Artemis - Duna Mission Architecture

[jinnantonix]

Overview:

It is 2030 and KASA has completed a pilot plant demonstrating ISRU, mining water ice and making fuel in the depths of a crater at the Mun's south pole.  KASA is planning a program of three missions to Duna utilising fuel mined on the Mun.

Challenge:

1. Create at least one orbital craft / space station with a minimum of 8 pressurised seats and four docking ports, to be used for fuel and crew transfer.
2. Establish an ISRU facility at the Mun south pole to make fuel.  Surface mining operations may not use solar power.
3. Launch 4 Kerbals from the KSC in a command pod/re-entry vehicle, and plant a flag on Duna. All 4 Kerbals must stand on the surface of Duna.
4. Deploy a Duna habitat,  modelled by a requirement for a minimum of 2 pressurised seats per Kerbal, excluding seats in the lander craft. 
5. Prior to landing on the Mun and Duna, deploy a probe to mark a suitable landing site.  Must include a resource scanner.
6. Deploy a minimum of three RA-15 relay satellites, in Duna orbit, to provide continuous communications coverage.

Rules:

• Stock parts and DLC only.  No part mods are allowed.  No EVA Construction. No airbreathing engines are allowed
• Visual, informational and flight control mods (eg MechJeb) are allowed
• No cheating, including debug menu, kraken drives, file editing or Hyperedit (except for testing)
• All fuel transfers must be at either the ISRU facility on the Mun, or between craft docked at the orbital craft / space station
• All Kerbals sent to Duna must return alive to the surface of Kerbin. No Kerbal can remain away from Kerbin for more than 3 Kerbal years, or it is assumed he/she dies of radiation exposure
• Crew cabins and lander cans may not be occupied while in atmospheric flight, but may be used on the Duna and Mun surface and in vacuum.  No command chairs allowed
• Kerbals must remain in a pressurized seat at all times except on the surface of Kerbin, Mun and Duna.  An airlock is not a pressurized seat. Jet packs not allowed
• The Duna habitat must be a single contiguous structure, a new Duna habitat must be established with each new mission and additional missions must land in different biomes
• No aerobraking of any craft with Kerbals aboard in Kerbin's atmosphere except when doing a direct (or "skip") re-entry.  A stock Heat Shield on the reentry capsule is therefore mandatory.   "Direct" means:  every part that aerobrakes at Kerbin with a Kerbal must land on Kerbin following the aerobrake"   Duna aerobraking of a craft assembly is allowed provided the crew is behind the heat shield.
• No craft may enter the SOI of any planet or moon except Kerbin, Mun and Duna.  Minmus and Ike are forbidden
• Gravity assists are not allowed
• Mining for ore is allowed only within 2 degrees of latitude of the Mun south pole, and must not rely on any solar energy.  No mining on Kerbin or Duna.
• Habitat and Space station must be able to generate power, sufficient to allow lights to be left on and the battery does not ever go flat
• Rovers may not travel more than 1 km from the Duna landing site
• All craft and habitats on the Mun and Duna may touch the surface only with stock lander legs or wheels

Scoring

• Five points awarded for each Challenge task completed (maximum=30 points)
• An additional point is awarded for aesthetics for each component  (maximum = 8 points):
  • Launch vehicles 
    • Initial
    • Resupply
  • Space station with docked craft
  • Mun ISR facility and craft
  • Duna transfer vehicle
  • Duna Lander
  • Duna Habitat
  • Re-entry capsule
• The mission value =
  the sum of points - (the cost of all launches from the KSC to complete 3 Duna landings)/100,000

Submission:

• Provide video or images of all craft and key mission moments, with the resource window open
• Show launch craft in the VAB  showing craft cost, and technical specifications.  Any parts that are purely for aesthetics may be deleted.
• Calculate the total cost of all launches to complete 3 Duna missions

Notes:

• Only entries that are considered within the spirit of this challenge will be accepted.  Any use of game exploits will invalidate the entry. 
• If you want to use a mod, and you are not sure, ask me
• No recovery cost of craft landing at Kerbin
• Default settings only, if you change any setting you have broken this rule
• Clipping may be used for aesthetics purposes. Clipping parts where the overall volume is approximately maintained is allowed.  All parts must appear adjacent to each other, and appear functional
• Aesthetics will be determined by both form and function, with points lost for obvious faults.  Since aesthetics can be subjective, feel free to message me with questions/images prior to submission, and I will advise. 
  Rule of thumb:  If a part is included, but without it included the rules may be met AND mission completed  AND it has negligible impact on aerodynamics, then it may be excluded from the cost of the mission.

 

Leaderboard:  (In order of mission value)

1. @Death Engineering extremely impressive and grand, includes a fully functioning Gateway station  (25.2).
2. .
3. .
4.  

Rogues Gallery (In order of submission) - for entries that are incomplete and/or do not meet the rules requirements

1. @camacju.  A very frugal design using a re-usable sky crane, and refuelling in Mun orbit.
2. .
3. .
4. 
    

 

 

 

Edited April 16, 2022 by jinnantonix

[jinnantonix]

Basic idea is this:

• Launch rockets from the VAB
• Establish ISRU at the Mun south pole
• Launch a mission to Duna, using the Mun ISRU facility to reduce costs
• Provide a total cost for 3 identical Duna missions.

 

Edited August 11, 2021 by jinnantonix

[Mars-Bound Hokie]

I have a few questions,

1. Do our vehicles have to be launched from the VAB, or are we allowed to launch them from the SPH?
   1. If so, then I may have a few ideas for Duna SSTOs that is bound to save money (in terms of overall cost, since you'll eventually end up with the craft back)
2. "Establish ISRU at the Mun south pole" - does it necessarily have to be at the Munar south pole?
   1. Not that it should be a problem.
   2. Personally, I go for a refueling stop on Minmus. However, the spaceplanes I have in mind for the mission should be able to land on the Mun.
3. "Launch a mission to Duna, using the Mun ISRU facility to reduce costs" - do I have to land on Duna's surface, or do I just have to establish a parking orbit around the planet? Also, since the spaceplanes I have in mind have their own ISRU capabilities, then is the Munar presence really necessary?
   1. For that matter, what would be the purpose of those missions? What needs to be done for this challenge to be completed?

[jinnantonix]

On 7/20/2021 at 12:41 PM, Mars-Bound Hokie said:

I have a few questions,

1. Do our vehicles have to be launched from the VAB, or are we allowed to launch them from the SPH?
   1. If so, then I may have a few ideas for Duna SSTOs that is bound to save money (in terms of overall cost, since you'll eventually end up with the craft back)
2. "Establish ISRU at the Mun south pole" - does it necessarily have to be at the Munar south pole?
   1. Not that it should be a problem.
   2. Personally, I go for a refueling stop on Minmus. However, the spaceplanes I have in mind for the mission should be able to land on the Mun.
3. "Launch a mission to Duna, using the Mun ISRU facility to reduce costs" - do I have to land on Duna's surface, or do I just have to establish a parking orbit around the planet? Also, since the spaceplanes I have in mind have their own ISRU capabilities, then is the Munar presence really necessary?
   1. For that matter, what would be the purpose of those missions? What needs to be done for this challenge to be completed?

@Mars-Bound Hokie the concept here is to  do a simulation of the future (post) Artemis program with an architecture for a mission to Duna/Mars that utilises ISRU, mining for water in the deep craters of the Mun/Moons south pole.  So in answer to your questions>

1.  The concept is to encourage realistic multistage vertical lift rockets that might be next generation, perhaps with a recoverable first stage.  Try to think of what SpaceX or Blue Origin would do if they have their craft refuelled at the Moon. 
2. Yes, Munar south pole.  The Moons south pole is where NASAs Artemis program is looking for ice for making fuel. 
3.  Yes, land on Duna's surface. The idea is to architect multiple manned missions for planting flags  on the red planet, and doing some science and stuff - using Munar refuelling.

Here is draft of what I am thinking:

Challenge:

• Create an orbital space station with a minimum of 8 pressurised seats, providing a staging point for refuelling
• Establish an ISRU facility at the Mun south pole to make fuel, and craft for delivering it to the space station
• Plant a flag on Duna.  A minimum of 4 kerbals must be sent, and all must land on the surface of Duna
• While on Duna, habitat is modelled by a requirement for a minimum of 2 pressurised seats per Kerbal, excluding seats in the lander craft

Option:  Send additional missions to Duna to demonstrate re-usability.  Additional missions must land in different biomes and establish new habitats.

Rules:

• Stock parts and DLC only.  No part mods are allowed.  (perhaps a separate leaderboard for modded entries?)
• Visual, informational and flight control mods (eg MechJeb) allowed

Submission:

• The mission value is the sum of the cost of all launches from the KSC to complete 4 missions to Duna.
• Fairings to be subtracted from the launch cost to encourage aesthetics.

 

 

Edited July 21, 2021 by jinnantonix

[camacju]

Are spaceplanes allowed even? Or does everything have to use vertically launched rockets?

Also I'm assuming we have to land a new 8-seater habitat for each of the four missions?

Edited July 22, 2021 by camacju

[jinnantonix]

46 minutes ago, camacju said:

Are spaceplanes allowed even? Or does everything have to use vertically launched rockets?

Also I'm assuming we have to land a new 8-seater habitat for each of the four missions?

We all love spaceplanes.  But spaceplanes are not really what this challenge is about.  I don't see spaceplanes being a solution for future Mars exploration, do you?  KSP has unrealistic physics/ aerodynamic / recoverability modelling that make fully recoverable SSTOs viable, but that's not going to work IRL.  To encourage development of near real world solutions I would have a rule that excludes any recovery costs.  I think also the cost of non functional fairings and adapters would be zero to encourage aesthetically accurate solutions.

Yes, a new habitat in a different biome.  KSP would allow building a rover, but the model does not include geographical hazards which would make a large long range rover non viable, and I am looking for modelling what would be feasible IRL.

 

[camacju]

Okay - would the following general infrastructure/plan be ok? I'll admit I haven't read much about Artemis's Mars plan so I don't know what would be in the spirit of that.

Infrastructure:

-Surface mining base - set up in some way, the exact way doesn't really matter
-Fuel delivery rocket
-Nuclear tug with 8 seats in Kerbin orbit

Plan:

-Lander and surface habitat launch and dock with nuclear tug
-Tug transfers to Mun orbit where it's refueled by fuel delivery rocket
-Tug uses Kerbin and Mun assists to aerobrake around Duna with only ~225 m/s spent
-Standard Duna landing - parachute down, rocket back up, dock with tug
-Tug uses Ike and Duna assists to aerobrake around Kerbin with <400 extra m/s spent
-Lander parachutes down
-Repeat

[jinnantonix]

@camacju yes I think you are on the right track.  Just a few points ...

• It is a requirement to show the launch and deployment of all craft, including the nuclear tug and mining base, as well as the lander and surface habitat for each mission
• Only craft docked at the space station/nuclear tug may transfer fuel
• Craft may only be in Kerbin, Mun and Duna SOI.  Minmus and Ike don't exist IRL.  Mining is only allowed at the Mun south pole. (latitude > 88 degrees south) and cannot use solar power
• The cost of the program is measured by the cost of all launches, and to simplify the modelling, there is no recovering of costs of craft landing on Kerbin
• You only need to complete one Duna mission.  You can use this to calculate the total cost of 3 Duna missions

Also

• Crew cabins may not be occupied while in atmospheric flight, so command pods / re-entry vehicles are mandatory.  No command chairs allowed in flight

• Kerbals must remain in a pressurized seat at all times except on the surface of Kerbin, Mun and Duna.  An airlock is not a pressurized seat. Jet packs not allowed. 

I am still working out the rules to make sure the challenge produces realistic entries.  Any suggestions appreciated.

 

Edited July 22, 2021 by jinnantonix

[jinnantonix]

Challenge details moved to the OP.

 

 

Edited July 29, 2021 by jinnantonix

[Death Engineering]

Hi @jinnantonix ! Well, this challenge is right up my alley and is something I'd probably do outside of a challenge. Time could be a factor since I'm still plugging along in the Life on Laythe challenge.. but I would get to this and complete it.

[camacju]

A couple further questions:
-Would a survey satellite (to determine the best place near the south pole to mine ore) need to count toward launch cost? If so, that's fine, but it would be easier if I could have a survey done before landing.
-Are crew cabins allowed for a surface habitat and for vacuum flight? It's only for the ascent vehicle and Duna lander that command pods are required?
-How reusable are we allowed to get? For example could I pull a SpaceX and use the same booster for all three/four Duna missions? Or is all Kerbin-atmospheric rocket hardware required to be single use? Similarly what's the restriction on reusing the Duna lander?
-Does each Duna habitat have to be contiguous or can it consist of several separate "buildings" within a few meters of one another? If it must be contiguous, can it be assembled with EVA construction once on Duna?
-Is ISRU required? If I find that I can do three Duna missions for lower cost if I don't use ISRU vs if I do, will I be allowed to do that? If this isn't in the spirit of the challenge, then please let me know.

My general plan now revolves around the fact that the nuclear engine is efficient but expensive, so I want to use it for as much stuff as possible.

Duna mission 1:
Crew launches with command pods, nuclear tug, mining module, orbital habitation, and surface habitation
Mun transfer
Nuclear tug lands with mining module, refuels, goes back to orbit
Duna transfer
Nuclear tug lands with surface habitat and command pods, detaches habitat, launches back to orbit
Kerbin transfer
Command pods detach from nuclear tug and land, nuclear tug injects into low Kerbin orbit

Duna mission 2:
Crew launches with just command pods and surface habitat
Mun transfer
Refueling nuclear tug at Mun
The mission will then proceed the same as mission 1

Duna mission 3:
same as mission 2

[jinnantonix]

@camacjugreat questions, here's my thoughts, let me know what you think.

-Would a survey satellite (to determine the best place near the south pole to mine ore) need to count toward launch cost? If so, that's fine, but it would be easier if I could have a survey done before landing.

• A probe to find a landing site on the Mun would be necessary, plus I think comms satellites for Duna.  I will mandate them in the rules.

• Prior to landing on the Mun and Duna, a probe must land to mark a suitable landing site.  Must include a resource scanner.

• A minimum of three relay satellites must be deployed in Duna orbit to provide continuous communications coverage.

-Are crew cabins allowed for a surface habitat and for vacuum flight? It's only for the ascent vehicle and Duna lander that command pods are required?

• Yes, crew cabins and hitchhikers are OK for surface and vacuum.  Pods required for any crewed atmospheric flight on Kerbin or Duna.

-How reusable are we allowed to get? For example could I pull a SpaceX and use the same booster for all three/four Duna missions? Or is all Kerbin-atmospheric rocket hardware required to be single use? Similarly what's the restriction on reusing the Duna lander?

• Re-usability should be encouraged where it is realistic.  So the Duna lander could be re-usable.  The idea of re-using the launch vehicle first stage is OK and realistic, but to keep the challenge simple , there is no recovery of costs for landing on Kerbin.  Perhaps a rule like this?:
  • If the first stage of a launch vehicle is recovered, 50% of the cost of the stage (minus fuel) may be subtracted for the launch cost.

-Does each Duna habitat have to be contiguous or can it consist of several separate "buildings" within a few meters of one another? If it must be contiguous, can it be assembled with EVA construction once on Duna?

• Although EVA construction is cool, allowing it would disadvantage anyone using an older version of KSP, so its use is disallowed.  Multiple Duna habitats is not realistic, so the habitat must be a contiguous construction.

-Is ISRU required? If I find that I can do three Duna missions for lower cost if I don't use ISRU vs if I do, will I be allowed to do that? If this isn't in the spirit of the challenge, then please let me know.

• I was wondering if anyone would ask that.   It's an interesting question, because if it was demonstrated, it could make a mockery of the whole Artemis program (god forbid).  A crazy Kerbal invention might succeed, which would be disappointing, it would need to be realistic.  I will give this some thought and respond in a day or two.

My general plan now revolves around the fact that the nuclear engine is efficient but expensive, so I want to use it for as much stuff as possible.

• Your plan looks good.  Add probes and relays..

[camacju]

24 minutes ago, jinnantonix said:

Multiple Duna habitats is not realistic, so the habitat must be a contiguous construction.

I was thinking something like this NASA proposal:

Multiple separate habitat "buildings" that don't need to be connected by pipes, but can be.

Or this one:

Multiple special purpose buildings

[jinnantonix]

@camacjuIf they can be connected, then connect them.  Docking ports aren't that expensive.

With regard to your question about not using ISRU, and going direct to Duna.  Do you know if there is a significant difference between the KSP model and Real Solar System with regard to using Mun/Moon gravity assist.  In KSP it makes a marked difference to required dV.  I have never heard of any serious plans for using the Earths moon as a slingshot to Mars, and I am wondering why.  Probably because IRL the orbital tilts dont match up?

[camacju]

There's this:

https://link.springer.com/article/10.1007/s40295-020-00229-w

In case it's paywalled, here's the abstract:

Lunar gravity assist is a means to boost the energy and C3 of an escape trajectory. Trajectories with two lunar gravity assists are considered and analyzed. Two approaches are applied and tested for the design of missions aimed at Near-Earth asteroids. In the first method, indirect optimization of the heliocentric leg is combined to an approximate analytical treatment of the geocentric phase for short escape trajectories. In the second method, the results of pre-computed maps of escape C3 are employed for the design of longer Sun-perturbed escape sequences combined with direct optimization of the heliocentric leg. Features are compared and suggestions about a combined use of the approaches are presented. The techniques are efficiently applied to the design of a mission to a near-Earth asteroid.

Edit: Also, there's the Nozomi spacecraft, which used multiple Earth and Moon flybys due to having a smaller than expected delta-v budget . Unfortunately, the spacecraft failed before it could get to Mars, but there's definitely historical precedent.

Edited July 23, 2021 by camacju

[jinnantonix]

Yes, but no mention of Mars.

I found this:  https://space.stackexchange.com/questions/4027/has-luna-been-used-for-gravity-assist-for-interplanetary-probes

As for why it is not used regularly, it's because usually time is of the essence. If you're trying to hit a particular outgoing trajectory to, say, Mars, which is good for maybe two or three weeks once every two years, the Moon would be potentially in a useful position for a gravity assist for only a few days during that time, if at all.

You need about three weeks of launch days to have a sufficient probability of launching, and your spacecraft and launch system must accommodate that entire period. So you could not mine the benefit of a lunar assist that might be available over only a few days.

That's all if you launch directly to escape. If you plan to hang around in Earth orbit and use longer-lived propulsion systems to escape, then you could plan to use a lunar assist, so long as you assure that you get into orbit in time to take advantage of it. Nozomi did that, using lunar flybys to reduce the propellant needed to escape and inject.

Towards the end of the MER-A 21-day launch period there was a little dip in the C3 curve. It was due to distant lunar flybys on those days.

The orbital period of the Mun is much less than the Earths moon, and orbital tilts are quite well aligned.  Based on this I would say that any KSP model that uses a Mun slingshot is not realistic.

 

Edited July 23, 2021 by jinnantonix

[Death Engineering]

11 hours ago, camacju said:

Multiple separate habitat "buildings" that don't need to be connected by pipes, but can be

This has worked very well for me in another challenge.. but that was with mod parts. Probably could conjure something up with cabin bits, I guess.

 

[camacju]

On 7/22/2021 at 8:03 PM, jinnantonix said:

I was wondering if anyone would ask that.   It's an interesting question, because if it was demonstrated, it could make a mockery of the whole Artemis program (god forbid).  A crazy Kerbal invention might succeed, which would be disappointing, it would need to be realistic.  I will give this some thought and respond in a day or two.

This idea isn't that crazy actually.

Since you disallowed solar panels on the mining rig, that means that either RTGs or fuel cells must be used as power generation. RTGs are extremely expensive so fuel cells must be used to optimize cost. The small Convert-o-tron and drill-o-matic aren't efficient enough to make a net profit from fuel cells, so the large ones must be used. The large convert-o-tron consumes 30 electric charge per second and each large drill-o-matic consumes 22.5 electric charge per second. This means that three fuel cell arrays are required. The mining rig also will need rover wheels, and the medium rover wheels aren't large enough to drive around a 2.5 meter rover without some offsetting, so large wheels are required.

The minimal mining rig costs about 42k funds and weighs 13 tons. In contrast, launching 13 more tons of liquid fuel tanks instead of the mining rig will be more than enough for one more full Duna mission, and a 42k fund refuelling mission can launch enough liquid fuel to complete five Duna missions instead of the required three.

So unless more than five Duna missions are flown, at least with the design I'm currently using, a mining rig will be a lot more expensive than just launching extra fuel for three Duna missions. And even in real life, fuel mass will probably be a lot less than the mass of a refinery, especially if xenon is used for the tug spacecraft.

Edited July 24, 2021 by camacju

[jinnantonix]

2 hours ago, camacju said:

This idea isn't that crazy actually.

Since you disallowed solar panels on the craft, that means that either RTGs or fuel cells must be used as power generation. RTGs are extremely expensive so fuel cells must be used. The small Convert-o-tron and drill-o-matic aren't efficient enough to make a net profit from fuel cells, so the large ones must be used. The large convert-o-tron consumes 30 electric charge per second and each large drill-o-matic consumes 22.5 electric charge per second. This means that three fuel cell arrays are required. The mining rig also will need rover wheels, and the medium rover wheels aren't large enough to drive around a 2.5 meter rover without some offsetting, so large wheels are required.

The minimal mining rig costs about 42k funds and weighs 13 tons. In contrast, launching 13 more tons of liquid fuel tanks instead of the mining rig will be more than enough for one more full Duna mission, and a 42k fund refuelling mission can launch enough liquid fuel to complete five Duna missions instead of the required three.

So unless more than five Duna missions are flown, at least with the design I'm currently using, a mining rig will be a lot more expensive than just launching extra fuel for three Duna missions. And even in real life, fuel mass will probably be a lot less than the mass of a refinery, especially if xenon is used for the tug spacecraft.

The rule about solar power not being used for ISRU is intentional since it is highly unlikely the Artemis plan will be able to use solar power in the depths of craters where no sunlight has fallen for millenia.  I realise that this makes the ISRU more expensive, and one must therefore wonder if it's worthwhile.  This  challenge is intended to optimise the design so as to verify that it is cost effective. 

My design gets payback by the end of the second mission, so I disagree with your calculations somewhat.

RTGs may be expensive, but they provide a lot of power continuously and this can be the basis of a relatively lightweight ISRU rig.  IRL I see efforts to make a refinery that is low mass, and generates modest amounts of energy over a long period.  https://www.nasa.gov/mission_pages/tdm/fission-surface-power/index.html#:~:text=NASA plans to demonstrate and,Moon by the late 2020s.  I do not doubt this will be costly, but you can't make solar energy work where the sun don't shine. 

Future Mars missions need a fuel that is not only very weight efficient, but can also generate enough thrust to launch a Mars lander from surface to orbit.  Hydrogen may be used as a nuclear propellant, but introduces the problem of boil off for the return journey.  I question if xenon propellant and ion engines offer a good solution considering the high mass of a Mars exploration craft.  It's anyone's guess what the best fuel will be, but I am thinking hydrazine , ammonia, and/or methane, which are reasonably well modelled by KSP in terms of energy density.

Edited July 24, 2021 by jinnantonix

[camacju]

Does your design use the large mining equipment? If so, then I think 42k funds is basically a low bound on a mobile mining rig.

If you're using bipropellant rockets for everything, I could see a payback occurring after fewer than three missions, but my design uses about 2000 liquid fuel per Duna mission and launching 5000 more liquid fuel to LKO costs a lot less than 42k funds.

[jinnantonix]

5 minutes ago, camacju said:

Does your design use the large mining equipment? If so, then I think 42k funds is basically a low bound on a mobile mining rig.

If you're using bipropellant rockets for everything, I could see a payback occurring after fewer than three missions, but my design uses about 2000 liquid fuel per Duna mission and launching 5000 more liquid fuel to LKO costs a lot less than 42k funds.

I am using small mining equipment and an RTG.   It's slow but it works.

[camacju]

Ok, the RTG is about half as expensive as I thought it was for some reason. Yeah that seems like the best option. Still though, 25k funds is probably enough to just launch all the required stuff for another couple missions.

I'll do a non-mining submission just to see how low I can do three Duna missions however

Edited July 24, 2021 by camacju

[jinnantonix]

17 minutes ago, camacju said:

Ok, the RTG is about half as expensive as I thought it was for some reason. Yeah that seems like the best option. Still though, 25k funds is probably enough to just launch all the required stuff for another couple missions.

I'll do a non-mining submission just to see how low I can do three Duna missions however

Great.  I'm keen to see the comparison.

[camacju]

Ok, here's my attempt at a no-mining architecture:

VAB, launch

Spoiler

The modules of this mission:

Vulkan - Nuclear tug, 800 liquid fuel capacity. The nuclear engine is used a lot in this mission. 19.2k funds, most of which is the nuclear engine

Turing - Eight kerbal surface habitat with 1 ton of ore. Doubles as high strength landing gear. 2.9k funds.

Tarjan - Four kerbal descent/ascent module with parachutes. 8.6k funds.

Bezout - Four kerbal orbital habitat and fuel tanker, 1200 liquid fuel capacity. Together with Tarjan it meets the eight pressurized seat restriction. 3.3k funds

Rossum - LKO fuel tanker, 4400 liquid fuel capacity. 6.3k funds

Full stack with all modules and launcher. 85860 funds in VAB, counting fairings and aesthetic parts

On pad

Throttling down Twinboar to increase efficiency in lower atmosphere

SRBs detached, Twinboar pushes to suborbital

Twinboar runs out before circularization finishes

Vulkan's nuclear engine finishes circularization

Journey to Duna

Spoiler

Rossum is left in LKO, the other modules transfer to Duna across three kick burns

Duna approach

Duna aerobrake

Bezout is left in orbit, Vulkan is half fueled for Duna ascent

Parachutes deployed. Turing's impact tolerance is 40 m/s so I use it as landing gear - the parachutes on Tarjan are enough to slow down

Landed

Repacking chutes

Climbing down to Turing

Flag!

Climbing back up - no EVA propellant used

The Vulkan tug fits into the square gap in the Turing base so it's easy to detach and launch, as well as re-dock to a subsequent mission
 

Return trip

Spoiler

Reunited with Bezout, going home

Kerbin aerobrake

Dropping Tarjan into suborbital trajectory

Circularizing

Descent

Landed

Second mission's rocket

Spoiler

27929 funds

On pad

Launch

Circularizing

Sustainability calculation:

6400 liquid fuel at launch
6300 in LKO
Journey to Duna and back costs just under 1600 liquid fuel
Each resupply mission (new command pods and habitat) brings 500 liquid fuel
After four resupply missions, 2k liquid fuel left - so this setup will last for five missions in total before a new dedicated fuel tanker needs to be launched

Three missions will cost 141718 funds or about 47.2k each - five missions will cost 197576 funds or about 39.5k each. For only three or four missions however, the resupplies wouldn't need to bring fuel up.

Cost with mining for three missions vs no mining:
Resupply missions would have identical cost since I wouldn't need to bring fuel in either case. Only reason I have extra fuel is because I didn't optimize the rocket well.
So this basically boils down to, how much funds can I save by ditching the Rossum fuel tanker and replacing it with a mining module? The launcher could be smaller, but definitely not 20K funds smaller, so mining will probably be more expensive up to 5 missions, beyond which I'd have to use a dedicated refueling launch. I think mining would break even at the sixth mission and definitely be cheaper for 7+ missions.

Later today I'll try to optimize the fuel tanker and launchers for only three Duna missions. I could probably shave off a good bit of cost

[camacju]

I got the main launch down to 76942 funds:

And the resupplies down to 24830 funds:

Three Duna missions now cost 126.6k or 42.2k per mission