Author Topic: Lockheed Martin proposes a mega-lunar lander: 62 tons and an elevator  (Read 18691 times)

Offline GWH

You do know that these chemicals are manufactured on earth in industrial quantities, while methane isn't?
For the reasons that water isn't harvested in the form of ice locket in frozen soil, its perfectly available for most applications in the form of natural gas.

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That means the manufacturing is well understood.
In regards to ISRU, one question that rarely comes up is whether or not manufacturing of a chemical is an understandable process. Rather it's available quantities of the chemical components and the complexity of the process.
So what's the value in making that process more complicated?
Rather than say it's a total dead end, I should have said "It's a more complicated path that no one seems to be interested in pursuing vs. the handful talking about the market propellants directly derived from water ice today."

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Just don't fire the thing near earth. Mars is already hazardous due to perchorates. Venus is full of sulfuric acid. The moon dust is hazardous, while the lunar water deposits contains chemical poisons. If you really are this worried about this, you should be freaking out about nitrogen oxides from cars - of which some of it is naturally NTO.

 :o Ummm.... maybe concerns about launch failures in launching from Earth? Seeing as how the entire plan outlined in the paper is reliant on Earth sourced propellant. You can hand wave away those concerns all you want, but it can pretty well be guaranteed to come up as an issue.
« Last Edit: 10/10/2018 01:31 AM by GWH »

Offline Joseph Peterson

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Few things would be worse than plans for another hypergolic fueled lander.  >:(

...

It has no commonality with propellants of any modern western rocket in use or on the drawing board (meaning any use of excess propellant is a no go).

If you limit yourself to launch vehicles and ignore Orion, Dragon, Cygnus, Starliner, Gateway, deep space probes, commercial satellites, space telescopes, or basically everything but launch vehicles that uses chemical propulsion, sure.
If ZBLAN can't pay for commercial stations, we'll just have to keep looking until we find other products that can combine to support humans earning a living in space.

Offline brickmack

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None of that is relevant to the excess propellant issue

Offline Joseph Peterson

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None of that is relevant to the excess propellant issue

Was this a reply to me?

If so, how is virtually every spacecraft using the same storable propellant type not relevant to the hypothetical excess hypergolic propellant issue?
If ZBLAN can't pay for commercial stations, we'll just have to keep looking until we find other products that can combine to support humans earning a living in space.

Offline hamerad

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None of that is relevant to the excess propellant issue

Was this a reply to me?

If so, how is virtually every spacecraft using the same storable propellant type not relevant to the hypothetical excess hypergolic propellant issue?

I would guess it has something to do with the fact that none of them are designed to be refueled in orbit, i could be wrong though.

Offline KelvinZero

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Few things would be worse than plans for another hypergolic fueled lander.  >:(

...

It has no commonality with propellants of any modern western rocket in use or on the drawing board (meaning any use of excess propellant is a no go).

If you limit yourself to launch vehicles and ignore Orion, Dragon, Cygnus, Starliner, Gateway, deep space probes, commercial satellites, space telescopes, or basically everything but launch vehicles that uses chemical propulsion, sure.
I would agree with GWH about not wanting a hypergolic lander, but the problem would not be no commonality with the propellant, but no commonality with the major existing HSF-scaled engines and associated infrastructure (incl. propellant). Even more than that, hypergolic is probably totally unsuitable for ISRU. If we go back to the moon IMO ISRU should be the major goal. We go to stay. We are not just trying to answer a handful of science questions but develop technology towards eventual space settlement.

Offline speedevil

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I would agree with GWH about not wanting a hypergolic lander, but the problem would not be no commonality with the propellant, but no commonality with the major existing HSF-scaled engines and associated infrastructure (incl. propellant). Even more than that, hypergolic is probably totally unsuitable for ISRU. If we go back to the moon IMO ISRU should be the major goal. We go to stay. We are not just trying to answer a handful of science questions but develop technology towards eventual space settlement.
It might be notably easier to set up a ISRU system if you are not limited to two ton payloads.

I do not believe a SSTO hydrogen/oxygen engined lunar tug, aimed mostly at costing five billion dollars rather than a specific operational capacity has much place in latter expansion once you've got ISRU up and running.
Any learning done on how to produce this object teaches us more-or-less nothing applicable to how to proceed with future landers costed for commercial launch and commercial fuel, with ISRU propellant.

This is not saying BFS should be the only thing we fund, but that what we fund to get us to the future should not be predicated on making demonstration vehicles which do not actually teach us anything meaningful.
Learning how to make a 10% lighter hydrogen tank to produce it at $500M a time isn't it.
A rocketlabs inspired lander stage, running on methalox, storing the methane to take off, and using ISRU oxygen, for example might be.

If the vehicle isn't teaching you things, then any argument based around what it can teach you for the future falls away, and you should do it for the least cost possible.





Offline Joseph Peterson

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None of that is relevant to the excess propellant issue

Was this a reply to me?

If so, how is virtually every spacecraft using the same storable propellant type not relevant to the hypothetical excess hypergolic propellant issue?

I would guess it has something to do with the fact that none of them are designed to be refueled in orbit, i could be wrong though.

Gateway(or whatever it is being called today) is being designed to be refueled.  I believe the same applies to B330.  There are efforts underway to refuel satellites that weren't designed to be refueled.  Adding refueling capability to Dragon, Orion, and Starliner so they can operate in LLO is simple enough for rocket engineering.

The point that I am making is that virtually every spacecraft that uses chemical propulsion uses hydrazine, meaning there are plenty of potential customers for excess propellant.  I see zero reason to argue that excess hydrazine is a problem we need to worry about.  Conversely,  I am drawing a blank for current kit that could be potential customers for excess hydrolox.  Basing a Lunar development program on a propellant that nobody currently uses, built with landers that can only deliver 1 tonne of cargo despite needing 40 tonnes of propellant in NHRO, is asking for a future with a nearly useless Lunar propellant plant we can't afford to build.

I would agree with GWH about not wanting a hypergolic lander,

Let me be clear.  I would prefer to have a propellant that is less toxic than hydrazine.  The problem is making the economics work without a $20+ billion NASA exploration budget to create demand in a reasonable time frame.

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but the problem would not be no commonality with the propellant, but no commonality with the major existing HSF-scaled engines and associated infrastructure (incl. propellant).

False.  Dragon, Orion, and Starliner all use hydrazine.

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Even more than that, hypergolic is probably totally unsuitable for ISRU.

Not totally unsuitable for ISRU, assuming we find the proper mix of elements.  That said, the cost of setting up a hydrazine plant and its supply chain is not economically viable compared to shipping propellant to LLO from Earth.

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If we go back to the moon IMO ISRU should be the major goal. We go to stay. We are not just trying to answer a handful of science questions but develop technology towards eventual space settlement.

Developing Lunar ISRU is a science problem.  As of today there are only six sites, the Apollo landing sites, which have been studied enough that they could contain inferred mineral resources.  Science needs to be done to measure resources before we can seriously consider creating proven reserves(in other words, functional ISRU).  Denigrating the amount of science needed to be done by calling it a handful of science questions is improper. 

A note on mineral resource classification:

While terminology varies, there are five basic categories.

Inferred resources:  Samples have been analyzed but are of limited quantity or certainty(Think Apollo missions).
Indicated resources:  Samples have been analyzed allowing reasonable estimates of what is there.
Measured resources:  Samples have been analyzed which give a high degree of confidence, of the grade, tonnage, shape, densities, physical characteristics and mineral content.
Probable reserves: Measured resources that can probably be economically mined and processed.
Proven reserves:  Measured resources that can actually be economically mined and processed.

Note that all five classifications requiring physically testing samples.  Satellite, or in the case of the Moon, LCROSS, data only points scientists toward where sample holes need to be dug.  Rovers such as Curiosity are necessary(barring scifi tech like Star Trek scanners) to reach the first mineral resource classification tier in space.  In some limited cases, the composition of the Martian atmosphere for example, these rovers can take us as far as measured resources, but we still need to solve the economic problems before ISRU can become a reality.
If ZBLAN can't pay for commercial stations, we'll just have to keep looking until we find other products that can combine to support humans earning a living in space.

Offline speedevil

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Developing Lunar ISRU is a science problem.  As of today there are only six sites, the Apollo landing sites, which have been studied enough that they could contain inferred mineral resources.  Science needs to be done to measure resources before we can seriously consider creating proven reserves(in other words, functional ISRU). 
In principle, hydrolox driven from imported hydrogen with native oxygen resources could be an option to enable hydrolox to play a meaningful role.
Oxygen is considerably easier to find, and reasonable simulants from the landing sites could help with development, rather than the considerably harder task of actually locating resources to mine water.
A lander like the above, if re-oxygened on the moon could put down some 15 tons of payload, and take off with a similar large payload.
(I have not done the maths).

Offline A_M_Swallow

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{snip}
Let me be clear.  I would prefer to have a propellant that is less toxic than hydrazine.  The problem is making the economics work without a $20+ billion NASA exploration budget to create demand in a reasonable time frame.

{snip}

Masten Space Systems are working on the XL-1 lunar lander NET 2021. Its propellant will be MXP-351, a non-toxic storable hypergolic propellant system.

The Masten/ULA Xeus lander is due to use H2 and O2 as propellant.

Offline KelvinZero

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(1)-->Let me be clear.  I would prefer to have a propellant that is less toxic than hydrazine.  The problem is making the economics work without a $20+ billion NASA exploration budget to create demand in a reasonable time frame.

(2)--> False.  Dragon, Orion, and Starliner all use hydrazine.

(3)--> Not totally unsuitable for ISRU, assuming we find the proper mix of elements.  That said, the cost of setting up a hydrazine plant and its supply chain is not economically viable compared to shipping propellant to LLO from Earth.

(4)--> Developing Lunar ISRU is a science problem.  As of today there are only six sites, the Apollo landing sites, which have been studied enough that they could contain inferred mineral resources.  Science needs to be done to measure resources before we can seriously consider creating proven reserves(in other words, functional ISRU).  Denigrating the amount of science needed to be done by calling it a handful of science questions is improper. 

(1) Nah. If you can't do it in a sensible manner, then chose smaller goals you can do in a sensible manner. Doing shoddy quick HSF is just an enormously expensive boondoggle to kill real progress.

(2) I think you have missed the point about "no commonality with the major existing HSF-scaled engines" but it might be me. I know Dragon uses hydrazine but is anyone suggesting using the superdraco? I assumed we would have to develop a new engine. Even if it shares the same fuel it would be a different engine. You choose hydrazine for reliability, but the engines that get a hundred times more development will probably be more reliable as well as better performance and less toxic.

(3) lets not niggle.

(4) Absolutely I support doing science and prospecting.. ASAP and (initially) robotically. You can probably do those fine with existing small hypergolic engines. We don't know how much ice is really there. We know even less about hinted CO. It is totally ridiculous to be pushing for specific enormously expensive HSF architectures before sending something to have a decent poke around at the poles. (Im not accusing you of that, you could accuse me of the same thing. it is a general frustration of mine. It is something I have said over and over on this site.)

Offline Joseph Peterson

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Developing Lunar ISRU is a science problem.  As of today there are only six sites, the Apollo landing sites, which have been studied enough that they could contain inferred mineral resources.  Science needs to be done to measure resources before we can seriously consider creating proven reserves(in other words, functional ISRU). 
In principle, hydrolox driven from imported hydrogen with native oxygen resources could be an option to enable hydrolox to play a meaningful role.
Oxygen is considerably easier to find, and reasonable simulants from the landing sites could help with development, rather than the considerably harder task of actually locating resources to mine water.
A lander like the above, if re-oxygened on the moon could put down some 15 tons of payload, and take off with a similar large payload.
(I have not done the maths).

One problem is creating meaningful oxygen production with a cargo limit of 1 tonne per trip.  The only economically viable way I see to do this using the Lockmart design requires heavy modifications and "sacrificing" the spacecraft for tanks.

The larger problem is that there simply isn't a market for hydrolox in space, outside of proposals.  My preference is to spend the money on doing stuff on the Moon.  Once we are doing enough stuff, Lunar propellant or oxidizer production makes economic sense over terrestrial hydrazine production and shipping.  Figuring out what stuff makes sense is going to take years, so we should ignore Lunar propellant production for now. 


Masten Space Systems are working on the XL-1 lunar lander NET 2021. Its propellant will be MXP-351, a non-toxic storable hypergolic propellant system.

The Masten/ULA Xeus lander is due to use H2 and O2 as propellant.

MXP-351 shares the same fatal flaw as hydrolox for the purposes of this conversation, no commonality.  Keep in mind the point I initially responded to was the claim that using hydrazine risks having unused propellant.  As far as I know no spacecraft, let alone commercially viable ones, use MXP-351, meaning no other potential customers.


(1) Nah. If you can't do it in a sensible manner, then chose smaller goals you can do in a sensible manner. Doing shoddy quick HSF is just an enormously expensive boondoggle to kill real progress.

(2) I think you have missed the point about "no commonality with the major existing HSF-scaled engines" but it might be me. I know Dragon uses hydrazine but is anyone suggesting using the superdraco? I assumed we would have to develop a new engine. Even if it shares the same fuel it would be a different engine. You choose hydrazine for reliability, but the engines that get a hundred times more development will probably be more reliable as well as better performance and less toxic.

(3) lets not niggle.

(4) Absolutely I support doing science and prospecting.. ASAP and (initially) robotically. You can probably do those fine with existing small hypergolic engines. We don't know how much ice is really there. We know even less about hinted CO. It is totally ridiculous to be pushing for specific enormously expensive HSF architectures before sending something to have a decent poke around at the poles. (Im not accusing you of that, you could accuse me of the same thing. it is a general frustration of mine. It is something I have said over and over on this site.)

1)  That is what I am advocating.  Spending tens, if not hundreds, of billions figuring out how to make Lunar propellant that no spacecraft currently uses, especially if we have to detour through Gateway, is not sensible.  Sending some robots to do basic science so we know where humans should land, and more importantly what they will need to take with them, is.

2)  I choose hydrazine because Dragon, Orion, and Starliner all use the propellant.  This is most definitely not no commonality.

3)  Well don't claim something is impossible when it isn't.

4)  Agreed, which is a large part of why I don't like this Lockmart proposal. 

The 5 tonne payload Ceres fully-reusable lander concept I am toying around with could deliver 200+ kg to the Lunar surface while still being reusable.  200 kg is sufficient for a good enough rover with science package, or proof-of-concept hardware for a telescope on the far side.  As I tried and apparently failed to describe in my Initial scouting of 144 potential landing sites topic, https://forum.nasaspaceflight.com/index.php?topic=45641.0, sample return is also possible for what we currently spend for one year of SLS/Orion development. 

I hope you aren't trying to claim that a lander that can carry a 5 tonne habitat module from orbit to Ceres' surface and back is an enormously expensive HSF architecture, because it isn't.  What it is is a cheap(cheap because it shares commonality with existing hardware and propellants used on spacecraft) high thrust kick stage for SEP tugs(to take advantage of the Oberth effect) with landing legs and debris shielding that happens to be capable of landing on anything Lunar size or smaller.  In other words, good enough for the science we need to do before contemplating sending humans.  Theoretically this design could be scaled up, but we're nowhere near ready science-wise, so I haven't bothered designing a lander able to land the hab module on the Moon. 
If ZBLAN can't pay for commercial stations, we'll just have to keep looking until we find other products that can combine to support humans earning a living in space.

Offline GWH

Who cares about hypergolic use in spacecraft, its a trivial mass in comparison to the mass needed for significant delta V. For which every crew sized launch vehicle uses either hydrolox of kerolox for, and soon methalox. Hypergolics play a secondary role in these areas. Yes there may be a market for GEO sats but in that realm electric propulsion is becoming more prevalent anyway. It's like if you could make your own fluids for your car, where would you put your efforts, gasoline or motor oil?

As for the payload of the proposed lander, the "cargo" is only 5 tonnes but the Orion derived crew capsule is more like 15-20... it should be obvious that if being used for base building a cargo only variant  would be developed and capable of 20+ tonnes.

Offline Joseph Peterson

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Who cares about hypergolic use in spacecraft, its a trivial mass in comparison to the mass needed for significant delta V. For which every crew sized launch vehicle uses either hydrolox of kerolox for, and soon methalox. Hypergolics play a secondary role in these areas. Yes there may be a market for GEO sats but in that realm electric propulsion is becoming more prevalent anyway. It's like if you could make your own fluids for your car, where would you put your efforts, gasoline or motor oil?

As for the payload of the proposed lander, the "cargo" is only 5 tonnes but the Orion derived crew capsule is more like 15-20... it should be obvious that if being used for base building a cargo only variant  would be developed and capable of 20+ tonnes.

The point I was responding to was wasted hypergolics.  My response was, and still is, there are plenty of existing potential customers for any unused propellant.

With regard to the points you raise:

Orion's service module carries roughly 9 tonnes of MMH/NTO, which is most certainly not trivial, nor secondary.  Orion and the service module do not use hydrolox, kerolox, or methalox, so these masses aren't even trivial.  They are non-existent.  The same applies to the other two capsules that could be used for the Moon, Dragon and Starliner.

The Orion crew capsule mass is roughly 10 tonnes including, reentry hardware.  Please do not add 5-10 tonnes(plus the mass of unnecessary reentry hardware which I'm not bothering to try to look up) of non-existent mass just to try to make an invalid point.  I have access to the internet and can quickly google Orion information.

The cargo capacity of the proposed lander is 1 tonne, not 5 tonnes as you mistakenly claim.

From the pp 5, section 4.1 of the whitepaper ncb1397 posted here in this thread, https://forum.nasaspaceflight.com/index.php?topic=46491.msg1863150#msg1863150, we know this lander proposal only has 5 km/s.  The devil is in the details, but a fully reusable cargo-only lander is looking at a payload on the order of 10 tonnes when operating from Gateway, without a safety margin.  A hydrazine lander based in LLO can match this without subtracting the dry mass for the crew cabin, deep space hardware necessary for the far longer transit times, or eliminating the margin for safety and/or plane changes.  Pull out all the extra bits need for the journey from the surface to NHRO but not the short trip from LLO and the crew version could easily hit 15 tonnes.  Remove the habitat completely and make a cargo only and we're talking 20-25 tonnes.

In response to your car fluid reference, please compare proper fluids.  In this analogy replace gas with diesel and oil with gasoline, then add the fact that no one else uses diesel.  The question then becomes do you build your own refinery to produce diesel or go to the gas station to buy a tanker full of gasoline?  My preference is to take advantage of existing infrastructure and buy a tanker full of gasoline rather than build my own diesel refinery.

The truth is Gateway based architectures are a poor choice if the goal is the Moon.  We can land far more cargo on the surface using SEP tugs to transfer hydrazine from MEO(above the inner Van Allen belts to avoid frying the SEP tug) to LLO to fuel landers compared to using hydrolox in NHRO.  The trivial mass is humans and the ships needed to transport them.  The mass we need to worry about maximizing is cargo that can take the slow but more propellant efficient SEP tugs between Earth and Lunar orbits, which is primarily storable chemical propellant unless we want to wait for BFR.  While that propellant could one day be hydrolox, that day isn't here yet.  At the rate SLS/Orion is progressing, storable hydrolox available in Lunar orbit is at least a decade away.  Time is money and I see no reason to waste time when we already have good enough.  Using that time/money to do stuff on the Moon is far more efficient.
If ZBLAN can't pay for commercial stations, we'll just have to keep looking until we find other products that can combine to support humans earning a living in space.

Offline A_M_Swallow

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{snip}
One problem is creating meaningful oxygen production with a cargo limit of 1 tonne per trip.  The only economically viable way I see to do this using the Lockmart design requires heavy modifications and "sacrificing" the spacecraft for tanks.

The larger problem is that there simply isn't a market for hydrolox in space, outside of proposals.  My preference is to spend the money on doing stuff on the Moon.  Once we are doing enough stuff, Lunar propellant or oxidizer production makes economic sense over terrestrial hydrazine production and shipping.  Figuring out what stuff makes sense is going to take years, so we should ignore Lunar propellant production for now. 


Masten Space Systems are working on the XL-1 lunar lander NET 2021. Its propellant will be MXP-351, a non-toxic storable hypergolic propellant system.

The Masten/ULA Xeus lander is due to use H2 and O2 as propellant.

MXP-351 shares the same fatal flaw as hydrolox for the purposes of this conversation, no commonality.  Keep in mind the point I initially responded to was the claim that using hydrazine risks having unused propellant.  As far as I know no spacecraft, let alone commercially viable ones, use MXP-351, meaning no other potential customers.

{snip}

Once the lander is in use and a MXP-351 propellant depot is in orbit then commonality works the other way. New spacecraft are made compatible with the XL-1.

Offline Joseph Peterson

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{snip}
One problem is creating meaningful oxygen production with a cargo limit of 1 tonne per trip.  The only economically viable way I see to do this using the Lockmart design requires heavy modifications and "sacrificing" the spacecraft for tanks.

The larger problem is that there simply isn't a market for hydrolox in space, outside of proposals.  My preference is to spend the money on doing stuff on the Moon.  Once we are doing enough stuff, Lunar propellant or oxidizer production makes economic sense over terrestrial hydrazine production and shipping.  Figuring out what stuff makes sense is going to take years, so we should ignore Lunar propellant production for now. 


Masten Space Systems are working on the XL-1 lunar lander NET 2021. Its propellant will be MXP-351, a non-toxic storable hypergolic propellant system.

The Masten/ULA Xeus lander is due to use H2 and O2 as propellant.

MXP-351 shares the same fatal flaw as hydrolox for the purposes of this conversation, no commonality.  Keep in mind the point I initially responded to was the claim that using hydrazine risks having unused propellant.  As far as I know no spacecraft, let alone commercially viable ones, use MXP-351, meaning no other potential customers.

{snip}

Once the lander is in use and a MXP-351 propellant depot is in orbit then commonality works the other way. New spacecraft are made compatible with the XL-1.

So you want to redesign Orion for MXP-351.

How many years will that add before EM-1 flies?

Repeat the question for Gateway.

I don't expect SpaceX to invest the engineering time needed to change Dragon propellant types.

Bigelow fired most of their propulsion engineers in 2016 and I haven't seen evidence of a hiring round to replace them.  I'm not seeing a near term Lunar orbit customer here.

My gut tells me Boeing won't reengineer Starliner without a sizable development contract.  I'd put this customer as possible, but don't count on them.

GSO satellites have refresh times on the order of 15 years.  Customers are going to want to see the propellant in action before they make the switch, assuming they don't go with SEP.  We could build a Lunar hydrolox plant using hydrazine landers and develop long term storage in the time it takes for a GSO MXP-351 market for excess propellant in Lunar orbit to mature.

I'm not seeing how this doesn't violate KISS unless we don't plan on returning to the Moon until the 2030s.

Recall that the point of contention is unused propellant in Lunar orbit.  I'm not saying MXP-351 is a dead end for everything, only the issue at hand.
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Offline A_M_Swallow

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So you want to redesign Orion for MXP-351.

{snip}


Not really. I was thinking about designing daughter of Altair to use MXP-351.
This thread is about lunar landers.

NASA can reasonably expect to have a MXP-351 propelled cargo lander on the Moon within 3 to 5 years.

Online MATTBLAK

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I would be a fan of that idea!! A 2 or 4 person crewed Lander that is refuelable and reusable that masses about 25 to 30 tons fully loaded could be sent to lunar orbit or the Gateway ahead of a crewed mission. Launch vehicle could be a 1x shot SLS or 2x Vulcans with distributed launch. I've been wondering where the 40 odd tons of cryogenic propellants would come from each time for the Lockheed Martin monster Lander. Tanker Module to the Gateway between crewed missions with automated refuelling? Would that be a Commercial supply services contract? Would the Orion bring some of that propellant each time as a co-manifested payload?

Would a 30 ton Lander fueled by MXP-351 have decent mass fractions to do the job as a 4x person Lander and have relatively good Habitation volume for a nearly two week sortie mission? What would it's supplemental payload down mass be: 200-to-400kgs? Could there be a Cargo version fielded as well as a Crewed Lander? Payload down mass in the 4 or 5 metric ton class? Or realistically, more like only two tons?

I sort of like the LockMart Lander - but unless it were forward-designed for Mars missions, able to be fitted for a aeroshell/heatshield and strong legs able to withstand .38g or better, then why the huge, 22 ton dry mass?

So many questions...
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Offline A_M_Swallow

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MXP-351 has an Isp of 322 seconds.

It should be possible to design a reusable man rated cargo lander. When used as a manned lander instead of cargo it could land and ascend a cabin module. A cabin module may be similar in size and mass to the Dragon 2 or CST-100. The cabin module would need life support including power and an oxygen gas tank but not the propulsion system or heat shield. The payload interface will need defining.

Astronauts will demand fly-by-wire. Their radar could display the guidance radar built into the lander module. The lander can think it is being radio controlled.

Offline Joseph Peterson

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This thread is about lunar landers.


Sort of, but no matter how often I reiterate that I was, and still am, trying to refute the erroneous claim that hypergolics in Lunar orbit that aren't used for a Lunar lander will be wasted I keep getting tangential responses.  The fact of the matter is that virtually every spacecraft in existence uses hydrazine, including all three crew capsules which could be used in the near term, and both Lunar station proposals.  On the very narrow point of wasted propellant, using anything but hydrazine is risky.

Returning to the first two words of my previous paragraph, this topic is about a single Lunar lander, specifically Lockmart's proposal.  Adding a page of responses that turn what should be an obvious point into a quagmire is asking for posts to be trimmed.  If anyone wants to continue debate the potential for different types of propellant in Lunar orbit to be wasted due to no other potential customers, it would be best to start a new topic.

On the bright side, this long tangent did lead me to discover something in the whitepaper worth talking about.  Once again I ask readers to direct their attention to pp5 of the LM whitepaper.  Once again the link can be found in ncb1397's post on the first page, link here for your convenience, https://forum.nasaspaceflight.com/index.php?topic=46491.msg1863150#msg1863150.

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First and foremost, only LOX/LH2 provides the performance required for a single stage lunar lander operating from the Gateway orbit, where the round trip ∆V is in excess of 5000 m/s.

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The key attributes for this single stage, fully reusable crewed lunar lander are:
Capability of delivering a crew of up to 4 from the Gateway to the lunar surface
Capability of delivering 1 metric ton of payload to the surface per mission
Capability of operating on the surface for up to 2 weeks
Capability of returning the crew to the Gateway without maintenance or refueling while on the surface
Total ΔV capability of 5 km/s

The last time I checked, "in excess of 5000 m/s" is greater than "5 km/s".  Therefore, according to LM's own whitepaper, this LM lander proposal is not capable of operating from Gateway.

Based on information in this thread, https://forum.nasaspaceflight.com/index.php?topic=44812.0, I use 6 km/s for Gateway based reusable landers.  6 km/s includes a safety margin.  Assuming the same dry mass of 22 tonnes and 450 s isp, this lander proposal needs 64(63.68 round up to maintain two significant figures) tonnes of hydrolox* to deliver the advertised capabilities.

* I have no formal training in rocket engineering and there is no answer key in the back of the book I can use to check my work.  When I apply the rocket equations to a 5 km/s 22 tonne dry mass spacecraft with 450 s hydrolox engines, I come up with 46.31 tonnes of propellant.  Given that this whitepaper is known to contain one egregious error, I wouldn't be surprised if LM's 40 tonnes of propellant figure is also incorrect.  Could someone please check my and LM's homework?
If ZBLAN can't pay for commercial stations, we'll just have to keep looking until we find other products that can combine to support humans earning a living in space.

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