Author Topic: Lagrangian Point Gateways Stations for Lunar, NEA, Mars, and Beyond  (Read 56596 times)

Offline RocketmanUS

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The focus will be for the Lagrangian point gateways for Lunar, NEA, and Mars missions as this seems to be the near term goals for most human space flight.

Will focus on the location of each Lagrangian point that might be used for these proposed missions. There benefits to each type of mission. The type and configuration of a station if any at these points and their possible uses there.

There is also the types of vehicles needed to get to these gateways and to the above three surface destinations both for crew and cargo. But not about the launch vehicles from the surface of the Earth. I will say that there are different types such as ELV's, HLV's, and RLV's.

First we need to know what we need and are we going for exploration and or colonization. Then we can see who has the hardware or can develop what will be needed. This is not a one nation or private organization concept. It will take team work. Different nations and different private organizations want to benefit from one or more of these locations. They each share some of the same needs while each has it's own needs too.

The foundation to all this is the gateway stations and the in space vehicles that can deliver crew and cargo to and from these gateway stations. I believe it will be easier for multiple nations and organizations to use the gateway system much like international airports than to go it alone.

This is coming from thread:
NASA Exploration Destinations, Goals, International Collaboration - Aug 28, 2012 
http://forum.nasaspaceflight.com/index.php?topic=29918.msg962838#msg962838
And should be reply #119 by clongton followed by three post of my own.

Edit:
This is not about were the funds would come from or policies.
It is about the hardware and how it can be used.

Links to articles:
http://www.nasaspaceflight.com/tag/gateway/
http://www.nasaspaceflight.com/2012/03/dsh-module-concepts-outlined-beo-exploration/
« Last Edit: 10/18/2012 06:47 pm by RocketmanUS »

Offline Robert Thompson

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imho My little feasible pony is to observe increased online/Internet fluency with respect to halo orbits, Lissajous orbits, lunar radio umbra at EML2, lunar far side science missions, and halo communications configurations. Crossing fingers for something like Wired.com to drop 'Lissajous'.

My big pony: If (since) Smaug hoards the treasure, send a droid that runs on diesel, pick a fight with the unknown, harvest war stories. Leave the very massive word "colonization", an elapsed integration of many small data points along multiple vectors occurring through emergent phenomena, to future historians. Don't lick the moon. Rather, show me the money. JWST budget says some photons are more equal than others. Start with those kinds of photons which the moon offers, or enables, and crowdsource, multination, or sell your grandmother if required, for Guffman is not coming. Meat upflux "strongly depends" on data downflux, and not vice versa. imho

Offline Andy DC

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Already many threads on this, but to help this one, here's Chris' collection of articles on it.

http://www.nasaspaceflight.com/tag/gateway/

Offline JohnFornaro

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imho My little feasible pony is ... Lissajous...

My big pony: ... Don't lick the moon. ... Meat upflux ...

Well okay then.  Why didn't you say so earlier?
Sometimes I just flat out don't get it.

Offline HappyMartian

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Where is the money coming from? Mars robot missions are going on a money diet. 

A robust human asteroid mission is not affordable, and you want to talk about Mars and beyond? OK? Forget L1 and L2. They do nothing but add costs for Lunar polar ISRU missions. 

Do Lunar propellant ISRU and you can reduce the costs of needed Earth launchers for asteroid and Mars missions. Hauling propellant out of the Lunar gravity well to a high Lunar orbit for an asteroid mission staging assembly location is a lot easier than hauling it in the Earths deep gravity well all the way to L2.

Low cost human and robotic Lunar ISRU missions are affordable. Going directly to the Moon also reduces radiation risks.



...
The key idea is that NASA's money is limited.
...
The article notes that the total Near-Earth Asteroid Human Space Exploration Architecture, using the Commercial Launch/Propellant Depots program costs, is around $83 billion dollars.

And, the total Near-Earth Asteroid the NASA Heavy Lift baseline program is about $122 billion dollars.

And, the Apollo program costs were about $120 billion dollars.


The article notes, "The black line in Fig. 12 represents the
available exploration budget based on several assumptions
like cancellation of the International Space Station program.
Based on current budget projections for NASA, a flat line
budget of $3B to $4B seems to be more realistic.
Even with the commercial launch/propellant depot
having 32 percent less cost, either the Near-Earth
Asteroid program needs to be scaled back or a less
aggressive program like lunar science and in-situ
resource development may be a better choice.
"

From: Evolved Human Space Exploration Architecture Using Commercial Launch/Propellant Depots  By Dr. Alan Wilhite, Dr. Dale Arney, Christopher Jones, and Patrick Chai
At: http://www.newspacewatch.com/docs/IAC-12.D3.2.3.x15379-NASAStudy.pdf
...


L1 and L2 are currently useless for what we can afford to do.


Cheers!

Edited.
« Last Edit: 10/18/2012 03:24 pm by HappyMartian »
"The Moon is the most accessible destination for realizing commercial, exploration and scientific objectives beyond low Earth orbit." - LEAG

Offline Robotbeat

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The opposite is true.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

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Offline RocketmanUS

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Comparing LEO and GEO departures to EML-2.

I think for a SEP OTV ( orbital transfer vehicle ) it would be easier for it to travel between GEO and EML-2 compared to LEO and EML-2. I was thinking along the lines a capsule could be sent to GEO, dock with the OTV and crew would transfer between the two vehicles.

For the crew capsule returning from GEO back to Earth, how does it compare from returning from LEO, velocity, time, ect? Would it be easier and cheaper to make a capsule that can go to GEO than EML-2?

So would it be better to go direct from LEO to EML-2 by capsule or LEO to GEO by capsule then to EML-2 by an OTV?

Getting to EML-1 and or EML-2 would be our main gateway that I believe will be needed. What one will be first, I don't know. I do think we will end up with both.

Where is the money coming from? Mars robot missions are going on a money diet.
{snip}
As this thread is not about who will fund it, to answer your question, I was thinking along something like an international airport. Many airline use it and they end up paying for it. Keep in mind we have a whole globe to work with both private and government. I want to take what is already in place and being planned on ( both private and government ) and use it to our advantages to use the gateway system to get more than just on type of BLEO program of the ground. I'm not asking for added funding, just use what we already have on the books in a more functional and cost effective way.

So back to the hardware and the placement of the gateways.

Offline neilh

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Where is the money coming from? Mars robot missions are going on a money diet.
{snip}

That's a good point. Most of the focus on the usefulness of depots has been for human missions, but would having depots in place allow for more cost-effective robotic missions to Mars and the outer planets?
Someone is wrong on the Internet.
http://xkcd.com/386/

Offline RocketmanUS

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Where is the money coming from? Mars robot missions are going on a money diet.
{snip}

That's a good point. Most of the focus on the usefulness of depots has been for human missions, but would having depots in place allow for more cost-effective robotic missions to Mars and the outer planets?
That would be an assembly station in LEO and propellent depot with the use of RLV's. Such a station could be used as our LEO gateway to EML1/2. If there was a high increase in usage then a dedicated gateway to EML1/2 could be added. Our there is the option of having two of these stations at different inclinations.

Offline RanulfC

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Where is the money coming from? Mars robot missions are going on a money diet.
{snip}

That's a good point. Most of the focus on the usefulness of depots has been for human missions, but would having depots in place allow for more cost-effective robotic missions to Mars and the outer planets?
Yes by the same means/methods. More throw-weight and delta-V if you refuel before starting. Manned and unmanned could benifit, as long as the depot has the right propellant and the transfer equipement is compatible.

Of course that's "part" of the conflict generated by the idea of depots is which propellant and how they'd operate ;)

Randy
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

Offline A_M_Swallow

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Where is the money coming from? Mars robot missions are going on a money diet.
{snip}

That's a good point. Most of the focus on the usefulness of depots has been for human missions, but would having depots in place allow for more cost-effective robotic missions to Mars and the outer planets?

Working out how cost effective may be a complex question however it would allow heavier probes.

On another thread it was calculated that an Ariane 5 could send 7 tonnes to EML-2.  So by refuelling a 7 tonne dry weight probe can be sent to orbit Mars.

The 7 tonne includes docking hardware, refuelling hardware, thrusters, fuel tanks and RCS.  Transfer propellant, (Mars RCS propellant?) and Mars landing propellant could be refuelled at the EML-2 depot.

Offline RocketmanUS

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Where is the money coming from? Mars robot missions are going on a money diet.
{snip}

That's a good point. Most of the focus on the usefulness of depots has been for human missions, but would having depots in place allow for more cost-effective robotic missions to Mars and the outer planets?
Yes by the same means/methods. More throw-weight and delta-V if you refuel before starting. Manned and unmanned could benifit, as long as the depot has the right propellant and the transfer equipement is compatible.

Of course that's "part" of the conflict generated by the idea of depots is which propellant and how they'd operate ;)

Randy
The ACES based depot was to be globally compatible. So for all this to work it does need to be globally compatible.

Where is the money coming from? Mars robot missions are going on a money diet.
{snip}

That's a good point. Most of the focus on the usefulness of depots has been for human missions, but would having depots in place allow for more cost-effective robotic missions to Mars and the outer planets?

Working out how cost effective may be a complex question however it would allow heavier probes.

On another thread it was calculated that an Ariane 5 could send 7 tonnes to EML-2.  So by refuelling a 7 tonne dry weight probe can be sent to orbit Mars.

The 7 tonne includes docking hardware, refuelling hardware, thrusters, fuel tanks and RCS.  Transfer propellant, (Mars RCS propellant?) and Mars landing propellant could be refuelled at the EML-2 depot.

We will need to send hardware to Mars before crew. The cargo's EDS  ( launchers US ) could be refuel in LEO. Or in the future if and when there is a reusable lander for Mars, the cargo could go throw the gateway system.

Offline RanulfC

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The ACES based depot was to be globally compatible. So for all this to work it does need to be globally compatible.
Agreed, but there are going to have to be "secondary" systems too. A lot of RCS systems still use hypergolics propellants and that's probably not going to change greatly for a while.

For an unmanned mission the 9-day low-delta-V transfer orbit to L2 followed by a refueling makes the full US-Delta-V available for transfer trajectory or payload mass.

Speaking of ACES in general (and the RL-10 in particular) anyone have an idea of what is replacing the RL-10 and Centaur now that the RL-10 is no longer going to be produced?

Where is the money coming from? Mars robot missions are going on a money diet.
{snip}

That's a good point. Most of the focus on the usefulness of depots has been for human missions, but would having depots in place allow for more cost-effective robotic missions to Mars and the outer planets?

Working out how cost effective may be a complex question however it would allow heavier probes.

On another thread it was calculated that an Ariane 5 could send 7 tonnes to EML-2.  So by refuelling a 7 tonne dry weight probe can be sent to orbit Mars.

The 7 tonne includes docking hardware, refuelling hardware, thrusters, fuel tanks and RCS.  Transfer propellant, (Mars RCS propellant?) and Mars landing propellant could be refuelled at the EML-2 depot.

We will need to send hardware to Mars before crew. The cargo's EDS  ( launchers US ) could be refuel in LEO. Or in the future if and when there is a reusable lander for Mars, the cargo could go throw the gateway system.
[/quote]
Part of the "fun" here is that with the gateway assuming a refueling capability we can "throw" the EDS/payload on a low-delta-V trajectory to the gateway, refuel the EDS and have a lot more delta-V available which in and of itself opens a lot of possible missions and operations that are not available now. It also makes a lot of missions less "time-constrained" if you can pre-position them.

There is also the possiblity of reducing the propellant loading of the US to allow more payload mass if you have the means to refuel in LEO and then again at L2.

Randy
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

Offline neilh

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Do Lunar propellant ISRU and you can reduce the costs of needed Earth launchers for asteroid and Mars missions. Hauling propellant out of the Lunar gravity well to a high Lunar orbit for an asteroid mission staging assembly location is a lot easier than hauling it in the Earths deep gravity well all the way to L2.
...
L1 and L2 are currently useless for what we can afford to do.

FYI delta-v between low lunar orbit and EML2 is just 0.64 km/s (compared to, say, 4.04 km/s to go from LEO to low lunar orbit).
« Last Edit: 10/18/2012 11:48 pm by neilh »
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Offline Robotbeat

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The delta-v between high lunar orbit and EML1 or EML2 is very, very small.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

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Offline neilh

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The delta-v between high lunar orbit and EML1 or EML2 is very, very small.

I was actually attempting to look it up online but couldn't find it...
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http://xkcd.com/386/

Offline Robotbeat

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...Hauling propellant out of the Lunar gravity well to a high Lunar orbit for an asteroid mission staging assembly location is a lot easier than hauling it in the Earths deep gravity well all the way to L2. ...
Just what sort of high lunar orbit should we use? How about lunar-synchronous orbit? ;)

(That's a trick question.  ;D)
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline neilh

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...
The key idea is that NASA's money is limited.
...
The article notes that the total Near-Earth Asteroid Human Space Exploration Architecture, using the Commercial Launch/Propellant Depots program costs, is around $83 billion dollars.

And, the total Near-Earth Asteroid the NASA Heavy Lift baseline program is about $122 billion dollars.

And, the Apollo program costs were about $120 billion dollars.


The article notes, "The black line in Fig. 12 represents the
available exploration budget based on several assumptions
like cancellation of the International Space Station program.
Based on current budget projections for NASA, a flat line
budget of $3B to $4B seems to be more realistic.
Even with the commercial launch/propellant depot
having 32 percent less cost, either the Near-Earth
Asteroid program needs to be scaled back or a less
aggressive program like lunar science and in-situ
resource development may be a better choice.
"

From: Evolved Human Space Exploration Architecture Using Commercial Launch/Propellant Depots  By Dr. Alan Wilhite, Dr. Dale Arney, Christopher Jones, and Patrick Chai
At: http://www.newspacewatch.com/docs/IAC-12.D3.2.3.x15379-NASAStudy.pdf
...


L1 and L2 are currently useless for what we can afford to do.

I read through the paper again and I believe you misunderstood the passage you keep on citing. The passage isn't describing (presumably robotic) lunar science and ISRU as alternatives to establishing depot(s) at EML2, but rather as alternative activities that you can use an EML2 depot -for-.
« Last Edit: 10/18/2012 11:57 pm by neilh »
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Offline Robotbeat

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The delta-v between high lunar orbit and EML1 or EML2 is very, very small.

I was actually attempting to look it up online but couldn't find it...
That's because "high lunar orbit" is ill-defined.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

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Offline HappyMartian

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...
The key idea is that NASA's money is limited.
...
The article notes that the total Near-Earth Asteroid Human Space Exploration Architecture, using the Commercial Launch/Propellant Depots program costs, is around $83 billion dollars.

And, the total Near-Earth Asteroid the NASA Heavy Lift baseline program is about $122 billion dollars.

And, the Apollo program costs were about $120 billion dollars.


The article notes, "The black line in Fig. 12 represents the
available exploration budget based on several assumptions
like cancellation of the International Space Station program.
Based on current budget projections for NASA, a flat line
budget of $3B to $4B seems to be more realistic.
Even with the commercial launch/propellant depot
having 32 percent less cost, either the Near-Earth
Asteroid program needs to be scaled back or a less
aggressive program like lunar science and in-situ
resource development may be a better choice.
"

From: Evolved Human Space Exploration Architecture Using Commercial Launch/Propellant Depots  By Dr. Alan Wilhite, Dr. Dale Arney, Christopher Jones, and Patrick Chai
At: http://www.newspacewatch.com/docs/IAC-12.D3.2.3.x15379-NASAStudy.pdf
...


L1 and L2 are currently useless for what we can afford to do.

I read through the paper again and I believe you misunderstood the passage you keep on citing. The passage isn't describing (presumably robotic) lunar science and ISRU as alternatives to establishing depot(s) at EML2, but rather as alternative activities that you can use an EML2 depot -for-.


Neil, L2 based Lunar missions cost more and add risk.

1. If you use the much vaunted low delta-v transfer EML1 can double the mission time from the Earth to the Moon compared to Apollo missions.

2. If you use the much vaunted low delta-v transfer it takes 8.83 days to get from Earth to EML2, and then another 3 days to get to Lunar surface. The minimum of a total 11.83 days or more of complex mission time before you can fire up your Lunar Lander's hydrolox rocket engines adds risk and significant hydrogen boil off issues.

3. To "solve" the hydrogen boil off issues, the L2 crowd goes with a much lower efficiency liquid methane and liquid oxygen propellant combination which drives up mission costs. Remember that every kilogram of unneeded weight you have to place on the Moon means you have to pay for 500 extra pounds of launcher mass on the Earth.

4. The Hydrolox RL10, not a methane/oxygen rocket engine, is the preferred propellant and rocket engine for the unknown asteroid mission described in that paper I cited because of its higher efficiency and lower costs, but for Moon missions the L2 crowd tries to sell the idea of using an unknown, yet to be built, and lower efficiency methane/oxygen rocket engine with zero flight history and unknown reliability.

5. Why saddle future Moon missions with a cost raising, inefficient methane/oxygen rocket engine architecture when the easiest propellants to make on the Lunar polar areas are liquid hydrogen and liquid oxygen?

6. Radiation exposure risks are much higher on the much vaunted low delta-v transfer L2 missions that last at least 11.83 days from Earth to the Lunar surface. And if the crew returns with the Lander to L2, then gets in the Orion and heads back to Earth for a minimum of 23.66 mission days in transit for a Lunar mission that doesn't include more than an hour or two on the Lunar surface.

7. If the Orion spacecraft is not used by the crew for the L2 to Lunar orbit and Lunar orbit to L2 portions of the mission, then the Lunar Lander is in reality a deep space vehicle and is going to be much heavier than needed because the crew cabin will need to be larger than it would be for a more direct Apollo style mission, and also the L2 based Lander would be heavier than is needed because it will need radiation shielding material equal to that on the Orion.

8. If the Orion is used by the crew for the Earth to L2 to Lunar orbit and Lunar orbit to L2 portions of the mission and then returns Earth while always using the much vaunted low delta-v transfers, then the L2 based missions would have a crew staying inside the Orion for a prohibitively long 23.66 mission days of transit duration, or longer, which clearly exceeds the designed Orion Mission capability of 21 days and thus makes claims about EML2 space station enabling low total delta-v transfers for L2 missions to the Moon as obvious nonsense.



Page 5
"EML2 located beyond the Moon
•
∼450000 km from the Earth
•
∼65000 km from the Moon

–No advantages as staging node and it complicates the system"


And, Page 20, "CONCLUSIONS

When considering the requirements of manned missions (fast trajectories, safety, etc.), a staging node at EML1,2 is not as favourableas other options (node in LLO)
–
EML1,2 offer
•
Lower orbit maintenance costs
•
Intrinsic global access and anytime return capability
•
Continuous communications with the Earth
–
But the total ΔV and mission duration are larger
–
3.8-4 km/s for the transfer from LEO to EML1
–
5-5.3 km/s for descending/ascending from the lunar surface
–
0.7 km/s for return from EML1 to direct Earth entry
–
Total Delta-V ∼10.5 km/s (compared to 9.7 km/s NASA ESAS)
–
Total mission duration is longer

Orbital stations at EML1,2 would be have more advantages for supporting also manned interplanetary missions (Mars) apart from lunar exploration"

From: TRAJECTORIES TO/FROM THE EARTH-MOON LAGRANGIAN POINTS L1 AND L2 FOR THE HUMAN EXPLORATION OF THE MOON 
By Raϊl Cadenas, Carlos Corral van Damme, Simone Centuori    EUROPEAN WORKSHOP ON SPACE MISSION ANALYSIS   December 10-12, 2007
ESA/ESOC, Darmstadt, Germany
Available at:



See also:
"Hardware and technologies from NASA’s Cryogenic Propulsive Stage (CPS):
• Cryogenic LOX/LH2 propellants will reduce mass compared to storable propellants
• Common propellants will allow designers to leverage propellant storage, propulsion, and pressurization technologies in order to reduce cost and improve reliability
• Subsystems including avionics, power, and passive thermal protection can be carried over directly from CPS to reduce cost and improve reliability"

And, "Combining an in-space stage with a single stage lander provides a fully reusable solution for lunar surface access from L2 when combined with in-space propellant loading"

And, "Potential paths for future study of the proposed lunar lander design include:
Evaluation of alternate orbital basing locations including Low Lunar Orbit, Earth-Moon L1, GEO, and other high Earth orbits

• Compare those alternate basing options with the E-M L2 option explored here"

From: Lunar Surface Access from Earth-Moon L2
At: http://www.sei.aero/eng/papers/uploads/archive/SEV-L2-Lander-Presentation_1Oct2012.pdf

Note on page 24 of that pdf, a hydrolox Lunar Lander is 3.6t lighter than a comparable methane based reusable lander doing the same mission


I added the bold.

"The Constellation Program thus combined the Lunar Orbit Rendezvous method which was used by Apollo with the Earth Orbit Rendezvous method."
From: Constellation program
At: http://en.wikipedia.org/wiki/Project_Constellation#cite_note-BBC_cancels_Moon_return-4

The Constellation Program wasn't perfect, but it didn't intentionally make the Orion astronauts fly long and complicated missions and take unneeded risks.
 
Do you want a heavier and more expensive methane/oxygen Lunar Lander L2 architecture with an unknown rocket engine in order to provide a political L2 fig leaf to NASA's 'no human Moon spaceflights policy' or do you want much lower radiation risk and less complicated direct flights to the Moon with an efficient and affordable ISRU hydrolox based reusable Lander architecture?


Cheers!
"The Moon is the most accessible destination for realizing commercial, exploration and scientific objectives beyond low Earth orbit." - LEAG

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