NASA's Artemis Program Updates and Discussion Thread 5

[VSECOTSPE]

Here’s a small lander that might work by 2030:

Goldin wanted “incredible breakthroughs” costing at most a few hundred million dollars rather than billions. The HLR team responded by focusing on bare-minimum lightweight concepts such as Option C’s “small lander”...

To save weight, HLR would use an unpressurized open-cockpit lunar landing vehicle weighing just 4,565kg with fuel. The vehicle is 3.9 meters tall and 5.6 meters wide. The space-suited crew of two receives oxygen and other life support consumables via umbilicals from the LLV. In the illustration here, arrows indicate foot restraints and ladder. [What a ride that would be!]

Pic at:

https://nss.org/lunar-base-studies-1996-human-lunar-return/

[TheRadicalModerate]

Remember, the Dumbacher argument is that there's a simpler, lower-risk way to do HLS than with the LSS and its attendant refueling.  What you have here is anything but simple.

With three modules rather than two or one it is operationally more complex. On the other hand it requires no new technology, which reduces uncertainty and risk in the development timeline. The modularity also means it can use existing launch vehicles, though it might take three Falcon Heavies and a pair of (non-life-critical) dockings.

Further, Dumbacher didn't specify the crew size of his simpler lander. If it's only two astronauts making a jaunt from NRHO to the lunar surface and back the three modules could fit on two Falcon Heavies.

This scheme is basically the same as the 2018 NASA reference HLS.
    https://en.wikipedia.org/wiki/Human_Landing_System#Reference_design

It's also not incredibly far off the Blue Origin initial proposal that NASA rejected (although that used hydrolox for the descent and transfer elements).

[Eric Hedman]

Here’s a small lander that might work by 2030:

Goldin wanted “incredible breakthroughs” costing at most a few hundred million dollars rather than billions. The HLR team responded by focusing on bare-minimum lightweight concepts such as Option C’s “small lander”...

To save weight, HLR would use an unpressurized open-cockpit lunar landing vehicle weighing just 4,565kg with fuel. The vehicle is 3.9 meters tall and 5.6 meters wide. The space-suited crew of two receives oxygen and other life support consumables via umbilicals from the LLV. In the illustration here, arrows indicate foot restraints and ladder. [What a ride that would be!]

Pic at:

https://nss.org/lunar-base-studies-1996-human-lunar-return/

Oh you have a sense of humor.

[DanClemmensen]

Here’s a small lander that might work by 2030:

Goldin wanted “incredible breakthroughs” costing at most a few hundred million dollars rather than billions. The HLR team responded by focusing on bare-minimum lightweight concepts such as Option C’s “small lander”...

To save weight, HLR would use an unpressurized open-cockpit lunar landing vehicle weighing just 4,565kg with fuel. The vehicle is 3.9 meters tall and 5.6 meters wide. The space-suited crew of two receives oxygen and other life support consumables via umbilicals from the LLV. In the illustration here, arrows indicate foot restraints and ladder. [What a ride that would be!]

Pic at:

https://nss.org/lunar-base-studies-1996-human-lunar-return/

Might work, except not with SLS/Orion. I don't think you can live in a suit for 6.5 days. You need a pressurized spacecraft in LLO.

[JohnFornaro]

I’ve always considered myself a moon-first person but most people have rebuffed me when I spoke about this, saying “We’ve already done the moon. So let’s just go to Mars”.

I couldn't disagree more. 

Remember when BHO visited NASA and gave a speech about the Moon? "We've been there and done that" [BTDT], or something along those lines.  It was a short speech, because he had to go to the golf course for the umpteenth time.

BTDT is the most unscientific argument wielded by the so-called scientists around these parts.  The whole point of colonizing the inner solar system is exactly doing "that" over and over again.

[VSECOTSPE]

Here’s a small lander that might work by 2030:

Goldin wanted “incredible breakthroughs” costing at most a few hundred million dollars rather than billions. The HLR team responded by focusing on bare-minimum lightweight concepts such as Option C’s “small lander”...

To save weight, HLR would use an unpressurized open-cockpit lunar landing vehicle weighing just 4,565kg with fuel. The vehicle is 3.9 meters tall and 5.6 meters wide. The space-suited crew of two receives oxygen and other life support consumables via umbilicals from the LLV. In the illustration here, arrows indicate foot restraints and ladder. [What a ride that would be!]

Pic at:

https://nss.org/lunar-base-studies-1996-human-lunar-return/

Oh you have a sense of humor.

Just trying to help Dumbacher achieve his dreams…

[Ariane7]

Dumb archer ? did he took an arrow in the knee... by himself ? https://en.wikipedia.org/wiki/Arrow_in_the_knee
(I'll see myself out)

[lrk]

Here’s a small lander that might work by 2030:

Goldin wanted “incredible breakthroughs” costing at most a few hundred million dollars rather than billions. The HLR team responded by focusing on bare-minimum lightweight concepts such as Option C’s “small lander”...

To save weight, HLR would use an unpressurized open-cockpit lunar landing vehicle weighing just 4,565kg with fuel. The vehicle is 3.9 meters tall and 5.6 meters wide. The space-suited crew of two receives oxygen and other life support consumables via umbilicals from the LLV. In the illustration here, arrows indicate foot restraints and ladder. [What a ride that would be!]

Pic at:

https://nss.org/lunar-base-studies-1996-human-lunar-return/

Might work, except not with SLS/Orion. I don't think you can live in a suit for 6.5 days. You need a pressurized spacecraft in LLO.

The LOS carries a small unpressurized Lunar Landing Vehicle and a 2.5 meter long Command Module capable of supporting two astronauts for up to 19 days during the Earth-Moon transfer.

Nothing in that proposal about the crew living in their suits for 6.5 days? 

[DanClemmensen]

Here’s a small lander that might work by 2030:

Goldin wanted “incredible breakthroughs” costing at most a few hundred million dollars rather than billions. The HLR team responded by focusing on bare-minimum lightweight concepts such as Option C’s “small lander”...

To save weight, HLR would use an unpressurized open-cockpit lunar landing vehicle weighing just 4,565kg with fuel. The vehicle is 3.9 meters tall and 5.6 meters wide. The space-suited crew of two receives oxygen and other life support consumables via umbilicals from the LLV. In the illustration here, arrows indicate foot restraints and ladder. [What a ride that would be!]

Pic at:

https://nss.org/lunar-base-studies-1996-human-lunar-return/

Might work, except not with SLS/Orion. I don't think you can live in a suit for 6.5 days. You need a pressurized spacecraft in LLO.

The LOS carries a small unpressurized Lunar Landing Vehicle and a 2.5 meter long Command Module capable of supporting two astronauts for up to 19 days during the Earth-Moon transfer.

Nothing in that proposal about the crew living in their suits for 6.5 days?

True. Nothing in that proposal about meeting Orion in NRHO, either, and that is what was (inadequately) trying to convey. This proposal is incompatible with SLS/Orion.

[sdsds]

Nothing in that proposal about the crew living in their suits for 6.5 days? 

The architecture included surface rendezvous with a pre-positioned habitat.

Lots more info on this and other lander architectures here:
https://www.lpi.usra.edu/lunar/strategies/Connolly_NASA-SP-2020-220338_LunarLanders.pdf

[TheRadicalModerate]

Nothing in that proposal about the crew living in their suits for 6.5 days? 

The architecture included surface rendezvous with a pre-positioned habitat.

Lots more info on this and other lander architectures here:
https://www.lpi.usra.edu/lunar/strategies/Connolly_NASA-SP-2020-220338_LunarLanders.pdf

Before we dive down this rabbit hole, if we can agree that any replacement of the current two HLS systems with some kind "small" (not) lander--or any other lander--is going to take much longer than just driving to completion on the two HLS contracts already in place, then we're done.

IMO, the Dumbacher statement was... dumb.

[pochimax]

Yes, your calculations compellingly demonstrate the two-stage hypergolic design doesn't work if we want a crew of four on the surface for a week. A 3-stage hypergolic lander might work though.

3-stage lander modules:
- ascent module from surface to LLO;
- descent module from LLO to surface;
- tug module loiters in LLO and does all the other propulsion.

Remember, the Dumbacher argument is that there's a simpler, lower-risk way to do HLS than with the LSS and its attendant refueling.  What you have here is anything but simple.

No lunar landing is ever going to be easy. But to claim that a traditional lunar lander with a crash stage is just as risky in developing than a lander using cryogenics and refueling... I couldn't disagree more. It seems pretty obvious to me.

[VSECOTSPE]

Yeah, to be clear my post on Goldin’s old open cockpit lunar lander was a joke.  Folks may want to run the numbers for fun, but it’s not intended as a serious solution.

[sdsds]

I chose to make allowance for Dumbacher's faults, and forgive him when he offends me. Interpreted generously he was likely proposing a 'low capability' and 'low development risk' lander rather than a 'low mass' or 'low volume' lander; something fully expended and propelled by hypergolics. This certainly isn't the best thread for lander design discussions, but in the context of what's relevant here: I wouldn't be horribly surprised if Dumbacher envisions something that would only fit under an SLS-diameter fairing.

Yeah, to be clear my post on Goldin’s old open cockpit lunar lander was a joke.

Yes, clearly a joke, and a fun one! It can't be taken seriously for Artemis III because the Foundation Surface Habitat certainly wouldn't be available in 2030. (Unless it were in the form of a landed Starship HLS.)

Folks may want to run the numbers for fun

In addition to being fun, it might prove the counter-factual: "If Dumbacher didn't blindly support SLS he wouldn't be proposing a lander like this."

[TheRadicalModerate]

First, a note on my previous mass estimates:  I'd put a bunch of stuff in the wrong row, and messed up my model.  I have revised numbers for hypergolics, methalox, and hydrolox "small" landers here.  Bottom line:  A Block 1B can handle the hydrolox version, a Block 2 can handle hydrolox and methalox, but it's still the case that neither can handle the hypergolic version.

Now:

No lunar landing is ever going to be easy. But to claim that a traditional lunar lander with a crash stage is just as risky in developing than a lander using cryogenics and refueling... I couldn't disagree more. It seems pretty obvious to me.

First, sdsds's version didn't have a crasher; it was an NRHO-LLO-NRHO transfer element.  So it requires at least one additional crewed RPOD, and an additional on-orbit assembly step.

All of these were looked at extensively by NASA before the BAA's for HLS went out, and their reference missions used the 3-stage TE architecture.  But when the bids came in, Blue's National Team bid used the 3-stage architecture, and SpaceX used the single-Starship HLS with refueling.  We know how that came out.

Note that Blue, after their litigious phase, pretty much acknowledged that the 3-stage needed to be relegated to the dustbin of history, and their SLD/SLT bid:

1) Used a single stage.
2) Required refueling from a tanker in NRHO.
3) Required (implicitly) several New Glenn lift tankers to LEO, to fill the NRHO tanker.

These are exactly the same architectural elements as SpaceX has.  Admittedly, because it's a much smaller vehicle, it requires fewer lift tankers.  On the other hand, unlike the SpaceX architecture, a freshly launched Blue Moon Mk2 needs refueling in NRHO.  The LSS can do HEEO-NRHO-loiter-RPOD-LS-NRHO-RPOD on one tank of prop, so the depot never needs to go to NRHO.  For Blue, the Cislunar Transport has to drag itself to NRHO and back.

[Vultur]

While this might not be the best day to say it (after another upper stage Starship failure), I don't think refueling is necessarily a problem. I think it'll be necessary to do much more than Apollo did.

[JulesVerneATV]

NASA Uses GPS On the Moon For the First Time

https://science.slashdot.org/story/25/03/05/0155218/nasa-uses-gps-on-the-moon-for-the-first-time#comments

[sdsds]

[...]

No lunar landing is ever going to be easy. But to claim that a traditional lunar lander with a crash stage is just as risky in developing than a lander using cryogenics and refueling... I couldn't disagree more. It seems pretty obvious to me.

First, sdsds's version didn't have a crasher; it was an NRHO-LLO-NRHO transfer element.  So it requires at least one additional crewed RPOD, and an additional on-orbit assembly step.

Right. The attached sketch might give a clearer sense of the design. The green section is the orbital module. It is docked to the blue ascent module at the yellow ring. The orbital module loiters in LLO while the descent module takes the ascent module to the surface. The ascent module returns to LLO, docks with the orbital module, and then orbital module propulsion takes it back to NRHO.

All of these were looked at extensively by NASA before the BAA's for HLS went out, and their reference missions used the 3-stage TE architecture.  But when the bids came in, Blue's National Team bid used the 3-stage architecture, and SpaceX used the single-Starship HLS with refueling.  We know how that came out.

Cryogenic propulsion is so cool, no one wants to bid a big dumb hypergolic propulsion solution. Each module fits on a single FH launch but: "Oh! Three launches is so many to get a lander to NRHO." <snicker>

[yg1968]

The failures of IM-2 and Starship yesterday show the importance of redundancy in any commercial or public-private partnership programs including a potential new commercial crew to Mars program.

I am a big fan of Intuitive Machines, SpaceX and other commercial companies but I am also a big fan of redundancy for any commercial or public-private partnership program. Redundancy is essential.

[deltaV]

(a) perfect the technologies to keep a single crew healthy (750 day mission) in microgravity and space radiation environment for the length of time it takes to make a trip to mars (360 days for an opposition-class mission), with a 30 day lunar surface mission to document how crews adjust to low gravity after microgravity, then back to microgravity for another 360 days, and finally back to full gravity when they come home. A SINGLE crew does this; a 750 day opposition-class mission. This is stuff we need to know before sending anyone that far away, where they can’t be rescued.

Opposition class Mars missions are silly since there's very little time spent on the Martian surface exploring compared to the time spent in space receiving health problems from radiation and zero gee. Conjunction class missions are better so Artemis should prepare for those, i.e. ~300 days spent on the lunar surface. Designing for this wouldn't be trivial since you'd need to handle issues such as the lunar night but it's important to do so if we want to prepare for either Mars or a more serious moon program.

BTW expected deaths per unit of exploration completed is a better metric IMO to optimize than expected deaths per mission is. Moon or Mars missions that spend more time on the surface are likely better at expected deaths per unit of exploration completed than shorter missions since the numerator, i.e. loss of crew risk from transportation to and from Earth, probably won't increase significantly but the denominator, i.e. exploration completed, will probably increase a lot.