Starship Artemis Contract & Lunar Starship

[xvel]

Falcon 9 second stage is aluminum (something)grid. A thick slab of aluminum hogged out to leave a rectangular grid of ribs. This so so different from SS's thin stainless plate that extrapolation isn't much more than guesswork.

Falcon loiter times on direct GEO missions are about 6 to 8 hours. Both stages of Falcon use skin and stringer construction, much like Starship. Orthogrid or isogrid would not be much different in thermal terms anyway. It's a data point for the models, but hardly a prototype. And the models should already be pretty good, thermal modeling for these sorts of problems is quite advanced.

I could swear I saw an inside tank pic showing what looked kind a hogged out grid. I used to remember thing but can't remember how long ago that was.

I bet you confused ULA Vulcan with Falcon 9 somehow

[Stan-1967]

Yep, ULA has the isogrid.  Here it is around the 21 minute mark.  However this video is for the methalox booster core, not the hydrolox Centaur upper stage.  So who knows what is used for the Centaur for enabling mission duration?  ULA has great technology they could integrate into Centaur with the IVF and ACES programs.

""

[meekGee]

Falcon 9 second stage is aluminum (something)grid. A thick slab of aluminum hogged out to leave a rectangular grid of ribs. This so so different from SS's thin stainless plate that extrapolation isn't much more than guesswork.

Falcon loiter times on direct GEO missions are about 6 to 8 hours. Both stages of Falcon use skin and stringer construction, much like Starship. Orthogrid or isogrid would not be much different in thermal terms anyway. It's a data point for the models, but hardly a prototype. And the models should already be pretty good, thermal modeling for these sorts of problems is quite advanced.

I could swear I saw an inside tank pic showing what looked kind a hogged out grid. I used to remember thing but can't remember how long ago that was.

Dragon maybe?

[thespacecow]

In SpaceX's case tanker/depot/HLS are all variant of the launch vehicle upper stage, I don't think that's the case for Blue Origin. Blue's tanker share tankage with their LV upper stage, but use a different engine, I don't think the Transporter and Mk2 lander is a variant of GS2. Thus it's correct to say Blue Moon has more unique elements and more complex.

I suspect that Blue is all-in on this alternate plan.  I expect the CT and BM1.5 thrust structures to be very close to identical, and of course the engines are identical.  Since they've started floating the idea of BM1s and a BM1.5 as a conops, I assume that CT is now based on BM1 inside the fairing, and CT and BM1.5's tankage will be close to common.

My comment is entirely based on POR, I can't comment much on the alternative plan since we know so little about them.

As for conops, Starship only does refueling in Earth orbit, Blue Moon requires additional refueling in NRHO, that's also more complex.

If we're sticking with Orion in NRHO, then Starship needs somewhat higher energy to refuel than VLEO, and even then, the margins are very tight.  If that FCC technical annex is correct, they're planning on a refueling in an HEEO final tanking orbit, which almost certainly means they're refueling twice, the first one being in VLEO.

I assumed Starship HLS will need two refuelings in Earth orbit, but based on the new BM Mk2 conops diagram, their Transporter will need two refuelings in Earth orbit too, so in this aspect the two are evenly matched, one is not better than the other.

[Brigantine]

Recirculate propellant through the depot to maintain chill.

If you transfer propellants by electric pumps, that makes sense. I guess you need functional cryo pumps to do much active cooling in the first place. Good idea, my question is just when will we see suitable cryo pumps?

[Robotbeat]

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.

[TheRadicalModerate]

I assumed Starship HLS will need two refuelings in Earth orbit, but based on the new BM Mk2 conops diagram, their Transporter will need two refuelings in Earth orbit too, so in this aspect the two are evenly matched, one is not better than the other.

Yeah, I'm still puzzled by that.  I'd think that it would be straightfoward to design the CT to be large enough to carry a BM2 full load of prop, plus enough to return to LEO propulsively, so that the CT only had to receive prop in VLEO.

I've been wondering if getting a GS2 to meet the CT in a higher orbit has the property of requiring an integral number of GS2's to completely fuel.  Haven't worked out the math on that, though.

[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.

[meekGee]

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.

I don't think he even believes that.  It's a trial balloon - he wants to see how far it'll go...

BO might pitch itself as having a chance to catch up and gain an advantage *in the very narrow context of a footprints mission to the surface*, but no rational observer would think they're ahead rn, or that any of it translates into long term capabilities.

[JIS]

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.   

[steveleach]

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.

To me this all feels like it could be summarised with "Blue Origin are doing things the way I'm familiar and comfortable with, SpaceX aren't."

[meekGee]

To me this all feels like it could be summarised with "Blue Origin are doing things the way I'm familiar and comfortable with, SpaceX aren't."

...as in "... the nonsense with stainless steel structures..."

People who dismiss SpaceX don't die off, they just get replenished.

In this context, one company is thinking about the moon,whereas the other is thinking about Artemis.  This can only play out one way.

[JIS]

To me this all feels like it could be summarised with "Blue Origin are doing things the way I'm familiar and comfortable with, SpaceX aren't."

...as in "... the nonsense with stainless steel structures..."

People who dismiss SpaceX don't die off, they just get replenished.

In this context, one company is thinking about the moon,whereas the other is thinking about Artemis.  This can only play out one way.

C'mon guys, this is pretty lame though process.
The reason to use Stainless Steel structures was to enable faster and cheaper prototyping and higher temperature resistance for reentry.
None of this is applicable to HLS and to any other expendable deep space starship variant (depot). The only reason they keep using stainless steel for these applications is the common heritage with the initial Starships. This could be reasonable for the rocket stages but it is dubious for HLS crew cabin, landing legs and some other specialized stuff.

As I said in the past I suspect the true reason is to minimise upfront effort on Artemis project. Yes, it could be a heretic thought which is hard to die off.

Still, I think I will not cry when ppl have bad thoughts about my ideas but what I'm sad to read is when someone have doubts about me being dedicated SpaceX fan. I might not want to drink all of their kool-aid but I'm ready to drink most of the good stuff.

[envy887]

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".

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

That's not a "pretty much finished product", it's an entire new crewed spacecraft.

Orion is also the opposite of "lightweight". The capsule structure is designed for reentry and splashdown and can't be lightweighted without a ground-up redesign. It's twice the volume of the Apollo LM module, which was purpose built for super light weight, and which still weighed 5 t wet, while Mk1 is designed to land 3 t. And the LM didn't even have enough delta-v to reach NRHO, and almost certainly wouldn't meet NASA crew rating standards. Factor all that in and you're looking at about 12 t minimum for an Orion-based ascent stage.

That isn't happening in the 38 months between now and the end of 2028. 38 months might get it to CDR, but not to a demo and crew flights. Crew spacecraft don't happen that fast. The Apollo LM took 6 years, Crew Dragon took 8 years, Starliner is going on 13 years and still doesn't work, and Orion 21 years and hasn't even flown crew yet.

The easier alternative is a new crew module designed from scratch to be superlightweight and which remains attached to Mk1. That's maybe vaguely possible in 38 months.

[envy887]

The reason to use Stainless Steel structures was to enable faster and cheaper prototyping and higher temperature resistance for reentry.

None of this is applicable to HLS and to any other expendable deep space starship variant (depot). The only reason they keep using stainless steel for these applications is the common heritage with the initial Starships. This could be reasonable for the rocket stages but it is dubious for HLS crew cabin, landing legs and some other specialized stuff.

As I said in the past I suspect the true reason is to minimise upfront effort on Artemis project. Yes, it could be a heretic thought which is hard to die off.

What makes you think the HLS landing legs are stainless steel? The renders look more like F9's composite legs.

Do you even know for sure that the crew cabin is stainless, and not a composite or aluminum structure on top of the stainless tanks?

[Roy_H]

Recirculate propellant through the depot to maintain chill.

If you transfer propellants by electric pumps, that makes sense. I guess you need functional cryo pumps to do much active cooling in the first place. Good idea, my question is just when will we see suitable cryo pumps?

Interesting, I hadn't given any thought to this, but I imagine that it would be easier to put condensers in the top of the tanks to turn the vapors into liquid. I believe this is already worked out for active cooling systems. No specialized cryo pump necessary.

For pumping from one ship to another I have described a system here:

Click on link ^

Pumping the vapors instead of liquids simplifies the process.

[DanClemmensen]

The reason to use Stainless Steel structures was to enable faster and cheaper prototyping and higher temperature resistance for reentry.
None of this is applicable to HLS and to any other expendable deep space starship variant (depot). The only reason they keep using stainless steel for these applications is the common heritage with the initial Starships. This could be reasonable for the rocket stages but it is dubious for HLS crew cabin, landing legs and some other specialized stuff.

As I said in the past I suspect the true reason is to minimise upfront effort on Artemis project. Yes, it could be a heretic thought which is hard to die off.

The reason HLS uses stainless steel is to minimize development time and effort by maximizing commonality in design, components, and manufacturing.  This allowed SpaceX to bid HLS at half the price and about 20 times the capability of the alternative HLS bids. I do not know of anyone who thinks the Starship HLS design is optimal by any other metric. SpaceX intends to build hundreds of Starships per year. It's more cost-effective for SpaceX and NASA to use two "suboptimal" HLS per year than it would be to use two hand-crafted custom-designed HLSs at ten times the cost.

NASA did not buy HLS. NASA bought a transportation service to transport two astronauts from NRHO to the Lunar surface and back. The applications we have been discussing more recently go far beyond that service.

[OTV Booster]

Falcon 9 second stage is aluminum (something)grid. A thick slab of aluminum hogged out to leave a rectangular grid of ribs.

Both stages of Falcon use skin and stringer construction, much like Starship.

I could swear I saw an inside tank pic showing what looked kind a hogged out grid. I used to remember thing but can't remember how long ago that was.

https://forum.nasaspaceflight.com/index.php?topic=30981.msg1586339#msg1586339

Looks like stringers and skin to me.

Well, that does look like stringers & skin. Damn, I hate when I jump between universes.

[OTV Booster]

Falcon 9 second stage is aluminum (something)grid. A thick slab of aluminum hogged out to leave a rectangular grid of ribs. This so so different from SS's thin stainless plate that extrapolation isn't much more than guesswork.

Falcon loiter times on direct GEO missions are about 6 to 8 hours. Both stages of Falcon use skin and stringer construction, much like Starship. Orthogrid or isogrid would not be much different in thermal terms anyway. It's a data point for the models, but hardly a prototype. And the models should already be pretty good, thermal modeling for these sorts of problems is quite advanced.

I could swear I saw an inside tank pic showing what looked kind a hogged out grid. I used to remember thing but can't remember how long ago that was.

Dragon maybe?

No, I've got a memory of a hard hat kneeling on a board and doing fiddly work in a long tube of grid and have always associated it with F9.


Damn universe jumps.

[OTV Booster]

Recirculate propellant through the depot to maintain chill.

If you transfer propellants by electric pumps, that makes sense. I guess you need functional cryo pumps to do much active cooling in the first place. Good idea, my question is just when will we see suitable cryo pumps?

Would we recognize them if we saw them? They wouldn't be all that big - I think.