Starship Artemis Contract & Lunar Starship

[OTV Booster]

This site:
https://www.axflow.com/en-ie/your-business/our-solutions-to-your-applications/pumping-technologies-for-various-liquids/pumping-cryogenic-liquids


Has some cryo pumping info.


Low viscosity fluids with poor lube properties. OTOH, a vapor bearing should be easy.


There are still settling issues but if the tanker is fully topped off and the circuit to the cooler avoids open tankage the problem is minimized. Using a large lazy low pressure pump avoids cavitation damage. If a void does migrate to the intake it shouldn't be big and a small cold gas goose will move it.

[OTV Booster]

IMO, doing Mars without doing the moon works at small scale but at the scale Elon intends, lunar resources (ie water) make a big difference. The up front costs are high but looking at it as an investment, how many synods would it take to hit breakeven?

Depends heavily on the cost, and even more the practicality/reliability/longevity of the lunar infrastructure. I am not sure a lunar rail gun would necessarily have the longevity to *last* until breakeven; none of this works unless Starship is very very cheap, and building big stuff on the Moon won't be cheap, so a railgun would have to launch a lot of mass in its lifetime to break even.

If propellant launched by Starship is $50/kg that's $50 000/ton. If a lunar railgun costs $10B it would have to launch 200 000 tons to break even. How bad is the rail erosion?

And if things have scaled up to where you could do a lunar rail gun, Starship propellant might be cheaper than $50/kg. For a 200t v4, that's $10M/tanker launch; I think Musk is aiming for cheaper than that.

And I think $10B is very optimistic for a giant lunar railgun plus the equipment to mine from Lunar polar craters.

And you're probably really competing against the marginal cost of launching more Starship tankers, not the "fully burdened" cost.

So given all that, I don't think lunar propellant will ever make sense in cost terms - if propellant is expensive enough to make it make sense, then you can't afford to do things on a large enough scale to justify it; if propellant is cheap enough to do things in space on a huge scale, then it's too cheap to justify getting it from the Moon.

This would change if the Moon infrastructure was largely already built for some other reason, or if the advantage wasn't cost - e..g if it was just impossible to get launch authorization for thousands of Starships per synod.

We're both speculating on things too far in the future and too technically different than what exists today to have very informed opinions.


Will the moon be a few isolated research stations? Or will the moon as a destination grow as demand for space lift has expanded in the last decade? This one dimension changes the economics of ISRU. It's a chicken/egg thing. If demand increases, infrastructure that will then amortize faster can be justified. OTOH, speculative infrastructure can drop costs, stimulate growth and demand, and justify itself.


Whoever who can judge, then follow the middle path between the extremes will make a lot of money. Or ignore it and invest elsewhere.

[Vultur]

IMO, doing Mars without doing the moon works at small scale but at the scale Elon intends, lunar resources (ie water) make a big difference. The up front costs are high but looking at it as an investment, how many synods would it take to hit breakeven?

Depends heavily on the cost, and even more the practicality/reliability/longevity of the lunar infrastructure. I am not sure a lunar rail gun would necessarily have the longevity to *last* until breakeven; none of this works unless Starship is very very cheap, and building big stuff on the Moon won't be cheap, so a railgun would have to launch a lot of mass in its lifetime to break even.

If propellant launched by Starship is $50/kg that's $50 000/ton. If a lunar railgun costs $10B it would have to launch 200 000 tons to break even. How bad is the rail erosion?

And if things have scaled up to where you could do a lunar rail gun, Starship propellant might be cheaper than $50/kg. For a 200t v4, that's $10M/tanker launch; I think Musk is aiming for cheaper than that.

And I think $10B is very optimistic for a giant lunar railgun plus the equipment to mine from Lunar polar craters.

And you're probably really competing against the marginal cost of launching more Starship tankers, not the "fully burdened" cost.

So given all that, I don't think lunar propellant will ever make sense in cost terms - if propellant is expensive enough to make it make sense, then you can't afford to do things on a large enough scale to justify it; if propellant is cheap enough to do things in space on a huge scale, then it's too cheap to justify getting it from the Moon.

This would change if the Moon infrastructure was largely already built for some other reason, or if the advantage wasn't cost - e..g if it was just impossible to get launch authorization for thousands of Starships per synod.

We're both speculating on things too far in the future and too technically different than what exists today to have very informed opinions.


Will the moon be a few isolated research stations? Or will the moon as a destination grow as demand for space lift has expanded in the last decade? This one dimension changes the economics of ISRU. It's a chicken/egg thing. If demand increases, infrastructure that will then amortize faster can be justified. OTOH, speculative infrastructure can drop costs, stimulate growth and demand, and justify itself.


Whoever who can judge, then follow the middle path between the extremes will make a lot of money. Or ignore it and invest elsewhere.

Yeah, that's more or less what I was saying in the last paragraph - if there is other (unrelated) demand for the lunar infrastructure, then the cost may make sense*. But building lunar infrastructure from scratch just for Mars propellant most likely doesn't.

*Though it still depends heavily on how practical/maintainable/reliable/long-lasting the lunar infrastructure can be made. If you have major activity on the Moon (much larger scale than current Artemis plans), propellant ISRU on the Moon for launch from the Moon makes sense. Launching that propellant by mass driver/railgun for other uses beyond the Moon only makes sense (even if the ice mining and propellant manufacturing is already paid for by lunar launch uses) if the mass driver/railgun has a decent service life.

[OTV Booster]

I think the Starship HLS architecture is simpler than the Blue Moon one. Number of launches isn’t architectural complexity but instead number of unique elements.

Architecturally, they're almost identical.  SpaceX uses a tanker, a depot, and an HLS, all based on a common propulsion technology and launcher, with refueling occurring before the crew boards.  Blue uses a tanker (a GS2), a depot (the Cislunar Transporter), and an HLS, all based on a common propulsion technology (BE-7) and launcher, with refueling occurring before the crew boards.

It's fair to argue that ZBO for hydrolox is a lot more complicated than ZBO or near-ZBO for methalox.  But it's equally fair to argue that an architecture that requires 3-5 launches is simpler than one that requires 10-15 launches.

The big difference between SpaceX and Blue is that SpaceX is ahead of Blue by 2-4 years.

Why do you think that SpaceX has 2-4 years lead on Blue Origin? I assume it is in regards to Artemis program. It is hard to see any SpaceX lead at all.

1. SpaceX reused booster of their launcher but is in the middle of major upgrade. BO recovered their booster with no major design changes expected.

2. SpaceX launcher upper stage is in the middle of major iteration, lot of work expected to ensure reusability. Blue Origin seem to be pretty much finished with the design of their second stage.

3. SpaceX tanker should be tested in 2026, based on Starship. BO tanker is based on NG second stage, however it is not needed for flags&footprint mission.

4. SpaceX long loiter depot progress is unknown. BO cislunar transporter progress is unknown.

5. SpaceX HLS progress: component testing, based on Dragon. BO HLS: component testing, MK1 demo moon landing in 2026.

New Glenn's flight rate is lower than Starship's by about a factor of 4. SpaceX is flying Dragon today, upon which many of the systems on HLS are based. Blue has nothing comparable (Not New Shepard). SpaceX has extensive test flights of Starship already, which buys down risk on loiter. (Not to mention hundreds of Falcon launches.)

I don't get why you consider Blue Origin's upper stage an advantage. HLS basically is a Starship upper stage. SpaceX's systems have far more commonality.

For flags & footprint lunar mission BO needs only few NG launches. That should be no problem as the development of NG is close to be finished. For the same mission SpaceX needs many more flights, refueling and capabilities. Starship is far from having finished development. Because of extremely complex SpaceX HLS architecture the Starship development will take years to deliver any payload at all to cislunar space. BO can do it "tomorrow'. SO there is a clear advantage for BO in regards of launch vehicles.

Regarding the crew cabin the situation is similar. Instead of going the Dragon way, SpaceX is pushing Starship nose cone "battle star" type of cabin. This incredibly hurt their mission profile. I assume that BO Flags&footprint would go with cooperation with LM and their Orion derived cabin. This is pretty much finished product and lightweight compared to the "battle star".

Forget the nonsense with stainless steel structures, elevator, two airlocks, 600m3 living space, hangar, dedicated landing engines etc. Sounds like BO has much better plan than SpaceX.   

As I said before the only missing part is the ascend module, which should be based on "off the shelf' storable propellants technology.

SpaceX seems to have much less to offer. Dozens of launches, dozens of refueling, unfinished technology everywhere you look. It is actually not surprising that NASA is skeptical with their schedule. Everyone is and Musk is not getting any better with SpaceX development schedules.

Having said this I can still see Starship as being very useful at some point. Once the SpaceX propellant depot is established at LEO, the deep space optimised expendable starships could be very useful to deliver cargo. But that should be very different Starship from what we are seeing now. The current starship is optimised for Starlink LEO missions and perhaps also LEO tanker missions. Makes no sense to send it beyond LEO.

SS is not 'optimized' for one specific mission although a starlink deployment hatch is currently looking like a common element. That will change with need. SS is a flexible design that can do many different missions. It's a little like the DC-3/C-47 which could haul passengers, cargo and paratroopers and tow gliders.


It is overkill for a first crewed lunar lander but not for the fifth, sixth and seventh. SpaceX pioneered the amazing concept of cost optimization in spaceflight. If they had set aside the SS design and started an entirely different architecture when they submitted their bid there is absolutely no evidence that it would have been faster than what they are doing now and every reason to believe the finished product would be two or three orders of magnitude more expensive per launch - because it would be a two or three landing dead end.


Blue might be able to beat SX to the first landing. Maybe. They have never exhibited anything remotely like rapid development. Maybe Dave Limp has brought some mojo and this is changing.


Making predictions is hard. Especially if it's about the future.

[OTV Booster]

IMO, doing Mars without doing the moon works at small scale but at the scale Elon intends, lunar resources (ie water) make a big difference. The up front costs are high but looking at it as an investment, how many synods would it take to hit breakeven?

Depends heavily on the cost, and even more the practicality/reliability/longevity of the lunar infrastructure. I am not sure a lunar rail gun would necessarily have the longevity to *last* until breakeven; none of this works unless Starship is very very cheap, and building big stuff on the Moon won't be cheap, so a railgun would have to launch a lot of mass in its lifetime to break even.

If propellant launched by Starship is $50/kg that's $50 000/ton. If a lunar railgun costs $10B it would have to launch 200 000 tons to break even. How bad is the rail erosion?

And if things have scaled up to where you could do a lunar rail gun, Starship propellant might be cheaper than $50/kg. For a 200t v4, that's $10M/tanker launch; I think Musk is aiming for cheaper than that.

And I think $10B is very optimistic for a giant lunar railgun plus the equipment to mine from Lunar polar craters.

And you're probably really competing against the marginal cost of launching more Starship tankers, not the "fully burdened" cost.

So given all that, I don't think lunar propellant will ever make sense in cost terms - if propellant is expensive enough to make it make sense, then you can't afford to do things on a large enough scale to justify it; if propellant is cheap enough to do things in space on a huge scale, then it's too cheap to justify getting it from the Moon.

This would change if the Moon infrastructure was largely already built for some other reason, or if the advantage wasn't cost - e..g if it was just impossible to get launch authorization for thousands of Starships per synod.

We're both speculating on things too far in the future and too technically different than what exists today to have very informed opinions.


Will the moon be a few isolated research stations? Or will the moon as a destination grow as demand for space lift has expanded in the last decade? This one dimension changes the economics of ISRU. It's a chicken/egg thing. If demand increases, infrastructure that will then amortize faster can be justified. OTOH, speculative infrastructure can drop costs, stimulate growth and demand, and justify itself.


Whoever who can judge, then follow the middle path between the extremes will make a lot of money. Or ignore it and invest elsewhere.

Yeah, that's more or less what I was saying in the last paragraph - if there is other (unrelated) demand for the lunar infrastructure, then the cost may make sense*. But building lunar infrastructure from scratch just for Mars propellant most likely doesn't.

*Though it still depends heavily on how practical/maintainable/reliable/long-lasting the lunar infrastructure can be made. If you have major activity on the Moon (much larger scale than current Artemis plans), propellant ISRU on the Moon for launch from the Moon makes sense. Launching that propellant by mass driver/railgun for other uses beyond the Moon only makes sense (even if the ice mining and propellant manufacturing is already paid for by lunar launch uses) if the mass driver/railgun has a decent service life.

My expectation is expanding use. One biggie will be a nice fat radio telescope on farside. Another would be power for facilities and rovers throughout the dark period. Then of course there is rocket propellant for local use.


The biggest stumbling block for water mining is dealing with the dust but that problem is common to all lunar operations. Once water bearing regolith is in hand, apply heat to a closed container and the water sublimates. A lot of details glossed over. That's what engineers are for.


I was using 'rail gun' a bit generically. Mass driver is probably better. Whatever it is that gets levitated, then flung.


Musk would probably keep SX as a transportation company and spin off HydreX to mine, WyndeX in partnership with Wyndham for tourist facilities and SpandeX for surface transportation. Interlocking ventures to further his goals.

Lunar water production will be expensive and low quantity to start but over time volume would grow and costs would drop. It could be highly automated. This is what musk does. And if a million people on Mars is his goal he's not taking the short view.

[Robotbeat]

A sling launch is better. No need to levitate (which is annoying to pull off). No long track to build, just a big spool you can launch in one go.

[TheRadicalModerate]

Why do you think that SpaceX has 2-4 years lead on Blue Origin? I assume it is in regards to Artemis program. It is hard to see any SpaceX lead at all.

1. SpaceX reused booster of their launcher but is in the middle of major upgrade. BO recovered their booster with no major design changes expected.

You don't think there's going to be a major upgrade with New Glenn sometime in the next couple of years?  Why?

It seems a lot of the upgrades that SpaceX is pursing are performance-based.  Blue hasn't gotten to that point yet, but it's highly unlikely that they're going to hit the 45t to LEO metric without a fair amount of fiddling.

BTW:  They really need the 45t to LEO.  Without it, my guess is that the accelerated plan they're proposing to NASA won't work.

It's not often I get to say "toldja so" within two days of posting something:  Blue Origin announces New Glenn upgrade plans.

[OTV Booster]

A sling launch is better. No need to levitate (which is annoying to pull off). No long track to build, just a big spool you can launch in one go.

I do see the utility but intentionally putting your gas in a sling?

[Robotbeat]

A sling launch is better. No need to levitate (which is annoying to pull off). No long track to build, just a big spool you can launch in one go.

I do see the utility but intentionally putting your gas in a sling?

?

[JaimeZX]

I read page 1 with interest but still trying to figure out what happens when the sling launcher releases the payload on one side and then... becomes hugely unbalanced? Obviously I'm missing something here, but also page 2 of that article.

[Paul451]

I read page 1 with interest but still trying to figure out what happens when the sling launcher releases the payload on one side and then... becomes hugely unbalanced? Obviously I'm missing something here, but also page 2 of that article.

I don't know about that specific article, but generally when using lunar regolith as a countermass, it is released at the same time as the payload. Also if the countermass is heavier than the payload, it is on a shorter arm, so its release velocity is lower, so there's no risk of it entering near-orbit.

[Robotbeat]

Also, if the ballast is greater than the payload mass, it takes away less of the overall energy when released. If the ballast is 10 times the payload mass, the ballast is carrying away only one tenth as much kinetic energy as the payload.

[OTV Booster]

Also, if the ballast is greater than the payload mass, it takes away less of the overall energy when released. If the ballast is 10 times the payload mass, the ballast is carrying away only one tenth as much kinetic energy as the payload.

That leaves me confused. Didn't Newton say something about equal and opposite?


OTOH, mass*velocity^2. This confusion happens at so great a frequency my brain Hertz.

[OTV Booster]

Also, if the ballast is greater than the payload mass, it takes away less of the overall energy when released. If the ballast is 10 times the payload mass, the ballast is carrying away only one tenth as much kinetic energy as the payload.

If the target is L1, launch from the middle of far side with two equal loads going opposite directions having apalune at L1. Velocity would be low enough to allow a cheap plane change into a halo orbit. And being equal loads it avoids the issue that Hertz my brain.


More seriously, is there a solution that launches unequal loads from a pole that approach L1 at low V? One going direct and one going around farside and needing little enough correction to be worthwhile.

[Vultur]

Also, if the ballast is greater than the payload mass, it takes away less of the overall energy when released. If the ballast is 10 times the payload mass, the ballast is carrying away only one tenth as much kinetic energy as the payload.

That leaves me confused. Didn't Newton say something about equal and opposite?


OTOH, mass*velocity^2. This confusion happens at so great a frequency my brain Hertz.

.

Momentum vs energy.

Equal and opposite forces create differing velocities on differing masses.

Since momentum is proportional to velocity and kinetic energy is proportional to square of velocity, the heavier mass with the same momentum (thus less velocity) has much less kinetic energy.

[Brigantine]

Momentum vs energy.

Equal and opposite forces create differing velocities on differing masses.

Since momentum is proportional to velocity and kinetic energy is proportional to square of velocity, the heavier mass with the same momentum (thus less velocity) has much less kinetic energy.

To close the loop here - saying the same thing in different words:

Energy = Force * distance
Forces are equal and opposite
The distance is proportional to radius i.e. length of the arm
radius * total angle, or if you prefer the inscribed circle * # of revolutions.

Torque is also force * distance (but this distance is just the radius)
Energy = Torque * total angle

[OTV Booster]

Thanks, both of you. Now I'm gonna spend the evening balancing .223s against .45s. Duh.

[OTV Booster]

The more I think about SpaceX harvesting lunar water to further their Martian  goals the more interesting it gets and the less appropriate for this discussion.


Here's a new thread to discuss it. maybe I can get catdir to move some messaged.


https://forum.nasaspaceflight.com/index.php?topic=63950.0

[JIS]

Why do you think that SpaceX has 2-4 years lead on Blue Origin? I assume it is in regards to Artemis program. It is hard to see any SpaceX lead at all.

1. SpaceX reused booster of their launcher but is in the middle of major upgrade. BO recovered their booster with no major design changes expected.

You don't think there's going to be a major upgrade with New Glenn sometime in the next couple of years?  Why?

It seems a lot of the upgrades that SpaceX is pursing are performance-based.  Blue hasn't gotten to that point yet, but it's highly unlikely that they're going to hit the 45t to LEO metric without a fair amount of fiddling.

BTW:  They really need the 45t to LEO.  Without it, my guess is that the accelerated plan they're proposing to NASA won't work.

It's not often I get to say "toldja so" within two days of posting something:  Blue Origin announces New Glenn upgrade plans.

C'mon. Where exactly is the SpaceX lead of 2-4 years? New Glen 7x2 is de facto finished product. They have lunar landing and commercial launches lined up. Can you see anything similar for Starship? New Glen 9x4 is just a long term growth path. Something like Starship V4. Every company has this. Why New Glen 9x4 was announced right now makes perfect sense.     

IMO the problem for BO lunar architecture is LHX refueling and lack of their experience with the crew cabin. They removed LHX refueling. Not sure how they want to address the crew cabin. The simple but expensive way would be to subcontract the cabin to LM.   

[meekGee]

C'mon. Where exactly is the SpaceX lead of 2-4 years? New Glen 7x2 is de facto finished product. They have lunar landing and commercial launches lined up. Can you see anything similar for Starship? New Glen 9x4 is just a long term growth path. Something like Starship V4. Every company has this. Why New Glen 9x4 was announced right now makes perfect sense.     

...

Maybe because NG 7x2 is a Falcon 9/H competitor, and Falcons are flying and reflying almost 200 times per year from 3 towers...  Talk about "finished product"...  NG hasn't even reflown once, and only carried mini payloads so far.

NG 9x4 meanwhile is a...  Falcon H competitor, and won't show up until long after SS v4 (and FH) are both retired...

A Starship competitor meanwhile doesn't even exist on BO's drawing boards, except as a concept.

So yeah, you heard it here first...  And it's a lot more than a 4 years gap, despite the enthusiasm from one good flight.

"When you get to the end zone, try to act as if you've been there before".