ESA needs to save NASA’s Moon plans.

[Beccab]

9 minutes ago, Stosh said:

what exactly is the point of 2 week duration Lunar sorties?

Going on the moon?

[tater]

11 minutes ago, Stosh said:

At some point in time you have to send people to practice new skills and install new equipment, otherwise what exactly is the point of 2 week duration Lunar sorties?

The initial missions have been set to be about that. I think there is the possibility of them increasing to 30-40 days or so (Gateway). Surface missions are limited by the lunar day. Hence the idea of the surface base being at crater rims that are in near constant sunlight.

Gateway is just a space station. The only difference is that is it in almost constant sunlight, and has no radiation protection due to half the sky being rock  (and the Moon is out in front/side of the magnetopause much of the time).

4 minutes ago, Exoscientist said:

You could like the SpaceX Dragon put the launch escape hypergolic thrusters on the capsule, eliminating the launch escape tower. You would have like the Dragon an escape system that worked all the way to orbit. 

You would then put more propellant on it so the same thrusters could be used for lunar orbit insertion, eliminating the service modules propulsion systems. Note though some of the dry mass of the service module would have to be retained since it contains some consumables and the power systems.

   Robert Clark

In the context of SLS/Orion that would mean a new CSM. Lesse, Orion started life in ~2004 with Constellation, and it will certainly not launch all up until whenever Artemis II is—so 2024? So we can expect an Orion replacement bythe same people in 2042.

 

[Stosh]

23 minutes ago, Beccab said:

Going on the moon?

Boots and Flags 2.0?

[Stosh]

22 minutes ago, tater said:

The initial missions have been set to be about that. I think there is the possibility of them increasing to 30-40 days or so (Gateway). Surface missions are limited by the lunar day. Hence the idea of the surface base being at crater rims that are in near constant sunlight.

Gateway is just a space station. The only difference is that is it in almost constant sunlight, and has no radiation protection due to half the sky being rock  (and the Moon is out in front/side of the magnetopause much of the time).

In the context of SLS/Orion that would mean a new CSM. Lesse, Orion started life in ~2004 with Constellation, and it will certainly not launch all up until whenever Artemis II is—so 2024? So we can expect an Orion replacement bythe same people in 2042.

 

ISTR that Gateway will also be a Comms hub.

~3 week roundtrips, two weeks surface, ceratinly are longer than Apollo. But Gateway LD studies seem more useful to NEO and Mars trips. Gateway is US National Lab 2.0, for not just analog but realistic exposure all the time in Radiation studies.

More importantly with Gateway, Artemis survives National politics by having us foreigners sign onto the accords (20 Partners now with France the other day?) and spreading out development across other tax payers.

If ESA has another destination, beyond commercial LEO, they will have even more reason to develop a Human Launch capacity as well - so backup for the inevitable launch accidents that ground space programs.

Maybe even us Canadians will finally pony up the money and buy a full capsule ride and stay at the Gateway Hotel. Beer Pong in Micro Gravity?

 

[tater]

3 minutes ago, Stosh said:

ISTR that Gateway will also be a Comms hub.

Which could be done with a couple satellites (better, and for less $).

3 minutes ago, Stosh said:

~3 week roundtrips, two weeks surface, ceratinly are longer than Apollo. But Gateway LD studies seem more useful to NEO and Mars trips. Gateway is US National Lab 2.0, for not just analog but realistic exposure all the time in Radiation studies.

The surface is the only place that matters. Yeah, 2 weeks is better than 3 days, but Gateway doesn't help, it costs dv. With a flight cadence of 1/year, there are no long duration radiation studies possible, as no one will be there for a long duration—and any study using just instruments could be done with a small spacecraft. Not to mention the ethics of putting people in a harsh radiation environment just to do what, see how much more cancer they get? At least on the surface, or on a Mars mission, the trade is the value of the mission, vs the risk of poor health outcomes later. Astronauts would likely take that risk to walk on Mars, or explore the lunar suface, why take that risk to be a lab rat?

 

1 minute ago, Stosh said:

More importantly with Gateway, Artemis survives National politics by having us foreigners sign onto the accords (20 Partners now with France the other day?) and spreading out development across other tax payers.

The money contributed by "not US taxpayers" is functionally zero.

Gateway itself is a waste of time for the foreseeable future. It exists solely because SLS/Orion is awful, and can't go anywhere. There are pro arguments for the Gateway that can be made, but it's pushes entirely because Orion can't do better.

[sevenperforce]

1 hour ago, Exoscientist said:

You could like the SpaceX Dragon put the launch escape hypergolic thrusters on the capsule, eliminating the launch escape tower. You would have like the Dragon an escape system that worked all the way to orbit. 

You would then put more propellant on it so the same thrusters could be used for lunar orbit insertion, eliminating the service modules propulsion systems. Note though some of the dry mass of the service module would have to be retained since it contains some consumables and the power systems.

You are describing a completely new spacecraft.

Putting massive propellant tanks on this new Frankenorion would not only require a complete redesign of the capsule, but it wouldn’t fit within the existing OML. And even if it did fit, it would make Orion vastly heavier, which in turn means you need more thrust on the LAS system, which means more propellant, and so on and so forth. The existing escape tower is sized only for pulling the capsule away, not the service module too.

Also real-world engines have minimum throttle ranges, so you would still need a separate service propulsion system somewhere for OMS. 

2 hours ago, Exoscientist said:

I get if we take the delta-v to enter and exit lunar orbit as 800 m/s, it is variable depending on altitude, and the Isp for the hypergolics as 3200 m/s, the crewed lunar lander can be about 50% larger to about 22 tons.

dV to enter or exit lunar orbit from an Earth trajectory is 900-930 m/s. 

2 hours ago, Exoscientist said:

 Also, note you should separate the cargo and crew flights. I get about 25 tons  payload one way to lunar surface using hypergolics with no Orion or service module included.

SLS can’t fly more than once a year at most so using it to send cargo to the moon is a non-starter. 

[tater]

6 minutes ago, sevenperforce said:

SLS can’t fly more than once a year at most so using it to send cargo to the moon is a non-starter. 

It could send a large hab or something. In one of the threads (Artemis?) I suggested that because SLS won't go away (politics), it would be best used to deliver a large object to the surface. With RL-10 as the engine, a BLock 2 could get 22t dry to the surface—that's very slightly lower than the planned mass of the Bigelow 330 for an idea of how big a hab could be sent with that mass. It could just be a several deck high, 8.4m tube (SS like)—or hammerhead it, and make it more like 10m dia. At the nominal upper limit for Block 1b, 40t to TLI, more like 19t to the surface.

A far better use of SLS, IMHO.

Looks like Al for ISS pressure vessels is 4.8mm, looks to be under 1 ton per 10m dia ring, 2m high (thinking of it like Starship, but AL). There is then Whipple shielding on top, etc, so call it 2 tons/ring. Would be easy to make a 3 crew deck tall habitat with that dry mass budget, maybe put the props (hydrolox) on top—no fairing, make it a nose cone, dual use).

[Exoscientist]

 About the Centaur as the lander,  there is this proposal described here:

 

 

ToughSF @ToughSf

Outline by

@ulalaunch

for a lunar lander based on the Centaur upper stage. It can use a large and efficient RL-10 engine and then land on its side, bringing its payload close to the Moon's surface. There's variants for crew, cargo, wet workshops and more https://ulalaunch.com/docs/default-source/exploration/dual-thrust-axis-lander-(dtal)-2009.pdf…

 

 

 

 

 

https://twitter.com/ToughSf/status/1429836316569710594?s=20&t=65-rQRRJheV4YJPO4m02mQ

 I like the horizontal landing using side thrusters. Note these would be multiple pressure-fed thrusters, avoiding the cost and complexity of pump-fed rocket engines.

  Robert Clark

[tater]

44 minutes ago, Exoscientist said:

 I like the horizontal landing using side thrusters. Note these would be multiple pressure-fed thrusters, avoiding the cost and complexity of pump-fed rocket engines.

In general I used to as well, but I am thinking something different here.

NASA image from the 90s. Ignore (or dont!) the inflatable section. Obviously the biconic plus heat shield is not needed, either. This could be the entire "fairing" of SLS. The upper pat as tankage, crea area right at the bottom (use legs that can level and lower to virtually sit it on the regolith (any difference being because of leveling). Diameter could be 8.4 to 10m (similar to Lunar Starship).

[RCgothic]

So send an empty crew capsule with a Rosie the rocketeer mannequin. Actually exposing crew to unnecessary radiation in a pointless and difficult-to-abort-to orbit is the stupidest type of mission.

The chances of irradiating a crew would be halved by putting them on the surface where they can actually do useful work.

And a changeover station is not required when the lander can accommodate an entire crew and both lander and capsule can just mate to each other directly.

 

[SunlitZelkova]

9 hours ago, Beccab said:

This also means you can get to the surface as much cargo as the LM, which is equal to an extremely limited and compact rover and a couple surface experiments. If your lunar rocket can only launch once a year and can only get a negligible amount of cargo to the surface you've effectively done worse than Apollo; add to that the fact that the costs are roughly comparable to the Apollo program, and you'll hardly get further than the point Apollo got.

An Ariane upper stage won't save Artemis, nor SLS. The ideal way for the program to develop would be to gradually abandon the latter, switching to Starship plus if needed a less unsustainable commercial LEO capsule to launch the crew (Starliner, Dragon or Dream Chaser all work in this context). Hell, if needed you can even use the ISS or one of its successors as a staging ground, both to check out the lander and simplify operations

The last sentence is this is an interesting comment, as it would basically bring us back to the SEI lunar architecture of the early 90s.

One problem would be that tacking Starship on to the ISS for checkout and refurbishment might affect experiments that require microgravity.

Adding such a module as part of the Axiom station would be neat though.

Such a scenario would be similar to SEI in other ways, too. IIRC SEI’s Mars lander was based on the lunar lander but with a jettisonable heat shield. Just what exactly might constitute a Mars transfer vehicle is open to discussion IMO, but using Starship as a lander- whether it be met in orbit by a propulsively braked MTV or the crew actually ride in it all the way- makes sense given that the Moon lander is Starship.

4 hours ago, tater said:

In general I used to as well, but I am thinking something different here.

NASA image from the 90s. Ignore (or dont!) the inflatable section. Obviously the biconic plus heat shield is not needed, either. This could be the entire "fairing" of SLS. The upper pat as tankage, crea area right at the bottom (use legs that can level and lower to virtually sit it on the regolith (any difference being because of leveling). Diameter could be 8.4 to 10m (similar to Lunar Starship).

Now I know where Space Force got the idea for their Moon lander from lol.

[Beccab]

4 hours ago, SunlitZelkova said:

Such a scenario would be similar to SEI in other ways, too. IIRC SEI’s Mars lander was based on the lunar lander but with a jettisonable heat shield. Just what exactly might constitute a Mars transfer vehicle is open to discussion IMO, but using Starship as a lander- whether it be met in orbit by a propulsively braked MTV or the crew actually ride in it all the way- makes sense given that the Moon lander is Starship.

Yep! In some sense, the SEI was so damn expensive only because they mostly ignored available rockets - had they only maintained the Early Lunar Access part of the plan (lander launches on Shuttle, TLI stage launches on Ariane 5 or Titan IV), that would have been an architecture allowing far more growth than the plan we did end up with, which is, well, nothing. Of course, both the Titan IV and Shuttle were really too expensive for such an architecture to be sustainable for long and carrying cryogenics in the payload bay is a big risk; but if the available facilities were expanded to allow for both rockets to do, say, 10 flights per year, we could have had a decent lunar base about at the same time we started building the ISS for less money than that. This wouldn't have happened because NASA was all for a LEO station before going back beyond it and there's 0 chances there would have been the money to do both, but still

[Stosh]

12 hours ago, tater said:

 

 

The money contributed by "not US taxpayers" is functionally zero.

Gateway itself is a waste of time for the foreseeable future. It exists solely because SLS/Orion is awful, and can't go anywhere. There are pro arguments for the Gateway that can be made, but it's pushes entirely because Orion can't do better.

No argument, SLS/Orion has been beaten to death among Space Enthusiasts as the best anyone could come up with and receive bipartisan support in the US, Perhaps because of Sheldon's "Great Experiment" with UBI? Certainly not because it was a great way to destroy the BEST reuseable engine from the entire US space program.

Gateway is SLS/Orion's destination (*cough*space station Freedom to justify the Shuttle program"cough") and NASA would appreciate a like, mind you i bet Bipartisan support, and the UBI,  was more important.

 Hate Me for pointing out the obvious

"The money contributed by "not US taxpayers" is functionally zero."  Yes, you only get *another* RMS while we in Canada get an Astronaut on Artemis II, so yes "functionally zero." in your Country, sorry if our investment in robotcs inspires someone in a lesser country.. Sorry

Lke it or not, NASA, 20 International partners and counting, see way MORE opportunity in 'the future of' Gateway and "Basic Research" YMMV

 

4 minutes ago, Stosh said:

No argument, SLS/Orion has been beaten to death among Space Enthusiasts as the best anyone could come up with and receive bipartisan support in the US, Perhaps because of Shelby's "Great Experiment" with UBI? Certainly not because it was a great way to destroy the BEST reuseable engine from the entire US space program.

Gateway is SLS/Orion's destination (*cough*space station Freedom to justify the Shuttle program"cough") and NASA would appreciate a like, mind you i bet Bipartisan support, and the UBI,  was more important.

 Hate Me for pointing out the obvious

"The money contributed by "not US taxpayers" is functionally zero."  Yes, you only get *another* RMS while we in Canada get an Astronaut on Artemis II, so yes "functionally zero." in your Country, sorry if our investment in robotcs inspires someone in a lesser country.. Sorry

Lke it or not, NASA, 20 International partners and counting, see way MORE opportunity in 'the future of' Gateway and "Basic Research" YMMV

 

My apologies  editied to replace Sheldon with Shelby. Middle Age and Fat Finger Syndrome are a potent mix.

[tater]

29 minutes ago, Stosh said:

"The money contributed by "not US taxpayers" is functionally zero."  Yes, you only get *another* RMS while we in Canada get an Astronaut on Artemis II, so yes "functionally zero." in your Country, sorry if our investment in robotcs inspires someone in a lesser country.. Sorry

All that matters is money to compare contributions. By the time people are at Gateway, the total expenditure by US taxpayers will have been 10s of billions, then like $5B a mission.

The only value of international cooperation in terms of moving the ball down the field is that it makes it more protected politically inside the US.

29 minutes ago, Stosh said:

Lke it or not, NASA, 20 International partners and counting, see way MORE opportunity in 'the future of' Gateway and "Basic Research" YMMV

Gateway is completely useless. If Starship works, I'd kill Gateway immediately if it was up to me, it's pointless.

There is no "basic research" to be done at Gateway that can't be done on ISS. Stations are only good for research on people, anything else would be better minus all the associated vibration. The only difference between NRHO and LEO  is the thermal and radiation environment. The former has to be dealt with or the people die, so there is nothing really to study. It works, and people can stay, or it doesn't, and they never come back and have to build a new one (and it's understood well enough it would just work minus an eqp failure). Radiation? That's humans as lab rats. Send some up, then see if the people that spend the most time die earlier.

BTW, there is no experimentation at Gateway for radiation exposure via different habitats, etc. The amount of shielding required is outside the scope of commercial throw to TLI. The amount of regolith required to drop radiation tonormal levels is something like 2 meters.

Do the radiation exposure on the Moon, then at least the people are doing something cool while they get exposure.

Edited June 16, 2022 by tater

[Stosh]

52 minutes ago, tater said:

All that matters is money to compare contributions. By the time people are at Gateway, the total expenditure by US taxpayers will have been 10s of billions, then like $5B a mission.

The only value of international cooperation in terms of moving the ball down the field is that it makes it more protected politically inside the US.

Gateway is completely useless. If Starship works, I'd kill Gateway immediately if it was up to me, it's pointless.

There is no "basic research" to be done at Gateway that can't be done on ISS. Stations are only good for research on people, anything else would be better minus all the associated vibration. The only difference between NRHO and LEO  is the thermal and radiation environment. The former has to be dealt with or the people die, so there is nothing really to study. It works, and people can stay, or it doesn't, and they never come back and have to build a new one (and it's understood well enough it would just work minus an eqp failure). Radiation? That's humans as lab rats. Send some up, then see if the people that spend the most time die earlier.

BTW, there is no experimentation at Gateway for radiation exposure via different habitats, etc. The amount of shielding required is outside the scope of commercial throw to TLI. The amount of regolith required to drop radiation tonormal levels is something like 2 meters.

Do the radiation exposure on the Moon, then at least the people are doing something cool while they get exposure.

"The only difference between NRHO and LEO  is the thermal and radiation environment. The former has to be dealt with or the people die, so there is nothing really to study. It works, and people can stay, or it doesn't, and they never come back and have to build a new one (and it's understood well enough it would just work minus an eqp failure). Radiation? That's humans as lab rats. Send some up, then see if the people that spend the most time die earlier."

So no baisc research with "sensors and trying out potential solutions to the differences between NRHO and LEO" - Got it

"just do cool stuf" -  Got It

I understand. I bow out - looking forward to your book on reforming NASA

i will turn my attention to my foolish country wasting money to "move the ball down the field".

Clearly NASA will sell the idea of Space science to anyone

[tater]

6 hours ago, Stosh said:

So no baisc research with "sensors and trying out potential solutions to the differences between NRHO and LEO" - Got it

Sensors don't need a multi-billion dollar human-rated platform, they can be in a small (cheap) satellite.

 

6 hours ago, Stosh said:

"just do cool stuf" -  Got It

Do things worth doing, and the risk the astronauts experience at least has a payoff other than variable rates of cancer. Also, there are no plans for stays at Gateway that exceed something like a month until 2030s (then ~2 months), so there's no useful long term data possible anyway. There is nothing else to do there, and it comes at huge cost. It will cost more to send 4 people to Gateway for a few weeks total as it does to keep the entire ISS running for a year.

 

6 hours ago, Stosh said:

I understand. I bow out - looking forward to your book on reforming NASA

Not doing things that are useless with finite resources is not a rare opinion. Many think Gateway is a waste of time. It only exists because the SLS/Orion system is not capable of real missions.

 

6 hours ago, Stosh said:

i will turn my attention to my foolish country wasting money to "move the ball down the field".

If other countries want it so much, they should have to do what NASA does to send crew to ISS—pay per seat to SpaceX/Boeing (soon for the latter). For ISS that is ~$50M/seat. For Gateway that's more like $1.2B/seat. Seems pretty reasonable, participant countries can get an astronaut to a distant lunar orbit for what in the grand scheme of things is not a lot of money. I'm fine with the US giving away or trading seats to ISS to our friends, $50M is not a lot of money. Billions? Pony up or stay home.

I had a friend who was a single guy, and he'd invite himself to dinner at my house all the time. Which was fine, as he'd often show up with some really cool raw materials for all of us, and I'd end up cooking it. If he had shown up and just ate our food, I would also not have cared, I liked him (he died a few years ago, hence past tense). Had he shown up and complained about what we served for dinner, or said we should buy Wagyu beef when he was coming over? How would anyone react? You seem to be making the Wagyu beef argument, you're inviting yourself to dinner, then complaining that some of us think we should feed you choice grade ribeye at $15/lb instead of Wagyu at $150/lb even though you thoughtfully brought a bag of chips as a side dish.

 

EDIT: Take ESA as an example. The ESA member states have a cumulative GDP that is similar to the US, yet the ESA budget is a small fraction of the NASA budget. It seems totally reasonable to expect that their contributions should offset costs incurred for different missions they participate in with NASA. For SLS/Orion, they are trading the SM for that. The SM is some hundreds of millions each, so by the time crew goes to Gateway (late 2020s), they get a seat as they will have pitched in ~$1B in service modules not counting dev costs. I'm cool with that, but going forward, they need to spend more.

Edited June 16, 2022 by tater

[sevenperforce]

On 6/16/2022 at 9:24 AM, tater said:

 

On 6/16/2022 at 2:49 AM, Stosh said:

So no baisc research with "sensors and trying out potential solutions to the differences between NRHO and LEO" - Got it

Sensors don't need a multi-billion dollar human-rated platform, they can be in a small (cheap) satellite.

 

Yep. Gateway does nothing for human spaceflight that sending somebody on a lunar free-return wouldn’t do anyway. Don’t get me wrong; I’d love to see the moon up close too. But humans aren’t needed to do anything at Gateway that they couldn’t do at ISS.

It’s like if you were a marine biologist and you were planning a research excursion to the Great Barrier Reef and someone said “well instead of taking a boat straight there, let’s build a floating research platform half a mile past it and have a boat take you there and you can practice some open water snorkeling and then we’ll send a different boat to take you from the platform to the reef.” And you ask “why can’t I practice snorkeling right here in the bay?” and they say “well the risk of shark attack will be higher at the floating platform so that’s something different.”

[tater]

On 6/19/2022 at 7:07 AM, sevenperforce said:

Yep. Gateway does nothing for human spaceflight that sending somebody on a lunar free-return wouldn’t do anyway. Don’t get me wrong; I’d love to see the moon up close too. But humans aren’t needed to do anything at Gateway that they couldn’t do at ISS.

From Eric Berger's recent article:

Quote

The internal schedules reveal that NASA is going to spend the entirety of the next decade, if not longer as schedules inevitably slip, building the Lunar Gateway.

NASA has bought 2 Lunar Starship missions. An uncrewed test, and Artemis III.

Assume LSS is 80t. I_sp 378, 1200t props. LSS has 10,277 m/s dv in LEO. LEO to the surface and back to LLO is ~8100 m/s. LEO to the surface and back to NRHO is ~9150 m/s.

In short, even with total LSS dry mass up to 109t, LSS can fly from LEO to the surface, and go to NRHO. Gateway is obviated by LSS entirely—that or send the PPE with a multi-hub docking port to stick on the front of LSS. Now it can use electric prop for station keeping, and the volume is ~ISS. No need for any other crap on it, and it's literally already paid for.

Or just leave it in a frozen LLO, and send a tug to distant orbit to take Orion down to LLO. If EUS is a thing, then take Orion direct to LLO, and trash Gateway.

[SunlitZelkova]

Regardless of whether it is a second, modified Starship HLS or takes the form it currently is in, would using Gateway as a man-tended experiment platform make sense?

Studying the effects of radiation on humans in that environment with it is dumb, but man-tended platforms have been proposed before for LEO, and they could have value.

ESA had a backup plan for the Columbus module of Space Station Freedom, in which it would launch with a propulsion unit on an Ariane 5 and then be periodically visited by Hermes, bringing experiments back and forth.

The astronauts would pickup experiments and bring new ones, or have them delivered in Dragon-X or HTV-XG and then just offload them and set them up. All four then descend to the surface for their surface expedition, with not much happening otherwise at Gateway.

[tater]

6 hours ago, SunlitZelkova said:

but man-tended platforms have been proposed before for LEO, and they could have value.

Except in this case people only go there via Orion, so the station is unoccupied ~96% of the time.ISS needed "berthing" as a thing, but that is not going to be needed going forward I think. I think the staging of payloads over time makes some sense when they have to be sent in small amounts for lack of a large vehicle... except Starship changes that.

Here, I will quote myself from above:

21 hours ago, tater said:

Assume LSS is 80t. I_sp 378, 1200t props. LSS has 10,277 m/s dv in LEO. LEO to the surface and back to LLO is ~8100 m/s. LEO to the surface and back to NRHO is ~9150 m/s.

10,227 m/s. For the 80t SS (not a lot of cargo there) what I did not say is that it's back in LLO with ~2177 m/s left. It can ALMOST get back to LEO propulsively. If it was stretched it could (more tanks, so either replacing some crew volume, or making it taller).

Serious mission planning that considers this could do all kinds of things.

I would think about landing a LSS "hab" that lacks the capability of returning to LLO. In short, it has low margin, and stretches the crew volume at the expense of tank volume. That buys them an extra deck or two—also puts the airlock deck 3-6m closer to the surface. Want the Hab to have crew rotated to it more often than a week or 2 once a year? Have an LSS stretched so that it can make the RT to the lunar surface from LEO. Crew boards in LEO via commercial crew, undocks from CCV, leaving it in LEO and heads to the Moon (all 4 crew). These will always be an issue with supplies, so somehow the crew needs to have months of consumables loaded into any "sustainable" lunar lander. Refilling props is one problem, but it still needs supply ships like ISS, and humans need to float inside, then move the food, etc into the LSS, packing all the nooks and cranies with food, like a submarine going on a long cruise. So that gets done in LEO, too. Maybe the crew has to fly up after refilling props, but then stays for a supply SS to come with however many tons of food. etc. 

They land, and could actually live in their LSS, though it has less room, or they can EVA to the Hab, and live there. Obviously they need to take the supplies across, and perhaps they take some each day, with excess supplies brought for contingencies eventually stockpiling the Hab for contingencies. If their ride fails to restart, say, they might end up with a few months of extra supplies at the hab, and a rescue could be mounted.

Expanding the base could be via more 1-way Starships, such vehicles could be packed with supplies as people only need to be able to get in enough to unload them, and the remaining volume becomes crew area.

[Exoscientist]

 

 I forgot Robert Zubrin also says the SpaceX plan of multiple refuelings for lunar or Mars flights is a bad idea. He says using the Starship as a lunar lander is like using an aircraft carrier for white water rafting. He also suggests using a smaller “mini Starship” that would stage off the Starship to do the landings. He notes this way you could do the missions with no refueling flights required. Plus the Starship not having to land on the Moon or Mars would be reusable.  Zubrins refers to his approach as Mars Direct 2.0:

Mars Direct 2.0 - Dr. Robert Zubrin - IAC 2019

https://www.youtube.com/watch?v=z5k7-Y4nZlQ

 Robert Clark

Edited June 22, 2022 by Exoscientist
Added slide from presentation showing no refueling flights needed if staging done in LEO.

[SunlitZelkova]

16 hours ago, tater said:

Except in this case people only go there via Orion, so the station is unoccupied ~96% of the time.ISS needed "berthing" as a thing, but that is not going to be needed going forward I think. I think the staging of payloads over time makes some sense when they have to be sent in small amounts for lack of a large vehicle... except Starship changes that.

Here, I will quote myself from above:

10,227 m/s. For the 80t SS (not a lot of cargo there) what I did not say is that it's back in LLO with ~2177 m/s left. It can ALMOST get back to LEO propulsively. If it was stretched it could (more tanks, so either replacing some crew volume, or making it taller).

Serious mission planning that considers this could do all kinds of things.

I would think about landing a LSS "hab" that lacks the capability of returning to LLO. In short, it has low margin, and stretches the crew volume at the expense of tank volume. That buys them an extra deck or two—also puts the airlock deck 3-6m closer to the surface. Want the Hab to have crew rotated to it more often than a week or 2 once a year? Have an LSS stretched so that it can make the RT to the lunar surface from LEO. Crew boards in LEO via commercial crew, undocks from CCV, leaving it in LEO and heads to the Moon (all 4 crew). These will always be an issue with supplies, so somehow the crew needs to have months of consumables loaded into any "sustainable" lunar lander. Refilling props is one problem, but it still needs supply ships like ISS, and humans need to float inside, then move the food, etc into the LSS, packing all the nooks and cranies with food, like a submarine going on a long cruise. So that gets done in LEO, too. Maybe the crew has to fly up after refilling props, but then stays for a supply SS to come with however many tons of food. etc. 

They land, and could actually live in their LSS, though it has less room, or they can EVA to the Hab, and live there. Obviously they need to take the supplies across, and perhaps they take some each day, with excess supplies brought for contingencies eventually stockpiling the Hab for contingencies. If their ride fails to restart, say, they might end up with a few months of extra supplies at the hab, and a rescue could be mounted.

Expanding the base could be via more 1-way Starships, such vehicles could be packed with supplies as people only need to be able to get in enough to unload them, and the remaining volume becomes crew area.

Surprisingly and yet unsurprisingly similar to SpaceX’s early Mars plans (crew live in converted Starships).

[tater]

8 hours ago, Exoscientist said:

 

 

 I forgot Robert Zubrin also says the SpaceX plan of multiple refuelings for lunar or Mars flights is a bad idea. He says using the Starship as a lunar lander is like using an aircraft carrier for white water rafting. He also suggests using a smaller “mini Starship” that would stage off the Starship to do the landings. He notes this way you could do the missions with no refueling flights required. Plus the Starship not having to land on the Moon or Mars would be reusable.  Zubrins refers to his approach as Mars Direct 2.0:

https://www.youtube.com/watch?v=z5k7-Y4nZlQ

Zubrin completely misses the point here. He's wed to old ideas. Sure, if you have an expendable vehicle, use the minimal possible to accomplish the mission. This is simply not needed. His analogy is wrong headed. It is like saying that using a 737 to fly from Albuquerque to Denver is "too big." Why, when you could do the same flight in a Cessna, or other smaller aircraft? Because the 737 is for you, the passenger, cheaper.

If EDL fails entirely for SS at Earth, then obviously an expendable upper stage (lander in this case) could do the job in the old-fashioned way, but if reuse is a thing, multiple reflights is nothing at all.

What characterizes Mars Direct to me is splitting the ascent and decent/hab elements (the former with ISRU on Mars, anyway). Sending a hab ahead, and making the lander a tiny sortie lander makes a certain amount of sense to me. Then use Starship for more massive cargoes. In this forum I have in fact suggested that a small lander could have a Starship derived prop depot that could have propellants for multiple small lander sorties. Transfer crew in lunar orbit to a small lander, then fly them to the surface—to be housed in a lunar base, which might in the early days consist of Starships, as they are huge at ~675 sqft (~63m²) per deck, and they would have 3-4 decks.

Still, SpaceX does things to move the ball down their own field. Mars is the target, mini starship is not a Mars thing.

Edited June 22, 2022 by tater

[Exoscientist]

 The intent is to make manned spaceflight to the Moon routine, or at least as routine as flights to the ISS are now. That’s not going to happen when it takes 8 to 16 launches of a Saturn V class launcher for a single mission to the Moon. By the way, Robert Zubrin estimated it would actually take ~20 launches of the Starship under the current proposal that has the Starship meetup with the astronauts in the Orion capsule at the Gateway to take them to the Moon and then back again to the Gateway, and then from there using the Orion for the trip back to Earth. This is because of the large amount of fuel needed for going back and forth to the Gateway:

Op-ed | Toward a coherent Artemis plan.

by Robert Zubrin — May 18, 2020

https://spacenews.com/op-ed-toward-a-coherent-artemis-plan/https://spacenews.com/op-ed-toward-a-coherent-artemis-plan/

It is extremely important to keep in mind the only reason why NASA proposes using the Gateway in the first place is because the SLS without an extended upper stage does not have enough power to take the Orion to low lunar orbit about the Moon and back again. With an extended upper stage, that eliminates the need for the, much derided, Gateway with its great added cost and time delay, and eliminates the need for the ~20 flights for the Starship. The SLS could mount the mission to the lunar surface by itself with no need for the Starship.

Note the ESA is actually more in favor of a lunar base than is NASA. By the supplying an Ariane 5/6 to serve as the extended upper stage for the SLS that would go a long way to insure that it happens.

 

  Bob Clark

Edited July 27, 2022 by Exoscientist

[RealKerbal3x]

45 minutes ago, Exoscientist said:

The intent is to make manned spaceflight to the Moon routine, or at least as routine as flights to the ISS are now. That’s not going to happen when it takes 8 to 16 launches of a Saturn V class launcher for a single mission to the Moon.

As I said on the first page, this is the sort of thinking that makes sense if your large number of launches have to be made with a big expendable booster, ie SLS or Saturn V. Every architecture designed with those launch vehicles in mind has been all about minimising the total number of launches, because cadence is low and you have a large amount of hardware thrown away every flight.

It all falls apart when you consider a large, reusable rocket such as Starship. Even if we assume that Starship only manages to get launches as cheap as $70m (the same as a Falcon 9 launch), then 16 launches is still only a little over half of the cost of a single SLS launch at $2b. Put rapid reuse into the equation - as SpaceX is required to do for the HLS contract - and you have something that definitely approaches a routine.

45 minutes ago, Exoscientist said:

By the supplying an Ariane 5/6 to serve as the extended upper stage for the SLS that would go a long way to insure that it happens.

You should probably read through all the posts on the rest of this thread explaining why kitbashing SLS and Ariane is probably unworkable.