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

[jinnantonix]

Background

The Artemis program is a space program carried out by NASA, and partners such as ESA, with the goal of landing "the first woman and the next man" on the lunar south pole region by 2024.  The program begins with precursor flights on commercial space vehicles such as the Delta IV Heavy, with the soon to be completed new launch capability, the Space Launch System (SLS) - a super heavy launch vehicle in development by NASA, and which will carry the Orion Crew Capsule and other components for the program. The Space Launch System is derived from the Ares V design, initially developed under the Constellation program which was cancelled due to funding constraints caused by the GFC.  Now, with approved funding, and a plan to leverage commercial launch capabilities where appropriate, the Artemis program may proceed, and will include an unmanned test flight during Artemis 1 around the moon, with a launch date slated for 2021. The program includes building the Lunar Orbital Platform-Gateway (LOPG) which will be launched into a Lunar L2 Near Rectilinear Halo Orbit. Artemis 2 will be the first manned launch of SLS/Orion slated for 2023 with a launch of Artemis 3 carrying the first crew to return to the lunar surface in 2024.

 

This Mission

The goal is to complete an accurate simulation of the Artemis Program in Real Solar System. The intention is to execute each part of the program as accurately as possible, along the proposed timeline, and with replica craft that match the real equivalents in appearance, scale, mass and dimensions.

When the program is completed, the components will be used to design and simulate a manned (kerballed) mission to Mars.

 

Simulator

Kerbal Space Program v1.7.3 with Making History and Breaking Ground

Primary Mods

• Real Solar System by @NathanKelland many others
• RealSolarSystemVisualEnhancements * by @Phineas Freak
• Real Visual Enhancements (RVE) by @pingopete
• Scatterer by @blackrack 
• Minimum Ambient Lighting by @Red3Tango

Part Mods

• SSTU labs by @Shadowmage
• Procedural Parts by @Starwaster
• Restock and Restock+ by Various
• BetterSRBs by @OhioBob
• Tweakscale by @Gaius
• Kerbalized SpaceX by @harrisjosh2711

Tools & Utilities

• MechJeb by @sarbian;

* Note.  Visual effects are not yet supported for RSS in v1.7.3.

 

 

Edited August 19, 2019 by jinnantonix

[jinnantonix]

Artemis Program Schedule:

Testing Phase:

• Date     Craft                                     Mission
• 2010     LAS                                      Pad Abort-1 Test [video]
• 2012     THEMIS 1 and 2                Redirect two satellites into lunar Lagrange point L1 and L2
• 2014     Delta IV Heavy                   Orion Exploration Flight Test-1
• 2019     PeaceKeeper                     Ascent Abort-2 Test [video]
• 2021     Atlas V                                Commercial Lunar Payload Services (CLPS) Mission 1 +
• 2021     SLS Block 1                       Artemis 1         Uncrewed lunar orbit
• 2022     SLS Block 1 Crew             Artemis 2         Crewed lunar flyby on free-return trajectory

Lunar Exploration and Orbital Platform Gateway Construction (speculative *):

• 2022      Falcon Heavy**                Artemis 3a        Power Propulsion Element, Minimal Habitation Module (Modified Cygnus)
• 2024      Falcon Heavy**                Artemis 3b        Expendable 3-stage Lunar Lander delivery to LOPG
• 2024      SLS Block 1B Crew          Artemis 3          Crewed lunar landing, Orion and Lunar Surface Logistics 
• 2025      Falcon Heavy**                Artemis 4a         Uncrewed delivery to LOPG of re-usable Lunar Lander.
• 2025      SLS Block 1B Crew          Artemis 4           Crewed delivery of ESPRIT and crewed lunar landing
• 2026      Falcon Heavy**                Artemis 5a         Uncrewed delivery of fuel resupply module and lunar descent vehicle
• 2026      SLS Block 1B Crew          Artemis 5           Crewed delivery of International Habitation 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
• 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 Asset" (large lunar surface module) to LOPG
• 2028      SLS Block 1B Crew           Artemis 8          Delivery of Airlock Module and lunar landing of crew and "Asset"

+ Assuming Peregrin Lander wins the contract

* The actual schedule for LOPG construction is not yet set by NASA, this is a suggested proposal

** NASA is under negotiation for commercial carriers, single launch of Falcon Heavy is assumed only.  Multiple launches of smaller launch vehicles is feasible, although adds the complexity and risk of more robotic docking operations.

 

Edited September 8, 2019 by jinnantonix

[Gremillion]

I've been working on this for a few months, as well:
 

Spoiler

SLS core stage green run (I had to perform this to make sure my tank was the correct size to match the IRL SLS).

Spoiler

SLS Block 2 (w/ Dynetics boosters) in flight.
 

Spoiler

Separation of the Dynetics boosters.

Spoiler

Orion and EUS in orbit (this was launched by a "Block 2D", but I can't remember what the exact configuration was.

I also have tried Sobol's SLS pack, and it looks great but I am having ignition issues with some of the parts:

Spoiler

 

Edited August 6, 2019 by Gremillion

[Lithobrake]

This looks really cool!

[jinnantonix]

Hi @Gremillion

Thanks for your post.  Looks like you are having some success with your SLS replica.  What engines did you use for main and secondary stages?  Did you match thrust with real world equivalents?  How about engine efficiency?

[Gremillion]

34 minutes ago, jinnantonix said:

Hi @Gremillion

Thanks for your post.  Looks like you are having some success with your SLS replica.  What engines did you use for main and secondary stages?  Did you match thrust with real world equivalents?  How about engine efficiency?

For the SSTU SLS I used SSTU's RS-25s with the "D/E" config, if I recall correctly. I learned later that you have to use Powered Explicit Guidance to get her to orbit, or very carefully massaged curves. The SLS is kind of a strange rocket by Kerbal standards.

All statistics and performance values were as close as I could get them to real world hardware. My SLSes are all flown in RSS/RO.

[jinnantonix]

Testing Phase:

Artemis 3 Mission Simulation

https://imgur.com/a/4n5nx1w

The Lunar Gateway(PPE and MHM) is not yet in place, so this is really just a test run to check that the lunar lander components all work OK.  So far all good, just a few minor tweaks, and some effort to get rid of a few glitches in the graphics. 

The mass of the Orion is incorrect in this test, so is invalid.

Design Notes:

Spoiler

This test used the standard SSTU command pod and service module, which are around half the mass than the actual Orion and Service module.  I have modified the part files to increase the mass, but this means that I now have much less payload available in the SLS Block 1B.  (13 tons).  It is not possible to include the entire lunar lander on the SLS as in this test.  Instead, the program will assume the add-on payload that will be deployed is a Cygnus type logistics supply module.

The Artemis Crewed Lunar Lander Concepts suggest using either the Lockheed-Martin fully reusable lander, or the three-stage lander.  I have opted for the latter as there are some serious inefficiencies in re-usable concept.  Further I have opted for using hypergolic fuels, as hydrogen boil off makes hydrolox systems inefficient for lunar orbital use.

The engines used in this test are various configurations of the Super DRACO.  However in accordance with the concepts for the Advanced Exploration Lander, the Ascent and Transit Vehicles are intended to be re-usable, however the Super DRACO is not designed for more than a few firings.  To resolve, the Ascent Vehicle and Transit Vehicle (re-usable components) will use the Aerojet AJ10-190 or Space Shuttle Orbital Maneuvering System.  The expendable Descent Vehicle will use the Super DRACO as it is lower cost, and provides a better TWR.

The proposed 3-stage Advanced Exploration Lander concept by a NASA team suggests a crew of up to four, however my testing indicates that this would add a considerable amount of weight to the craft, and ultimately it becomes too massive to deploy in a single launch of the SLS Block 1B.  The design I use has a crew of 2.  It is possible that a crew of 4 -5  may be feasible with the SLS Block 2.

The test showed the Orion re-orienting  shortly after TLI similar to Apollo.  This is not appropriate because the prograde burn at the Moon is provided by the Transit Vehicle engines, whereas with Apollo it came from the Service Module engine.  For Artemis missions, the Orion does not re-orient in flight.  The Crewed Lunar Lander separates from the Orion after docking at the LOPG, and redocks with the Minimal Habitation Module (MHM) for crew transfer.

 

Edited August 15, 2019 by jinnantonix

[jinnantonix]

Testing Phase:

• 2010     LAS                                      Pad Abort-1 Test [video]
• 2014     Delta IV Heavy                   Orion Exploration Flight Test-1 [video]
• 2019     PeaceKeeper                     Ascent Abort-2 Test [video]

 

 

[jinnantonix]

Commercial Lunar Payload Service -  Mission 1

It is proposed that by 2021, NASA will award a contract for the first Commercial Lunar Payload Service, to deliver science equipment and mini rovers to the lunar surface.  One contender for the contract is Astrobotic Technology with their Peregrine Lander.  This video simulates CLPS Mission 1 assuming Astrobotic wins the contract.  It is expected that NASA will utilise CLPS to execute reconnaissance at Artemis program lunar landing sites.

Edit:  This video assumes launch on an Atlas V, however it is likely the first CLPS mission will launch on a ULA Vulcan.

Design Notes:

Spoiler

The Peregrine Lander craft has sufficient dV to enter low polar lunar orbit, allowing the craft to choose any surface location.  The craft matches design, dimensions, and mass, and uses 5 x "Ant" engines set to a maximum thrust of 667N to match the proposed Aerojet Rocketdyne ISE-100 engines.  

It is proposed that the Peregrine Lander be launched on an Atlas V commercial launch vehicle.  In order to keep payload delivery costs down, it is proposed to launch the Peregrine Lander "piggy-backing" on a Cygnus standard supply delivery to the ISS, and using the larger Atlas V 531 series rocket.  After ejecting the Cygnus in LEO, the Atlas V second stage executes TLI, on a trajectory to impact on the lunar surface.  5 hours after TLI, the Peregrine separates from the booster and executes a minor correction burn to intercept the Moon at a Pe of 20km over the pole.  Utilising the Oberth effect, Peregrine burns to LLO, requiring a dV of 850m/s, and establishes an orbit at 60km altitude, awaiting landing site alignment.  Landing requires a dV of 1700 m/s , with final landing requiring a burn of the 12 x miniature RCS thrusters to maintain attitude.

 

Edited September 4, 2019 by jinnantonix

[jinnantonix]

Artemis 1:  Orion Lunar Orbital Test

Proposed launch, July 2021 on the NASA SLS Block 1 launch vehicle with Orion spacecraft.  Artemis 1 mission: Lunar orbital test flight and launch of 13 CubeSats.

 

 

 

 

Edited August 19, 2019 by jinnantonix

[Geschosskopf]

That seems to have worked quite well.  I have a few questions, though.

Watching the launch, I got the impression you clipped a bunch of SRBs into the same spots to make it look like you only had 2 SRBs.  Why not just create a new SRB part by copying the normal one, then upping the fuel and trust to match that of the multiple ones?  That would reduce part count and also make staging explosions less likely.

From looking at the schematic drawing of the mission, it looks like the plan is to launch ESE from the Cape, then doing a plane change into an equatorial orbit.  But it looked liked you didn't do that.  So does the drawing look that way just for clarity of the notes?

The sketch also shows 4 burns in lunar orbit.  1) capture into elliptical, 2) circularize at Ap, 3) drop Pe back to low orbit, 4) leave for home.  But in the video, it looked like you stayed in an elliptical orbit.  Or did I miss something?

[jinnantonix]

Hi @Geschosskopf

Quote

Watching the launch, I got the impression you clipped a bunch of SRBs into the same spots to make it look like you only had 2 SRBs.  Why not just create a new SRB part by copying the normal one, then upping the fuel and trust to match that of the multiple ones?  That would reduce part count and also make staging explosions less likely.

I spent a long time developing the SRBs.  I tried to modify maxthrust and fuel capacity in a single booster pair, but ended up with SRBs that are much heavier than the real boosters, or did not burn long enough.  I found clipping some SRBs (from the BetterSRB mod) into the bottom of an unmodified Kickback got exactly the right dimensions ,thrust, mass and burn time to match real world.  (Stock SRBs SUCK!)  The part count (and resultant launch pad explosions) has occasionally been a problem, but judicious autostrutting eventually fixed that.  I also switched settings to "Indestructible Buildings" as the SLS and Falcon Heavy are both so large, and boosters so powerful,  they destroy the pad at launch.

Quote

From looking at the schematic drawing of the mission, it looks like the plan is to launch ESE from the Cape, then doing a plane change into an equatorial orbit.  But it looked liked you didn't do that.  So does the drawing look that way just for clarity of the notes?

The sketch also shows 4 burns in lunar orbit.  1) capture into elliptical, 2) circularize at Ap, 3) drop Pe back to low orbit, 4) leave for home.  But in the video, it looked like you stayed in an elliptical orbit.  Or did I miss something?

I didn't follow the the infographic, it conflicts with other information I have on the proposed Artemis 1 mission. 

Firstly the launch goes east from the Cape exactly when in lunar planer alignment so there is no wasteful plane change burn needed.  Why would you launch any other way?

There is conflicting information on the whether Artemis 1 will go to circular orbit with 4 burns.  Future missions will never put the Orion in circular orbit, rather they will involve a single retrograde burn of the engines to go into NRHO, adjust to encounter the Lunar Orbital Platfrom - Gateway, then use thrusters to rendezvous and dock with the LOP-G.  Crew then transfer to the LOP-G, and the 3-stage lunar lander.  At the end of the mission, the crew reboard the Orion to return to Earth. 

This is a more accurate infographic : https://www.nasa.gov/image-feature/artemis-1-map/ showing the Orion burning once to going into elliptic orbit, then "Orbital Maintenance " burns while in a Distant Retrograde Orbit (DRO) at Ap= 38,000 nmi which I believe is proposed to be sufficiently similar to NRHO for test purposes.   In the video I did similar to this.

In the video I did 2 burns for return, (a) prograde to exit lunar SOI, then (b) retrograde with Pe at 70km from Earth's surface.  This is different to the intended return manouevre, which is (a) retrograde to low Pe over the moon and (b) utilise Oberth, prograde burn to Earth.  The latter is not possible to model accurately in KSP because there are no Lagrange points.  However I will attempt to show this in future videos (if it doesn't use too much dV)

 

 

Edited August 16, 2019 by jinnantonix

[jinnantonix]

Artemis 2:  Orion crewed lunar flyby

Proposed launch, July 2022 on the NASA SLS Block 1 launch vehicle with Orion spacecraft.  Artemis 2  mission: Lunar flyby with 4 crew and launch of CubeSats.

 

Edited August 17, 2019 by jinnantonix

[Geschosskopf]

9 hours ago, jinnantonix said:

Hi @Geschosskopf

I spent a long time developing the SRBs.  I tried to modify maxthrust and fuel capacity in a single booster pair, but ended up with SRBs that are much heavier than the real boosters, or did not burn long enough.  I found clipping some SRBs (from the BetterSRB mod) into the bottom of an unmodified Kickback got exactly the right dimensions ,thrust, mass and burn time to match real world.  (Stock SRBs SUCK!)  The part count (and resultant launch pad explosions) has occasionally been a problem, but judicious autostrutting eventually fixed that.  I also switched settings to "Indestructible Buildings" as the SLS and Falcon Heavy are both so large, and boosters so powerful,  they destroy the pad at launch.

Hmmm....  If the single-SRB thing is too heavy, you might need to create a new SRB fuel resource with a lower density than standard.

 

9 hours ago, jinnantonix said:

Firstly the launch goes east from the Cape exactly when in lunar planer alignment so there is no wasteful plane change burn needed.  Why would you launch any other way?

That's what I thought should happen  

 

9 hours ago, jinnantonix said:

There is conflicting information on the whether Artemis 1 will go to circular orbit with 4 burns.  Future missions will never put the Orion in circular orbit, rather they will involve a single retrograde burn of the engines to go into NRHO, adjust to encounter the Lunar Orbital Platfrom - Gateway, then use thrusters to rendezvous and dock with the LOP-G.  Crew then transfer to the LOP-G, and the 3-stage lunar lander.  At the end of the mission, the crew reboard the Orion to return to Earth. 

This is a more accurate infographic : https://www.nasa.gov/image-feature/artemis-1-map/ showing the Orion burning once to going into elliptic orbit, then "Orbital Maintenance " burns while in a Distant Retrograde Orbit (DRO) at Ap= 38,000 nmi which I believe is proposed to be sufficiently similar to NRHO for test purposes.   In the video I did similar to this.

But that graphic shows the Orion on a big orbit around the Moon, too.  See the gray path on the side toward Earth?  I also found this story about EM-1 talking about 4 burns.  It's about 1/2way down the page, 2nd paragraph under the schematic drawing of the ESM.

https://www.nasaspaceflight.com/2018/08/digging-details-orions-em-1-test-flight/#more-57538

I find all this talk of DRO and NRHO somewhat confusing as I've only been aware of such things for a few months.  Thus, I probably have some fundamental misunderstandings  .  But from what I can tell, DRO is equatorial while NRHO (at least if orbiting the Moon instead of L1 or L2) is polar.  Here's a video showing what they look like.

https://youtu.be/X5O77OV9_ek

So, there's nearly 90^ of inclination between them.  How do you get from one to the other without a relatively large burn?  And why would you even want to go from 1 to the other?  If the destination is a station in NHRO (so you can biome-hop just like in KSP ) wouldn't you be better served to go straight to NHRO from Earth (again, like biome-hopping in KSP) ?

[jinnantonix]

Hi @Geschosskopf

Quote

But from what I can tell, DRO is equatorial

Agree that DRO is equatorial,  and according to your video it is circular.  So now the infographics make sense, thanks for advising.  My assumption was the the test burns were intended to simulate entering NRHO which involves retrograde burn to relative zero velocity, then immediate prograde burn returning to an elliptical orbit .  However it could also be that NASA's plan is that the craft prograde burns to circular orbit (DRO), then immediately (the fact that the craft is in orbit for only 6 days suggests this) burns back to an elliptical orbit - consuming a similar amount of fuel.

Quote

while NRHO (at least if orbiting the Moon instead of L1 or L2) is polar.

From your video it is clear that NRHO is neither equatorial nor polar, the craft is not actually in orbit around the Moon (in the normal sense).  However as there are no Lagrange points in KSP the nearest equivalent is a lunar polar orbit.  I have already tested entering polar orbit direct from TLI (Ap=60,000km, Pe = 2,000km)  - my Orion has plenty of fuel for this, even carrying a 6 ton payload, with plenty of fuel remaining to return to Earth.

Edited August 17, 2019 by jinnantonix

[Geschosskopf]

19 hours ago, jinnantonix said:

Hi @Geschosskopf

Agree that DRO is equatorial,  and according to your video it is circular.

Well, in 2-body KSP, you can SIMULATE it as circular.  But in real 3-body life, it's kidney-shaped when viewed from Earth along the line of sight to the Moon in the Earth-Moon rotating frame.  As I THINK I understand things, it's far enough away from the Moon that Earth's gravity can counteract the uneven lunar gravity that makes things in low lunar orbit crash fairly soon.

19 hours ago, jinnantonix said:

From your video it is clear that NRHO is neither equatorial nor polar, the craft is not actually in orbit around the Moon (in the normal sense).  However as there are no Lagrange points in KSP the nearest equivalent is a lunar polar orbit.  I have already tested entering polar orbit direct from TLI (Ap=60,000km, Pe = 2,000km)  - my Orion has plenty of fuel for this, even carrying a 6 ton payload, with plenty of fuel remaining to return to Earth.

I disagree.  The video states at 0:42 that NRHO orbits are polar (at least when Moon is inside their loop).  Not 90^ inclination but pretty close, and as you can see their inclinations change back and forth either side of center over time.  Both DRO and NRHO are 3-body orbits, or families of orbits sharing the same general properties.  The whole NRHO family of orbits resembles a slinky with 1 end on L2 and the other on L1, with the Moon being inside the coil (and close to 1 side of it).  The Gateway thing is on the coil of the slinky that's over the Moon's pole.

The only reason I can see for putting Orion into DRO is just to keep it from crashing over a long-term test mission.  If Gateway is really supposed to be in NRHO, then it definitely makes more sense for Orion to go there instead DRO, if the Gateway is supposed to allow the lander to drop on any biome.

[jinnantonix]

Quote

The video states at 0:42 that NRHO orbits are polar

It says: " nearly polar ", it is not exactly polar because NRHO is a 3-body orbit.  Otherwise, I entirely agree with you.  The video is excellent, though I had to watch it 3 times to understand the whole "slinky" thing.

I propose to model the NRHO in KSP as a highly elliptical orbit, with the Ap over the south pole, as this will best allow the proposed telecommunications relay capability from the lunar south pole.

I don't fully understand why NASA proposes DRO rather then NRHO, I suspect it may have something to do with safety or recoverability in case of system failure.  I am certain there is no intention to ever transition from DRO to NRHO.

I will also redo the Artemis 1 mission from scratch showing the Orion burning into DRO, new video is pending. DONE

Edit:  I figured out why they go to DRO.  The Orion stays in DRO for about 6 days or about 1/3 of a lunar orbit before burning retrograde to elliptical orbit.  By shifting the position of Pe, this allows a single burn utilising the Oberth effect to attain a trajectory directly back to Earth.  (It doesn't explain why they don't go to NRHO and do a proper test  ).

Edited August 18, 2019 by jinnantonix

[jinnantonix]

Artemis 3

The final stage of Artemis phase 1, is initial establishing of the Lunar Orbital Platform - Gateway, and a crewed lunar landing in the darkness of Shackleton Crater at the lunar south pole. 

The high level plan for Artemis 1, 2 and 3 is as follows:

          

The component craft for the Artemis 3 mission comprises the following:

1. Power and Propulsion Element (PPE), being developed by Maxar Technologies (8.0 tons, including 2t of Xenon propellant)
2. Minimum Habitat Module, being developed by Northrop Grumman - a modified Cygnus standard module (3.75 tons approx)
3. Advanced Exploration Lander,  developed by NASA and partners.  3 stage - Ascent, Descent and Transit Vehicles.  (14.5 tons approx)
4. Orion with crew of 4 (launch mass 25.8 tons) and lunar surface logistics module (9.8 tons)

Design Proposal:

The first three components are to be delivered on commercial spacecraft.  In order to minimise cost and risk, I propose that the SpaceX Falcon Heavy ($150M per launch) be used, two launches with each launch carrying ~`16 ton payload to lunar insertion, and a single robotic docking procedure in lunar orbit.  The final component, Orion with crew of 4 and logistics, will be launched on the Space Launch System (SLS Block 1B), and will rendezvous and manually dock with the LOP-G in lunar orbit.

Artemis 3a: integrates and fully tests the PPE and MHM on Earth along with a small expendable hypergolic  General Transit Vehicle (GTV) providing 800 m/s delta-V to decelerate the PPE/MHM into NRHO. The GTV is a smaller version of the Lunar Transit Vehicle (stage 1 of the Advanced Exploration Lander), a relatively low cost craft comprising a single SuperDraco engine, fuel tanks and remote control system.  Launch Vehicle is the SpaceX Falcon Heavy.

Spoiler

The initial LOP-G configuration includes (from top) Minimal Habitat Module , Power and Propulsion Element and General Transit Vehicle.  Total mass of craft 15.5 tons at launch.

 

Artemis 3b:  integrates and fully tests the 3 stages of the Advanced Exploration Lander on Earth.  The craft comprises Lunar Ascent Vehicle (crew of 2), Lunar Descent Vehicle (which remains on the lunar surface) and Lunar Transit Vehicle which provides propulsion for entry into NRHO and rendezvous with the LOP-G, transport of LAV and LDV to low lunar orbit, and rendezvous with LAV after surface mission completion, thence return crew to the LOP-G.  The prototype AEL craft will be fully expendable, however future AEL craft will have re-usable LAV and LTV components.  Launch Vehicle is the SpaceX Falcon Heavy.  The AEL will rendezvous with the LOP-G, and will dock with the MHM under robotic control from Earth.

Spoiler

The Lunar Lander comprises (from top), Lunar Ascent vehicle, Lunar Descent Vehicle, and Lunar Transit Vehicle.  Launch mass is 14.5 tons.  The craft includes solar panels to power the Ascent and Transit Vehicles while in flight, and an RTG in the descent stage to power the craft in the darkness of Shackleton Crater .

 

Artemis 3:  integrates the Orion spacecraft (crew of 4) with a supply module containing lunar surface and transit logistics.  Launch Vehicle is the SLS Block 1B.

After rendezvous, logistics equipment will be transferred to the Advanced Exploration Lander.  2 crew will remain at the LOP-G. while a pilot and a scientist will transfer to the AEL, and land at the lunar south pole.  After 2 weeks on the surface carrying out scientific studies, they will launch in the Lunar Ascent Vehicle and return to the LOP-G with a small payload of moon rocks.  The crew of 4 will then board the Orion and return to Earth.

Spoiler

Orion and Lunar Surface Logistics Supply module.  Total launch mass is 35.6 tons, excluding LAS.  

 

Edited August 19, 2019 by jinnantonix

[jinnantonix]

Artemis 3 - Lunar Orbital Platform and Advanced Exploration Lander.

 

 

[Geschosskopf]

On 8/17/2019 at 11:33 PM, jinnantonix said:

It says: " nearly polar ", it is not exactly polar because NRHO is a 3-body orbit.  Otherwise, I entirely agree with you.  The video is excellent, though I had to watch it 3 times to understand the whole "slinky" thing.

Yeah, in the Moon-centered frame, it looks like a banana peel draped over the north pole  :).

 

On 8/17/2019 at 11:33 PM, jinnantonix said:

I propose to model the NRHO in KSP as a highly elliptical orbit, with the Ap over the south pole, as this will best allow the proposed telecommunications relay capability from the lunar south pole.

This is another thing I don't quite understand.  Because the whole NRHO family of orbits is based on the L1 and L2 points on a line between Earth and Moon, the one that goes over the Moon's pole is always essentially face-on to Earth.  While this keeps the Gateway always visible from Earth for communications, it also means the Gateway orbit is 2x 90^ out of plane to the approach path of a ship leaving Earth.  1x for being near-polar instead of equatorial and 1x for being face-on instead of edge-on to the approaching ship.  IOW, about the worst possible target for efficient transfers on a direct approach.  So why is this advantageous in real life?  Is there a funky 3-body way of getting there that's less wasteful?

Of course, in 2-body KSP, polar orbits around Mun retain a constant orientation so vary between being edge-on and face-on to Kerbin as Mun goes around.  Thus, if you want to rendezvous easily with something in polar Mun orbit, you just wait until Mun carries the orbit around to be edge-on to Kerbin.  Then you just adjust your approach a bit up or down to arrive tangent to the top or bottom of the target orbit, depending on which way you need to go around Mun.  

 

2 hours ago, jinnantonix said:

Artemis 3 - Lunar Orbital Platform and Advanced Exploration Lander.

Very nice station-building.  I think this video also shows the double plane-change I was talking about above.

[jinnantonix]

Quote

The Gateway orbit is 2x 90^ out of plane to the approach path of a ship leaving Earth.  ... about the worst possible target for efficient transfers on a direct approach.

Edit:
I just went back to a quicksave on this last launch to check, and while NRHO is 90deg to the direction of the Earth from the Moon, it is definitely NOT 90deg to "the approach path of a ship leaving Earth".  An efficient TLI has Earth Ap just beyond the orbit of the moon, and then the Moon moves along its orbit into the encounter.  The ship therefore encounters the Moon at approximately 90 deg to the Moon - Earth direction, or close to the plane of the NRHO, so if the encounter with the LOPG is close to the NRHO Ap, then the delta-V is much less than the worst case of 200m/s (90 deg orbital plane change)

 

Edited August 20, 2019 by jinnantonix

[jinnantonix]

In late 2023, NASA commissions Astrobotic to dispatch a Peregrine Lander to Shackleton Crater on a ULA Vulcan rocket to act as a beacon for the Artemis 3 lunar landing.  The solar panel is replaced with a small RTG (there is no sunlight in the crater).  Equipment includes high efficiency LEDs, along with instruments to provide accurate topographic maps of the crater floor.  There is comprehensive testing of relay telecommunications via the LOP-G.

Shackleton Crater.  Only the crater rim receives sunlight.  The floor is permanently dark, and so ancient water ice deposits from billions of years of comet impacts remains available as water ice across the crater floor.  NASA aims to use this H2O to create fuel for future missions to heliocentric space, and in particular to Mars.  The Artemis lunar landings seek to survey the resource, and test the advanced and complex equipment needed for converting water ice to usable fuel, and ultimately to establish a lunar base for managing a lunar refueling station.

Edited August 21, 2019 by jinnantonix

[jinnantonix]

Artemis 3 - Crewed Lunar Landing

July 2024, a crew of 4 launches on the SLS Block 1B in an Orion and with several tons of equipment and supplies on a 21 day mission.  After 4 days the Orion completes a rendezvous with the LOP-G, docks the logistics module, and then docks the Orion to the MHM.  The crew loads the prototype Advanced Exploration Lander with supplies and equipment, and spends 2 days preparing the AEL for launch.  A pilot and scientist board, launch and burn the AEL into low lunar orbit.  The Lunar Transit Vehicle detaches, and remains in orbit, while the crew descends to land at Shackleton Crater, guided by the Peregrine beacon.  After landing, the crew spend a week conducting experiments, then launch and dock the Lunar Ascent Vehicle with the Lunar Transit Vehicle in LLO.  The craft docks with the LOP-G, and the lunar crew transfer to the MHM.  The prototype AEL and spent logistics module is undocked via remote robotic control to burn into suborbital trajectory.  The LOP--G orbit is adjusted by firing the ion engines to ensure orbital stability until the next mission.  The crew board the Orion, and return to Earth.

Design Notes:

The AEL Transit Vehicle currently has insufficient fuel capacity to rendezvous with the LOP-G and complete the lunar landing.  It is assumed that the logistics module launched on the SLS includes hypergolic fuel pumps and supplies to refuel the LTV while at the LOP-G.  Artemis 4 includes the ESPRIT module which provides fuel pumping capabilities for Aerozine, NTO and Xenon, and future missions will include fuel supply.

The detaching and disposing of the AEL and logistics module is not mandatory, and they may be maintained in position to provide additional crew space for future missions.  Additional docking ports will be provided with the delivery of the International Habitat module on Artemis 4.

 

Edited August 21, 2019 by jinnantonix

[Geschosskopf]

On 8/21/2019 at 4:49 PM, jinnantonix said:

July 2024, a crew of 4 launches on the SLS Block 1B in an Orion and with several tons of equipment and supplies on a 21 day mission.  After 4 days the Orion completes a rendezvous with the LOP-G, docks the logistics module, and then docks the Orion to the MHM. 

I was puzzled by moving the Orion to another port after the initial docking.  So I'm guessing you can't crawl through the logistics module?  But you can still open an end of it root around for the specific thing you need?  I sure hope they pack the logistics module in the order you'll really need the stuff

 

On 8/21/2019 at 4:49 PM, jinnantonix said:

The AEL Transit Vehicle currently has insufficient fuel capacity to rendezvous with the LOP-G and complete the lunar landing.

That's disappointing, considering a Kerbal-style rescue mission isn't really part of the plan    I blame LTV.  I used to work for an aerospace company of that name and it went bust, so it's an ill-omened name.

 

On 8/21/2019 at 4:49 PM, jinnantonix said:

  It is assumed that the logistics module launched on the SLS includes hypergolic fuel pumps and supplies to refuel the LTV while at the LOP-G.  Artemis 4 includes the ESPRIT module which provides fuel pumping capabilities for Aerozine, NTO and Xenon, and future missions will include fuel supply.

The detaching and disposing of the AEL and logistics module is not mandatory, and they may be maintained in position to provide additional crew space for future missions.  Additional docking ports will be provided with the delivery of the International Habitat module on Artemis 4.

I'm wondering what they're going to do to control the nasty lunar dust.  Given the experience of Apollo, I"m sure they'll try something but I still wouldn't want to bunk in a used AEL can that had seen a week of dirty astronauts stomping in and out.  Silicosis is no joke.  It's mankind's oldest industrial disease, killing folks since the Stone Age.

Hmmm, what about dust in the Gateway itself?  If you can't isolate it to the lander, the Gateway's going to get pretty dirty after a few missions, too.

Can the LTV fly itself?  That is, can it move itself from 1 docking port to another?  Such as from the back of the old lander can to the back of a new lander's descent stage?  Or say pull the old lander can off the station, toss it into a suborbital trajectory, then return to the station?  If not, then what's the point in refueling it?  It's stuck on the old lander can.

Anyway, this is a fascinating thread.  But it's spoiling the real thing.  I probably won't even watch it when it happens.  It'll seem like a rerun  

[jinnantonix]

4 hours ago, Geschosskopf said:

I was puzzled by moving the Orion to another port after the initial docking.  So I'm guessing you can't crawl through the logistics module?   

As I understand it, the Cygnus (which this module is based on) consists of two basic components: the Pressurized Cargo Module (PCM) and the Service Module (SM). The SM includes hypergolic fuel tank, engines and electronics with no access internally from the PCM, so no ability for the astronaut to pass.  The other reason for the double docking is that the Orion be used to dock the module manually, the Cygnus typically is berthed at the ISS using a robotic arm, which at this stage is not delivered to the LOP-G.  After docking the Cygnus, the Orion decouples from the Cygnus, then docks again so the astronauts can access the MHM.

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That's disappointing, considering a Kerbal-style rescue mission isn't really part of the plan

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.
 

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I'm wondering what they're going to do to control the nasty lunar dust.

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.
 

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Can the LTV fly itself?  

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. 

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.

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It's spoiling the real thing. 

I am sure there are many surprises still in store.  e.g. the recent agreement that the first Peregrine Lander will launch on a new ULA Vulcan rocket.  All indications up until last week was that it would launch on an Atlas V.

The really interesting stuff is still just speculation.  What resources will they find in Schackleton Crater?  Water ice, frozen CO, CO2, nitrogen compounds?  Will ISRU be possible?  Will ISRU produce LH2 (needs expensive and heavy cryo equipment) or more stable methane or ammonia?  How will the refueling be done, and where?  How will fuel be refined, and how will it get to the LOP-G.  Will future interplanetary missions use NERVA engines (with LH2, methane or ammonia,  or a combination).  Or is the future methane/LOX? - it is becoming a popular idea with the development of the Raptor and BE-4 engines.  How much will re-usability feature in the architecture?   Will commercial operators get there first, or will they have their technology contracted into NASA's plan?

 

 

Edited August 23, 2019 by jinnantonix