totm dec 2023 Artemis Discussion Thread

[tater]

Looks like with methlox for the lander, it closes. 26.5t for Orion CSM, 18.5t for the lander could work. That extra 60s of I_sp helps a lot. I'm basically assuming close to a LM dry mass here, a several hundred kg more for each stage (500kg is ~25% more than Apollo for the Ascent stage, though).

I didn't count on boiloff, though, so what little margin I left might need to eat into the extra dry mass to cover that.

[tater]

Actually, I screwed up! The 45t throw to TLI is assuming that the 45t cargo was under the fairing on the pad.

It would get to LEO with more residuals if it only flew with 18.5t, or even over 20t. That means the throw to TLI could be higher, easily closing this, maybe even with storable props.

Edited December 12, 2019 by tater

[jinnantonix]

4 hours ago, tater said:

You don't send people for that, that's what robots are for. 

That argument could be used for any proposed space exploration, to the Moon, Mars, anywhere.  But ... finding water on the Moon and establishing a fuel manufacturing facility there is an extremely complex task, and would be the best reason I can think of to send humans anywhere in space.  Repairing deep space probes and satellites is also a good reason.  Humans going to Mars is a distant dream, that in my opinion may never happen as robotic technology and AI improve.

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"Artemis" is tied to SLS.

Correct.  Everyone agrees the SLS is small and expensive, but it is currently the only properly rated means to get humans to lunar orbit and back to the Earth's surface in a single launch.  Eventually it will be replaced, but that would be at least a decade away, and NASA does not want to wait a decade.  The key to executing Artemis is to keep the number of launches of the SLS to one per mission, all other LVs WILL be commercial.  ie the Boeing lander concept will not be approved.  In my opinion, even the launch of the Lunar Asset on Artemis 8 should if possible replace the SLS Cargo with a commercial vehicle if available (think BFR or New Glenn), or EOR of multiple commercial launches.

@tater your arguments against SLS are all correct, but alternatives entail delaying the whole program for many years.  Some of us are happy the program exists and is showing some ambition.

 

[tater]

7 hours ago, jinnantonix said:

That argument could be used for any proposed space exploration, to the Moon, Mars, anywhere.  But ... finding water on the Moon and establishing a fuel manufacturing facility there is an extremely complex task, and would be the best reason I can think of to send humans anywhere in space.  Repairing deep space probes and satellites is also a good reason.  Humans going to Mars is a distant dream, that in my opinion may never happen as robotic technology and AI improve.

I'm happy with having human exploration, but given the COST of SLS/Orion, if your plan is for human sortie missions to find the location to do ISRU via humans on the surface, and we need to check... say 10 places, first. Then you just added a decade. For the amount of money spent on ONE such mission, you could check more than 10 places.

If you want it while you are still alive, you'd want that work done by robots.

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Correct.  Everyone agrees the SLS is small and expensive, but it is currently the only properly rated means to get humans to lunar orbit and back to the Earth's surface in a single launch.  Eventually it will be replaced, but that would be at least a decade away, and NASA does not want to wait a decade.  The key to executing Artemis is to keep the number of launches of the SLS to one per mission, all other LVs WILL be commercial.  ie the Boeing lander concept will not be approved.  In my opinion, even the launch of the Lunar Asset on Artemis 8 should if possible replace the SLS Cargo with a commercial vehicle if available (think BFR or New Glenn), or EOR of multiple commercial launches.

ISRU on the Moon, if the basic survey work to find a landing spot to do the ISRU has to be done by by humans is also at least a decade away.

 

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@tater your arguments against SLS are all correct, but alternatives entail delaying the whole program for many years.  Some of us are happy the program exists and is showing some ambition.

I didn't suggest delaying it, cause that's not a thing, they will spend this money if they fly or not---mission accomplished (the SLS/Orion mission is not spaceflight, and never has been). I said that survey work for a base location should be done by robots. This is flatly true.

Then, I was suggesting that if they are going to fly SLS 1 time per year, we'd be better with SLS launching something useful (a lander of any kind), vs something where SLS is a huge waste (Orion). Orion is a holdover to Constellation, and the Constellation architecture that Orion was designed to be part of had what amounts to SLS Block 2 Cargo as the only vehicle in the SLS class. Ares I to loft Orion, dock to Altair still on Ares V upper stage. Go to Moon. The problem with SLS is that it was never designed with a mission in mind (not counting "spend money in these places"), and the problem with Orion is that it WAS designed with a mission in mind, but it's a mission incompatible with sitting on top of SLS.

If we are stuck with Orion---which we are---it would be better to retrofit the mission it was designed to accomplish back onto it.

 

EDIT: Looks like any Artemis stuff in the near future (4-5 years, anyway) can only be proposed with Block 1, as EUS will not be a thing by 2024 according to NASA.

Edited December 12, 2019 by tater

[jinnantonix]

On 12/13/2019 at 1:16 AM, tater said:

I didn't suggest delaying it, cause that's not a thing,

Of course it is.  NASA can delay if they want, they just don't want to.  

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they will spend this money if they fly or not---mission accomplished (the SLS/Orion mission is not spaceflight, and never has been).

Nonsense.

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I said that survey work for a base location should be done by robots. This is flatly true.

Agreed, that's what projects like Peregrine lander and  Moon Viper are for.  But these are just about finding a suitable site  ... for a human landing.

[tater]

45 minutes ago, jinnantonix said:

Of course it is.  NASA can delay if they want, they just don't want to.  

It's funded from Congress, NASA has no choice at all. The funding has, and will continue for the foreseeable future, the outcome space nerds want---spaceflight---can certainly be delayed, but the spending? Nope, 2-4 billion a year until it's obviated by something else.

 

45 minutes ago, jinnantonix said:

Nonsense.

SLS/Orion is not about any mission in space at all. Some have been grafted on as make-work, but there is nothing it can actually do by itself. If it had a mission as a goal, it would have been designed differently (CH₄ or RP-1 as the fuel, for starters, hydrolox sustainers are idiotic, they should have saved that for S2).

45 minutes ago, jinnantonix said:

Agreed, that's what projects like Peregrine lander and  Moon Viper are for.  But these are just about finding a suitable site  ... for a human landing.

Yeah, so we can just land a hab when we find a suitable site. You can send a lot of robots for multiple billions of dollars (one SLS/Orion launch).

[jinnantonix]

8 hours ago, tater said:

It's funded from Congress, NASA has no choice at all. The funding has, and will continue for the foreseeable future, the outcome space nerds want---spaceflight---can certainly be delayed, but the spending? Nope, 2-4 billion a year until it's obviated by something else.

Nonsense.  Congress can and will cancel funding if there is no progress.  Artemis in total represents progress, so the funding stays in place.  The alternative is to cancel Artemis and Orion/SLS, and revert to missions with zero human involvement, all robotic.  From a technical viewpoint, I think that is an OK decision, but is bad PR for the space program. Considering the progress to date, I think it is better to proceed.
 

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SLS/Orion is not about any mission in space at all. Some have been grafted on as make-work, but there is nothing it can actually do by itself. If it had a mission as a goal, it would have been designed differently (CH₄ or RP-1 as the fuel, for starters, hydrolox sustainers are idiotic, they should have saved that for S2).

Nonsense.  Orion has been designed for the unique ambition of human rated deep space mission architecture - ad hoc LEO operations, Moon HL , or heliocentric missions.   It is the only human rated program for beyond LEO proposed for completion in the next decade.  Get it?  Who else is building the capability to safely get humans beyond LEO?   Get it ????????
 

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Yeah, so we can just land a hab when we find a suitable site. You can send a lot of robots for multiple billions of dollars (one SLS/Orion launch).

There is no plan to land a hab on the moon.  Artemis will use humans as a tool to establish ISRU on the moon, the goal is not habitation.

[tater]

12 hours ago, jinnantonix said:

Nonsense.  Congress can and will cancel funding if there is no progress.  Artemis in total represents progress, so the funding stays in place.  The alternative is to cancel Artemis and Orion/SLS, and revert to missions with zero human involvement, all robotic.  From a technical viewpoint, I think that is an OK decision, but is bad PR for the space program. Considering the progress to date, I think it is better to proceed.

They "can" do lots of things, but they won't. They are very much suffering from the sunk cost fallacy, plus, well, politics.

The OIG report didn't change anything, did it? Boeing gets treated as an "excellent" partner, and rewarded for their incompetence (this is the NASA OIG talking, not me). Nothing is slowing this gravy train. If the goal is to explore the Moon with humans, SLS/Orion is a terrible tool, and rational decision makers would have made a very different vehicle. Boeing is the grown up partner though, they make great stuff, and the extra cost is to.. oh, wow, Starliner... yikes. (yeah, cheap shot, but we pay far more for them, so they're supposed to catch all this before).

 

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Nonsense.  Orion has been designed for the unique ambition of human rated deep space mission architecture - ad hoc LEO operations, Moon HL , or heliocentric missions.   It is the only human rated program for beyond LEO proposed for completion in the next decade.  Get it?  Who else is building the capability to safely get humans beyond LEO?   Get it ????????

You apparently don't "get it." It was designed to do nothing at all save have a heatshield on Orion to survive BLEO EDL (ie: Orion is designed for BLEO direct EDL, the rest is designed to loft certain tons to BLEO (and those tons are not driven by a specific mission, they are simply target numbers irrespective of need). By "designed to do nothing," I mean that it had no specific mission goal at all. This is just a fact. The simple counterfactual is: suggest a goal (landing humans on the Moon, for example), then design clean sheet systems to accomplish that goal and then compare those notional systems (and more critically their capabilities) to SLS. Does SLS hit the same numbers? Not if you assume Orion as the crew component that all must include.

So of the system in question, we have SLS, the Orion capsule, and the ESM. The system can't do anything in any of those domains it's supposedly for that has any utility at all. Heliocentric? Do tell, sending Orion to Mars for Artemis IV, are we? Or in KSP terms just outside the Earth's SOI to achieve some contract award? ARM was a garbage mission for humans (robot would be better). I'm all for landing humans on the Moon again, but SLS is incapable of this.

1. SLS can't loft any existing capsule that can survive BLEO EDL such that it (one SLS stack) can land crew on the Moon, and return safely to the Earth (the notional max TLI throw could do Apollo, but we'd need an Apollo-mass capsule, etc, which we don't have). This is not just true of Block 1, but ALL blocks of SLS, even Block 2 with advanced boosters. No check mark here. SLS does not, and can not ever be an efficient way to design a crewed lunar surface architecture, it's too expensive, and will NEVER have the capability assuming 2:

2. Orion capsule, OTOH, while heavy, can do what you are suggesting. I'm not a huge fan, but I'll accept that it works. The problem of course is that it's so heavy that SLS's (currently notional) max capability is ~Saturn V throw to TLI, but the Orion capsule is ~2X the mass of the Apollo capsule. Just the capsule, mind you, because, 3:

3. The European SM is useless for any useful BLEO missions (sorry, the only useful mission I can imagine is the lunar surface). It's a holdover from Constellation---where the Orion CSM was to be launched by "not-SLS" (really "not-Ares V" ). The Orion CSM can actually come home from LLO---as long as it doesn't have to do the LOI burn itself. That architecture was a distributed launch architecture where Altair did the LOI burn for the stack.

To be useful and cost effective in an "all SLS" to the lunar surface regime, the throw to TLI needs to include the Orion CSM, and a lander, all in one launch. Either the lander, or the EUS needs to do the LOI burn. That has to be on the order of what, approaching 160 tons to TLI (the CSM/lander stack, plus prop residuals in the EUS)?

 

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There is no plan to land a hab on the moon.  Artemis will use humans as a tool to establish ISRU on the moon, the goal is not habitation.

A "hab" is literally anything primarily designed for humans to live in for any length of time. Gateway is to have a habitation module, albeit a small one. Humans spending any length of time on the surface (days, to weeks) would benefit from a dedicated habitat, vs living out of a tiny lander. Any SLS-based architecture to the lunar surface will have a tiny lander (tiny in crew volume). Lunar dust is nasty, and if you expect those sorts of EVAs, it would be far better to have a purpose-built hab, sent ahead some way or another, so that the suits can be separated from the sleeping quarters, etc (the dust is insidious).

The goal would not be "habitation," but if you send people to work, they require  a habitat to function.

Edited December 20, 2019 by tater

[tater]

BTW, my suggestion of landing a "hab" at the site where presumably we are doing ISRU, etc is because I see it as the best possible reuse this Artemis architecture allows.

Reuse of the lander? That seems amazingly unlikely to me, and any such use will likely cost far more than single use landers given the size of the landers in question---particularly when they are also asked to be temporary habs for days/weeks.

Places for reuse, IMHO?

LEO-->cislunar tugs, perhaps?

Habitats that get reused every mission, such that the landers themselves can be as small as possible (enough to carry the crew, and the supplies for the mission, but no extra living volume required).

 

[DAL59]

Given that a single Starship has more volume than the ISS, and the landing crew is at most 4 people, couldn't they just live in a preposisitoned starship for a year or more?  Heck, why even bother with SLS at all for this?  Use it for an outer planets prove. Given its launch cost of 1-2 billion dollars, you could send literally hundreds of people to the moon on Starship in 2024 for the same price as sending 4 via SLS.  Also, if they still aren't finished ONE SLS after a decade, how can they be expected to have a launch cadence capable of supporting lunar habitation?  SpaceX  has started building multiple rockets of similar size, and these will be ready with just a year or two.  SLS is built for a one time heavy payload, like maybe a Pluto orbiter or Mars-Earth transfer habitat, not for supporting a space station.

[jinnantonix]

5 minutes ago, DAL59 said:

Given that a single Starship has more volume than the ISS, and the landing crew is at most 4 people, couldn't they just live in a preposisitoned starship for a year or more?  Heck, why even bother with SLS at all for this?  Use it for an outer planets prove. Given its launch cost of 1-2 billion dollars, you could send literally hundreds of people to the moon on Starship in 2024 for the same price as sending 4 via SLS. 

Starship is a really long way from sending anyone, anywhere.  

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Also, if they still aren't finished ONE SLS after a decade, how can they be expected to have a launch cadence capable of supporting lunar habitation? 

Once SLS is proven for crewed space flight, with Artemis 1 and 2, SLS is expected to launch once a year for about 8 years.  It is unlikely to be required after that as commercial vehicles are expected to be ready for human flight.

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SpaceX  has started building multiple rockets of similar size, and these will be ready with just a year or two. 

Not for humans.

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SLS is built for a one time heavy payload, like maybe a Pluto orbiter or Mars-Earth transfer habitat, not for supporting a space station.

SLS is built to carry a human rated payload to beyond LEO destinations.  The first use is Artemis:  cislunar operations, in particular as part of developing the Lunar Gateway, and delivering crew to and from.  There is no other craft capable of this that will be ready within a decade.

[RCgothic]

The only thing SLS is any good for is enormous C3 for unmanned probes, which kind of obviates the expense of man-rating the thing.

SLS cannot by itself land a manned mission on the moon. It can't comanifest enough payload.

Orion by itself is never going beyond earth's sphere of influence. It's too small. Orbital construction is required.

I would rather scrap the pair of them and delay the manned space flight programme in exchange for a design that can either put man back on the moon in a single launch, or preferably a big dumb cheap booster that can put massive payloads into leo frequently and inexpensively and rendezvousing with a capsule put into orbit on a far smaller man-rated booster, usable for many purposes. Ares really did have the right idea.

Edited December 22, 2019 by RCgothic

[tater]

If Starship starts flying, all bets are off, I tend to not really consider it seriously for Artemis as a result (but as soon as it flies...).

I still prefer the ULA cislunar architecture they have been pushing for ages, but it will not get political traction because it competes with SLS (Shelby, look it up, lol). Sad, because an ACES-based cislunar architecture is pretty cool. The reuse part takes on a whole different dimension when you can reuse s a tug, and potentially reuse most things once in space.

[jinnantonix]

20 hours ago, RCgothic said:

SLS cannot by itself land a manned mission on the moon. It can't comanifest enough payload.

So what?  Apollo (even on Saturn V) could not deliver a manned mission to the moon's polar regions.  Multiple flights are required for that, and the Moon's poles are the proposed target.

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Orion by itself is never going beyond earth's sphere of influence. 

Orion by itself can't get off the launch pad.  Orion with SLS/EUS is capable of cislunar operations.  But with LEO rendezvous with a suitable booster (e.g. a naked FHe second stage) - it is capable of polar moon landings, heliocentric missions, perhaps more.

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 I would rather scrap the pair of them and delay the manned space flight programme in exchange for a design that can either put man back on the moon in a single launch

The aim is not to put a man on the moon, it is to develop fuel manufacturing there.  This could be done entirely by robot, but human involvement makes it politically charged.  Yes, Orion/SLS is expensive, but what price should we pay for the PR associated with next big step for human space exploration?

Edited December 23, 2019 by jinnantonix

[kerbiloid]

56 minutes ago, jinnantonix said:

The aim is not to put a man on the moon, it is to develop fuel manufacturing there.  This could be done entirely by robot

Sometimes it's easier to replace a robot with a human, because monkeys are better with monkey wrenches.

[tater]

8 hours ago, jinnantonix said:

So what?  Apollo (even on Saturn V) could not deliver a manned mission to the moon's polar regions.  Multiple flights are required for that, and the Moon's poles are the proposed target.

If crew missions to the poles was the design goal, then you design an architecture that can do that from the start. I agree that SLS in distributed launch is of capable of that, but multiple SLS launches for 1 mission is flatly absurd. It's simply too expensive to make sense. What's the goal? To decrease cost in cislunar space via ISRU! What's the plan? To build ISRU on the Moon using a rocket that once dev is amortized costs what at 2 per year? 3-6 billion? (3.something annual cost divided by 2 plus optimistic marginal cost, and a pro rata share of dev north of 50 billion). ISRU needs to be cheaper all-in per kg than launching props to cislunar some other way or it's a waste of time, and it starts the game 50 billion in the hole if it uses SLS.

Again, SLS should go right to cargo version, and Orion should go "not SLS" then maybe SLS isn't a total waste of all that money.

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Orion by itself can't get off the launch pad.  Orion with SLS/EUS is capable of cislunar operations.  But with LEO rendezvous with a suitable booster (e.g. a naked FHe second stage) - it is capable of polar moon landings, heliocentric missions, perhaps more.

Yeah, this is the right way, I agree. More Constellation like. This is not because I like Constellation as a program, but because the human spacecraft we have right now, Orion, was designed for the Constellation mission, so that's pretty much what it needs to have to be useful for anything.

Of course as soon as you start doing distributed launches with better launch vehicles than SLS, you basically obviate SLS.

Currently the ONLY advantage of SLS is 100% notional at this point: an 8.4 m diameter fairing (or even a 10m one, which is more notional). That of course requires EUS (doesn't exist), then the fairing. (dunno about VAB/MLP requirements)

 

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The aim is not to put a man on the moon, it is to develop fuel manufacturing there.  This could be done entirely by robot, but human involvement makes it politically charged.  Yes, Orion/SLS is expensive, but what price should we pay for the PR associated with next big step for human space exploration?

I'm a huge fan of human spaceflight. I think it's worth a lot just for the inspirational aspect of it. It just sickens me to see a program that is so rudderless and wasteful.

Edited December 23, 2019 by tater

[tater]

If we ever get to the point where landing on the Moon is a routine thing, we definitely need dedicated landing pads.

[kerbiloid]

11 hours ago, tater said:

dedicated landing pads.

Or portable helipads... heligrills?.. helitrampolines?..
https://www.soloy.com/portable-heliport.html

Spoiler

P.S.
That space below is probably for rocket copters and their plumes.

P.P.S.
Hooligan Labs have such mod for KSP, but it's outdated. Though, maybe still works, as probably it's just an animated model..

Edited December 27, 2019 by kerbiloid

[jinnantonix]

On 12/27/2019 at 7:07 AM, tater said:

 

I question whether those ejecta paths cross NRHO.

[tater]

3 hours ago, jinnantonix said:

I question whether those ejecta paths cross NRHO.

What does Phil Metzger know, right?

He's literally the guy NASA has working on large lander engine plume regolith interactions for... Artemis.

[jadebenn]

On 12/26/2019 at 2:07 PM, tater said:

If we ever get to the point where landing on the Moon is a routine thing, we definitely need dedicated landing pads.

If a 40 ton lander does that, that's yet another nail in the coffin of the boneheaded idea of bringing down an entire Starship to the Lunar surface.

Edited January 4, 2020 by jadebenn

[sh1pman]

27 minutes ago, jadebenn said:

If a 40 ton lander does that, that's yet another nail in the coffin of the boneheaded idea of bringing down an entire Starship to the Lunar surface.

No, it only means that Starship will need dedicated landing pads. 

[jadebenn]

21 minutes ago, sh1pman said:

No, it only means that Starship will need dedicated landing pads. 

I think you're underestimating the difficulty of building a reinforced concrete structure on another celestial body.

Look at how much effort goes into building one on Earth, then consider you have zero local infrastructure, an extremely limited amount of construction materials, and an absolutely tiny construction crew working in one of the most hazardous environments known to man.

Building the pad alone would almost certainly be a multi-year effort.

[Wjolcz]

3 minutes ago, jadebenn said:

I think you're underestimating the difficulty of building a reinforced concrete structure on another celestial body.

Look at how much effort goes into building one on Earth, then consider you have zero local infrastructure, an extremely limited amount of construction materials, and an absolutely tiny construction crew working in one of the most hazardous environments known to man.

Building the pad alone would almost certainly be a multi-year effort.

Can't regolith be formed into bricks? I'd imagine that if you can do that to soil on Earth then regolith would probably not be much different or even better suited for that since the particles are rather sharp and pointy. Maybe they would "lock" onto each other on the micro scale.

Has anything like this ever been tried?

[jadebenn]

3 minutes ago, Wjolcz said:

Has anything like this ever been tried?

Do you really need to ask?

No. It's completely untreaded ground.