RCgothic

With or without the upgrade the deluge system probably could withstand a launch-realistic test firing because it will have to in a launch. A full flight duration firing is of course quite different and any system to withstand that would need a tank capacity far larger than is reasonable. But they still won't do a full power launch simulation of the system because the launch clamps can't hold down a partially-fuelled stack at full thrust, and there's no good reason to take the small but potentially severely consequential risk of fully fuelling a stack and lighting the engines except for conducting an actual launch.

Agreed with most of what he said up until 17mins or so. I like ALPACA, but not more than either of the other two HLS solutions and I'm willing to wait. In my opinion getting back to the moon fast is not as important as getting back in a cost effective and scalable fashion, so I'm not especially upset ALPACA wasn't picked looking at the potential of the ones that were. Secondly, Starship doesn't need to be fully crew-rated for Earth entry descent and landing to perform creed lunar missions, and that wouldn't hold things up particularly in the absence of SLS. The crew can meet Starship in LEO via Dragon/Starliner, or even putting Orion atop an expendable Superheavy is something that looks comparatively quick and cheap. With Orion's oversized LAS and Superheavy's potentially high flight rate (even expendably), getting Superheavy crew-rated for launch really wouldn't that big a deal. Thirdly, even ALPACA would have needed orbital refuelling. This is just something we need to master, and he doesn't even doubt we will. So once again my disagreement is on schedule not feasibility, and so each to their own.

Saturn V could manage upwards of 140t to LEO and did not have a reasonably sized lander.

The capability options were interesting but additional complexity for greater performance isn't going to help with the cost, cadence, comanifest volume or schedule issues.

There just isn't any way to modify any part of SLS/Orion without making the cost and schedule problem worse, not better. All the low-cost/high-cadence architectures that we could reasonably achieve within 10 years are Earth Orbit Rendezvous using some combination of Falcon/Superheavy/Vulcan/New Glenn and Dragon/Starship HLS/BO HLS and probably Starliner once they finally get that flying. The biggest modifications to those basic elements we could get completed in a reasonable timescale and budget would be an expendable upper stage for Superheavy, and maybe one new service/propulsion module.

The key to a cost-effective replacement for SLS is for the love of Jeb never award any more business to Boeing, Aerojet Rocketdyne or Northrop Grumman.

1 Exploration Upper Stage for Artemis IV Contract Value: $9.7B Number of articles: 1 Cost per SLS1B: $482m That isn't how maths works. NASA keep trying to pretend tax dollars spent on R&D don't count, but actually they do.

Hey kids, you too can design a rocket with fantasy performance if you make an error in the 1st stage dry mass figure used for the DV calculations! The gross mass at burnout figure was correct, but later where the spreadsheet used dry mass for the DV calc it wasn't using the same figure. More reasonable values for payloads were 2-stage 165t to LEO and 75t direct to TLI. It's still got multiple useful applications though, unlike SLS. The 205t 3-stage payload might be a little low on the TWR side at liftoff though - down to 1.13. Apologies for the quality, I applied a filter to soften the raster a bit. @sevenperforce I've got 1st stage dry mass about 5% plus engines, 2nd & 3rd stages 8% plus engines, both significantly heavier than the STS super lightweight external tank. The reason it's not J2-X on the 2nd stage is 6-7 don't fit at an 8.4m diameter.

I've been messing about with a design I might have chosen in 2011 instead of SLS. It keeps the 5-segment SRBs and 8.4m form factor to keep congress happy, but the first stage uses 3x RD-171Ms (or maybe a 171M and 4 RD180s) and the 2nd stage uses 7x J2s. It would be capable of throwing 285t payload to LEO. With an optional 285t 3rd stage (2x J2-X) it could throw around 120t to TLI in a single launch (in this case the 3rd stage ignition would need to begin prior to achieving LEO), and would weigh 4180t on the pad and stand ~95m tall to the 3rd stage payload adaptor. The 3rd stage can be placed fully fuelled into LEO to meet a payload already there. 200t to TLI or 120t to TMI. Credible Mars missions and lunar surface bases? Yup. These are all within the transporter crawler and VAB margins, would have though there might be a challenge with the SRBs bridging two stages and RD engines would probably have run into foreign issues by now. Fun exercise

In order to get 41t of lander to NRHO takes ~48.5t to TLI.

It may be overkill for that, but eventually the mission planners start asking "Well what isn't it overkill for?" And that's when things get exciting. (Even more exciting). Personally I'm never going to get excited or feel motivated to support downgrading the mission to what SLS can limp into a lunar round trip. Compared to what we could have once mission planners wake up to what we can do with Starship and the BO lander architectures? No thanks. Even if using the current architectures takes a decade longer than an alternative (and as previously discussed it would only be the other way around), I still wouldn't make that trade. A skeletal mission could only lead to flags and footprints, disappointment, and cancellation. There's no scope for future progression. The HLS architectures give access to the entire solar system and obsolesce the grossly over expensive SLS/Orion ESM at the same time. There's one good part of the Artemis Programme and HLS is it.

Want to do it with a Boeing Lander? They don't have a lander. Want to do it in a single launch? Can't get a meaningful mission through NRHO. Don't want to go through NRHO? That's the only place SLS Orion can go. Want to do a skeletal mission? Why? Also no lander and certainly not safer. Want to go sooner? That's not what changing the mission parameters gets.

As others have said, it's not the regulation it's the opaqueness of the process that's frustrating.

The battle between F4Fs and Zeros with one side suffering disproportionate casualties brings to mind a "Lanchester Square Collapse". Also it would appear that Zeros favouring heavy short-range firepower and manoeuvrability folds in with the doctrine of getting on the target's tail rather than deflection shooting where more individual shots from further away might be more useful.

Contact still not established, hope fading. https://www.theguardian.com/world/2023/sep/26/india-chandrayaan-3-vikram-lander-pragyan-sleep-mode-failure This article is a bit deficient in explaining that this would be a mission extension and a failure to establish communications is not a mission failure.

NSF stream with Eric Berger last night was pretty certain no starship flight before late October at the earliest.

Lying down not only protects you from being tossed, but helps to take you out of the path of flying debris. If you survive the initial blast, within a few minutes do your best to put out any fires, restore the integrity of your current location's exterior against fallout, then retreat to the location furthest from any exterior boundaries for at least 24h unless immediately threatened by some other hazard like fire. The danger from fallout should reduce by ~80% over this time.

Makes sense with the Raptor performance increase.

You're basically describing mass effect fields from Mass Effect. Copy across.

Pics or it didn't happen, basically.

XKCD1235

What I read there is another typical "leave us alone" statement of vagary by the FAA. The license may come as early as next month, but they haven't actually said there's no possibility it won't come as early as today. They could have said "The license will be issued in October". Or "The license *won't* be issued in September". But they didn't. Meaningless. It'll come when it comes.

That's definitely a thing you do when ready to launch.

There is right now a commercial flight around the moon scheduled.