Author Topic: HLS Option B and the Sustaining Lunar Development Phase (Appendix P) (Read 158931 times)

DanClemmensen · « **Reply #940 on:** 12/21/2022 04:39 pm »

Quote from: VSECOTSPE on 12/21/2022 03:59 pm

Lunar Starship may develop major technical issues/delays. That doesn’t change the fact that NASA/Congress had an insane approach to civil human space exploration that funded a heavy lifter and capsule for years with nothing for landers or other necessary elements of an actual exploration architecture. That’s fundamentally why we’re going to spend $4B to $5B+ a year for Orion/SLS for years to come with no human lunar landing. Any SpaceX issues would be added to that already lengthy and elongated timeline, not the original cause of it.

Yep, the Artemis program schedule is crazy. If SpaceX had not existed the HLS would have been something similar to the NASA reference design, the BO/"National team" ILS, or the Dynetics ALPACA. Given contract award in Q1 2021, I do not think that any of these designs could have been implemented in time for an uncrewed demo in 2023 and a crewed Artemis III landing in 2024. All of the designs called for multiple major subsystems to be delivered to NRHO somehow. Starship HLS is complex and therefore risky but not necessarily more complex than any of the alternatives. The technical risks are different, but not necessarily worse in aggregate.

Starship HLS requires that the basic Starship architecture must work, and this is a big unknown. Economically, I think SpaceX must at a minimum be able to recover the boosters. HLS itself and the Depot are already expended, and expendable tankers can be used for the demo and for Artemis III. The major remaining tech risk is in-orbit propellant transfer.

Jim · « **Reply #941 on:** 12/21/2022 04:56 pm »

Quote from: VSECOTSPE on 12/21/2022 03:59 pm

snip That doesn’t change the fact that NASA/Congress had an insane approach to civil human space exploration that funded a heavy lifter and capsule for years with nothing for landers or other necessary elements of an actual exploration architecture. That’s fundamentally why we’re going to spend $4B to $5B+ a year for Orion/SLS for years to come with no human lunar landing. snip

That is why ARRM existed

Jim · « **Reply #942 on:** 12/21/2022 04:59 pm »

Quote from: Ben Baley on 12/19/2022 10:08 am

I know it's unlikely but just the thought of having someone there to greet the astronauts as they transfer from the relatively cramped Orion to the roomy LSS, makes me feel warm and fuzzy inside.

What makes you LSS will be roomy?

Robotbeat · « **Reply #943 on:** 12/21/2022 05:07 pm »

Quote from: Jim on 12/21/2022 04:59 pm

Quote from: Ben Baley on 12/19/2022 10:08 am

I know it's unlikely but just the thought of having someone there to greet the astronauts as they transfer from the relatively cramped Orion to the roomy LSS, makes me feel warm and fuzzy inside.

What makes you LSS will be roomy?

We’ve seen mock ups of the airlocks, and each is about 3m tall by 3m in diameter, meaning each of the two airlocks alone have more volume than the habitable volume of Orion. And there will only be 2 people on HLS (at first).

https://ntrs.nasa.gov/api/citations/20220003725/downloads/22%203%207%20Kent%20IEEE%20paper.pdf

deadman1204 · « **Reply #944 on:** 12/21/2022 05:10 pm »

Quote from: Robotbeat on 12/21/2022 05:07 pm

We’ve seen mock ups of the airlocks, and each is about 3m tall by 3m in diameter, meaning each of the two airlocks alone have more volume than the habitable volume of Orion. And there will only be 2 people on HLS (at first).

I would take mockups of any of the crew space in HLS with a grain of salt right now. Major design things like propellant transfer have not been worked out yet. These could eat into what space is available.

Robotbeat · « **Reply #945 on:** 12/21/2022 05:16 pm »

Quote from: deadman1204 on 12/21/2022 05:10 pm

Quote from: Robotbeat on 12/21/2022 05:07 pm
We’ve seen mock ups of the airlocks, and each is about 3m tall by 3m in diameter, meaning each of the two airlocks alone have more volume than the habitable volume of Orion. And there will only be 2 people on HLS (at first).
I would take mockups of any of the crew space in HLS with a grain of salt right now. Major design things like propellant transfer have not been worked out yet. These could eat into what space is available.

Not as big of a grain of salt as I would to take for those implying that LSS, which is built on a platform that nominally has ~1000m^3 volume for cargo (and which is designed for that internal volume to be pressurized during flight for stiffness), will be less roomy than Orion which has a habitable volume of less than 10m^3.

DanClemmensen · « **Reply #946 on:** 12/21/2022 05:22 pm »

Quote from: Robotbeat on 12/21/2022 05:07 pm

Quote from: Jim on 12/21/2022 04:59 pm
Quote from: Ben Baley on 12/19/2022 10:08 am

I know it's unlikely but just the thought of having someone there to greet the astronauts as they transfer from the relatively cramped Orion to the roomy LSS, makes me feel warm and fuzzy inside.

What makes you LSS will be roomy?
We’ve seen mock ups of the airlocks, and each is about 3m tall by 3m in diameter, meaning each of the two airlocks alone have more volume than the habitable volume of Orion. And there will only be 2 people on HLS (at first).

https://ntrs.nasa.gov/api/citations/20220003725/downloads/22%203%207%20Kent%20IEEE%20paper.pdf

That's about 21 m³. I assume they will have a clever way to avoid exhausting all that gas to the outside every time they use it. Maybe pump it down to a lower pressure or use inflatable bladders or both?

Robotbeat · « **Reply #947 on:** 12/21/2022 05:28 pm »

Yes. Pump it down, just like on ISS.

(BTW, that’s why “space smells like bacon”… that’s the smell of the oil in the vacuum pumps used to pump down the airlocks into ISS, IIRC)

Robotbeat · « **Reply #948 on:** 12/21/2022 05:29 pm »

Note also that in the Starship HLS source selection document, SpaceX got attaboys for having large volume capabilities, actually satisfying the surface habitable volume requirements for even sustaining missions without a dedicated surface habitat. If that’s not an implication of roominess, then what is??

Ben Baley · « **Reply #949 on:** 12/21/2022 10:14 pm »

The HLS may not end up being roomy compared to a house but considering the volume they're starting from I find it hard to believe it won't feel roomier than any spacecraft/station preceding it.

punder · « **Reply #950 on:** 12/22/2022 12:52 am »

Quote from: deadman1204 on 12/21/2022 01:49 pm

Not really sure what your point was, but it kinda seemed like you said everyone else sux but spaceX got big brain power?

LOL! Wish I could have said it as succinctly as you just did!

How soon we forget. Every week we watch SpaceX land a Saturn 1B-size booster on a barge in the ocean, and forget how a few years ago the mighty and wise industry watchers (including execs at my own company, for what it’s worth) assured us that doing such a thing *once* is impossible.

We forget how Boeing was going to hand newbie SpaceX its butt in the Commercial Crew program.

We forget the abysmal US share of the global commercial launch market in the 2000s. I wonder what percentage of the now humongous US share belongs to SpaceX?

Does past performance guarantee future results? Of course not. I’m just amused that, despite all its accomplishments, SpaceX, we are reminded by those all-knowing industry watchers, is doomed to fail. Any minute now.

JEF_300 · « **Reply #951 on:** 12/22/2022 03:37 am »

If this thread is about Appendix P, then isn't it explicitly NOT about Starship?

DanClemmensen · « **Reply #952 on:** 12/22/2022 03:40 am »

Quote from: JEF_300 on 12/22/2022 03:37 am

If this thread is about Appendix P, then isn't it explicitly NOT about Starship?

HLS Option B is the sole-source extension of the SpaceX HLS contract. It is explicitly mentioned in the thread title. It has the same technical requirements as the Appendix P HLS.

TheRadicalModerate · « **Reply #953 on:** 12/22/2022 05:33 am »

Quote from: Ben Baley on 12/21/2022 10:14 pm

The HLS may not end up being roomy compared to a house but considering the volume they're starting from I find it hard to believe it won't feel roomier than any spacecraft/station preceding it.

If you put the main part of the crew pressure vessel in the ogive portion of the payload bay, that's about 300m³, excluding the airlocks.

The airlocks will have to go down on the same deck as any unpressurized cargo, the hatch, and the stowed elevator, all of which are probably just above the LCH4 dome.

I still think that the LSS will have the LCH4 dome and inter-tank bulkhead re-jiggered to hold 1500t of prop. If that's the case, then the cylindrical portion of the payload bay will only be 2.3m high. If the airlocks turn out to be that height and 2.5m in diameter (I think the 3m-ish diameter in the simulator is way too wide for two airlocks), then the airlocks would another 23m³ or so.

If I'm wrong and they stick with 1200t, then putting in the crew module just in the ogive makes for an 8m climb down into the airlocks. That's not a problem in shirtsleeves, but it's a little more challenging structurally, and you probably want a contingency to haul an injured crewmember, in an EVA suit, up into the main space for medical attention. Then maybe it's better to put some or all of the main crew volume in the cylindrical portion.