Author Topic: Boeing to propose SLS-launched lander for HLS bid  (Read 43124 times)

Offline jadebenn

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Re: Boeing to propose SLS-launched lander for HLS bid
« Reply #20 on: 10/26/2019 03:29 am »
It may need more than two SLS, since they'll be using SLS Block 1 Cargo which can only throw 26t to TLI, this is not enough for a full lunar lander, at least not in NASA's estimate. In NASA's IP 03 scenario, a 3rd commercial launch is needed, so using a SLS doesn't buy you much.
For Block 1, maybe. Once Block 1B is operational, they should have no issue shooting the lander up in one go.
« Last Edit: 10/26/2019 03:30 am by jadebenn »

Offline TrevorMonty

Re: Boeing to propose SLS-launched lander for HLS bid
« Reply #21 on: 10/26/2019 03:59 am »
How does lander handle boiloff at gateway while waiting months for crew mission

Offline GWH

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Re: Boeing to propose SLS-launched lander for HLS bid
« Reply #22 on: 10/26/2019 06:34 am »
A 2nd SLS shouldn't have anywhere near the cost of 2x a single SLS. Plus flight rates of landers are so low development costs of a simpler 2 stage could represent significant savings in comparison to 3 cheaper launches.

 I eagerly await to see how this turns out, competition and multiple solutions are a good thing. In a perfect world we'd see improvements to SLS tied to this proposal (EUS for example).

Offline meberbs

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Re: Boeing to propose SLS-launched lander for HLS bid
« Reply #23 on: 10/26/2019 05:14 pm »
If you're that confident the bid will be financially uncompetitive, then you should have nothing to worry about.
I saw a post in another thread indicating that SLS costs wouldn't count against Boeing's bid, which would be horrifically bad contracting practice if true. As long as that is not the case, it is unfortunate to see Boeing price itself out of the competition by insisting on SLS so they can double dip on the profits.

In all seriousness, do you think Boeing is stupid? If they didn't think an SLS-launched bid was competitive they wouldn't propose it.
While off topic for this site, and a different division of Boeing, there is some evidence to support a "yes" answer to that question in recent news.

Completely failing to accurately predict what is competitive is not unusual especially for a big company like Boeing. Go take a look at the CLPS thread where Lockheed overbid by a factor of 2.

Offline brickmack

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Re: Boeing to propose SLS-launched lander for HLS bid
« Reply #24 on: 10/27/2019 12:49 am »
Pressure vessel is likely to be based on Starliner along with life support.

This figure from a few months ago shows a pressure vessel with no apparent Starliner commonality. Ascent stage design has changed slightly since then (addition of an EVA hatch in the side vs expensable airlock in the descent stage), but probably still the same basic pressure vessel shape

I eagerly await to see how this turns out, competition and multiple solutions are a good thing. In a perfect world we'd see improvements to SLS tied to this proposal (EUS for example).

Thats my hope. NASAs solicitation said basically that any bidder using SLS would have to prove no impact to NASAs other missions, that seems impossible with what we know about SLS production capacity. Also called it "SLS-derived", and Bridenstine made a statement recently about SLSs flightrate being dependent on what Boeings willing to invest. Something radical like engine section reuse would be needed to make this viable, I bet Boeing will bid that as a packaged deal. Would also make SLS a lot more useful in the medium term

Online envy887

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Re: Boeing to propose SLS-launched lander for HLS bid
« Reply #25 on: 10/27/2019 01:08 am »
A 2nd SLS shouldn't have anywhere near the cost of 2x a single SLS. ...

If they can build 2 in the same time as 1, maybe. But Boeing can only make 1 per year, and were already planning to do that. To up the flight rate Boeing needs to invest in SLS production.

Offline TaurusLittrow

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Re: Boeing to propose SLS-launched lander for HLS bid
« Reply #26 on: 10/28/2019 06:09 pm »
A 2nd SLS shouldn't have anywhere near the cost of 2x a single SLS. ...

If they can build 2 in the same time as 1, maybe. But Boeing can only make 1 per year, and were already planning to do that. To up the flight rate Boeing needs to invest in SLS production.

Let's see, that makes eight RS-25s per annual lunar sortie. ChaChing.

Offline ncb1397

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Re: Boeing to propose SLS-launched lander for HLS bid
« Reply #27 on: 10/28/2019 10:55 pm »
So if Boeing wins the bid, they will have to launch two SLS's to get astronauts in Orion and the lander to the moon by in space docking.  Wow, a moon landing for about $3 billion or more per landing.  Not counting the LOP-G station.  This is way expensive to use the SLS. 

It may need more than two SLS, since they'll be using SLS Block 1 Cargo which can only throw 26t to TLI, this is not enough for a full lunar lander, at least not in NASA's estimate. In NASA's IP 03 scenario, a 3rd commercial launch is needed, so using a SLS doesn't buy you much.

Trying to evaluate these claims, I used a model of the Apollo hardware. It seems that the lunar module with an additional transfer stage based off the descent module but scaled 11%(both fuel and mass) with the landing gear removed has a total stack delta v of ~5.3 km/s (with the HLS required 525 kg up and 865 kg down). This seems to be the stack delta v requirements of a NRHO based trajectory to a polar region of the moon as long as you reduce the delta v for the trip to NRHO by a few hundred m/s[1]. Total stack (minus the payload that is offloaded to Orion/gateway logistics services) would be 26.3 t which is within the capability of SLS Block 1 to a NRHO ballistic trajectory that reduces the NRHO transfer to <200 m/s[2].

[1]https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160003079.pdf
[2] https://s3-us-west-2.amazonaws.com/advspace.publicshare/Parrish+et+al+-+Survey+of+BLTs+to+NRHO.pdf

Of course, what Boeing described was a two stage lander, but as far as the feasibility of putting an integrated lander on a Block 1 that meets the HLS requirements, I think it definitely can be done. The system that NASA was assuming did have higher masses for a lander, but I'm pretty sure that had to carry more crew and cargo than the requirements for the 2024 landing system. They also had to function independently as they would be shipped up seperately which may increase mass. You would then evolve the lander and use the Block 1B to carry the additional weight of the beefier lander to meet the "sustainable" phase requirements (more crew, global access, etc.).

edit: NASA was estimating the minimum mass for a 3 stage system that met their "desired requirements" was 9 + 12 +12 t or 33 t. Fitting it to 27 t would be a reduction of 20% which sounds achievable given their numbers would have engineering margins built in regardless.
« Last Edit: 10/28/2019 11:25 pm by ncb1397 »

Offline spacenut

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Re: Boeing to propose SLS-launched lander for HLS bid
« Reply #28 on: 10/29/2019 12:44 am »
It is a shame SLS isn't as good as the old Saturn V in LEO performance.  After 13 billion dollars and it will take two SLS launches to equal one Saturn V.  They should have used either liquid boosters or a single stick two stage rocket. 

Offline jadebenn

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Re: Boeing to propose SLS-launched lander for HLS bid
« Reply #29 on: 10/29/2019 01:49 am »
It is a shame SLS isn't as good as the old Saturn V in LEO performance.  After 13 billion dollars and it will take two SLS launches to equal one Saturn V.  They should have used either liquid boosters or a single stick two stage rocket.
How relevant is SLS LEO performance as a performance metric when all currently-planned payloads are BEO? If SLS had been designed to maximize payload to LEO and not payload BEO, it would have a very different upper stage.

Speaking of upper stages, your comparison neglects Block 1B. That's the SLS that's in the Saturn V's neck of the woods when it comes to overall performance, not the Block 1 with its "placeholder" upper-stage.

Online envy887

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Re: Boeing to propose SLS-launched lander for HLS bid
« Reply #30 on: 10/29/2019 04:49 pm »
It is a shame SLS isn't as good as the old Saturn V in LEO performance.  After 13 billion dollars and it will take two SLS launches to equal one Saturn V.  They should have used either liquid boosters or a single stick two stage rocket.
How relevant is SLS LEO performance as a performance metric when all currently-planned payloads are BEO? If SLS had been designed to maximize payload to LEO and not payload BEO, it would have a very different upper stage.

Speaking of upper stages, your comparison neglects Block 1B. That's the SLS that's in the Saturn V's neck of the woods when it comes to overall performance, not the Block 1 with its "placeholder" upper-stage.

LEO performance doesn't matter much for lunar missions. But Block 1B at ~39 t to TLI is still quite far from Saturn V at 48+ t. This is exacerbated by the fact that Orion+ESM has a much lower available delta-v than Apollo, which means that any mission using Orion+ESM needs more mass to TLI than Apollo did.

A more powerful Orion SM would help a lot, particularly if it were hydrolox (e.g. based on Centaur 5+ Long with MLI and IVF).

Offline Proponent

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Re: Boeing to propose SLS-launched lander for HLS bid
« Reply #31 on: 10/29/2019 04:54 pm »
It's rather ironic that it's so difficult to piece together a lunar mission using Orion, when Orion was originally designed for a lunar mission.

Online envy887

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Re: Boeing to propose SLS-launched lander for HLS bid
« Reply #32 on: 10/29/2019 05:14 pm »
So if Boeing wins the bid, they will have to launch two SLS's to get astronauts in Orion and the lander to the moon by in space docking.  Wow, a moon landing for about $3 billion or more per landing.  Not counting the LOP-G station.  This is way expensive to use the SLS. 

It may need more than two SLS, since they'll be using SLS Block 1 Cargo which can only throw 26t to TLI, this is not enough for a full lunar lander, at least not in NASA's estimate. In NASA's IP 03 scenario, a 3rd commercial launch is needed, so using a SLS doesn't buy you much.

Trying to evaluate these claims, I used a model of the Apollo hardware. It seems that the lunar module with an additional transfer stage based off the descent module but scaled 11%(both fuel and mass) with the landing gear removed has a total stack delta v of ~5.3 km/s (with the HLS required 525 kg up and 865 kg down). This seems to be the stack delta v requirements of a NRHO based trajectory to a polar region of the moon as long as you reduce the delta v for the trip to NRHO by a few hundred m/s[1]. Total stack (minus the payload that is offloaded to Orion/gateway logistics services) would be 26.3 t which is within the capability of SLS Block 1 to a NRHO ballistic trajectory that reduces the NRHO transfer to <200 m/s[2].

[1]https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160003079.pdf
[2] https://s3-us-west-2.amazonaws.com/advspace.publicshare/Parrish+et+al+-+Survey+of+BLTs+to+NRHO.pdf

Of course, what Boeing described was a two stage lander, but as far as the feasibility of putting an integrated lander on a Block 1 that meets the HLS requirements, I think it definitely can be done. The system that NASA was assuming did have higher masses for a lander, but I'm pretty sure that had to carry more crew and cargo than the requirements for the 2024 landing system. They also had to function independently as they would be shipped up separately which may increase mass. You would then evolve the lander and use the Block 1B to carry the additional weight of the beefier lander to meet the "sustainable" phase requirements (more crew, global access, etc.).

edit: NASA was estimating the minimum mass for a 3 stage system that met their "desired requirements" was 9 + 12 +12 t or 33 t. Fitting it to 27 t would be a reduction of 20% which sounds achievable given their numbers would have engineering margins built in regardless.

I'm pretty sure that it's more optimal to make the lander bigger, and have it help with TLI. SLS Block 1 with a TLI payload pushes that heavy core stage dry mass to a high energy, and the sooner you get rid of that 100+ t of burnout mass the better. Ideally, it would only go close enough to orbit that the gravity losses during the ICPS burn are minimal.

The extreme case would be a 95,000 kg 3-stage lander that ICPS can just put into 185 km LEO. The transfer stage would be 67 t wet and put 28 t of payload through TLI assuming a 10% dry mass and pressure fed hypergol ISP of 316. This is already ~1500 kg better than using Block 1 for the lunar transfer, despite the much worse ISP of the transfer stage compared to ICPS. With a pump-fed hypergol (5% dry mass, 339 ISP) that goes up to 33 t to NHRO with BLT, about 5500 kg more than a Block 1 with BLT.

Offline spacenut

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Re: Boeing to propose SLS-launched lander for HLS bid
« Reply #33 on: 10/29/2019 08:59 pm »
It is a shame SLS isn't as good as the old Saturn V in LEO performance.  After 13 billion dollars and it will take two SLS launches to equal one Saturn V.  They should have used either liquid boosters or a single stick two stage rocket.
How relevant is SLS LEO performance as a performance metric when all currently-planned payloads are BEO? If SLS had been designed to maximize payload to LEO and not payload BEO, it would have a very different upper stage.

Speaking of upper stages, your comparison neglects Block 1B. That's the SLS that's in the Saturn V's neck of the woods when it comes to overall performance, not the Block 1 with its "placeholder" upper-stage.

Even Saturn V with it's 3rd stage can do more than SLS.  SLS needs and upper stage it can't throw much toward the moon.  SLS needs 5 engines on the bottom and a good well designed upper stage, probably with a J2X or 2-3 BE-3U's to do any good. 

SLS is expendable.  SLS uses expensive engines.  SLS needs and upper stage.  SLS should have liquid boosters since they are more efficient weight wise than heavy solids.  SLS cost's too much for what it does.  SLS was designed by congressional mandate, not rocket scientists.  They may make 10 of them, but it is like the bridge to nowhere.  NASA is going to have to use other rockets to get their Gateway working, not just SLS.  So, why use SLS other than Orion?  Even Orion can be launched cheaper with two existing launchers.  One for Orion, and one for a pusher stage to dock and get it to the moon for far less cost. 

No money has been voted for to build Block 1B.  So, that is 3-5 years away and more money.   
« Last Edit: 10/29/2019 09:00 pm by spacenut »

Offline jadebenn

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Re: Boeing to propose SLS-launched lander for HLS bid
« Reply #34 on: 10/29/2019 10:28 pm »
No money has been voted for to build Block 1B.  So, that is 3-5 years away and more money.
Huh? EUS has been in all the NASA appropriations since 2016. They even showed-off some of the hardware in a presentation today:
 



Offline Zed_Noir

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Re: Boeing to propose SLS-launched lander for HLS bid
« Reply #35 on: 11/01/2019 05:54 am »
It's rather ironic that it's so difficult to piece together a lunar mission using Orion, when Orion was originally designed for a lunar mission.

The Constellation Orion have the Altair lander for the TLI burn. The Altair is more or less the current EUS stage equivalent with legs.

Offline woods170

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Re: Boeing to propose SLS-launched lander for HLS bid
« Reply #36 on: 11/01/2019 08:09 am »
It's rather ironic that it's so difficult to piece together a lunar mission using Orion, when Orion was originally designed for a lunar mission.

The Constellation Orion have the Altair lander for the TLI burn. The Altair is more or less the current EUS stage equivalent with legs.
It's rather ironic that it's so difficult to piece together a lunar mission using Orion, when Orion was originally designed for a lunar mission.

Also being discussed in the Lunar Gateway thread from this point forward: https://forum.nasaspaceflight.com/index.php?topic=46024.msg2009658#msg2009658

Offline MATTBLAK

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Re: Boeing to propose SLS-launched lander for HLS bid
« Reply #37 on: 11/01/2019 08:24 am »
It's rather ironic that it's so difficult to piece together a lunar mission using Orion, when Orion was originally designed for a lunar mission.

The Constellation Orion have the Altair lander for the TLI burn. The Altair is more or less the current EUS stage equivalent with legs.
I think you mean L.O.I. - lunar orbit insertion burn.
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Offline Zed_Noir

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Re: Boeing to propose SLS-launched lander for HLS bid
« Reply #38 on: 11/01/2019 09:00 am »
It's rather ironic that it's so difficult to piece together a lunar mission using Orion, when Orion was originally designed for a lunar mission.

The Constellation Orion have the Altair lander for the TLI burn. The Altair is more or less the current EUS stage equivalent with legs.
I think you mean L.O.I. - lunar orbit insertion burn.
Thanks for correcting my fuzzy recall of the Altair.

Offline TomH

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Re: Boeing to propose SLS-launched lander for HLS bid
« Reply #39 on: 11/01/2019 02:54 pm »
No money has been voted for to build Block 1B.  So, that is 3-5 years away and more money.
Huh? EUS has been in all the NASA appropriations since 2016. They even showed-off some of the hardware in a presentation today:
 


The EUS (Exploration Upper Stage) has been delayed. Spacenut is correct, Block IB is not flying soon. Block I with the ICPS upper stage is on slate, and only 1 per year is to be built. SLS is underpowered for the task at hand due to too few main engines, underpowered solid boosters, and a ridiculously small upper stage. It is also absurdly overpriced.

Tags: Boeing NASA SLS HLS lander 
 

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