The Artemis Program in Real Solar System - To the Moon and Beyond

[Geschosskopf]

14 minutes ago, jinnantonix said:

The lack of fuel capacity is actually not a serious problem.  It is resolved by being able to refuel from the Cygnus.  The equipment delivered in the Cygnus includes fuel pumps which manually attach via hoses run through the MHM, LAV and LDV, and connected to ports on the top of the LVT.  The LVT needs to be able to be refueled this way if it is to be reusable.  The fuel pumps remain stowed on the MHM, and will act as redundant spares to the ESPRIT fuel pumps.

I thought you meant the lander wasn't able to return to the station.

 

14 minutes ago, jinnantonix said:

It is a serious problem, but there is a simple answer.  The Lunar Ascent Vehicle habitation module includes an airlock, with room for two EVA suits, and a grate in the floor where dust can accumulate and can be easily cleaned out.  The astronauts maintain a protocol to ensure dust remains in the airlock, and never enters the living space.  By isolating the dust to the airlock, the astronauts are only temporarily exposed.  Also they could use 7 micron masks while in the airlock to minimise inhalation.

Well, I wish them good luck with that.  It doesn't strike me as being that easy a problem to solve.  Being a fireman, everything I do involves avoiding exposures and doing decontamination, whether the problem is hazmat, body fluids, or even good ol' smoke.  The latter is a huge thing these days, now being held responsible for firemen having about twice the cancer rate as normal people, but we hadn't paid it much attention before.  Hell, we used to glory in having the dirtiest gear as a sign of experience.  But even with the recent emphasis on cleanliness, there's just no way to avoid getting smoke particles on and in you.  I think the smoke particles are about the same size as lunar dust, most have been ionized so are sticky, and they get into every nook and cranny.  If lunar dust is anything like smoke, it's still going to be a problem.

 

14 minutes ago, jinnantonix said:

Yes, it allows remote control from Earth, via the LOP-G and also direct from Lunar Ascent Vehicle auxiliary console.  This is necessary to ensure safe docking of the craft with the LOP-G, and also with Lunar Ascent Vehicle in LLO.  The LAV and LDV do not have remote control, and are manually piloted from the LAV main console. 

Seriously manual control?  Or does the lander do like Apollo and run an automated program with human intervention if needed?

 

14 minutes ago, jinnantonix said:

Big question: Is it possible to dock the lunar lander with control from Earth (this is never been done before)?  If not then it should be possible to initially hold the lunar lander stationed near the LOP-G using occasional thruster bursts (controlled from Earth), and the Orion crew remote control dock the lander when they arrive at the LOP-G.

Surely an autonomous guidance system would be up to docking itself.  I mean, we now have cars that can park themselves   Why try to control if from home with the signal delay?

 

14 minutes ago, jinnantonix said:

The really interesting stuff is still just speculation. 

I suppose, but we won't know that until long after the mission comes home  

[jinnantonix]

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Surely an autonomous guidance system would be up to docking itself

Of course, and all space craft control will be at least semi-automated or scripted.  But the issue is, what to do if something goes wrong.  Being on hand to press the red button, and then to have the hands and minds to work around the problem - best scenario from a risk mitigation viewpoint  is when humans are at the location and directly observing and responding to the situation.  That's the whole reason for a crewed mission.

[jinnantonix]

In mid 2025, the new re-usable Advanced Exploration Lander is launched on a SpaceX Falcon Heavy, and rendezvous with the LOP-G.  Soon after NASA launches the ESPRIT module, a crew of 4 aboard an Orion.  The crew completes  another exploration mission in Shackleton Crater. determining the resources that are available there for ISRU.

 

[Geschosskopf]

On 8/22/2019 at 10:48 PM, jinnantonix said:

Of course, and all space craft control will be at least semi-automated or scripted.  But the issue is, what to do if something goes wrong.  Being on hand to press the red button, and then to have the hands and minds to work around the problem - best scenario from a risk mitigation viewpoint  is when humans are at the location and directly observing and responding to the situation.  That's the whole reason for a crewed mission.

Well yeah, but given that nobody's home at Gateway when the lander gets there, any emergency human intervention would come several seconds after events.  That seems like it would only be of use in the very early stages of the maneuver, before the lander's moving towards the station.  Once the lander's in the pipe, I'm thinking it's in the hands of the gods.

 

7 hours ago, jinnantonix said:

In mid 2025, the new re-usable Advanced Exploration Lander is launched on a SpaceX Falcon Heavy, and rendezvous with the LOP-G.  Soon after NASA launches the ESPRIT module, a crew of 4 aboard an Orion.  The crew completes  another exploration mission in Shackleton Crater. determining the resources that are available there for ISRU.

Nicely done.  But how is the lander reusable if the descent stage is left behind?  Are the just going to send out new descent stages?

[jinnantonix]

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But how is the lander reusable if the descent stage is left behind? 

I should say "partially re-usable".  NASA did have a plan for a fully re-usable Advance Exploration Lander, but it has serious deficiencies in terms of payload to surface, and a few others problems, not the least - at 50 tons it is too heavy to launch on current commercial rockets, or even the SLS Block 2.

My understanding is NASA plans for the Ascent Vehicle and Transit Vehicle to be re-usable, and use the more expensive but robust Space Shuttle Orbital Maneuvering Systems  AJ10-190 which has a 15 hour service life.  In this simulation I have assumed that NASA has developed a Mark 2 AJ10-190 model with a modified pressure chamber which is lighter and operates at half throttle,  I use two in the LAV (where NASA expects to use one), because I cannot figure out how to redock the LAV unless the engines are offset.  Not sure how NASA plans to to do it - regardless my solution works.

My Lunar Descent Vehicle is as cheap as I can make it.  Basically its a fuel tank with a pair of SuperDRACOs, no electronics other than a connection from the LAV through to the engine throttle (the craft lands at 20-30% throttle).  There is a shaft down the centre to allow refueling lines to be manually connected to the LTV and fuel resupply tank.  This space is also used for storage of lunar surface logistics and contingency supplies.

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Are the just going to send out new descent stages?

Apparently that's NASA's plan for the re-usable AEL.  They also intend to send with more fuel for the LAV and LTV, and I am assuming they would do this with a Northrop Grumman Cygnus (modified into a big hypergolic fuel tank), and this provides the navigation and communications capability with remote control to handle the docking at the LOP-G.  The integrated craft fits nicely as a payload on the Falcon Heavy, although I am sure NASA is keeping open the option of using multiple smaller rockets (to keep the fixed price contract negotiation competitive).

Artemis AEL Resupply Vehicle

[jinnantonix]

Artemis 5 - International Habitat Module and AEL Exploration Mission

• May 2026      Falcon Heavy**                Artemis 5a         Uncrewed delivery of fuel resupply module and lunar descent vehicle
• Jul   2026      SLS Block 1B Crew          Artemis 5           Crewed delivery of International Habitation Module and lunar landing

This mission launches a Falcon Heavy with a new expendable Lunar Descent Vehicle for integration with the Advanced Exploration Vehicle and additional supplies to the Gateway.  The SLS delivers the new International Habitat Module for the Lunar Orbital Platform.  While the lunar exploration mission continues to evaluate resources in Shackleton Crater, the crew on the Gateway establish the habitat for future missions.

 

 

[Geschosskopf]

On 8/24/2019 at 9:10 PM, jinnantonix said:

Apparently that's NASA's plan for the re-usable AEL.  They also intend to send with more fuel for the LAV and LTV, and I am assuming they would do this with a Northrop Grumman Cygnus (modified into a big hypergolic fuel tank), and this provides the navigation and communications capability with remote control to handle the docking at the LOP-G.  The integrated craft fits nicely as a payload on the Falcon Heavy, although I am sure NASA is keeping open the option of using multiple smaller rockets (to keep the fixed price contract negotiation competitive).

Seems rather strange.  Repeated missions to the same crater are going to clutter the area up with dead descent stages.  This will cause NASA all sorts of problems---excessive part count where they want to build a base eventually, difficulty in switching between EVA Kerbals astronauts, rovers, and the base due to focus having to cycle through all the old stages, etc.   And more practically, Muphey's Law dictates that one of these stages will be sitting exactly where they'll need to place an ISRU plant or even the main base itself.

 

On 8/27/2019 at 6:38 AM, jinnantonix said:

Artemis 5 - International Habitat Module and AEL Exploration Mission

This mission launches a Falcon Heavy with a new expendable Lunar Descent Vehicle for integration with the Advanced Exploration Vehicle and additional supplies to the Gateway.  The SLS delivers the new International Habitat Module for the Lunar Orbital Platform.  While the lunar exploration mission continues to evaluate resources in Shackleton Crater, the crew on the Gateway establish the habitat for future missions.

The video didn't show you how you played "Tower of Hanoi" to reassemble the lander.  I also didn't understand what the robot arm was doing in its brief appearance.  As i see i, lander reconstrustion had to have gone like this...

• One one side, from the Gateway out, you have the ascent stage, the new fuel tank, and the new descent stage.  On the other side, you have the transfer stage.
• First, the transfer stage flies around the station, grabs the new descent stage, and drags it a short distance away.
• Releasing the new descent stage, the transfer stage then grabs the new fuel tank and moves it to the other docking port where the transfer stage started.
• Transfer stage then goes back to the other side of the station, grabs the drifting new descent stage, and sticks it on the old ascent stage, which has remained in place the whole time.
• This whole dance would have to be repeated each time a new descent stage/fuel tank arrived.

Is that about right?

[jinnantonix]

@Geschosskopf there are certainly downsides to having a 3 stage lander.  But it is necessary to get maximum payload to the lunar surface.  I tested a re-usable SSTO and it was hopelessly inefficient in terms of payload ability.  However the 3 stage craft is intended only to be a temporary solution until ISRU is established.  I am certain that with fuel manufacture on the surface, a re-usable fuel tanker/lander is intended.  By then (~ 2030), the BFR and New Glenn will be launching 60 ton payloads into TLI, so I expect multiple tankers for redundancy, and they will be substantial craft, weighing up to 100 tons fully fueled.

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Muphey's Law dictates that one of these stages will be sitting exactly where they'll need to place an ISRU plant or even the main base itself.

According  to NASA's proposed agenda there will be 6 LDVs left in Shackleton Crater.  I don't think it will be too crowded, the crater is large.  I suspect also that NASA may reduce the number of surface missions, just sufficient to establish the ISRU.

I am not convinced there is a plan for a "main base".  Why have a permanent habitat in a place where humans can only survive for a short period due to radiation exposure? 

It may be a controversial idea, but I believe the "Lunar Surface Asset" is a nuclear powered autonomous roving ISRU facility.  Not a habitat.  I believe the plan is to deploy multiple such facilities.  Humans will visit only occasionally to service them and refuel.  I suspect also that the facility will do more than generate hydrogen and oxygen for fuel - it may also be capable of making ammonia for use as stable long-term propellant for NERVA nuclear engines.  I believe the future of space propulsion will be natural gas / methane for heavy lift from Earth and Mars, hydrogen/oxygen for Lunar lift, and uranium fueled nuclear fission and hydrogen and/or ammonia propellant for Earth/Moon orbital and deep space transfer.  

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what the robot arm was doing in its brief appearance. 

The robot arm isn't needed for KSP game-play so I didn't use it, although I could have.  From what I understand it will be used for assisting the robotic modules to dock and undock - at least that's what it is used for on the ISS.  I believe it is also intended to transfer surface samples to avoid contamination.

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The video didn't show you how you played "Tower of Hanoi" to reassemble the lander.

The process is this (although I didn't need to use the robotic arm):  

1. The transit vehicle and resupply module detaches and moves away to a safe distance.
2. The LTV detaches the  Cygnus resupply modules, which uses it's own engines and thrusters to de-orbit.
3. The LOP-G using thrusters reorients (spins on its axis) so the LTV and LDV ports are aligned
4. The robotic arm is used to assist with docking the LTV to the LDV
5. The LTV/LDV detaches and moves away to a safe distance
6. The LOP-G reorients so the LAV and LDV ports are aligned
7. The robotic arm is used to assist with docking the LDV/LTV to the LAV.

The crew will also need to refuel the LAV and LTV during this process.

The robotic arm is also used to detach future Cygnus resupply modules from the international habitat, and clear it from the LOP-G, therafter the Cygnus uses it's own engines and thrusters to de-orbit.

Edited September 3, 2019 by jinnantonix

[Geschosskopf]

34 minutes ago, jinnantonix said:

By then (~ 2030), the BFR and New Glenn will be launching 60 ton payloads into TLI, so I expect multiple tankers for redundancy, and they will be substantial craft, weighing up to 100 tons fully fueled.

I dunno.  New Glenn is only claiming 50 tons to LEO with a fully validated vehicle, rather less both earlier in the program and always for further afield.  https://yellowdragonblogdotcom.files.wordpress.com/2019/01/new_glenn_payload_users_guide_rev_c.pdf  But at least they have numbers solid enough to pitch to potential customers in official literature.  BFR,  or whatever Madman Musk is calling it today, is at present a moving target with a constantly changing baseline and a bunch of question marks.  Nothing anywhere as solid as the Blue Origins brochure linked above,  but more like just riding the hype train his hyperbole has engendered.  

 

34 minutes ago, jinnantonix said:

According  to NASA's proposed agenda there will be 6 LDVs left in Shackleton Crater.  I don't think it will be too crowded, the crater is large.  I suspect also that NASA may reduce the number of surface missions, just sufficient to establish the ISRU.

Just 6 is more than enough to trigger Murphy's Law  

 

34 minutes ago, jinnantonix said:

I am not convinced there is a plan for a "main base".  Why have a permanent habitat in a place where humans can only survive for a short period due to radiation exposure? 

I thought the whole point of Shackleton Crater was the shade it provided from the Sun, both for various ices to exist and to shield crews from radiation.  The mantra of NASA now is "we're going back to the Moon, this time to stay", and I've seen the plans (as shown on the NASA website) to live there.  In any case, the shade in the crater seems a better place to hang out, radiologically speaking, than the Gateway station.  Or maybe they can bury hab modules under piles of regolith.  Either way, it beats "sitting in a tincan far above the world"  

 

34 minutes ago, jinnantonix said:

It may be a controversial idea, but I believe the "Lunar Surface Asset" is a nuclear powered autonomous roving ISRU facility.  Not a habitat.

As the Circus only relies on Kerbals when automation can't generate crew and EVA reports, I see no controversy with this  

 

34 minutes ago, jinnantonix said:

The process is this (although I didn't need to use the robotic arm):  

Thanks for the explanation.  

[jinnantonix]

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New Glenn ... BFR

Both have valid high level designs for large mass, low cost cargo delivery to LEO, LLO and even Mars.  The trick is low cost fueling with methane, and re-usability of core stage.

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... Madman Musk...

What Elon says and what he hypes in the media is nonsense.  SpaceX on the other hand will continue to kick goals.  The underlying design of BFR (like New Glenn) is workable as a commercial heavy lifter, and I have no doubt SpaceX and New Glenn will compete for the lions share of launch contracts from 2025 onward.  But Starship is ridiculous.  Who is going to pay for it? 

Interesting for mine is that Starhopper has the exact features (TWR, mass, aerodynamics) of a re-usable Mars surface to orbit lifter.  The single Raptor would be replaced by variant quarter sized methanox engines, in a redundant quad configuration.  The below craft is built from a Falcon second stage fuel tank and a few stock components.  Tests fine from surface to SOI and back to surface with a fully propulsive landing at 75% thrust.

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just 6 is more than enough to trigger Murphy's Law

I am sure there's more than a half dozen serious landing hazards in Shackleton Crater.  That's' why they are sending Peregrine first.

 

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I thought the whole point of Shackleton Crater was the shade it provided from the Sun, both for various ices to exist and to shield crews from radiation.

That's not my understanding.  The perpetual shadows of the south pole is where the water (fuel) is at, along with other potential resources such as nitrogen compounds, CO, CO2, ammonia etc.  - that's the reason to go there.  Even shaded from the sun, crews would still be subject to cosmic radiation, hiding under regolith would be expensive to facilitate, perhaps dangerous too.  Long term habitation makes no sense.  Robotic vehicles with redundancy and the need for only occasional maintenance and refueling would be the more commercially viable solution.

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 "we're going back to the Moon, this time to stay"

That does not necessarily mean that humans will stay.  "We" could mean humans and our robotic proteges.

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I see no controversy with this

Really?  I think the mere mention of the word "nuclear" will have the loonies out picketing the launch pads.

 

Edited September 3, 2019 by jinnantonix

[jinnantonix]

Artemis 6 - Gateway US Habitat Module and Lunar Landing

• 2027      Falcon Heavy**                Artemis 6a         Uncrewed delivery of fuel resupply module and lunar descent vehicle
• 2027      SLS Block 1B Crew          Artemis 6           Crewed delivery of US Habitation Module,  and lunar landing

 

 

[Geschosskopf]

 

12 hours ago, jinnantonix said:

What Elon says and what he hypes in the media is nonsense.  SpaceX on the other hand will continue to kick goals.  The underlying design of BFR (like New Glenn) is workable as a commercial heavy lifter, and I have no doubt SpaceX and New Glenn will compete for the lions share of launch contracts from 2025 onward.  But Starship is ridiculous.  Who is going to pay for it? 

I agree that much of what Musk says, and the whole Starship thing, are ridiculous.  And I question (along with Forbes) if reusing rockets is really saving any money.  You need about 20% more rocket to do the same job as a 1-shot deal.  But OTOH, it does increase your tempo of operations if you can refurb a rocket faster than you can build a new one, so you get more jobs.

 

12 hours ago, jinnantonix said:

Interesting for mine is that Starhopper has the exact features (TWR, mass, aerodynamics) of a re-usable Mars surface to orbit lifter.

But wouldn't that have the same problems as a fully reusable lunar lander as we just discussed?  Of course, it takes a lot longer to get new stuff to Mars so there's more incentive for it, I guess.

 

12 hours ago, jinnantonix said:

That's not my understanding.  The perpetual shadows of the south pole is where the water (fuel) is at, along with other potential resources such as nitrogen compounds, CO, CO2, ammonia etc.  - that's the reason to go there.  Even shaded from the sun, crews would still be subject to cosmic radiation, hiding under regolith would be expensive to facilitate, perhaps dangerous too.  Long term habitation makes no sense.  Robotic vehicles with redundancy and the need for only occasional maintenance and refueling would be the more commercially viable solution.

Oh, I agree that permanent human habitation anywhere else in the solar system is more trouble than it's worth.   Either gravity's off, or there's no air, or there's no magnetic field, or all of the above.  So I don't see that happening.  But the same can be said of any crewed mission, yet they continue to happen, seemingly more due to emotion than necessity.  Thus, it wouldn't surprise me to see a permanently crewed lunar base someday, for just a few folks at a time.

 

12 hours ago, jinnantonix said:

Really?  I think the mere mention of the word "nuclear" will have the loonies out picketing the launch pads.

As long as they get incinerated during the launch, that's a good thing  

 

8 hours ago, jinnantonix said:

Artemis 6 - Gateway US Habitat Module and Lunar Landing

• 2027      Falcon Heavy**                Artemis 6a         Uncrewed delivery of fuel resupply module and lunar descent vehicle
• 2027      SLS Block 1B Crew          Artemis 6           Crewed delivery of US Habitation Module,  and lunar landing

Congrats on another successful mission and nice save from keeping the lander from tipping over.

I've noticed a lot of bounce in your lander legs.  What spring/damper ratio are you using?  I'd recommend increase damper a lot and reducing spring down to 0.5 or so.  Just be careful this doesn't make the engine bell touch the ground as such settings make the lander sit lower.

[jinnantonix]

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But wouldn't that have the same problems as a fully reusable lunar lander as we just discussed? 

Yes it does.  But Mars and the Moon are different beasts. 

1. Mars is a lot further away, so re-usability for any equipment that has been sent to Martian orbit has greater value.  I am assuming the only role for the re-usable "Starhopper" craft is to ferry humans to/from the Martian surface, so minimal payload requirement.  
2. I envisage that any surface logistics would be delivered to the surface of Mars on an expendable lander, one way traffic only.  This is because Mars has some atmosphere, so an efficient lander would comprise of a staged chutes and minimal propulsion on touchdown.

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What spring/damper ratio are you using? 

Spring is at 0.5 and damper at maximum, exactly as you have suggested.  In the video you see I forget to set RCS prior to touchdown, my bad.  It may not be apparent in the video, but the floor of Shackleton Crater in the KSP model is very rough, with very few flat areas to land.

[Wallygator]

Looks really cool. 

Are you also using RO? I didn’t see it in your mod list. 

[jinnantonix]

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Are you also using RO? 

No RO.  It's not supported at v1.7.3.  

 

[jinnantonix]

Artemis 7 - Lunar Surface Asset Delivery to Gateway

• 2028      Falcon Heavy**                 Artemis 7a        Uncrewed delivery of fuel resupply module and lunar descent vehicle
• 2028      SLS Block 1B Cargo         Artemis 7          Delivery of "Lunar Surface Asset" (large lunar surface module) to LOPG

 

[jinnantonix]

Artemis 8 - Airlock Module and Lunar Surface Asset Deployment

2028      SLS Block 1B Crew           Artemis 8          Delivery of Airlock Module and lunar landing of crew and "Asset"

 

 

[nasa legolas]

Damn, thats SO COOL. I want to try this now

[Geschosskopf]

I'm surprised the lunar lander transfer tug had enough macho to take down the massive mining rover along with the regular lander.  And I still don't understand how you play "Tower of Hanoi" with the various lander pieces.

[jinnantonix]

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I'm surprised the lunar lander transfer tug had enough macho to take down the massive mining rover along with the regular lander. 

The LTV had just enough fuel to do the job, remember the tank is designed to be big enough to decelerate with fully fueled LAV and LDV 850m/s from TLI to encounter with LOP-G, then have enough fuel for the lunar landing and return.  The tank looks small in the video, but it's not small.  By fully refilling the tank from a Cygnus resupply module the LTV has just enough dV to get the LSA and lander to LLO (100km alt).  

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And I still don't understand how you play "Tower of Hanoi" with the various lander pieces.

See below.   It is a done by remote control of the LTV.  The only trick is ensuring the ladder on the LDV lines up with the door of the LAV.  IRL the Orion crew would probably use the robotic arm to assist, but I didn't need to.

 

Edited September 9, 2019 by jinnantonix

[jinnantonix]

At the completion of the Artemis program, NASA will have a functioning Lunar Orbital Platform - Gateway in NRHO (near rectilinear halo orbit) around the Moon.  This simulation suggests that the best case outcome of the program is the deployment of a functioning ISRU facility at the Moon's South Pole.

What type of resource will ISRU be based on?

Water ice can be converted into hydrogen and oxygen.  If there are carbon compounds available, methane may be a possible fuel.  If there is nitrogen, perhaps ammonia, a very useful propellant for for NERVA engines as it is very stable, and unlike hydrogen and methane does not need costly cryogenics, and does not boil off over time.  Would it be feasible to manufacture hypergolic fuels, such as Aerozine/NTN?  All these options will require a lot of energy, and this cannot be provided by solar power in the darkness of the south pole.  Is it feasible to deploy nuclear power, sufficient to manufacture fuel at a suitable rate?  

 

What type of craft will be used?

Assuming fuel is manufactured on the lunar surface, NASA would need to contract for development of suitable craft to use the fuel.  I envisage the development of highly efficient re-usable nuclear tugs with ISP >800.  These  craft would utilise nuclear fuel for energy, possibly with NERVA engines (a well proven technology), and using lunar manufactured propellant (hydrogen, methane or ammonia).  They could be used for lifting payloads from LEO to lunar orbit, or for any number of deep space exploration needs, including ferrying payloads such as rovers and even humans to Mars orbit.  The craft would be re-usable, and only require occasional re-fuelling with nuclear fuel, most likely in LEO.  These craft would be capable of landing on the lunar surface for direct refueling from the ISRU facility.

 

A manned mission to Mars?

By 2030, it is likely that SpaceX and Blue Origin will be competing for launch contracts with their Falcon Super Heavy and New Glenn rockets.  Despite the hype, it seems unlikely that these craft will be human rated, concepts like Starliner seem fanciful from a commercial and safety perspective, and seem to just be a PR exercise.   However the ability to lift low cost interplanetary craft to orbit is feasible, and even likely.  Such craft would be autonomous, and potentially travel direct to Mars from LEO, or be refuelled in lunar orbit, to deliver surface logistics and redundant re-usable methane powered Martian ferry craft (MAVs) and ISRU facilities on the Martian surface in preparation for human arrival.  Human rated equipment would rendezvous via LOP-G and utilise Orion for ferrying to/from the Earth's surface.  A craft with spin gravity could dock with nuclear tugs for the trip to/from Mars orbit.  The MAVs would be used to ferry humans to/from the Martian surface.  By this means, an international effort could potentially land humans on Mars by 2040.

Edited September 15, 2019 by jinnantonix

[jinnantonix]

What type of craft will be used?

Below is the nuclear tug concept.  The three NERVA engines are arranged in a redundant N+1 configuration, on gimbal base so if one engine fails the others supply sufficient balanced thrust to make lunar orbit.  The craft refuels on the lunar surface from the South Pole ISRU facility, and consumes about 40% of the lower tank hydrogen fuel mass in achieving NRHO.  The craft then as sufficient dV to transport a habitation module with spin gravity from lunar NRHO to Mars orbit.  The upper tank contains sufficient ammonia propellant to return to lunar NRHO.

There will be two or three tugs operating to provide payload delivery to local asteroids, comets, Mars and Venus.

 

 

 

 

 

[Geschosskopf]

All very interesting.  The big question I now have, after your very informative posts above, is how are they going to get the necessary infrastructure for a fuel base to the Moon?  There's a lot of bulky equipment needed regardless of which type of fuel is there.  All the mining/drilling stuff, refining stuff, processing stuff, and of course sufficient storage tanks, all beyond whatever power plant it needs.  And there's going to be a lot of work for welders, pipe-fitters, electricians, crane operators, etc., in putting it all together.  Is there any sort of outline for that?  

[jinnantonix]

All good questions @Geschosskopf.  I think the problem is that we don't yet understand the resources that are available, all planning stems from that knowledge.  We need to get to Shackleton Crater and find out  - I would argue that Peregrine Lander should already be making plans.  Whatever the ultimate design of the ISRU facility, it is going to be a remarkable engineering feat.  I don't see tradesmen ever setting foot on the moon - all equipment will built on Earth to operate autonomously.  Whilst my roving robotic nuclear powered ISRU rig is a somewhat simplistic model, the ultimate solution cannot be too far from that concept, or the whole endeavour will be commercially non-viable, and launch from LEO will again be the preferred method for deep space exploration.

 

Edited September 15, 2019 by jinnantonix

[Geschosskopf]

2 hours ago, jinnantonix said:

All good questions @Geschosskopf.  I think the problem is that we don't yet understand the resources that are available, all planning stems from that knowledge.  We need to get to Shackleton Crater and find out  - I would argue that Peregrine Lander should already be making plans.  Whatever the ultimate design of the ISRU facility, it is going to be a remarkable engineering feat.  I don't see tradesmen ever setting foot on the moon - all equipment will built on Earth to operate autonomously.  Whilst my roving robotic nuclear powered ISRU rig is a somewhat simplistic model, the ultimate solution cannot be too far from that concept, or the whole endeavour will be commercially non-viable, and launch from LEO will again be the preferred method for deep space exploration.

My concern is the scale of the ISRU facility required to produce the industrial quantities of fuel needed for the fleet of interplanetary tugs, asteroid-bound ships,  Moon biome-hoppers, and all the other other ships lining up to use it.  The rover in the video you just linked is functionally the same as the one you built a few episodes back, just a prospector.  It's exactly the same as putting the ore Surface Scanner on a small rover in stock KSP.  It can't actually DO anything with the resources, it merely determines what's in the ground and the best places to dig for them.  Actual exploitation of the resources requires following up with the necessary industrial plant.  It's with this latter plant that I foresee issues.

Basically, to make fuel in the required volume in the available time between all the many customers, the plant has to be pretty big in total.  And the total plant will have to comprise numerous components each performing one of the MANY industrial processes along the way from raw lunar dirt to refined (and possibly cryogenic) rocket fuel.  Each of these components must therefore also be pretty big.  So at a minimum, you're looking at 1 heavy lifter launch per component, maybe several per component (especially for the storage tanks).  So you'll end up with a large collection of skid-load machinery pallets, all of which have to be interconnected for the plant as a whole to function.  Docking base components together in KSP is hard enough and that doesn't even consider the evil lunar dust being blasted into the connecting ports of 1 module by the landing of the next.  So I figure you'll need a bunch of pipe-fitters and electricians to hook all these modules into a functional whole.  And also mechanics to maintain the fleet of strip-mining excavators and dumptrucks.  After all, you'll have a LOT of spoil scooped up with the good stuff.  The good stuff has to be moved to the immobile ISRU plant and the useless dust and gravel hauled off to the spoil pile some distance away.

This industrial-scale lunar ISRU plant is a whole nuther thing compared to the idea of using ISRU on Mars to pre-make fuel for the return trip prior to the actual lander even leaving Earth.  In that case, you have only 1 customer ever and several years to produce the fuel.  The biggest thing you need for that application is the storage tanks, which are going to be about the same size as those in the lander so no big deal.,  But for a multi-customer, relatively short timespan ISRU station like the idea for the Moon, you need a LOT more stuff in all respects.  Either that, or you greatly reduce the number of customers and/or the frequency of customer visits  Which decreases the usefulness of the lunar ISRU base.