, we want longer duration stays on the surface - in fact, we state that we want to establish a permanent "outpost", to use it for exploration and future uses and as a basis of something - some Moon-based station even bigger and better. Right?
What options do we have now? Especially - do we have good options to do that now given that we plan to land in about 2 years?
It's kind of a hard technical question, and many would be tempted - with pretty good arguments - to answer negatively to that. Apollo program didn't have this as a good option - it actually turned out to have a tragedy of Apollo-1 and "successful failure" of Apollo-13 to have man on the Moon within 1960-s, with 6 landings. Should we say today "no, we don't have that kind of the urgency today, and we do have much more elevated safety requirements, so we should do things differently than what we can accomplish in 2 years"?
Maybe it's a good idea to still try to work as if we have some urgency. That is, we don't know when to land - we choose the time ourselves - and, frankly, this time the mission isn't just land and come back, as it was before - so we could justify a schedule slip. But how big? How long we can shift our plans to the right? Maybe we should do a waterfall-ish style rethinking and replanning and have a good, rather realistic plan for a modest sub-goal - say, analog of Apollo-10, or even Apollo-11, with "just" landing - but in such a way that it would lead us not to Apollo-17 and "bye", but towards the desired Moon outpost?
I don't quite agree with Destin's skepticism regarding multiple launches to refuel on LEO. We didn't do that before, but we didn't do a lot of things before Apollo which are practically taken for granted today, like successful launches from Earth and successful dockings. It's an interesting technical problem to solve for SpaceX, and I do believe they'll have a working solution (I'd probably start thinking with expandable flexible displacement device, inflatable with some gases, in the tanks), but I don't think it will be a show-stopper for orbital refueling plans.
However what Starship HLS brings us - and what other proposed solutions for lunar landers seems not to - is that transition from "boot on the regolith" missions to "permanent outpost" state. Yes it's harder to get to in the first place, and it's likely we won't have Starship HLS on the Moon in ~2 years, but it's still a pretty good component of what we need to have missions which go beyond Apollo achievements. So it might make sense to keep developing Starship, and LEO refueling, and if other Moon lander options will come first - good, if not, we'll have a landing system which is capable to scale for a bigger missions worthy of our century.
by ATMLOTTOBEER on 12/3/23, 8:20 PM
by pcdoodle on 12/3/23, 4:59 PM
by ziffusion on 12/3/23, 5:09 PM