SpaceX for Moon Base

[sanman]

https://www.space.com/37549-elon-musk-moon-base-mars.html

"To really get the public real fired up, I think we've got to have a base on the moon," the billionaire founder and CEO of SpaceX said today (July 19) at the 2017 International Space Station Research and Development (ISSR&D) conference in Washington, D.C.

"Having some permanent presence on another heavenly body, which would be the kind of moon base, and then getting people to Mars and beyond — that's the continuance of the dream of Apollo that I think people are really looking for," Musk told NASA ISS program manager Kirk Shireman, who interviewed him onstage at the conference.

Now that Musk has called for a Moon base to be established as part of getting humanity off-world, how will this impact SpaceX's overall roadmap into the future? It seems the Red Dragon missions are being shelved, as well as propulsive landings for Dragon in general.

If the recent creation of the US National Space Council may be leading to new plans coalescing in relation to the Moon, then is SpaceX merely reactively realigning with the way the winds (and dollars) are blowing? To what extent is Mars rocket now morphing into Moon rocket for the nearer term?

Since going to the Moon offers a distinct set of challenges compared to going to Mars, what particular issues will SpaceX most have to get a handle on, and how will they have to adjust their technology development to meet the new mission requirements?

In what ways can a Moon base help with SpaceX's long-term goals of colonizing Mars?
By pursuing a lunar agenda in near term, how much farther out does this push the SpaceX timeline for Mars?

Could Musk/SpaceX treat us to a Moon-landing/Moon-base video, just to show us what their vision for the Moon looks like?

[meekGee]

How come this thread was not started by WannaMoonBase?

[guckyfan]

Let me be cynical about it. This is as much about rivalry Elon Musk vs. Jeff Bezos. Elon would not leave that market to Bezos uncontended.

Edit: Elon would not let this push out the Mars plans.

[saundby]

I think the interest is more in servicing a Moon base effort than building one. However, I think it could help fund the buildup of propellant depots and the use of craft that use those depots. It'll also let SpX do some trades on whether to have a space-based fleet and transfer payloads between craft in space or to refuel ground-launched craft in orbit for flight onward to the Moon.

[sanman]

My thought was that Musk/SpaceX is doing this in reaction to some new Moon-related development -- and this might possibly be the recently announced US National Space Council deciding to go in for a Moon base.  Presumably, Musk and his people have their ear to the ground, and would catch wind of something like this coming down the pipeline, and that this may have then prompted them to revise their plans somewhat to swim with the flow.

Plus, Musk is a numbers guy, and the investment risk is much lower for lunar than for Mars missions. Perhaps as ITS development progresses, it's becoming apparent that some things may be too great a leap/risk, and that it's better to take smaller steps. ("Gradatim Ferociter"?)

If NASA were to offer up contracts relating to Moon Base operations, then would SpaceX mainly be competing for launch contracts only, or would they perform further roles and develop custom purpose-built hardware for that?

[TaurusLittrow]

EM can see which way the cash cow (NASA) is headed and wants to get in front of the herd. I can easily see a COTS- and CCP-like arrangement for the DSG with SpaceX one of the providers. ITS, for whatever reason, is being downsized/modified, and part of its development cost could be underwritten by such contracts. Meanwhile, BO/Bezos seems interested in supplying a moon base (Blue Moon) and it will be interesting to see whether SpaceX responds with proposals of their own.

[francesco nicoli]

Musk is a dreamer.
But he is a rational dreamer wh heads a company. Companies need revenue streams to survive; even more so, when their prime contractor is the Government.
Government is abandoning Mars plans, which we all know they were never completely engaged with. They had no rocket, no ship, no landing gear, no habitats, and no money to develop all that. Thus, Nasa is shifting to the Moon which seems to be a more realistic attempt to turn the tide and not corroborate the impression that the post-2008 era has been a complete failure; Trump is shifting to the moon because this gives him a realistic political payoff in possibly reasonable times. Musk is switching to the Moon because contract money is going there. And even if his ultimate goal remains Mars, he needs contract money to develop his Mars plans.
In sum: my generation may yet see a Mars landing in our lifetime, but I am born in 1988 so Im kinda new to the business. The "old" (experienced) folk here most likely won't. Personally I am fine with it, for any NASA Mars Mission was at risk of being an overly expensive flag&footprint exercise & nothing else, while a moon base is by definition more than that.

[TaurusLittrow]

Musk is a dreamer.
But he is a rational dreamer wh heads a company. Companies need revenue streams to survive; even more so, when their prime contractor is the Government.
Government is abandoning Mars plans, which we all know they were never completely engaged with. They had no rocket, no ship, no landing gear, no habitats, and no money to develop all that. Thus, Nasa is shifting to the Moon which seems to be a more realistic attempt to turn the tide and not corroborate the impression that the post-2008 era has been a complete failure; Trump is shifting to the moon because this gives him a realistic political payoff in possibly reasonable times. Musk is switching to the Moon because contract money is going there. And even if his ultimate goal remains Mars, he needs contract money to develop his Mars plans.
In sum: my generation may yet see a Mars landing in our lifetime, but I am born in 1988 so Im kinda new to the business. The "old" (experienced) folk here most likely won't. Personally I am fine with it, for any NASA Mars Mission was at risk of being an overly expensive flag&footprint exercise & nothing else, while a moon base is by definition more than that.

I think there's a fighting chance that aging baby boomers, ahem, may yet see human missions to the Mars "system" if not surface. Another reason to lay off the booze and fried food.

[clongton]

Since going to the Moon offers a distinct set of challenges compared to going to Mars, what particular issues will SpaceX most have to get a handle on, and how will they have to adjust their technology development to meet the new mission requirements?

I said in a different thread that while propulsive landing for Dragon 2 was being dropped that SpaceX propulsive landing development was not going away any time soon. And this is why.

The only way down to the lunar surface is propulsive landing. No atmosphere means no aero-capture and no parachutes. So all of the ITS-based landing profiles are out the window when we are talking about the moon. Landing will be done propulsively, just like the LM. SpaceX will have to continue development and perfection of propulsive landing. Dragon 2 may not use it but SpaceX will.

[eric z]

  With some great exceptions, it has been relatively lonely here being a MoonMan- now that Mr. Musk has signaled his interest we will have lots of company. Now is time for everyone to come together w/o delay on a unified strategy, and lobby the appropriators and administrations inevitably involved to get off their behinds and get rolling already!

[clongton]

I have always been a moon-first guy and unashamedly stated it many times on this forum.

We have an entire world right next door just begging to be exploited and developed and we are ignoring it.
Mars, to me, while exciting to consider has always been a leap too far except in the most limited form of boots and flags missions. In my view, bringing Mars into the human fold should be attempted only after we have been comfortably living and working on the moon for decades and exploiting its resources in a meaningful way that enables human expansion out into the solar system. Resources for beginning and sustaining human settlement of the Martian surface until it becomes self-sustaining should be sourced from the moon, not climbing out of earth's deep gravity well. Any attempt to do it without lunar resources is, in my view, extremely short-sighted and wasteful, and quite possibly doomed to failure because of the lack of sustainability. Both EML-1 and EML-2 are half way to anyplace in the solar system. Both locations are just a short hop from the lunar surface but may as well be half way to Jupiter if one is starting from the terrestrial surface.

Go to the moon first. Settle it. Develop it. Use it for what it is - Earth's stepping stone into the rest of the solar system.

[guckyfan]

Go to the moon first. Settle it. Develop it. Use it for what it is - Earth's stepping stone into the rest of the solar system.

I wish people would not say that. Moon is an interesting destination in itself. So go there, settle it, develop it.

A stepping stone it is not.

[JamesH65]

Go to the moon first. Settle it. Develop it. Use it for what it is - Earth's stepping stone into the rest of the solar system.

I wish people would not say that. Moon is an interesting destination in itself. So go there, settle it, develop it.

A stepping stone it is not.

I suppose it could be a stepping stone to other airless bodies in the solar system, since tech developed for the moon would be applicable to those sorts of places.

Whether other airless bodies are worthwhile is another question - I suspect some asteroids may well be.

[AncientU]

Let's go somewhere.

[blasphemer]

I wish people would not say that. Moon is an interesting destination in itself. So go there, settle it, develop it.

A stepping stone it is not.

A stepping stone in terms of technology. Things like closed loop life support systems, propellant depots, some ISRU and radiation shielding can be to a large degree perfected in cislunar space. These technologies will be a basic requirement not just for Mars, but everywhere.

But I agree that Moon is a worthy goal in itself. I would even say that either there will be a Moonbase and a Mars base, or there wont be any Mars base at all. It is hard to realistically imagine going straight for Mars, IMHO.



I want to see humanity get out there as soon as possible. Thats why Moon > Mars, mini-ITS > ITS and nothing > Red Dragon. All of these recent developments simplify the goal and thus bring us CLOSER to finally having some deep space presence. Then we can go from there, but 50 years stuck in LEO is more than enough!

[Nilof]

If you are developing a rapidly reusable SHLV, colonizing the moon makes a lot of sense, simply because you can build a large colony very quickly.

An MCT can be expected to make one trip to Mars per synod at the very most, more likely one every two synods. That translates to just 10-15 reuses of the expensive spacecraft over three decades. By comparison, the same spacecraft could do >1000 trips to cislunar space over a similar period, assuming that the supporting tankers can launch a couple times a week. The difference in cargo capacity per unit time is roughly two orders of magnitude.

As a general rule, the larger the scale of your space colonization project is, the more attractive the moon becomes. Afaik, the ITS has a launch capacity an order of magnitude or two higher than what O'Neill envisaged for lunar colonization in the high frontier.

[meberbs]

Any attempt to do it without lunar resources is, in my view, extremely short-sighted and wasteful, and quite possibly doomed to failure because of the lack of sustainability.

I agree with your points, and a permanent presence on the moon just makes sense as the next step. I don't think however that this part of your statement matches Musk's perspective. When BFR goes to Mars, it will probably be a straight from Earth situation, and Musk won't be waiting for lunar development to be far enough along to provide support. Musk just wants others to go to the moon so he can get revenue while testing the system there.

It seems to me that he was reducing the scale of BFR anyway for economic reasons (development costs, more economical for satellite and constellation deployment). The political wind shifting back to the moon may be part of it, but I think he would be promoting this anyway right now. His goal is to improve the economics of BFR development. If NASA gets together with ESA/maybe others, and starts on a moon base, Musk can get some development funding for BFR from them while marketing it as a Lunar COTS system. It doesn't seem likely he would be able to do the same with Mars, at least for the moon "NASA has done that before."

I don't think Musk is really being deceptive though "To really get the public real fired up, I think we've got to have a base on the moon," seems like a true statement to me and I'm betting he believes it too, he just thinks it will be even more awesome when he lands people on Mars. I think the timing will be interesting, Musk probably will try to send BFR to Mars in 2022 (he may say 2020 at first, but that is too unrealistic for me to consider), and I'd say would have a good chance at it by 2024 (unmanned). On the other hand if NASA does start on a moon base, it would be impressive for them to be placing the first modules on the moon by 2024. Even the current plan for the DSG would barely be started assembly.

[MATTBLAK]

If you can live on the Moon successfully; you could probably live nearly anywhere in the Solar System. The Moon is a useful analogue for living most places in the Solar System - with the likely exception of Titan. One could make glib comparisons between the Moon and Mars - that they are both vast, dry, airless deserts. Well; virtually airless, if you're Mars. But Mars has about twice the gravity of the Moon, a thousand times or so more atmosphere, a lot more water, milder extremes of temperature and a lot more surface area. Not to mention a day/night period about 24 hours long, not 672 hours.

Nonetheless; Mars is still a lot closer to the Moon in format than Triton, Enceladus or Europa etc. Only Mercury really compares to the Moon - but it's almost unreachable in the deep gravity well of the Sun, so we can discount any manned visits in our lifetimes. Yes; the Moon is not a literal stepping stone - I've had to explain this to several laymen recently who asked me earnest questions on the subject. For example; it's unlikely there is enough water at the poles to devote to making lots of rocket fuel for further sojourns into the Solar System. I think the best use of lunar water is for Outpost or Base inhabitants.

But it is a metaphorical stepping stone in a lessons-learned, meta-application way for what comes next. In-situ resource utilization for oxygen, water, materials for construction and 3D-printing, radiation shielding, dust-mitigation, system overhaul and 'bootstrapping', improvisation, sheer operations experience... The way that Apollo, the Salyuts, Skylab, Spacelab, Mir, ISS and Tiangong have all made a knowledge base for space operations to come. And another less-easily quantifiable metric has been spawned.

Inspiration.

A Lunar Outpost or Base is not easy - it will be hard. And in the past, we have done things not because they are easy; but because they are hard. Choose and mix your metaphors at will and as appropriate. We are not ready for Mars just yet. We are still in 'short pants'. We're simply not ready for the 'big boy pants' of Mars just yet.

[wannamoonbase]

How come this thread was not started by WannaMoonBase?

I was busy and had limited time yesterday.  I was looking to see if a thread like this was started already.

I'm really excited by EM's public openness to going to the moon first.

As others said above 'Go somewhere'.  Mars is exciting but the moon is close, frequent launch windows.

Let's go there, and use the soil to make oxygen for rockets and metals for 3D printers!

Edit: EM is going to built the Mother of all Rockets, he is going to need paying customers with large payloads.

[clongton]

A stepping stone it is not.

A stepping stone in terms of architecture. Interplanetary transportation imo and with few exceptions should not begin and end on the earth's surface. We simply *cannot* be constantly lifting everything up that very steep and deep gravity well, and then trying to bring everything back through a very destructive atmosphere. That puts SEVERE design constraints on the spacecraft, making it inefficient in each environment to some degree. Transportation between interplanetary bodies should be done with spacecraft designed from the beginning to operate efficiently in the vacuum of interplanetary space. Transportation down to and up from a planetary surface should be done in spacecraft that are specifically designed for the purpose of landing on a planetary or satellite surface, which is *very* different from the design requirements for transport between interplanetary bodies.

The Apollo Command Module could not, for all practical purposes, be designed to traverse to and land on the moon (although literally dozens of designs to do just that were developed and discarded) and the LM could not be designed to return to the earth's surface thru the atmosphere. We are dealing with 2 very, very different environments and the spacecraft designed to operate in them must, of necessity, be specifically designed for those environments. Interplanetary spacecraft should not ever have to depart from and land on a surface (ITS is the wrong approach - heresy I know but there it is). And landers should not ever have to traverse interplanetary space as the working spacecraft.

Everybody wants to go somewhere right now - especially after spending decades going round and round and round. We are ALL impatient (including me). However all these worlds have been around for a very long time and they are not going anywhere else anytime soon. Rushing things just to get it done, no matter how exciting that may be, is not the right thing to do. Plan the work and then work the plan. Take the long view. What is the most efficient (not quickest) way to spread humanity into the solar system? What is the most sustainable way to spread humanity into the solar system? Taking shortcuts and getting it done (relatively) fast is certain to doom the entire effort to failure. We need to take our time and do it right the first time.

So yes, the moon IS a stepping stone. It needs to be the HUB of interplanetary travel. It needs to be the departure and return point for interplanetary travel. It needs to be the source for provisioning and outfitting interplanetary spacecraft. It needs to be the source for provisioning and supplying fledgling planetary bases and settlements. We don't need just a few bases on the moon. We need cities on the moon. It's not a stop-over place. It is an entire world just begging to be settled, exploited, developed and used. Just because it's hard is not a reason not to do it. If we cannot do this on the moon then we have absolutely no business going anywhere else to try it.

[MATTBLAK]

This is why I think the Deep Space Gateway - or at least the similar concept of it in some sort of very high lunar orbit - could really be the main arrival and departure point for most of the rest of the Solar System. I'm with Chuck on that point. Landing on and placing Outpost(s) on the Moon should be a goal in of itself - not necessarily climbing in and out of the Moon's gravity well continuously. This is why I think a 'jumping-off' point of a Space Gateway or Propellant Depot/Farm could be pretty useful.

[TrevorMonty]

If a moonbase is going to be anymore than 6 people in government funded outpost, the moon will need to pay its way. Tourism might allow for few more permanents with regular visitors but 100s is going to need an export industry.
Selling water or rocket fuel to other government funded activities is also very limited market that can be met robotically.

I'm all for moonbases or mooncities just realist when it comes to economics. Up to now space exports have been limited to data (TV, communication, images, weather). High tech manufacturing is showing promise but even if successful may not make it out of LEO.

 Energy is a massive market that space can and needs to tap into.

[Darkseraph]

Expanding on the point about more frequent launch windows to the Moon, there are more benefits to this than economies of scale through more frequent reuse. SpaceX has a reputation for quickly iterating designs, even after accidents. Mars does not allow you iterate rapidly due to infrequent launch windows. If a mission fails or underperforms, it could take years before that technology can be attempted again with design fixes or upgrades.

The following can potentially be tested and iterated on the Moon more rapidly:

1. Methods to detect, extract and process water-ice from regolith.
2. Propellant production
3. Navigation and landing on rough terrain without the aid of GPS.
4. Tunnel Boring in a near-vacuum enviroment.
5. Autonomous retrieval of large space vehicles from uninhabited bodies.
6. Space suits and pressurized electrical vehicles.
7. Logistics of setting up a settlement on Mars in a similar environment.
8. Detection of subsurface voids (lava tunnels) and their entrances.

Obviously some techniques cannot be tested on the Moon that involve use of an atmosphere for EDL or propellant production. 

[wannamoonbase]

I think it's important to point out that for some people they think of going back to the moon or on to Mars in the Apollo Sorte style. 

I think a return needs to concentrate resources and build up capability in a single area.  Once something is established then you can roam and expand.

A huge advantage of the moon is being able to tele-operate equipment from earth.  There would be a significant build up and placement of resources before a human foot hits the surface.

[clongton]

A huge advantage of the moon is being able to tele-operate equipment from earth.  There would be a significant build up and placement of resources before a human foot hits the surface.

The time lag of Earth/Moon is 1.3 seconds - just long enough to be aggravating for teleoperations. I would suggest that the Space Gateway station be placed at EML-2 with a communications array at EML-1. Part of the crew function at the Gateway would be global teleoperation control of robotic activities on the surface in advance of human habitation. That does not necessarily preclude human sorties on the surface in the mean time. But at least in the beginning human stay time on the surface will be limited, while properly planned robotic operations can be monitored and controlled 24/7 from the Gateway Station at EML-2. As required human intervention on the surface can supplement/enable the continuing robotic operations from a nearby location (EML-2).

[savuporo]

The time lag of Earth/Moon is 1.3 seconds - just long enough to be aggravating for teleoperations.

There is nothing aggravating about 1.3 seconds of command lag. Predator drones have more than that, and Lunokhod did just fine with 40 y old tech

[Kansan52]

Moon Base
Rail gun launcher
L5 Habitat
Rest of the System

[blasphemer]

Isnt time lag actually the round trip time? Thats what is needed to actually see a response to a command. So time lag for Moon teleoperations is 2.6 seconds.

[punder]

I read Musk's comments with great relief. The Moon is something we can do soon, even, if it comes to it, with existing or near-term launch vehicles. But certainly there are many political monkey wrenches waiting to be thrown.

Besides water ice, the poles are the only places on the Moon where sunlight is available without interruption. Put up a tall mast and hang the arrays on it like sails, with a motor in the base to rotate the arrays continuously at 1rpM (1 revolution per Month, ha!). In 1/6 g and vacuum, the structure can be very lightweight. A really big array might be a circular arrangement of solar panels on the surface, with a 1rpM 45-degree mirror situated above. Again, at low g and with no wind, the mirror structure could be relatively insubstantial--something like beefed-up SpiderFab, with aluminized Mylar for the mirror. Like a giant ladies' compact sitting halfway open on the ground, turning like a slow-motion sunflower. My, what a lovely image.       

[AncientU]

A stepping stone it is not.

...
Everybody wants to go somewhere right now - especially after spending decades going round and round and round. We are ALL impatient (including me). However all these worlds have been around for a very long time and they are not going anywhere else anytime soon. Rushing things just to get it done, no matter how exciting that may be, is not the right thing to do. Plan the work and then work the plan. Take the long view. What is the most efficient (not quickest) way to spread humanity into the solar system? What is the most sustainable way to spread humanity into the solar system? Taking shortcuts and getting it done (relatively) fast is certain to doom the entire effort to failure. We need to take our time and do it right the first time.

...

emphasis mine

Appreciate you spending time to detail your thoughts... I'm sure they've had sufficient gestation over the last few decades!

One note:  This is the second time.  We won a race (a sprint, not a marathon) and neglected the long view -- and we are, or were, setting ourselves up to do that again at Mars.  Let's not...

[CuddlyRocket]

Besides water ice, the poles are the only places on the Moon where sunlight is available without interruption. Put up a tall mast and hang the arrays on it like sails, with a motor in the base to rotate the arrays continuously at 1rpM (1 revolution per Month, ha!). In 1/6 g and vacuum, the structure can be very lightweight. A really big array might be a circular arrangement of solar panels on the surface, with a 1rpM 45-degree mirror situated above.

It's probably cheaper, quicker and more reliable (no motors) to simply take up more solar cells. You can lie them on the ground and use local slopes to even things up through the lunar solar day.

[Phil Stooke]

A vertical cylinder works well too, always half illuminated whatever the solar azimuth is, and no need for motors etc.

[Phil Stooke]

"Isnt time lag actually the round trip time? Thats what is needed to actually see a response to a command. So time lag for Moon teleoperations is 2.6 seconds."

Yes... and 2.6 seconds didn't noticeably mess up Apollo communications.

[oiorionsbelt]

Besides water ice, the poles are the only places on the Moon where sunlight is available without interruption. Put up a tall mast and hang the arrays on it like sails, with a motor in the base to rotate the arrays continuously at 1rpM (1 revolution per Month, ha!). In 1/6 g and vacuum, the structure can be very lightweight. A really big array might be a circular arrangement of solar panels on the surface, with a 1rpM 45-degree mirror situated above.

It's probably cheaper, quicker and more reliable (no motors) to simply take up more solar cells. You can lie them on the ground and use local slopes to even things up through the lunar solar day.

Shackelton crater

[RocketmanUS]

https://www.space.com/37549-elon-musk-moon-base-mars.html

"To really get the public real fired up, I think we've got to have a base on the moon," the billionaire founder and CEO of SpaceX said today (July 19) at the 2017 International Space Station Research and Development (ISSR&D) conference in Washington, D.C.

"Having some permanent presence on another heavenly body, which would be the kind of moon base, and then getting people to Mars and beyond — that's the continuance of the dream of Apollo that I think people are really looking for," Musk told NASA ISS program manager Kirk Shireman, who interviewed him onstage at the conference.

Now that Musk has called for a Moon base to be established as part of getting humanity off-world, how will this impact SpaceX's overall roadmap into the future? It seems the Red Dragon missions are being shelved, as well as propulsive landings for Dragon in general.

If the recent creation of the US National Space Council may be leading to new plans coalescing in relation to the Moon, then is SpaceX merely reactively realigning with the way the winds (and dollars) are blowing? To what extent is Mars rocket now morphing into Moon rocket for the nearer term?

Since going to the Moon offers a distinct set of challenges compared to going to Mars, what particular issues will SpaceX most have to get a handle on, and how will they have to adjust their technology development to meet the new mission requirements?

In what ways can a Moon base help with SpaceX's long-term goals of colonizing Mars?
By pursuing a lunar agenda in near term, how much farther out does this push the SpaceX timeline for Mars?

Could Musk/SpaceX treat us to a Moon-landing/Moon-base video, just to show us what their vision for the Moon looks like?

Same launch vehicle can be used for either Lunar or Mars.

F9 could be used for Lunar with horizontal lander and in-space refueling for both lander and crew capsule.

https://forum.nasaspaceflight.com/index.php?topic=41682.0
ITS could be used for the moon or the smaller version we may see.

ITS would be better to test land on the moon first. However with ITS both Lunar and or Mars could be possible exploration and base missions. I see ITS still being developed just a smaller version than was presented last year. A flexible path forward without having to choose between the two from who ever may fund the launcher and possible missions.

[octavo]

Here's some pure speculation: The early destruction of the giant carbon fibre test tank, the unexpected complexity of FH, and Amos 6 have all helped to convince Musk that the IAC ITS is too ambitious, even for him. I think the smaller BFR, perhaps with lined tanks is the result.

We should also remember that Musk more and more, rubs shoulders with the political elite and probably has good reasons to punt the idea of milestone based competitive contracting and the Moon in 2* talks in as many weeks.

*When he spoke to the Governors he didn't specifically talk about a moon base, but he did deliberately reference Apollo

[guckyfan]

Since going to the Moon offers a distinct set of challenges compared to going to Mars, what particular issues will SpaceX most have to get a handle on, and how will they have to adjust their technology development to meet the new mission requirements?

It seems to land significant payload on the moon without surface propellant production they will need a tanker to LLO. So they need to make sure a tanker can survive LLO and earth return.

Otherwise not that much adjustment, I believe. They can land on the moon and drop cargo in a time of the lunar cycle that supports ITS thermal capability as it is. They won't develop any ground infrastructure IMO. They will leave that to others, just be the transport company. Unlike Mars where ITS will have the role of habitat for the first landing.

[KelvinZero]

Has anyone referenced Elon Musk's old moon comments? Im not sure how to find them, but I remember there were very old comments that a moon base would probably appear before a mars one. I see this not so much as a new direction as something he chose not to talk about for a while.

[Pipcard]

With all the talk of using lunar resources, what does that mean for hydrolox (if LCROSS turned out to be wrong about the apparent presence of carbon on the Moon), which SpaceX abandoned in favor of methane because of hydrolox's "PITA factor?"

[blasphemer]

In the long term, an aluminium oxygen rocket could make a lot of sense for the Moon. Both elements are very abundant on the Moon. Specific impulse is in low 200s but it this ought to be enough for a reusable lander since only 2.5 km/s is needed to get from the Moon to L1 or back.

Developing such Al-LOX reusable lander could be a worthwhile thing for NASA to do, while commercial space takes care of other things.

[guckyfan]

Has anyone referenced Elon Musk's old moon comments? Im not sure how to find them, but I remember there were very old comments that a moon base would probably appear before a mars one. I see this not so much as a new direction as something he chose not to talk about for a while.

I only remember a remark or two like We may go to the moon as well, just to demonstrate we can. But most people have interpreted that as Dragon around the moon at the time.

[AncientU]

With all the talk of using lunar resources, what does that mean for hydrolox (if LCROSS turned out to be wrong about the apparent presence of carbon on the Moon), which SpaceX abandoned in favor of methane because of hydrolox's "PITA factor?"

Fuel production should not be as mush of a necessity in Cis-Lunar operations as it is for Mars.  A reusable BFR with routine refueling trips to LEO can also be used do distribute fuel to Lunar vicinity.  ACES white paper described the utility of this approach with only 20 tonne deliveries to LEO, probably assuming a few $1,000k per tonne.  At a fraction of this cost, making fuel on the Lunar surface won't be first order of business.  Water extraction should help support initial outposts, and eventually may be for bulk fuel production.

Habs, power, mobility, communications (broadband everywhere, including things) will be initial infrastructure.  Water maybe next... for consumption; agriculture and fuel production later.

Hopefully initial outposts (plural is important here) will be expeditionary in nature -- from which large regions will be explored and prospected.  Travelers there should be very active and mobile, not just hunker down and stay alive.

[AncientU]

Has anyone referenced Elon Musk's old moon comments? Im not sure how to find them, but I remember there were very old comments that a moon base would probably appear before a mars one. I see this not so much as a new direction as something he chose not to talk about for a while.

I only remember a remark or two like We may go to the moon as well, just to demonstrate we can. But most people have interpreted that as Dragon around the moon at the time.

The old discussion also included 'demonstrating the technology' or some such phraseology... implied landing IIRC.

[octavo]

Water extraction should help support initial outposts, and eventually may be for bulk fuel production.

Are there any good estimates for just how much *easily* extractable water ice there is on the moon?

[su27k]

Has anyone referenced Elon Musk's old moon comments? Im not sure how to find them, but I remember there were very old comments that a moon base would probably appear before a mars one. I see this not so much as a new direction as something he chose not to talk about for a while.

You can search it at shitelonsays.com:

http://shitelonsays.com/transcript/elon-musk-at-mits-aeroastro-centennial-part-2-of-6-2014-10-24

I don't think the Moon is a necessary step, but I think if you've got a rocket and spacecraft capable of going to Mars, you might as well go to the Moon as well - it's along the way. That's like crossing the English Channel, relative to Mars. So, it's like, if you have these ships that could cross the Atlantic, would you cross the English Channel? Probably. It's definitely not necessary, but you'd probably end up having a Moon base just because, like, why not, ya know.

[GORDAP]

Since going to the Moon offers a distinct set of challenges compared to going to Mars, what particular issues will SpaceX most have to get a handle on, and how will they have to adjust their technology development to meet the new mission requirements?

It seems to land significant payload on the moon without surface propellant production they will need a tanker to LLO. So they need to make sure a tanker can survive LLO and earth return.

Otherwise not that much adjustment, I believe. They can land on the moon and drop cargo in a time of the lunar cycle that supports ITS thermal capability as it is. They won't develop any ground infrastructure IMO. They will leave that to others, just be the transport company. Unlike Mars where ITS will have the role of habitat for the first landing.

I know producing methane on the Moon's surface is problematic, but is LOX?  I thought I'd read that LOX should be pretty straightforward using a solar furnace, yes?  If so, that makes me wonder if, since methalox propellants are 75% LOX by mass, would it be feasible to think of a mission/ship profile that land on the surface with enough residual methane in the tanks (but no LOX) for return?  And avoid a LLO tanker?  Does the math work for this?

[TrevorMonty]

Besides water ice, the poles are the only places on the Moon where sunlight is available without interruption. Put up a tall mast and hang the arrays on it like sails, with a motor in the base to rotate the arrays continuously at 1rpM (1 revolution per Month, ha!). In 1/6 g and vacuum, the structure can be very lightweight. A really big array might be a circular arrangement of solar panels on the surface, with a 1rpM 45-degree mirror situated above.

It's probably cheaper, quicker and more reliable (no motors) to simply take up more solar cells. You can lie them on the ground and use local slopes to even things up through the lunar solar day.

A lander with solar panel mast is self deploying and very mass efficient. The motor isn't going wearout at 1 revolution per month. Those individual panels scatter over slopes don't deploy themselves.

[guckyfan]

Refuelling with LOX only would work very well, LOX is most of the propellant mass. You would not have to land the ascent LOX. It requires a different tank size ratio, so a dedicated moon lander. I have seen reports on producing oxygen from SiO2, which is abundant all over the moon and does not require using precious water. Heating it to melting using a solar furnace and then splitting it through electrolysis. Leaves a Si residue which may become useful later. But it is still experimental.

[KelvinZero]

You can search it at shitelonsays.com:

http://shitelonsays.com/transcript/elon-musk-at-mits-aeroastro-centennial-part-2-of-6-2014-10-24

Ok, thanks. That isn't exactly the comment I remembered but very likely I just misremembered it. I couldn't find a better one.

The comment as I remember it was more clear about a moon base before a mars base, but less clear on whether it was SpaceX, government or international. To me the implication was he hoped he could get paid to do moon missions if he provided a very good deal, and this could provide some development costs for Mars.

[DOCinCT]

Has anyone referenced Elon Musk's old moon comments? Im not sure how to find them, but I remember there were very old comments that a moon base would probably appear before a mars one. I see this not so much as a new direction as something he chose not to talk about for a while.

3 years ago at the Dragon 2 reveal Elon said: "Long term we really want to get to the point where there can be thousands of spaceflights a year, and ultimately where we can have a base on the moon and a base on Mars and become a multi-planet species and true space-fairing civilization. So that's where things need to go in the long term."
Updated:
From a Forbes article in April 2012: "He intends to go to Mars. When I asked him if he was g0ing to stop off at the Moon first, he told me that it's not a priority. 'I’m okay with going to the moon, but we've seen that movie before and remakes are never as good. It would be more significant to have a base on the Moon, rather than just going back.' "
I haven't found anything earlier than 2012.

[cppetrie]

Totally in agreement with what he said. Landing just to land is largely pointless. We've done that before. Yes, it could help prove out some tech, etc., but it's still sort of lame from an advancing space flight perspective since it has been done already. Building a permanent base/settlement on the moon, however, is a whole different story. Provides the same development opportunities as landing and more. And it's closer and more accessible for rapid advancement and proving out the tech. The vast majority of the tech for creating permanent habitation of the moon is applicable to Mars. Plus it isn't just a repeat. It's a freaking moon base!! That's a vision of going to the moon I can definitely get behind.

[raketa]

Let me be cynical about it. This is as much about rivalry Elon Musk vs. Jeff Bezos. Elon would not leave that market to Bezos uncontended.

Edit: Elon would not let this push out the Mars plans.

This not about Bezos, but about the affordable path to Mars. SpaceX could have in 5 years BFS that could land on Moon and come back.
Bezos will be lucky to have in 5 years capsule on LEO.
It takes the time to finish it even if you have all money in the world.

[BretShooter]

I think the moon will be a good place to test and possibly build the tunneling machines they will eventually use on Mars.  If they could build it on the moon, they wouldn't have to haul it up the gravity well.  Of course, landing in on Mars would be another challenge!

[dorkmo]

would it be possible to dissasemble the ISS segments and land them one at a time on the moon?

[wannamoonbase]

Refuelling with LOX only would work very well, LOX is most of the propellant mass. You would not have to land the ascent LOX. It requires a different tank size ratio, so a dedicated moon lander. I have seen reports on producing oxygen from SiO2, which is abundant all over the moon and does not require using precious water. Heating it to melting using a solar furnace and then splitting it through electrolysis. Leaves a Si residue which may become useful later. But it is still experimental.

Exactly, LunOx (Lunar Oxygen) would be the first industry on the moon.  Only need decent LOx and then reload ascent on the surface.  The logical step would then be a tanker from the Lunar surface to carry LunOx to LLO.  Then use it to return to earth.  As well it could ultimately become worth shipping LunOx to LEO and refuel for the return trips to the moon or onto Mars.

Why climb out of the Earth's gravity well if you don't need too?

I daydream daily about having the money, or business sense, to set up a prize, lets call it the 'Moon Dirt Prize' to develop Lunar resources technology.  Prizes for demonstrating the technology to start and growing in prize value as you work to flight hardware.  Not just limited to oxygen, there are lots of things to do with silicon, iron and titanium on the surface.  Building habitats and storage tanks with 3D printers, just need the feed stocks.

Using scarce water on the moon for rocket fuel, is very short sighted in my opinion when there is so much oxygen in other forms on the surface.  Need that water for making beer and coffee!!

Eventually launching from the lunar surface would be done with electromagnetic propulsion further leveraging the production of lunar resources.  (And thankfully that is something that some hyperloop folks should have ready for when it's needed.)

[Ictogan]

Exactly, LunOx (Lunar Oxygen) would be the first industry on the moon.  Only need decent LOx and then reload ascent on the surface.  The logical step would then be a tanker from the Lunar surface to carry LunOx to LLO.  Then use it to return to earth.  As well it could ultimately become worth shipping LunOx to LEO and refuel for the return trips to the moon or onto Mars.

Why climb out of the Earth's gravity well if you don't need too?

Because each one way trip between LEO the Lunar surface takes about 5.5km/s of delta-V. When considering that the tanker would need twice that to get from lunar surface to LEO and back to the lunar surface again, this becomes 11km/s - a similar amount to what's needed to get from earth's surface to LEO and back to earth's surface(assuming reentry with a heatshield and propulsive landing).

Delivering earth oxygen to LEO would still be a lot easier.

[AncientU]

Exactly, LunOx (Lunar Oxygen) would be the first industry on the moon.  Only need decent LOx and then reload ascent on the surface.  The logical step would then be a tanker from the Lunar surface to carry LunOx to LLO.  Then use it to return to earth.  As well it could ultimately become worth shipping LunOx to LEO and refuel for the return trips to the moon or onto Mars.

Why climb out of the Earth's gravity well if you don't need too?

Because each one way trip between LEO the Lunar surface takes about 5.5km/s of delta-V. When considering that the tanker would need twice that to get from lunar surface to LEO and back to the lunar surface again, this becomes 11km/s - a similar amount to what's needed to get from earth's surface to LEO and back to earth's surface(assuming reentry with a heatshield and propulsive landing).

Delivering earth oxygen to LEO would still be a lot easier.

The basic delta-v requirements are well defined in the ACES paper... delivering propellant to EML-2 puts it on the gravity well cusp -- ready to depart for interplanetary destinations or drop to the Lunar surface.  Tankers never will travel to Lunar surface (in a sane world that can do the maths*).

* Which I wished I lived in...

[envy887]

Exactly, LunOx (Lunar Oxygen) would be the first industry on the moon.  Only need decent LOx and then reload ascent on the surface.  The logical step would then be a tanker from the Lunar surface to carry LunOx to LLO.  Then use it to return to earth.  As well it could ultimately become worth shipping LunOx to LEO and refuel for the return trips to the moon or onto Mars.

Why climb out of the Earth's gravity well if you don't need too?

Because each one way trip between LEO the Lunar surface takes about 5.5km/s of delta-V. When considering that the tanker would need twice that to get from lunar surface to LEO and back to the lunar surface again, this becomes 11km/s - a similar amount to what's needed to get from earth's surface to LEO and back to earth's surface(assuming reentry with a heatshield and propulsive landing).

Delivering earth oxygen to LEO would still be a lot easier.

The basic delta-v requirements are well defined in the ACES paper... delivering propellant to EML-2 puts it on the gravity well cusp -- ready to depart for interplanetary destinations or drop to the Lunar surface.  Tankers never will travel to Lunar surface (in a sane world that can do the maths*).

* Which I wished I lived in...

Once significant infrastructure exists on the Moon, carrying lunar oxygen from the lunar surface to EML1/2 makes sense. Those points are 15 km/s round trip from Earth and only 5 km/s round trip from the lunar surface. And they are the closest points in Earth's vicinity to other planets and asteroids, delta-v wise.

[mme]

Let me be cynical about it. This is as much about rivalry Elon Musk vs. Jeff Bezos. Elon would not leave that market to Bezos uncontended.

Edit: Elon would not let this push out the Mars plans.

I'm sure Musk and Bezos are super competitive and have huge egos. But I also think both are too smart to let that get in the way their goals which are similar, but different.

I believe Musk will go to the Moon if he believes it supports getting humans to Mars sooner (preferably in his lifetime.)  Whether that support is technical, financial, or political is not important. If Musk perceives the Moon as a diversion, we'll let Bezos have it.

Bezos is more laser focussed on the step by step development of technologies and capabilities and much less on the specific use of the technologies (AFAICT.)

I suspect SpaceX needs the money, not the glory of going to the Moon.

[AncientU]

Exactly, LunOx (Lunar Oxygen) would be the first industry on the moon.  Only need decent LOx and then reload ascent on the surface.  The logical step would then be a tanker from the Lunar surface to carry LunOx to LLO.  Then use it to return to earth.  As well it could ultimately become worth shipping LunOx to LEO and refuel for the return trips to the moon or onto Mars.

Why climb out of the Earth's gravity well if you don't need too?

Because each one way trip between LEO the Lunar surface takes about 5.5km/s of delta-V. When considering that the tanker would need twice that to get from lunar surface to LEO and back to the lunar surface again, this becomes 11km/s - a similar amount to what's needed to get from earth's surface to LEO and back to earth's surface(assuming reentry with a heatshield and propulsive landing).

Delivering earth oxygen to LEO would still be a lot easier.

The basic delta-v requirements are well defined in the ACES paper... delivering propellant to EML-2 puts it on the gravity well cusp -- ready to depart for interplanetary destinations or drop to the Lunar surface.  Tankers never will travel to Lunar surface (in a sane world that can do the maths*).

* Which I wished I lived in...

Once significant infrastructure exists on the Moon, carrying lunar oxygen from the lunar surface to EML1/2 makes sense. Those points are 15 km/s round trip from Earth and only 5 km/s round trip from the lunar surface. And they are the closest points in Earth's vicinity to other planets and asteroids, delta-v wise.

EML-1/2 are only 2.5 km/s from the Moon's surface, 13-14 from Earth, and 0.14 below C3.
A convenient table about half way down article:
https://en.wikipedia.org/wiki/Delta-v_budget

Edit: I just noticed you stated round trip... our numbers match.

[Ictogan]

Exactly, LunOx (Lunar Oxygen) would be the first industry on the moon.  Only need decent LOx and then reload ascent on the surface.  The logical step would then be a tanker from the Lunar surface to carry LunOx to LLO.  Then use it to return to earth.  As well it could ultimately become worth shipping LunOx to LEO and refuel for the return trips to the moon or onto Mars.

Why climb out of the Earth's gravity well if you don't need too?

Because each one way trip between LEO the Lunar surface takes about 5.5km/s of delta-V. When considering that the tanker would need twice that to get from lunar surface to LEO and back to the lunar surface again, this becomes 11km/s - a similar amount to what's needed to get from earth's surface to LEO and back to earth's surface(assuming reentry with a heatshield and propulsive landing).

Delivering earth oxygen to LEO would still be a lot easier.

The basic delta-v requirements are well defined in the ACES paper... delivering propellant to EML-2 puts it on the gravity well cusp -- ready to depart for interplanetary destinations or drop to the Lunar surface.  Tankers never will travel to Lunar surface (in a sane world that can do the maths*).

* Which I wished I lived in...

Meant that mostly as a point against shipping lunar oxy to LEO, not to EML-2. Should have pointed that out.

[clongton]

Earth-Moon Transportation: We need to turn all this thinking completely around. We need to source propellant and oxidizer totally from lunar materials. Transportation between the lunar surface and LEO should be in a vehicle that departs lunar surface, not LLO, with full tanks, arrives in LEO with enough propellant and oxidizer remaining for the return trip to the lunar surface, again not to LLO. We need to stop thinking of the lunar surface as the destination. It's not. Instead it is the beginning and ending of the journey. LEO is the destination, not the moon. It is a round trip from the moon to LEO and return to the moon. Thought of that way it completely changes the way we think about this. Earth is left completely out of the equation. That's how we need to design the Earth-Moon transportation system. ALWAYS *begin* the trip from the location with the smallest gravity well with completely full tanks. And return there with what's left after destination arrival; pushing less mass because of the expended propellant. Forget about climbing up out of earth's deep gravity well just to get to LEO. Leave that to the taxis.

The delta-v requirements are lunar surface to LEO and back again, begun with full tanks.

[AncientU]

Earth-Moon Transportation: We need to turn all this thinking completely around. We need to source propellant and oxidizer totally from lunar materials. Transportation between the lunar surface and LEO should be in a vehicle that departs lunar surface, not LLO, with full tanks, arrives in LEO with enough propellant and oxidizer remaining for the return trip to the lunar surface, again not to LLO. We need to stop thinking of the lunar surface as the destination. It's not. Instead it is the beginning and ending of the journey. LEO is the destination, not the moon. It is a round trip from the moon to LEO and return to the moon. Thought of that way it completely changes the way we think about this. Earth is left completely out of the equation. That's how we need to design the Earth-Moon transportation system. ALWAYS *begin* the trip from the location with the smallest gravity well with completely full tanks. And return there with what's left after destination arrival. Forget about climbing up out of earth's deep gravity well just to get to LEO. Leave that to the taxis.

The delta-v requirements are lunar surface to LEO and back again, begun with full tanks.

I like your vision as a potential end point, but the pragmatist in me balks at 'designing' the full system that way. What we should do, IMO, is get started with what we have, which includes a fairly vibrant society (though clearly dysfunctional in many respects) on Earth with a few fossil spacecraft on the Lunar surface.  We want to arrive at a self-sustaining space infrastructure.  How do we go from here to there?

Waterfall development might be fine if the USG or some fictitious international collaboration is going to foot the entire bill -- which isn't likely -- so we have to depend on bootstrapping.  What can we start with, that is the question...

So, let's start from where we are and see where we can get.

[clongton]

I like your vision as a potential end point, but the pragmatist in me balks at 'designing' the full system that way. What we should do, IMO, is get started with what we have, ...

Didn't intend to suggest that we *start* there. It's what we want to transition to as rapidly as lunar ISRU development will allow.

[AncientU]

I like your vision as a potential end point, but the pragmatist in me balks at 'designing' the full system that way. What we should do, IMO, is get started with what we have, ...

Didn't intend to suggest that we *start* there. It's what we want to transition to as rapidly as lunar ISRU development will allow.

I wouldn't be surprised if the 'end point' is something along your lines, but markets tend to find the path of least resistance to getting the job done -- while radically altering what the 'job' itself entails.  Doing something gets things moving... where the trail leads is the adventure that I look forward to enjoying.

[AncientU]

This is essentially the fork in the road for 'exploring' space.  Do we just go, have what we have, use what we can get on the launch pad... and see what happens?  Quite a departure from the exquisitely planned mission approach, decades long roadmap approach.

[watermod]

This is essentially the fork in the road for 'exploring' space.  Do we just go, have what we have, use what we can get on the launch pad... and see what happens?  Quite a departure from the exquisitely planned mission approach, decades long roadmap approach.

The problem is a human one that vision disappears into bureaucracy with multi-decade plans.   In the end nothing useful happens.

[envy887]

Earth-Moon Transportation: We need to turn all this thinking completely around. We need to source propellant and oxidizer totally from lunar materials. Transportation between the lunar surface and LEO should be in a vehicle that departs lunar surface, not LLO, with full tanks, arrives in LEO with enough propellant and oxidizer remaining for the return trip to the lunar surface, again not to LLO. We need to stop thinking of the lunar surface as the destination. It's not. Instead it is the beginning and ending of the journey. LEO is the destination, not the moon. It is a round trip from the moon to LEO and return to the moon. Thought of that way it completely changes the way we think about this. Earth is left completely out of the equation. That's how we need to design the Earth-Moon transportation system. ALWAYS *begin* the trip from the location with the smallest gravity well with completely full tanks. And return there with what's left after destination arrival; pushing less mass because of the expended propellant. Forget about climbing up out of earth's deep gravity well just to get to LEO. Leave that to the taxis.

The delta-v requirements are lunar surface to LEO and back again, begun with full tanks.

Lunar surface to LEO and back is 11.8 kms, minimum (all propulsive). That's not much better than Earth surface to EML1/2 and back with aerobraking.

The main issue I have with starting at the lunar surface and taking the same vehicle all the way to LEO and back is it eliminates low thrust, high specific impulse vehicles.

Ideally, you would have deep space SEP/NEP/NTR taxis, shuttling propellant and cargo between dedicated high thrust vehicles for getting into and out of the gravity well.

[TrevorMonty]

Start from LEO with low cost fuel ($1000/kg) thanks to Blue and SpaceX RLV. Then add ISRU for surface to lunar orbit stage and eventually surface to LEO.

[sanman]

Lunar surface to LEO and back is 11.8 kms, minimum (all propulsive). That's not much better than Earth surface to EML1/2 and back with aerobraking.

The main issue I have with starting at the lunar surface and taking the same vehicle all the way to LEO and back is it eliminates low thrust, high specific impulse vehicles.

Ideally, you would have deep space SEP/NEP/NTR taxis, shuttling propellant and cargo between dedicated high thrust vehicles for getting into and out of the gravity well.

What about VASIMR? Nuclear-powered VASIMR from lunar surface to LEO and back could potentially do a lot of round trips.

[Pete]

If you are assuming enough infrastructure to bulk mine LOX on the Moon, and you want to figure out the best way to use it..
Why fiddle around with spaceships landing on the Lunar surface??

Build yourself a 1.2km mass driver flat on the surface of the moon, put some oxygen in a sturdy aluminum container (both obtainable from local regolith), and fire off the thing at a mere 50g.

That, and only a few dozen m/s of impulse (use oxygen venting if you have to!)  is quite sufficient to get the container to earth-moon Lagrange point, where it can be picked up and used wherever with minimal maneuvering.

Building a 50g mass driver is well within our capability.
Making it just over 1 km in length is not that large a project.
Making a container capable of handling 50g acceleration is not a problem, as long as you don't put squishy organics in it.

[Nilof]

Lunar surface to LEO and back is 11.8 kms, minimum (all propulsive). That's not much better than Earth surface to EML1/2 and back with aerobraking.

The main issue I have with starting at the lunar surface and taking the same vehicle all the way to LEO and back is it eliminates low thrust, high specific impulse vehicles.

Ideally, you would have deep space SEP/NEP/NTR taxis, shuttling propellant and cargo between dedicated high thrust vehicles for getting into and out of the gravity well.

What about VASIMR? Nuclear-powered VASIMR from lunar surface to LEO and back could potentially do a lot of round trips.

SEP gives you more power per unit mass than NEP at 1 AU from the sun. Both are really more capable in heliocentric orbits though, where their thrust is relatively high compared to the characteristic timescales of the orbit.

Electric propulsion to the moon takes a fairly long time compared to chemical, unfortunately. Depending on the launch rate of your tankers you might get more payload per unit time with chemical than with electric propulsion, because the chemical stage can be reused more time (unlike for mars trips where electric propulsion can potentially be reused more often because of more lenient launch windows).

Ultimately I think that tethers or any other reusable-propellant architecture is the best bet for getting stuff to the moon cheaply, since they can give you both the benefits of high throughput, short transfer times, and avoiding high propellant and energy expenditures. But near-term I think it's difficult to beat plain chemical propulsion for delivering payloads to the moon.

[AncientU]

We don't need exotic, someday solutions.  We have the technology to get a Cis-Lunar program running, refueling, landers, and all.  If we refuse to use it, why does anyone think we'll build more sophisticated systems?

There will be roles for SEP, NEP, whatever once infrastructure enables growth, and growth demands a range of solutions for different aspects of the tasks that are happening.  Like a great ship... must be underway to steer.

[guckyfan]

I note that this thread takes the opposite way most threads go. Usually there is a general discussion which ends with how it can be done with SpaceX assets.

Here we see a thread dedicated to what SpaceX might do for a Moon Base. That thread slips into general far distant future technologies and developments which have no connection whatsoever to what SpaceX does or may do in the foreseeable future.

[blasphemer]

The delta-v requirements are lunar surface to LEO and back again, begun with full tanks.

Why would you do that?? Such a huge delta-v would require massive propellant tanks and tiny payload. Not efficient at all. Unless I somehow misunderstood your post..

Here is how it should look like IMHO:

1. Launch from lunar surface with enough delta-v to reach LEO depot (2.74 km/s).
3. Refuel empty tanks at LEO depot, launch back to L1 with enough delta-v to reach it (3.77 km/s).
4. Refuel empty tanks at L1, burn for Moon surface with enough delta-v for landing (2.52 km/s).

Delta-v requirements for the spacecraft never exceed comfortable 4 km/s. Lunar surface depot and L1 depot is kept full mainly from Lunar ISRU, LEO depot is kept full mainly from Earth.


Alternatively, you could have a lander repeatedly going between Lunar surface and L1 depot, and a ship repeatedly going between LEO and L1, of course both refueling after each burn. Requires one more stop along the way and transfer of cargo but may be advantageous due to crafts being specialized for their task. Also alternatively, depot may be at LLO instead of L1.

[philw1776]

Lunar surface to LEO and back is 11.8 kms, minimum (all propulsive). That's not much better than Earth surface to EML1/2 and back with aerobraking.

The main issue I have with starting at the lunar surface and taking the same vehicle all the way to LEO and back is it eliminates low thrust, high specific impulse vehicles.

Ideally, you would have deep space SEP/NEP/NTR taxis, shuttling propellant and cargo between dedicated high thrust vehicles for getting into and out of the gravity well.

What about VASIMR? Nuclear-powered VASIMR from lunar surface to LEO and back could potentially do a lot of round trips.

No expensive to develop politically infeasible space Nuclear reactor exists.
VASIMR is unproven.
Even a multi-megawatt VASIMR has order of magnitude too little thrust to do lunar takeoff.
VASIMR is for deep space with T/W << 1

SEP LEO to LLO would be orders of magnitude more feasible.

[Norm38]

I can see SpaceX being interested in hauling cargo to the moon, not sure about bringing anything back but people. Their architecture is methane, their ISRU won't work. So how do any of their ships get back up off the surface while delivering any cargo?  The answer is they don't.

Cargo to build a base will be mostly one way. The big reusable ships deliver one-use landers to LLO, then head back to Earth. The landers get scrapped for their refined metals that a growing base needs.

Personel ride dedicated LLO-Surface taxis that refuel from ships/tankers/stations in LLO. Lunar supplied LOX can
come online when possible, but methane comes from earth. That way the amount of mass coming up from Luna, and hence fuel, is minimized.

SpaceX may supply the lunar taxi, they may not. I see them as bulk freight haulers.

[Robotbeat]

Pah, the BFS presented at IAC had 9.9km/s delta-V. It takes only 9km/s from LEO to the Moon's surface and then launching back and landing on Earth, maybe even less than that (8.6-8.8km/s) if you're clever.

So you already have ~1km/s in extra performance.

Now if you refuel in something like supersynch GTO instead of LEO, you'll add another >2km/s to that margin, giving you tons of extra performance for bringing cargo both ways.

[Nilof]

I can see SpaceX being interested in hauling cargo to the moon, not sure about bringing anything back but people. Their architecture is methane, their ISRU won't work. So how do any of their ships get back up off the surface while delivering any cargo?  The answer is they don't.

Cargo to build a base will be mostly one way. The big reusable ships deliver one-use landers to LLO, then head back to Earth. The landers get scrapped for their refined metals that a growing base needs.

Personel ride dedicated LLO-Surface taxis that refuel from ships/tankers/stations in LLO. Lunar supplied LOX can
come online when possible, but methane comes from earth. That way the amount of mass coming up from Luna, and hence fuel, is minimized.

SpaceX may supply the lunar taxi, they may not. I see them as bulk freight haulers.

According to the results from LCROSS, the ice in the cold traps is a mix of CO, H2O, and CO2. Methalox ISRU should be just as attractive for the Lunar poles as for Mars, the main difference being that you replace atmospheric ISRU with more mining for ice. The lunar equator, on the other hand, is a bit drier, so only LOX ISRU works there which tends to push design towards hydrolox due to its higher O/F ratio.

Alternatively, if planetary resources or some other company starts making propellant from carbonaceous chondrite NEO's, that could provide Methane + LOX as well, since carbonaceous chondrites are carbon rich. Methalox is a great propellant combination for ISRU almost everywhere, not just for Mars.

[savuporo]

Here's a novel idea for a SpaceX for moon base: bulk buy of F9 launches.

If you want a moon base, build a moon base and stop screwing around with more launch vehicles.

[M.E.T.]

Here's a novel idea for a SpaceX for moon base: bulk buy of F9 launches.

If you want a moon base, build a moon base and stop screwing around with more launch vehicles.

I don't understand the point you are making here. Are you saying a customer who wants to build a moon base could bulk buy F9 launches? If so, (assuming the F9 is capable of serving in this capacity), why is that mutually exclusive with SpaceX designing new launch vehicles in the meantime?

[savuporo]

If you want a moon base, build a moon base and stop screwing around with more launch vehicles.

I don't understand the point you are making here.

The point is that launch vehicles are not, and have not been for a while,  the obstacles for building a moon base. Building more of those is not going to help the case.

[Robotbeat]

If you want a moon base, build a moon base and stop screwing around with more launch vehicles.

I don't understand the point you are making here.

The point is that launch vehicles are not, and have not been for a while,  the obstacles for building a moon base. Building more of those is not going to help the case.

The upper stage of ITSy, which is the hardest part, is also supposed to be a lander. Buying 100 Falcon 9s won't get you any closer to a lunar lander, but building ITSy does.

[sanman]

The upper stage of ITSy, which is the hardest part, is also supposed to be a lander. Buying 100 Falcon 9s won't get you any closer to a lunar lander, but building ITSy does.

Will ITSy be able to handle the Moon? I guess with its large amount of engines, it's just a matter of shutting off more of them as you descend to lunar surface. But it's also meant to do aerobraking, which you don't need for the Moon - altho that might be good for return to Earth.

What would it take to optimize ITSy for the Moon?

[savuporo]

The upper stage of ITSy, which is the hardest part, is also supposed to be a lander. Buying 100 Falcon 9s won't get you any closer to a lunar lander, but building ITSy does.

Having an idea for a theoretical lander doesn't get you much closer to building a lunar base either. In fact, anything shaped as an upper stage is probably going to be a challenge due to payload egress problems.

As it happens, one of the most important features of the Shuttle was it's payload bay, for this certain big space construction project.

What would it take to optimize ITSy for the Moon?

It would have to stop being an upper stage

[Robotbeat]

The upper stage of ITSy, which is the hardest part, is also supposed to be a lander. Buying 100 Falcon 9s won't get you any closer to a lunar lander, but building ITSy does.

Having an idea for a theoretical lander doesn't get you much closer to building a lunar base either. In fact, anything shaped as an upper stage is probably going to be a challenge due to payload egress problems.

As it happens, one of the most important features of the Shuttle was it's payload bay, for this certain big space construction project.

What would it take to optimize ITSy for the Moon?

It would have to stop being an upper stage

The only information we have about ITS says that the upper stage IS A LANDER, not just could be or might be, but IS.

And you have to use a crane. So what? That's needed regardless.

[Robotbeat]

The upper stage of ITSy, which is the hardest part, is also supposed to be a lander. Buying 100 Falcon 9s won't get you any closer to a lunar lander, but building ITSy does.

Will ITSy be able to handle the Moon? I guess with its large amount of engines, it's just a matter of shutting off more of them as you descend to lunar surface. But it's also meant to do aerobraking, which you don't need for the Moon - altho that might be good for return to Earth.

What would it take to optimize ITSy for the Moon?

Yes.

And don't need to optimize it.

[Eer]

Earth-Moon Transportation: We need to turn all this thinking completely around. We need to source propellant and oxidizer totally from lunar materials. Transportation between the lunar surface and LEO should be in a vehicle that departs lunar surface, not LLO, with full tanks, arrives in LEO with enough propellant and oxidizer remaining for the return trip to the lunar surface, again not to LLO. We need to stop thinking of the lunar surface as the destination. It's not. Instead it is the beginning and ending of the journey. LEO is the destination, not the moon. It is a round trip from the moon to LEO and return to the moon. Thought of that way it completely changes the way we think about this. Earth is left completely out of the equation. That's how we need to design the Earth-Moon transportation system. ALWAYS *begin* the trip from the location with the smallest gravity well with completely full tanks. And return there with what's left after destination arrival; pushing less mass because of the expended propellant. Forget about climbing up out of earth's deep gravity well just to get to LEO. Leave that to the taxis.

The delta-v requirements are lunar surface to LEO and back again, begun with full tanks.

And this perspective gives entrepreneurs a business case basis to study how to close, which also creates new sources of funding, expanding the economies of the Earth-Moon system.  Now you have something somewhat similar to gathering beaver pelts as a rationale for a Hudson Bay Company investment in Canada, for example.

[AncientU]

Earth-Moon Transportation: We need to turn all this thinking completely around. We need to source propellant and oxidizer totally from lunar materials. Transportation between the lunar surface and LEO should be in a vehicle that departs lunar surface, not LLO, with full tanks, arrives in LEO with enough propellant and oxidizer remaining for the return trip to the lunar surface, again not to LLO. We need to stop thinking of the lunar surface as the destination. It's not. Instead it is the beginning and ending of the journey. LEO is the destination, not the moon. It is a round trip from the moon to LEO and return to the moon. Thought of that way it completely changes the way we think about this. Earth is left completely out of the equation. That's how we need to design the Earth-Moon transportation system. ALWAYS *begin* the trip from the location with the smallest gravity well with completely full tanks. And return there with what's left after destination arrival; pushing less mass because of the expended propellant. Forget about climbing up out of earth's deep gravity well just to get to LEO. Leave that to the taxis.

The delta-v requirements are lunar surface to LEO and back again, begun with full tanks.

And this perspective gives entrepreneurs a business case basis to study how to close, which also creates new sources of funding, expanding the economies of the Earth-Moon system.  Now you have something somewhat similar to gathering beaver pelts as a rationale for a Hudson Bay Company investment in Canada, for example.

But you still have the sequence backward.  People explored 'the new world' and discovered many valuable commodities -- mostly raw materials or similar as in most undeveloped locations -- and then went about making business cases around them.  Hudson Bay Company didn't invest in Canada trade because they knew beaver pelts would eventually be found and so a 'business case' could close.

We live on a water world... it is equally likely that it will remain cheaper to loft water out of the gravity well than it will be to mine it on the moon.  Certainly it is today and will be for the next many years.  Where the cross-over lies (five years, fifty years, never) is anyone's guess.

[spacenut]

The moon could supply oxygen.  It is in the soil as sand, not just water.  Liquid oxygen is heavy, so liquid methane could be brought from earth to be used in a return trip while filling up with lox on the surface.  This all goes back to L1 or L2 being a staging point.  Have one vehicle to go from moons surface to L1, then a vehicle from LEO to L1 and back.  Then smaller transfer vehicles like a F9 with Dragon II to ferry people from earth to LEO, then dock with LEO to L1 vehicle. 

Specialized vehicles may be cheaper in the long run like this.  In space and a moon lander will not have to deal with atmosphere. 

Moon centric infrastructure can be done in 20 ton increments using F9 only.  ITS or ITSy would be great when it gets going. 

My question of using an ITS moon lander is wouldn't it be over powered for soft landing on the moon if it is supposed to land on Earth.  I know it can be throttled down for Mars, but the moon? 

[rakaydos]

My question of using an ITS moon lander is wouldn't it be over powered for soft landing on the moon if it is supposed to land on Earth.  I know it can be throttled down for Mars, but the moon?

It helps that the moon ITS is carring more fuel when it lands than the mars ITS.  more mass makes up for less gravity.

[groundbound]

The upper stage of ITSy, which is the hardest part, is also supposed to be a lander. Buying 100 Falcon 9s won't get you any closer to a lunar lander, but building ITSy does.

Will ITSy be able to handle the Moon? I guess with its large amount of engines, it's just a matter of shutting off more of them as you descend to lunar surface. But it's also meant to do aerobraking, which you don't need for the Moon - altho that might be good for return to Earth.

What would it take to optimize ITSy for the Moon?

Yes.

And don't need to optimize it.

OTOH, wouldn't a vehicle optimized for LEO to lunar surface operation be extremely different than ITSy? There is a lot of stuff you could leave off, including a lot of the thrust and all of the aerostructure. I wonder if it would actually be a fairly easy new vehicle to design (measured against a lot of stuff that is hard.)

I don't know if this is well thought out, but what I'm asking is that if you do the block F9 buy mentioned above and assume that someone* designs and builds a single vehicle that doesn't exist today it might be cheaper than a lot of the alternatives.

*All we need is to find a spare billionaire laying around not doing anything who wants to get into the space biz but doesn't want to compete with Musk & Bezos.

[Robotbeat]

No, you still need the aero structure to get BACK to LEO or the Earth's surface. The extra thrust reduces gravity losses, so is not a pure loss.

[Asteroza]

Lunar return aerobraking is a thing (PICA-X was designed for it...)

[TrevorMonty]

The problem with using ITS for lunar missions is takes about 4-5 ITS launches per mission.
Using ITS as LEO tanker plus a smaller LV for crew would allow for more frequent trips. Using ACES derived, tankers, crew OTV and lander would allow 6 crew to do round trip from LEO using 100t of LH LOX. Alternatively a single launch of full lander would deliver almost 20t of cargo to surface plus a lander that could be converted to habitat.

Methane lander would do about 14t to surface. A crew mission would be down to 2-3 at guess, havn't done the maths.

[M.E.T.]

The problem with using ITS for lunar missions is takes about 4-5 ITS launches per mission.
Using ITS as LEO tanker plus a smaller LV for crew would allow for more frequent trips. Using ACES derived, tankers, crew OTV and lander would allow 6 crew to do round trip from LEO using 100t of LH LOX. Alternatively a single launch of full lander would deliver almost 20t of cargo to surface plus a lander that could be converted to habitat.

Methane lander would do about 14t to surface. A crew mission would be down to 2-3 at guess, havn't done the maths.

Do the above alternatives allow complete reusability? Or is the "lander that can double as a habitat" a mandatory side effect due to the vehicle's inability to return to Earth?

[gospacex]

My hunch is that when SpaceX talked to people ("tourists") interested in Moon flights, they quickly discovered that there is _vastly_ more interest in going _to_ the Moon, as opposed to going _around_ the Moon.

Having an actual Moon rock which you picked up with your own hands beats the hell out of having a picture of the Moon which you snapped from a capsule flying past it.

[wes_wilson]

My question of using an ITS moon lander is wouldn't it be over powered for soft landing on the moon if it is supposed to land on Earth.  I know it can be throttled down for Mars, but the moon?

It helps that the moon ITS is carring more fuel when it lands than the mars ITS.  more mass makes up for less gravity.

You can add more mass with more fuel or...  You could also transfer cargo from several of them to one of them in orbit and land very heavy with cargo. 

[Robotbeat]

The problem with using ITS for lunar missions is takes about 4-5 ITS launches per mission.
Using ITS as LEO tanker plus a smaller LV for crew would allow for more frequent trips. Using ACES derived, tankers, crew OTV and lander would allow 6 crew to do round trip from LEO using 100t of LH LOX. Alternatively a single launch of full lander would deliver almost 20t of cargo to surface plus a lander that could be converted to habitat.

Methane lander would do about 14t to surface. A crew mission would be down to 2-3 at guess, havn't done the maths.

SpaceX is developing ITSy to replace Falcon 9 and Heavy. So presumably would become cheaper per launch than either.

That makes 4-5 ITSy launches cheaper than using a separely developed smaller lander.

[TrevorMonty]

Even if ITS launches are so cheap, that 4-5 a mission is not problem. Still have crew vehicle waiting in orbit on the refuelling flights, all of which need to successful without significant delays. If ITS only departs LEO with partial fuel load it becomes lot more inefficient as propellant mass fraction goes down.

A separate lunar lander should have higher PMF as there is no heatshield, launch and reentry forces to factor in design.

If ISRU infrastructure is in place to refuel ITS on surface then dedicated more efficient OTVs and landers would exist to service LEO -moon route.

Where ITS will shine is as low cost cargo and tanker  to LEO and maybe EML1.

[rakaydos]

Even if ITS launches are so cheap, that 4-5 a mission is not problem. Still have crew vehicle waiting in orbit on the refuelling flights, all of which need to successful without significant delays. If ITS only departs LEO with partial fuel load it becomes lot more inefficient as propellant mass fraction goes down.

A separate lunar lander should have higher PMF as there is no heatshield, launch and reentry forces to factor in design.

If ISRU infrastructure is in place to refuel ITS on surface then dedicated more efficient OTVs and landers would exist to service LEO -moon route.

Where ITS will shine is as low cost cargo and tanker  to LEO and maybe EML1.

The advantage of ITSy is that it doesnt need lunar ISRU.

Lunar ISRU leans toward Al/Ox anyway, so an eventual lunar/LLO reusable lander wont be using methalox.

[DanielW]

Even if ITS launches are so cheap, that 4-5 a mission is not problem. Still have crew vehicle waiting in orbit on the refuelling flights, all of which need to successful without significant delays. If ITS only departs LEO with partial fuel load it becomes lot more inefficient as propellant mass fraction goes down.

A separate lunar lander should have higher PMF as there is no heatshield, launch and reentry forces to factor in design.

If ISRU infrastructure is in place to refuel ITS on surface then dedicated more efficient OTVs and landers would exist to service LEO -moon route.

Where ITS will shine is as low cost cargo and tanker  to LEO and maybe EML1.

There is no reason the crew needs to wait in orbit for refueling flights. Those can happen to a tanker before hand and the crew vehicle can launch to it once filled. You do need an additional tanker, but you would probably have more than one anyway.

[Pipcard]

The problem with using ITS for lunar missions is takes about 4-5 ITS launches per mission.
Using ITS as LEO tanker plus a smaller LV for crew would allow for more frequent trips. Using ACES derived, tankers, crew OTV and lander would allow 6 crew to do round trip from LEO using 100t of LH LOX. Alternatively a single launch of full lander would deliver almost 20t of cargo to surface plus a lander that could be converted to habitat.

Methane lander would do about 14t to surface. A crew mission would be down to 2-3 at guess, havn't done the maths.

SpaceX is developing ITSy to replace Falcon 9 and Heavy. So presumably would become cheaper per launch than either.

That makes 4-5 ITSy launches cheaper than using a separely developed smaller lander.

All I'm wondering is how long it would take to certify a crew vehicle (post-Challenger) that probably won't have a launch abort system if the currently known plans are still applicable.

[TrevorMonty]

No LAS is why ITS may never take crew to LEO.

[M.E.T.]

No LAS is why ITS may never take crew to LEO.

Do those certification requirements apply to non-Nasa flights too? If not, then ITSy can have a very busy life serving as a transport system for private industry, even if NASA remains unwilling to increase its risk tolerance slightly.

[Pipcard]

No LAS is why ITS may never take crew to LEO.

Do those certification requirements apply to non-Nasa flights too? If not, then ITSy can have a very busy life serving as a transport system for private industry, even if NASA remains unwilling to increase its risk tolerance slightly.

Anyways, I made a thread so this one doesn't get derailed any further.

[Space Colonist]

Does everyone realize this entire discussion is based on 3 sentences in an 80-minute discussion?
"If you want to get the public real fired up we gotta..gotta have a base on the Moon. Its like that would be pretty cool, and going beyond that getting people to Mars."
and
"Having some permanent presence on another heavenly body, kinda the Moon base and then getting people to Mars and beyond."

BTW each statement was followed up with "getting people to Mars." Anyone who think Elon's focus is wavering should pay closer attention.

[RocketmanUS]

Does everyone realize this entire discussion is based on 3 sentences in an 80-minute discussion?
"If you want to get the public real fired up we gotta..gotta have a base on the Moon. Its like that would be pretty cool, and going beyond that getting people to Mars."
and
"Having some permanent presence on another heavenly body, kinda the Moon base and then getting people to Mars and beyond."

BTW each statement was followed up with "getting people to Mars." Anyone who think Elon's focus is wavering should pay closer attention.

One launch system that could go to multiple destinations at a lower cost than other concepts, that is the sales pitch.

[giulioprisco]

So yes, the moon IS a stepping stone. It needs to be the HUB of interplanetary travel. It needs to be the departure and return point for interplanetary travel. It needs to be the source for provisioning and outfitting interplanetary spacecraft. It needs to be the source for provisioning and supplying fledgling planetary bases and settlements. We don't need just a few bases on the moon. We need cities on the moon. It's not a stop-over place. It is an entire world just begging to be settled, exploited, developed and used. Just because it's hard is not a reason not to do it. If we cannot do this on the moon then we have absolutely no business going anywhere else to try it.

I totally agree. Add to that the symbolic value of a permanent human presence on the moon. The moon is visible in the sky to anyone anywhere on our planet. Boys and girls will look at the sky, imagine people on the moon, think of future cosmic adventures, and dream to participate. Some of them will do great things.

[rakaydos]

So yes, the moon IS a stepping stone. It needs to be the HUB of interplanetary travel. It needs to be the departure and return point for interplanetary travel. It needs to be the source for provisioning and outfitting interplanetary spacecraft. It needs to be the source for provisioning and supplying fledgling planetary bases and settlements. We don't need just a few bases on the moon. We need cities on the moon. It's not a stop-over place. It is an entire world just begging to be settled, exploited, developed and used. Just because it's hard is not a reason not to do it. If we cannot do this on the moon then we have absolutely no business going anywhere else to try it.

I totally agree. Add to that the symbolic value of a permanent human presence on the moon. The moon is visible in the sky to anyone anywhere on our planet. Boys and girls will look at the sky, imagine people on the moon, think of future cosmic adventures, and dream to participate. Some of them will do great things.

When anyone can look up at a half moon at night, and see a city on the dark side... yea. It'll be "real" to everyone.

[Robotbeat]

So yes, the moon IS a stepping stone. It needs to be the HUB of interplanetary travel. It needs to be the departure and return point for interplanetary travel. It needs to be the source for provisioning and outfitting interplanetary spacecraft. It needs to be the source for provisioning and supplying fledgling planetary bases and settlements. We don't need just a few bases on the moon. We need cities on the moon. It's not a stop-over place. It is an entire world just begging to be settled, exploited, developed and used. Just because it's hard is not a reason not to do it. If we cannot do this on the moon then we have absolutely no business going anywhere else to try it.

I totally agree. Add to that the symbolic value of a permanent human presence on the moon. The moon is visible in the sky to anyone anywhere on our planet. Boys and girls will look at the sky, imagine people on the moon, think of future cosmic adventures, and dream to participate. Some of them will do great things.

When anyone can look up at a half moon at night, and see a city on the dark side... yea. It'll be "real" to everyone.

...you get points for correct use of "dark side."

However, it seems basically impossible to me that you would be able to see even a lunar megacity with a half moon. There wouldn't likely be that many exterior lights, and it'd be drowned out by the sunlit part of the Moon.

[Semmel]

Moonbase PR is actually a good point. Maybe direct some powerful near collimated beams at earth using telescope-like optics. Would cost some energy but seeing a bunch of bright spots close together would work great for the public.

[Beittil]

...you get points for correct use of "dark side."

However, it seems basically impossible to me that you would be able to see even a lunar megacity with a half moon. There wouldn't likely be that many exterior lights, and it'd be drowned out by the sunlit part of the Moon.

Thats ok, we can acually help them with their visibility problem from Earth

[ciscosdad]

Given Elon's recent comments and obvious interest in "Moon Base Alpha": Is anyone willing and able to do some calculation on what could be accomplished using an elliptical tanking earth orbit instead of circular?


Edit spelling

[nacnud]

Some quick numbers, a lot depends on how eccentric the orbit is. I was also wondering on the effect of the van allen belts.


Leo to Luna surface = 5.93 km/s
Luna surface to Leo = 2.74 km/s
Total = 8.67 km/s probably less with aerocapture.

Leo to GTO ~ 4km/s
Leo to EML1 ~ 3.8 km/s

[nacnud]

I found this chart interesting, with 150 tonnes of payload the fully fueled BFS has 6 km/s ∆v. Not quite enough for a return to Luna surface and back from LEO but enough to get there from GEO.

I guess they would refill the BFS in LEO, boost to some higher eccentricity orbit, refill from a tanker there and then head to the moon.

Also attached is a chart of ∆v around the Earth, Moon, and Mars.

Edit: typo

[Dave G]

I was a "moon first" guy for a while, but changed my mind to focus on Mars, mostly because of the perception of the general public, which is sort of "been there, done that".

But in reality, a viable plan to go to Mars could easily involve some Lunar testing, mostly because it's so close, and just to mentally gear up for it.

Also, in the case of SpaceX, lunar missions paid by someone else could help them financially to reach Mars.

[redliox]

I prefer Mars slightly more, but if SpaceX can pull it off either Luna or Mars are options, so long as someone pays for the trip.

[Dave G]

I found this chart interesting, with 150 tonnes of payload the fully fueled BFS has 6 km/s ∆v. Not quite enough for a return to Luna surface and back from LEO but enough to get there from GEO.

I guess they would refill the BFS in LEO, boost to some higher eccentricity orbit, refill from a tanker there and then head to the moon.

The presentation also mentioned propellant transfer in an elliptical orbit.

[meekGee]

Lunar landings are fine, but even SpaceX has no idea how to really do ISRU there, so it's limited to touch-and-go.

Other than graphics, there was no declaration of intent either.  IF some one pays them, they might take him/her/them there.

The intent is to colonize Mars, and that hasn't changed.

[Dave G]

Lunar landings are fine, but even SpaceX has no idea how to really do ISRU there, so it's limited to touch-and-go.

Not quite sure what you mean here.

Yes, Elon mentioned that there would be no methane/oxygen fuel production on the Moon, but he also mentioned that the space ship can make the return trip to Earth without it, due to the Moon's lower gravity.

As for other consumables, note that the Moon does have lots of water ice in permanently shaded areas of craters.  For this reason, many have proposed a Moon base at the South Pole.  This would also provide a constant source of sunlight for power.

• Constant sunlight unobstructed by any atmosphere
• Huge supply of water, which can be used to make oxygen
• 24/7 communications with Earth, with only a 1-second delay
not so bad...

[John Alan]

Lunar landings are fine, but even SpaceX has no idea how to really do ISRU there, so it's limited to touch-and-go.

Other than graphics, there was no declaration of intent either.  IF some one pays them, they might take him/her/them there.

The intent is to colonize Mars, and that hasn't changed.

I agree with you.
EM basically outlined this...
"Hey everyone... I'm going to build a space transport system that can lift 150 tons to LEO...
Max payload size about 8m dia and about 15m long... (if cone shaped 8.5m dia and 20m long is possible
And using tankers I can put that payload anywhere in the inner solar system for a fee...
With this slide... I show I can put 150 tons of crane able crates delivered to The Moon Surface... 
Call SpaceX if you have a need for such a delivery service..."

No mention of a SpaceX need to do this... He just intends to start a space trucking company for hire... 
And the folks that need crates and people delivered to the Moon... will help him get to Mars via cash flow... 

[MikeAtkinson]

Lunar landings are fine, but even SpaceX has no idea how to really do ISRU there, so it's limited to touch-and-go.

Not quite sure what you mean here.

Yes, Elon mentioned that there would be no methane/oxygen fuel production on the Moon, but he also mentioned that the space ship can make the return trip to Earth without it, due to the Moon's lower gravity.

O2 is available everywhere on the moon, and is much easier to obtain than the water ice in polar cold traps.

They can increase the landed payload by only loading enough O2 to land from the tankers, then filling up with the missing O2 on the moon. Direct 1-to-1 replacement of O2 with payload. It is also possible to use the same technique to increase the returned payload, though the benefit is not as great.

[oldAtlas_Eguy]

Lunar landings are fine, but even SpaceX has no idea how to really do ISRU there, so it's limited to touch-and-go.

Other than graphics, there was no declaration of intent either.  IF some one pays them, they might take him/her/them there.

The intent is to colonize Mars, and that hasn't changed.

I agree with you.
EM basically outlined this...
"Hey everyone... I'm going to build a space transport system that can lift 150 tons to LEO...
Max payload size about 8m dia and about 15m long... (if cone shaped 8.5m dia and 20m long is possible
And using tankers I can put that payload anywhere in the inner solar system for a fee...
With this slide... I show I can put 150 tons of crane able crates delivered to The Moon Surface... 
Call SpaceX if you have a need for such a delivery service..."

No mention of a SpaceX need to do this... He just intends to start a space trucking company for hire... 
And the folks that need crates and people delivered to the Moon... will help him get to Mars via cash flow... 

Worst case price for a Moon mission: 1 SC + 5 Tankers at a extremely pessimistic price each of $60M ->$360M for >25mt. Just how much more payload for the no-prop-needed on Moon scenario was unclear. Best case $120M for 150mt. In $/kg on Moon surface from <$1,000/kg to as high as $14,400. I believe it will be much closer in reality to the $1,000/kg value.

The lowest $/kg just to LEO is $3,000/kg and that is also from SpaceX with a F9.

Moon base here we come. It would be within ESA budget to develop palatalized Moon hardware and pay for its transport 2 times a year with a 6 month Lunar crew change-out. A <$1B annual program for a fully 365 day manned "Moon Village".

[oldAtlas_Eguy]

Lunar landings are fine, but even SpaceX has no idea how to really do ISRU there, so it's limited to touch-and-go.

Not quite sure what you mean here.

Yes, Elon mentioned that there would be no methane/oxygen fuel production on the Moon, but he also mentioned that the space ship can make the return trip to Earth without it, due to the Moon's lower gravity.

O2 is available everywhere on the moon, and is much easier to obtain than the water ice in polar cold traps.

They can increase the landed payload by only loading enough O2 to land from the tankers, then filling up with the missing O2 on the moon. Direct 1-to-1 replacement of O2 with payload. It is also possible to use the same technique to increase the returned payload, though the benefit is not as great.

A question is there is an unknown and that is how much frozen CO2 is also in the cold traps with the water ice? The BFR would a little more than 100mt of prop to return to Earth. 50mt of H2O and 50mt of C02 to make 100mt of Methalox prop. But any amount of CO2 recovered would help. The same hardware used on Mars to make prop would work here with little to no modification.

Not only would this definitely enable without question the delivery 150mt of payload but could also reduce number of tankers needed by 1. A nominal savings of $20M per mission. A 17% price reduction as well as the likelihood of a payload increase.

Get stuff there. Open mine. Produce water and CO2 (if possible). Produce methalox. Produce HydroLox (for other space transport users and even for fuel cell "buggies"/mining equipment. Build more habitats and infrastructure:landing pads, cargo handling, personnel transfer, prop manufacture, power systems, cooling systems, refining, smelting, etc.

[CuddlyRocket]

As for other consumables, note that the Moon does have lots of water ice in permanently shaded areas of craters.  For this reason, many have proposed a Moon base at the South Pole.  This would also provide a constant source of sunlight for power.

• Constant sunlight unobstructed by any atmosphere
• Huge supply of water, which can be used to make oxygen
• 24/7 communications with Earth, with only a 1-second delay
not so bad...

it's more difficult to get to the lunar poles, and if you also need to land on permanently lit areas, you're restricting yourself to a very small portion of the Moon - a portion that may not include areas you're interested in for other reasons.

You can produce oxygen from regolith anywhere on the Moon; it's a technology that has been demonstrated in the lab and just requires power. More power than required to electrolyse water, but you have to get the water in a form ready to be electrolysed in the first place! We don't know how to mine mixtures of ice and rock at super-cryogenic temperatures and then purify the water; and what are the power requirements for all those processes?

As for intermittent sunlight, I doubt that's going to faze the CEO of Tesla even if a fortnight of darkness is 28 times longer than half a day! Especially if you switch off your oxygen production when it's dark.

(And 24/7, 1 second delay, communications with Earth is possible over all the near side. )

[meekGee]

Didn't mean to start a general "how to build a moon base" argument.

As per the thread title, I was noting that Musk A) didn't show any intended flights to the moon, and B) only spoke about earth originated propellant.

In short, they showed that if someone (else) is interested, they can take them there.

Musk is smart to put it out there, and then let nature take its course.

[rakaydos]

Lunar landings are fine, but even SpaceX has no idea how to really do ISRU there, so it's limited to touch-and-go.

Other than graphics, there was no declaration of intent either.  IF some one pays them, they might take him/her/them there.

The intent is to colonize Mars, and that hasn't changed.

I agree with you.
EM basically outlined this...
"Hey everyone... I'm going to build a space transport system that can lift 150 tons to LEO...
Max payload size about 8m dia and about 15m long... (if cone shaped 8.5m dia and 20m long is possible
And using tankers I can put that payload anywhere in the inner solar system for a fee...
With this slide... I show I can put 150 tons of crane able crates delivered to The Moon Surface... 
Call SpaceX if you have a need for such a delivery service..."

No mention of a SpaceX need to do this... He just intends to start a space trucking company for hire... 
And the folks that need crates and people delivered to the Moon... will help him get to Mars via cash flow... 

Worst case price for a Moon mission: 1 SC + 5 Tankers at a extremely pessimistic price each of $60M ->$360M for >25mt. Just how much more payload for the no-prop-needed on Moon scenario was unclear. Best case $120M for 150mt. In $/kg on Moon surface from <$1,000/kg to as high as $14,400. I believe it will be much closer in reality to the $1,000/kg value.

The lowest $/kg just to LEO is $3,000/kg and that is also from SpaceX with a F9.

Moon base here we come. It would be within ESA budget to develop palatalized Moon hardware and pay for its transport 2 times a year with a 6 month Lunar crew change-out. A <$1B annual program for a fully 365 day manned "Moon Village".

I would increase your worst case by 50%, rendevusing with a half-refilled tanker in elliptical orbit in addition to the LEO tank fill.

Your overall point still stands, though... it is easilly within the reach of single-administration space program projects now.

[ciscosdad]

How do we balance the elliptical orbit with exposure to the Van Allen belts?
Do it all on Auto (unmanned) and  add crew at the last minute?
Set so apogee lower than VA belt?
Put in a Prop Depot so refueling can be manned and of Minimum duration?
Better to use L1 or L2?
Some combination of these?

[envy887]

Given Elon's recent comments and obvious interest in "Moon Base Alpha": Is anyone willing and able to do some calculation on what could be accomplished using an elliptical tanking earth orbit instead of circular?

My calculations show that the elliptical orbit is 200 km x 3600 km LEO, and 7.85 tanker flights are required. This assumes 150 tonnes delivered to the lunar surface and the ship returns to Earth empty.

There are some tricks that can improve this, such as lunar orbit rendezvous and fuel transfer between a full ship going down and an empty ship returning home.