totm dec 2023 Artemis Discussion Thread

[kerbiloid]

Depends on the Sentinel ICBM funding.

[Minmus Taster]

Whelp.

https://futurism.com/nasa-sls-moon-rocket-might-be-canceled

[Mr. Kerbin]

36 minutes ago, Minmus Taster said:

Whelp.

https://futurism.com/nasa-sls-moon-rocket-might-be-canceled

NOOOO!

I'VE WAITED TOO LONG

FOR THIS TO JUST BE CANCELLED 

AHHHHHHHHHHHHHHHHHHH

[tater]

36 minutes ago, Mr. Kerbin said:

NOOOO!

I'VE WAITED TOO LONG

FOR THIS TO JUST BE CANCELLED 

AHHHHHHHHHHHHHHHHHHH

Now is the time to kill things that need killing. NASA is facing some issues with a few programs:

1. ISS decommission, and what if anything replaces it.

2. Gateway, which partially came into being to bring all the ISS partners along to cislunar space.

3. SLS/Orion, which is very linked to #2—since the system is lousy, and can't do anything else.

 

The commercial stations program doesn't have enough money or momentum to ensure we have astronauts continuously in space. At some point very soon that needs to either happen, or ISS runs out of time without a replacement.

Gateway has always been kinda garbage, but since the primary NASA ISS partner was not interested in Gateway, it seems like an even bigger waste of money. The international partners for Gateway right now seem to want boots and flags on the lunar surface, and Gateway was the cost of entry—so it can go away as long as they still get their boots/footprints (sorry, Canada, no arms required except the ones attached to people).

SLS/Orion has been the largest share of the cash so far, and has done nothing useful yet. When fully operational, the capabilities can never be useful enough to justify the cost. Every single RS-25 on the core stage costs as much as an entire Starship stack. The SRBs cost a billion $. It's completely insane for a vehicle incapable of any useful mission. Orion, assuming they can sort the heat shield, can at least hold crew and get them home, hopefully. Maybe the best path is to fly the stages already 100% complete, then trash SLS. Keep Orion, but launch on another vehicle (New Glenn?). Work on an improved Orion CM with grossly more dv, and maybe stick it on top of Super Heavy (with an expendable stage 2)?

 

[Ultimate Steve]

Generally the idea behind Artemis as it is now was that there wasn't the political will to do a proper moon program where everything is funded and planned out from the beginning. Artemis made the best of a bad situation and relied on gluing everyone's desires together to make the program as cancellation resistant as possible and slowly asking for more funding until they've glued together a landing program made out of whatever additional pieces were politically fundable at any given time. Cancelling Artemis would upset a lot of allied nations, a lot of old space contractors, a lot of senators from Alabama, and a lot of new space contractors, and a lot of other people.

What they didn't anticipate is that private industry may soon be able to do a proper moon program pretty much by themselves that may reach the moon during a similar timeframe. I have mixed feelings about this. By all means sunk cost fallacy and all, but it must be really frustrating for the people working on SLS to get this close. That's about as far as I can go without getting into politics.

[darthgently]

1 hour ago, Ultimate Steve said:

Generally the idea behind Artemis as it is now was that there wasn't the political will to do a proper moon program where everything is funded and planned out from the beginning. Artemis made the best of a bad situation and relied on gluing everyone's desires together to make the program as cancellation resistant as possible and slowly asking for more funding until they've glued together a landing program made out of whatever additional pieces were politically fundable at any given time. Cancelling Artemis would upset a lot of allied nations, a lot of old space contractors, a lot of senators from Alabama, and a lot of new space contractors, and a lot of other people.

What they didn't anticipate is that private industry may soon be able to do a proper moon program pretty much by themselves that may reach the moon during a similar timeframe. I have mixed feelings about this. By all means sunk cost fallacy and all, but it must be really frustrating for the people working on SLS to get this close. That's about as far as I can go without getting into politics.

If we were in a post-scarcity scenario then continuing a publicly funded Artemis would be a simple thing to do.  But as it stands, continuing it means something/someone else sacrifices for it to continue.  And it isn’t like those sacrificing are volunteering.  At some point one might consider that rather than deeming it a tough call whether to continue, to instead deem it unethical to continue based on anyone’s opinion other than those making the sacrifice

Edited November 14 by darthgently

[tater]

1 hour ago, Ultimate Steve said:

Generally the idea behind Artemis as it is now was that there wasn't the political will to do a proper moon program where everything is funded and planned out from the beginning. Artemis made the best of a bad situation and relied on gluing everyone's desires together to make the program as cancellation resistant as possible and slowly asking for more funding until they've glued together a landing program made out of whatever additional pieces were politically fundable at any given time. Cancelling Artemis would upset a lot of allied nations, a lot of old space contractors, a lot of senators from Alabama, and a lot of new space contractors, and a lot of other people.

What they didn't anticipate is that private industry may soon be able to do a proper moon program pretty much by themselves that may reach the moon during a similar timeframe. I have mixed feelings about this. By all means sunk cost fallacy and all, but it must be really frustrating for the people working on SLS to get this close. That's about as far as I can go without getting into politics.

Artemis was making lemonade out of the lemon NASA has—SLS/Orion.

Cancelling Artemis would be a bad idea, but cancelling SLS/Orion would not. All the partners actually want is dusty spacesuits with their own flags on the shoulders, how they get there doesn't matter as long as the US taxpayer foots the large majority of the bill (I could say the same about so many international projects).

As long as there is the timelines don't change substantially, not sure I see a problem with keeping Artemis, dumping SLS.

Launch crew with existing crew vehicles (which for now is Dragon). Do Earth orbit Rendezvous with a tanked up transit vehicle (presumably a Starship variant). Land with HLS—first Starship, then the BO lander. Return to LEO, disembark crew to CCV, back home to Earth.

[StrandedonEarth]

4 hours ago, tater said:

Gateway has always been kinda garbage, but since the primary NASA ISS partner was not interested in Gateway, it seems like an even bigger waste of money....(sorry, Canada, no arms required).

Could the Gateway modules under production  construction function as the core of the next LEO station? Since Gateway won't be needed in its intended role once SLS is cancelled.

And SLS will be cancelled; it's painfully obvious that it's an expensive and practically useless dead end, and prime contractor Boeing would do well to back away from all things space right now until it gets its house back in order (best done by having an engineer in charge instead of an accountant).

[Codraroll]

On 11/14/2024 at 10:41 PM, Ultimate Steve said:

By all means sunk cost fallacy and all, but it must be really frustrating for the people working on SLS to get this close.

This close to what, is the big question. The only thing they were close to, was the start of a program reliant on a rocket that could fly every other year to the cost of several billion dollars. SLS was not about to do anything useful, or achieve anything. The program had to invent useless tasks only SLS could complete, because there were better and cheaper ways to achieve all other tasks that could also be done by other rockets. And the useful tasks no other rockets could do, SLS couldn't do either.

Let's face it, SLS was only ever good at costing money and being a rocket too powerful to use in low Earth orbit, yet too weak to go beyond Earth orbit. The longer it was kept on the table, the more money it would waste without being useful.

[RCgothic]

SLS was also really good at shaking sensitive scientific payloads to pieces with those enormous SRBs.

Nearly every bit of Artemis except the Landers and the EVA suits could be ditched and nothing of value would be lost. Getting rid of Gateway, Orion and SLS would save a lot of money for more regular flights and actual mission hardware.

[darthgently]

On 11/14/2024 at 6:40 PM, tater said:

Artemis was making lemonade out of the lemon NASA has—SLS/Orion.

Cancelling Artemis would be a bad idea, but cancelling SLS/Orion would not.

Good point and point taken.  I think even Starliner may be salvageable in lieu of Orion if it got to that ludicrous point.  That heat shield issue just doesn’t click, or the fact that it is taking so long to move on from doesn’t click.  Was Starliner designed to reenter from the moon? Idk

[darthgently]

What I’m reading here and there says that Starliner would need a heat shield upgrade and perhaps other upgrades to aero brake from lunar return

(That was supposed to merge with previous, but didn’t)

Edited Saturday at 09:35 AM by darthgently

[AckSed]

I believe it's time to truck out that Apogee video on redundancy using HLS:

tl;dw you can either truck astronauts up with Dragon to use HLS plus depot and tanker as a ferry to the landing system already in orbit, or adapt Dragon to add lunar navigation and radiation shielding, and a docking port on the trunk to allow use of the SuperDraco thrusters as an abort system.

[darthgently]

On 11/16/2024 at 8:55 AM, AckSed said:

I believe it's time to truck out that Apogee video on redundancy using HLS:

tl;dw you can either truck astronauts up with Dragon to use HLS plus depot and tanker as a ferry to the landing system already in orbit, or adapt Dragon to add lunar navigation and radiation shielding, and a docking port on the trunk to allow use of the SuperDraco thrusters as an abort system.

The title of that vid may end up being prescient

[tater]

On 11/16/2024 at 6:55 AM, AckSed said:

I believe it's time to truck out that Apogee video on redundancy using HLS:

As has been said (and shown) many times in this thread and the SpaceX thread, the mere existence of a functional SpaceX HLS obviates SLS.

[Exoscientist]

On 11/14/2024 at 1:44 PM, Minmus Taster said:

Whelp.

https://futurism.com/nasa-sls-moon-rocket-might-be-canceled

 

 The renewed discussions on the possibility SLS might be cancelled have renewed discussion of replacement architectures for returning us to the Moon. I mentioned in the thread: 

that because of the low production cost of the Starship, SpaceX should investigate a smaller system with the Starship as the 1st stage and a "mini-starship" as an upper stage. A key cost fact is SpaceX amply demonstrated with the Falcon 9 that the first stage is much easier to reuse than the upper stage. Then I estimated a $11.7 million cost for such a Starship/mini-Starship launcher as partially reusable. 

I calculated the expendable version might have an LEO  payload of 120 tons. Then based on the Falcon 9, if the Starship as 1st stage landed downrange this launcher might still get 80% payload of the expendable version. That would mean still 100 ton payload as partially reusable at a $11.7 million cost. That's a cost per kilo of ~$120 per kilo. That's nearly two orders of magntitude cheaper that the going rate just a few years ago, before SpaceX, of $10,000 per kilo. And even with the partially reusable Falcon 9, the price per kilo is still $3,000 per kilo. Quite importantly, because it doesn't need orbital TPS, orbital refueling, tank stretch or upgraded Raptors, this is a capability we have now. 

 I argue that this is better than the current approach. For instance the fully reusable Superheavy/Starship V2 will have payload at 100+ tons, and still need all of orbit capable TPS, orbital refueling, tank stretch and upgraded raptors. And it will need all of these to get a ca. $10 million reusable launch cost. But the SS/mini-SS will reach the same payload capability, at only be 1/3rd the size of the SH/SS, without the difficult technical advances.

 The advantage of this approach extends also to lunar missions. SpaceX wants a multiple refueling approach of SH/SS for lunar missions. This will be in the range of 18 total flights with refuleings, the orbital depot, and the Starship HLS itself. In contrast the SS/mini-SS can do it in a single launch. And the current plan needing 18 launches will actually be 18*4 = 72 times bigger than using a single Starship. Taking into account the size also of the mini-Starship the current SH/SS lunar plan will be about 50 times the size of just a single SS/mini-SS.

 A comparison of the relatively sizes of the two approaches for getting to the Moon:

 

 Compared to:

  Bob Clark

Edited Monday at 12:52 PM by Exoscientist

[tater]

Per Ken's video math, a SS v3 depot (2300t full) takes 9-10 flights to fill totally, or ~6 for enough to just to top off HLS. Assume HLS is V2 height, so 1500t props. 90t dry +10t cargo (per Ken's video). That gets a ferry flight with 8 launches—which counts leaving a depot in orbit. The ferry has 10.2 km/s of dv, 2.9 km/s more than it needs for a NRHO RT, 2 km/s more than it needs for LLO.

The Ferry needs ~170t of props to return from NRHO to LEO. That means the Ferry actually arrives at NRHO with an extra 320t of props. HLS needs 350t of props to do a RT from NRHO to the lunar surface. The HLS starts with 10.2 km/s in LEO, and arrives at NRHO with 490t of props for landing. This means it can do a RT  from NRHO, and it comes back to our Ferry with 33t of residual props...

It needs 350t to do a RT. The crew can transfer to the Ferry (or Gateway if that's a thing), the Ferry then gives HLS 320t of props, and HLS can now do another RT. This closes, though the next flight comes back to Gateway/NRHO with just 3t of props remaining—so Ferry heads home with HLS at just 323t props. Of course the next crew arrives with 320t more props. So now HLS has 643t of props, meaning the refill happens first (optimally before, then after flight, donating a few 10s of tons, then the rest later. Regardless, this CONOPS is completely sustainable.

[tater]

Note that the above is actually a rationale for Gateway as perhaps the crew stays there while the refills happen, so if there is an issue, they can camp out til another Ferry can pick them up.

Also, for clarity the HLS is V2, the surface to LEO ships are V3 (figured the tall one not best for a lander). It works even better if the Ferry is V3.

[RCgothic]

On 11/17/2024 at 5:18 PM, Exoscientist said:

A comparison of the relatively sizes of the two approaches for getting to the Moon:

 

 Compared to:

 

Cost of those top 18 launches: potentially $18m for 100t *payload* to lunar surface with basically any cadence once produced.

Cost of bottom launch: ~$99m not counting  expended spacecraft, for ~10t *total* to lunar surface and probably 1/10th as often bottlenecked by production of the bits that have to be expended.

 

 

Option 1 gets over 100 times as much usefulness accomplished (20 times as much payload 6 times as often, budget limited) on the same budget as option 2, so option 2 can get in the bin AFAIC.

Even if the reusable launch misses it's cost target by a factor of *10*, it's still over ten times better than expendable.

 

 

Purely considering a bid for an SLS replacement:

SpaceX can bid as much for Option 1 as for Option 2 per mission because nobody else can undercut them. Assume a 20% profit margin on Option 2. SpaceX makes $20m. For Option 1 they'd make $100m.

SpaceX should not bid Option 2 for anything.

And they should not accept a cheque to do Option 2 excepting that it doesn't distract from their pursuit of Option 1.

Edited Tuesday at 07:40 AM by RCgothic

[Exoscientist]

On 11/18/2024 at 4:03 PM, RCgothic said:

Cost of those top 18 launches: potentially $18m for 100t *payload* to lunar surface with basically any cadence once produced.

Cost of bottom launch: ~$99m not counting  expended spacecraft, for ~10t *total* to lunar surface and probably 1/10th as often bottlenecked by production of the bits that have to be expended.

 

 

Option 1 gets over 100 times as much usefulness accomplished (20 times as much payload 6 times as often, budget limited) on the same budget as option 2, so option 2 can get in the bin AFAIC.

Even if the reusable launch misses it's cost target by a factor of *10*, it's still over ten times better than expendable.

Purely considering a bid for an SLS replacement:

SpaceX can bid as much for Option 1 as for Option 2 per mission because nobody else can undercut them. Assume a 20% profit margin on Option 2. SpaceX makes $20m. For Option 1 they'd make $100m.

SpaceX should not bid Option 2 for anything.

And they should not accept a cheque to do Option 2 excepting that it doesn't distract from their pursuit of Option 1.

 For my cost estimates I was taking cost reductions by a factor of 10 in both scenarios by reusability. If for Superheavy/Starship you take it to be a reduction by a factor 100 in cost by reusability then the same would be true for Starship/mini-Starship and costs would be ca. $1 million per launch, still much lower than a supposed $18 million for 18 launches with reusability of the full Superheavy/Starship.

There really is no logical reason to use the multiple launch approach with 18 SuperHeavy/Starship launches to accomplish a single mission compared to a single launch approach of a rocket at only 1/3rd the size. It would be like the Apollo engineers running the numbers on the Saturn V and realizing it could do a Moon mission in a single launch, decided to do it instead with 50 launches of the Saturn V for that one single Moon mission.

 The argument of the greater payload of the multiple launch approach doesn’t hold water either. SpaceX said their multiple launch, multiple refueling approach can get 100 tons cargo to the lunar surface. The Starship/mini-Starship using an existing Falcon 9 upper stage or Centaur V upper stage as the lander can get 20+ tons cargo to the lunar surface. Then the equivalent of 50 launches of this launcher can actually get 1,000 tons to the lunar surface.

  Bob Clark

Edited 9 hours ago by Exoscientist
Clarity