Author Topic: NASA's Artemis Program Updates and Discussion Thread 3  (Read 704773 times)

Offline A_M_Swallow

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Re: NASA's Artemis Program Updates and Discussion Thread 3
« Reply #20 on: 07/30/2019 02:27 pm »
{snip}
Am I the only one under the delusion that Gateway would allow for reuse of this component?

The Gateway will allow reuse of the very expensive lunar lander ascent stages (including the cabins). To support refuelling the Minimal Habitat Modules (MHM) will have to have temperature controlled plumbing and wiring joining the 4 docking ports together.

To be included in the MHM development contract the plumbing requirements will have to be finalised within the next 2 months. We are talking about spending a few thousand dollars to save millions of dollars. The do it order needs to come down from NASA HQ within days.

All of the first lander stages are going to be throw away because the refuelling pumps and fuel tanks will not have been installed in the Gateway for the first crewed lunar landing in 2024. Hopefully they will have been installed by 2028.

It's not obvious that a gateway is needed to permit reuse.  It might help, but it needs to be established that it would help enough to offset its own cost.

Cost justification of lunar Gateway.

I am sticking to lunar operations so the science laboratories along with construction and maintenance of Mars Transfer Vehicles will need their own justification.

I am allowing for supporting landing a woman on the Moon and building a lunar base missions.




ItempriceReference
Launching a Falcon 9 $62 million https://www.spacex.com/about/capabilities
launching a Falcon 9 with crew Dragon $140-$175 million https://www.reddit.com/r/spacex/comments/2endx6/cost_of_dragon_v2_vs_soyuz/
Launching a Falcon Heavy $90 million https://www.spacex.com/about/capabilities
launching a Space Launch System (SLS) including Orion estimated $2,000 million or less https://arstechnica.com/science/2016/08/how-much-will-sls-and-orion-cost-to-fly-finally-some-answers
CLPS million to the lunar surface about $100 million https://spacenews.com/commercial-lunar-lander-company-terminates-nasa-contract
Buying the Power and Propulsion Element (PPE) $375 million https://spaceflightnow.com/2019/05/24/nasa-chooses-maxar-to-build-keystone-module-for-lunar-gateway-station
Buying the Minimal Habitat Module (MHM) (redacted)
Robotic Arm a few $hundred million paid by the Canadian Government
Gateway resupply mission (unknown)
Buying a Lander Ascent Stage (unknown)
Buying a Lander Transfer Stage (unknown)
Buying a lander Descent Stage (unknown)
Buying a fuelling module (unknown) guess $50 million
Development of a fuelling module (unknown)
Refuelling mission to Gateway (unknown) say Falcon Heavy + fuelling module = $90M + $50M = $140 million
Refuelling mission to free floating Ascent Stage (unknown) may involve an SLS
Cost of Lander Ascent Stage doing own station keeping (unknown)
Getting a fuelled three stage lander to lunar orbit without using the Gateway say $2 billion since probably only an SLS can transport any thing that heavy in one go


The Gateway provides station keeping facilities to the Ascent stage between missions and station keeping to the Orion during missions. Cargo is transfer from a Falcon Heavy to the cargo lander.

A mini Gateway consisting of PPE, MHM equipped to refuel the lander and robotic arm = $375M + (reacted) + a few $hundred million + crew Dragon on Falcon Heavy to assemble ($140M-$62M+$90M) say $1-$1.5 billion.

So the whole space station will cost less than a single SLS launch.

The transfer and descent stages of the lander are about the same complexity as an upper stage. Unfortunately the lander ascent stage will be as complex as an Orion or crew Dragon, use the development cost of the CST-100 as an estimation.

Refuelling a lander ascent stage at the Gateway = $112 million.

Refuelling a free flying lander ascent stage using an Orion and SLS around $2 billion.

Station keeping fuel need by reusable Ascent Stage for 6 months (needs calculating)
« Last Edit: 07/30/2019 02:29 pm by A_M_Swallow »

Offline su27k

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Re: NASA's Artemis Program Updates and Discussion Thread 3
« Reply #21 on: 07/30/2019 02:43 pm »
{snip}
Am I the only one under the delusion that Gateway would allow for reuse of this component?

The Gateway will allow reuse of the very expensive lunar lander ascent stages (including the cabins). To support refuelling the Minimal Habitat Modules (MHM) will have to have temperature controlled plumbing and wiring joining the 4 docking ports together.

To be included in the MHM development contract the plumbing requirements will have to be finalised within the next 2 months. We are talking about spending a few thousand dollars to save millions of dollars. The do it order needs to come down from NASA HQ within days.

I don't know how this would work, NASA doesn't know who will provide the lander and what kind of fuel the lander will use yet, seems difficult to write requirement in this situation.

I'm in the camp that says NASA needs to let companies design the architecture, if a company thinks they need a propellant depot at Gateway they can include it in their lander proposal, there are many ways to optimize this, let's not put restrictions on the architecture this early.

Offline butters

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Re: NASA's Artemis Program Updates and Discussion Thread 3
« Reply #22 on: 07/30/2019 04:02 pm »
{snip}
Am I the only one under the delusion that Gateway would allow for reuse of this component?

The Gateway will allow reuse of the very expensive lunar lander ascent stages (including the cabins). To support refuelling the Minimal Habitat Modules (MHM) will have to have temperature controlled plumbing and wiring joining the 4 docking ports together.

To be included in the MHM development contract the plumbing requirements will have to be finalised within the next 2 months. We are talking about spending a few thousand dollars to save millions of dollars. The do it order needs to come down from NASA HQ within days.

I don't know how this would work, NASA doesn't know who will provide the lander and what kind of fuel the lander will use yet, seems difficult to write requirement in this situation.

I'm in the camp that says NASA needs to let companies design the architecture, if a company thinks they need a propellant depot at Gateway they can include it in their lander proposal, there are many ways to optimize this, let's not put restrictions on the architecture this early.

This is the crux of the challenge facing NASA HSF: NASA doesn't want to be prescriptive about the architecture, but they must insist on NRHO staging to ensure a role for Orion, and they must insist that the lander elements cannot be assembled and refueled without being docked to the Gateway. NASA doesn't want to have to dictate that the ascent module and transfer stage both use hypergolic propulsion, they want the contractors to come to that conclusion themselves. NASA is not ready to turn over major architectural decisions to the contractors. They want the contractors to fill in the blanks in the provided Mad Lib with what they perceive to be the obvious solutions.

We've seen Lockheed's single-stage and two-stage lunar lander proposals. We know what SpaceX has in mind. We've seen a piece of Blue Origin's plans. We know that ULA/parents are interested in hydrolox refueling with ACES. I don't think NASA would have much success incentivizing various contractors to agree on an architecture where they can all play nicely with each other. SpaceX would take their methalox Starship ball and go home. A BlueBoeMart alliance could form around a hydrolox refueling architecture which could be problematic for Gateway as well as overall budget and schedule constraints.

It's likely that within 5-10 years, America will have two commercial space transportation systems with service to the lunar surface, representing two very different approaches to the problem, neither of which involves a space station in NRHO. NASA will have their choice of end-to-end transport solutions, and it will be up to them to design missions, rather than this asinine "if we builds the transportation, the demand for missions will come from elsewhere" nonsense.

Until then, we have to get through this Artemis phase, where NASA tries to build a horse by committee by hinting to the various contractors that the solution should have humps.

Offline A_M_Swallow

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Re: NASA's Artemis Program Updates and Discussion Thread 3
« Reply #23 on: 07/30/2019 04:15 pm »
{snip}
Am I the only one under the delusion that Gateway would allow for reuse of this component?

The Gateway will allow reuse of the very expensive lunar lander ascent stages (including the cabins). To support refuelling the Minimal Habitat Modules (MHM) will have to have temperature controlled plumbing and wiring joining the 4 docking ports together.

To be included in the MHM development contract the plumbing requirements will have to be finalised within the next 2 months. We are talking about spending a few thousand dollars to save millions of dollars. The do it order needs to come down from NASA HQ within days.

I don't know how this would work, NASA doesn't know who will provide the lander and what kind of fuel the lander will use yet, seems difficult to write requirement in this situation.

I'm in the camp that says NASA needs to let companies design the architecture, if a company thinks they need a propellant depot at Gateway they can include it in their lander proposal, there are many ways to optimize this, let's not put restrictions on the architecture this early.

We are describing pipes and connectors. A simple option is for the Gateway to have connectors for hydrogen, lox, methane and at least one form of hypergolic propellant.

There is no excuse for failure to define the shape of the drinking water and breathable oxygen connectors plus where about they go on the docking ports. These supply tanks inside the spacecraft.

If no liquid connectors are fitted to the Gateway's IDSS docking ports then a high level architectural decision has been taken that the space station is not the propellant depot. Having a second lunar space stations gets expensive.


Offline dglow

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Re: NASA's Artemis Program Updates and Discussion Thread 3
« Reply #24 on: 07/30/2019 04:38 pm »
Two questions:

1. Do there exist sound technical decisions for Gateway hardware to be directly involved in refueling? Specifically, would a tug/depot connecting to and refueling the ascent stage work equally well, and why or why not?

2. Regarding NRHO: I wish to know the extent to which it is necessitated, and by what exactly. I understand that it's a crutch for SLS+Orion shortcomings in the current block 1 configuration. Would moving to block 1b (EUS) plus, possibly, a larger SM obviate the need for NRHO? What about CLV resupply: do those transits require Gateway to be in NRHO, given it's only a one-way trip?
« Last Edit: 07/30/2019 05:04 pm by dglow »

Offline Toast

2. Regarding NRHO: I wish to know the extent to which it is necessitated, and by what exactly. I understand that it's a crutch for SLS+Orion shortcomings in the current block 1 configuration. Would moving to block 1b (EUS) plus, possibly, a larger SM obviate the need for NRHO? What about CLV resupply: do those transits require Gateway to be in NRHO, given it's only a one-way trip?

I believe the limiting factor is the Orion service module. It has the Delta-V to make the lunar transfer/return, but only to the higher NHRO orbit and not LLO. So yes, a larger SM would solve the problem, but I don't believe that is currently in the works.
« Last Edit: 07/30/2019 05:47 pm by Toast »

Offline woog

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Re: NASA's Artemis Program Updates and Discussion Thread 3
« Reply #26 on: 07/30/2019 07:41 pm »
https://www.nasa.gov/press-release/nasa-announces-us-industry-partnerships-to-advance-moon-mars-technology
NASA announces a partnership with companies in the industry for the Artemis program.
I find it interesting that it mentions both blue moon and starship.
a post handmade by woog

Offline dglow

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Re: NASA's Artemis Program Updates and Discussion Thread 3
« Reply #27 on: 07/30/2019 07:49 pm »
2. Regarding NRHO: I wish to know the extent to which it is necessitated, and by what exactly. I understand that it's a crutch for SLS+Orion shortcomings in the current block 1 configuration. Would moving to block 1b (EUS) plus, possibly, a larger SM obviate the need for NRHO? What about CLV resupply: do those transits require Gateway to be in NRHO, given it's only a one-way trip?

I believe the limiting factor is the Orion service module. It has the Delta-V to make the lunar transfer/return, but only to the higher NHRO orbit and not LLO. So yes, a larger SM would solve the problem, but I don't believe that is currently in the works.

Copy that, this was my understanding as well. Is the currently size of the SM a result of the ICPS-based limbo SLS is currently in?

Offline RonM

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Re: NASA's Artemis Program Updates and Discussion Thread 3
« Reply #28 on: 07/30/2019 07:55 pm »
https://www.nasa.gov/press-release/nasa-announces-us-industry-partnerships-to-advance-moon-mars-technology
NASA announces a partnership with companies in the industry for the Artemis program.
I find it interesting that it mentions both blue moon and starship.

These industry partnerships will benefit BLEO exploration plans whether they're Artemis or commercial. Good move by NASA.

Offline DistantTemple

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Re: NASA's Artemis Program Updates and Discussion Thread 3
« Reply #29 on: 07/30/2019 08:04 pm »
https://forum.nasaspaceflight.com/index.php?topic=48706.msg1972678#msg1972678

Brilliant.... NASA to work with SX to deliver fuel in orbit!!!

And I kept resisting saying this about the refuelling for Gateway and refuelling the lunar ascent stage - and if not refuelled then thrown away.... Now to read what it says!!!
We can always grow new new dendrites. Reach out and make connections and your world will burst with new insights. Then repose in consciousness.

Offline DistantTemple

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Re: NASA's Artemis Program Updates and Discussion Thread 3
« Reply #30 on: 07/30/2019 08:11 pm »
https://forum.nasaspaceflight.com/index.php?topic=48706.msg1972678#msg1972678

Brilliant.... NASA to work with SX to deliver fuel in orbit!!!

And I kept resisting saying this about the refuelling for Gateway and refuelling the lunar ascent stage - and if not refuelled then thrown away.... Now to read what it says!!!
even more relevant!!!
Quote
SpaceX of Hawthorne, California, will work with NASA’s Kennedy Space Center in Florida to advance their technology to vertically land large rockets on the Moon. This includes advancing models to assess engine plume interaction with lunar regolith.
edit: The other key point: (and put the quotes in quotes)
Quote
SpaceX will work with Glenn and Marshall to advance technology needed to transfer propellant in orbit, an important step in the development of the company’s Starship space vehicle.
« Last Edit: 07/30/2019 08:13 pm by DistantTemple »
We can always grow new new dendrites. Reach out and make connections and your world will burst with new insights. Then repose in consciousness.

Offline dglow

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Re: NASA's Artemis Program Updates and Discussion Thread 3
« Reply #31 on: 07/30/2019 08:20 pm »
Yep, this is really quite excellent. And let's hope that Glenn and Marshall share all that is learned about prop transfer with other players, too.

Offline Lar

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Re: NASA's Artemis Program Updates and Discussion Thread 3
« Reply #32 on: 07/31/2019 02:02 am »
Talking about why ...

... is, in my mind, the most important feature of this site.  Why are the policies as they are?  Why [your question here.]
We have another thread for that now, in space policy. This thread is for what and how, not why.

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Offline JohnFornaro

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Re: NASA's Artemis Program Updates and Discussion Thread 3
« Reply #33 on: 07/31/2019 12:08 pm »
Talking about why ...

... is, in my mind, the most important feature of this site.  Why are the policies as they are?  Why [your question here.]
We have another thread for that now, in space policy. This thread is for what and how, not why.

NOticed that yesterday.  Thx.
Sometimes I just flat out don't get it.

Online TheRadicalModerate

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Re: NASA's Artemis Program Updates and Discussion Thread 3
« Reply #34 on: 07/31/2019 05:53 pm »
2. Regarding NRHO: I wish to know the extent to which it is necessitated, and by what exactly. I understand that it's a crutch for SLS+Orion shortcomings in the current block 1 configuration. Would moving to block 1b (EUS) plus, possibly, a larger SM obviate the need for NRHO? What about CLV resupply: do those transits require Gateway to be in NRHO, given it's only a one-way trip?

I believe the limiting factor is the Orion service module. It has the Delta-V to make the lunar transfer/return, but only to the higher NHRO orbit and not LLO. So yes, a larger SM would solve the problem, but I don't believe that is currently in the works.

It took me a while before I had the "Duh!" moment on this, but everything makes sense when you realize that the "70 tonnes to LEO" number that's cited for Block 1 SLS means that the SRBs and core can get 70 tonnes to LEO, with no upper stage contribution at all.  That turns out to be close to what ICPS+OSA+ESM+fairings+CM+LAS weighs.  (That stack actually weighs 67 t, and 9 t of LAS and ESM fairings come off halfway through the launch, but that's made up for by the fact that the core puts the stack into an 80 x 1100 km orbit, which has about 320 m/s more specific energy than a standard 200 x 200 LEO.)

Then the ICPS can get about 27 tonnes to TLI, and that becomes your limit for how heavy the full on-orbit Orion stack can be.  (Again, a bit of a fudge, because TLI is lower because of the eccentric LEO, and the ICPS has to spend about 20 m/s to raise the perigee to about 150 km.)

The Orion CM is a relic from the Constellation days, and therefore the 10.7 tonne wet mass with crew is a given.  That means that the ESM must be the size that it is, which is 15.5 t.  Throw in a half tonne for the Orion Stage Adapter and you're close to your 27 t limit.

So there's no point in even thinking about a heavier ESM until Block 1B comes along with the EUS.  Given that EUS has been sent to perpetual limbo, it explains why everybody is pretty much resigned to NRHO for the foreseeable future.

Edit:  I left out the mass of the SLS core-to-ICPS interstage, which is likely about 2 tonnes.  That brings the GLOM of the stuff above the core to 69 t.
« Last Edit: 07/31/2019 06:04 pm by TheRadicalModerate »

Offline envy887

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Re: NASA's Artemis Program Updates and Discussion Thread 3
« Reply #35 on: 07/31/2019 05:58 pm »
2. Regarding NRHO: I wish to know the extent to which it is necessitated, and by what exactly. I understand that it's a crutch for SLS+Orion shortcomings in the current block 1 configuration. Would moving to block 1b (EUS) plus, possibly, a larger SM obviate the need for NRHO? What about CLV resupply: do those transits require Gateway to be in NRHO, given it's only a one-way trip?

I believe the limiting factor is the Orion service module. It has the Delta-V to make the lunar transfer/return, but only to the higher NHRO orbit and not LLO. So yes, a larger SM would solve the problem, but I don't believe that is currently in the works.

It took me a while before I had the "Duh!" moment on this, but everything makes sense when you realize that the "70 tonnes to LEO" number that's cited for Block 1 SLS means that the SRBs and core can get 70 tonnes to LEO, with no upper stage contribution at all.  That turns out to be close to what ICPS+OSA+ESM+fairings+CM+LAS weighs.  (That stack actually weighs 67 t, and 9 t of LAS and ESM fairings come off halfway through the launch, but that's made up for by the fact that the core puts the stack into an 80 x 1100 km orbit, which has about 320 m/s more specific energy than a standard 200 x 200 LEO.)

Then the ICPS can get about 27 tonnes to TLI, and that becomes your limit for how heavy the full on-orbit Orion stack can be.  (Again, a bit of a fudge, because TLI is lower because of the eccentric LEO, and the ICPS has to spend about 20 m/s to raise the perigee to about 150 km.)

The Orion CM is a relic from the Constellation days, and therefore the 10.7 tonne wet mass with crew is a given.  That means that the ESM must be the size that it is, which is 15.5 t.  Throw in a half tonne for the Orion Stage Adapter and you're close to your 27 t limit.

So there's no point in even thinking about a heavier ESM until Block 1B comes along with the EUS.  Given that EUS has been sent to perpetual limbo, it explains why everybody is pretty much resigned to NRHO for the foreseeable future.

And now you see why sinking all that time and effort into supersizing the core stage instead of building a real upper stage was such a waste.

Online TheRadicalModerate

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Re: NASA's Artemis Program Updates and Discussion Thread 3
« Reply #36 on: 07/31/2019 06:06 pm »

And now you see why sinking all that time and effort into supersizing the core stage instead of building a real upper stage was such a waste.

Look on the bright side:  nobody had to suffer through a Lagrange multiplier calculation to determine optimal staging.

Online jadebenn

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Re: NASA's Artemis Program Updates and Discussion Thread 3
« Reply #37 on: 07/31/2019 08:22 pm »
Except I'm not sure your calculations are right because that "70t to LEO" number is old, old, old and has not been used in any SLS materials for the past 2 years. The modern figure is 95t to LEO.

Online TheRadicalModerate

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Re: NASA's Artemis Program Updates and Discussion Thread 3
« Reply #38 on: 07/31/2019 08:46 pm »
Except I'm not sure your calculations are right because that "70t to LEO" number is old, old, old and has not been used in any SLS materials for the past 2 years. The modern figure is 95t to LEO.


That's because they smartened up and started using an apples-to-apples comparison, where all the prop in the ICPS went to putting a payload into the reference 200 x 200 LEO.

If you work out the math for just the SRBs and core, it comes out almost perfectly at 70 t.

Offline envy887

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Re: NASA's Artemis Program Updates and Discussion Thread 3
« Reply #39 on: 07/31/2019 08:48 pm »
Except I'm not sure your calculations are right because that "70t to LEO" number is old, old, old and has not been used in any SLS materials for the past 2 years. The modern figure is 95t to LEO.

95 t to LEO assumes the ICPS is depleted to reach 200 km circular LEO. I haven't seen any evidence that the Block 0 version can do 95 t without ICPS. It would be about 75 t but very sensitive to final burnout mass because the core stage is extremely large.

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