Moon AND Mars?

[Lumina]

For many years now, there's been a tension between "Mars first" and "Moon first" (or "Mars via the Moon") tendencies among space stakeholders. This thread is hoping to hear from space community people who've experienced this Mars vs. Moon tug-of-war first hand and to explore whether SpaceX' ITS system can eventually lead to a replacement of this zero-sum game by a "Moon AND Mars" (and other places) mental model.

Was this Mars-or-Moon zero-sum game mentality a product of the reality of limited resources, high costs per flight and restricted access to space?

Are we, thanks largely to SpaceX, at the dawn of an era when access to space will gradually become cheaper and more easy to come by?

Will Mars-or-Moon be replaced by Moon AND Mars?

Can the ITS fly regularly to the Moon, spreading the capital development costs of the Spaceship over many more flights?

Is there an opportunity for SpaceX to use profits from higher-frequency Moon flights to subsidize lower-frequency Mars flights?

[Coastal Ron]

Was this Mars-or-Moon zero-sum game mentality a product of the reality of limited resources, high costs per flight and restricted access to space?

I'd say yes, since NASA's budget is too small really to do anything beyond LEO with humans in the near future.

Are we, thanks largely to SpaceX, at the dawn of an era when access to space will gradually become cheaper and more easy to come by?

I think we'll have to be crediting Blue Origin too pretty soon, if their plans for New Glenn materialize.

Lowering the cost to access and travel through space has been the major barrier to expanding humanity out into space.  And because of that government programs have had to limit the scope of what they want to do, since any destination is likely a multi-decade long effort.

Will Mars-or-Moon be replaced by Moon AND Mars?

I have always felt that the priorities were backwards.  Instead of picking a destination and then designing a transportation specifically for it, that instead we should build a reusable transportation system that can help us reach ANY destination.

But Elon Musk is shortcutting the conversation on this because he has decided to place his bet on Mars, and SpaceX is in a much more capable position of going to Mars than the U.S. Government is.  Mainly because Elon Musk has identified a "need" that others believe in, whereas the U.S. Government really doesn't have a "need" to return to our Moon or go to Mars.

Can the ITS fly regularly to the Moon, spreading the capital development costs of the Spaceship over many more flights?

It could, but Musk is going to be focused on using SpaceX owned ITS vessels to go to Mars.  However, if someone were to buy or build one of their own (Musk alluded to that possibility) then they could use it any way they like - our Moon, or anywhere else in the solar system.

Is there an opportunity for SpaceX to use profits from higher-frequency Moon flights to subsidize lower-frequency Mars flights?

I'd say no.  I don't see any business model for doing things in space in the next few decades.

[TomH]

There are two things I would not be surprised to see happen:

1. An ITS test landing on Luna. Obviously it is not a perfect practice run, however it does offer an opportunity to do some systems tests and generate interest.

2. NASA contracting with SpaceX for some Lunar landings for scientific research and private corporations doing the same for tourism.

[DreamyPickle]

The Moon and Mars are so different that many of the technologies required only apply to one or the other. This means that treating it as a zero-sum game is not really irrational. Among the important differences:

- Efficient landing on Mars needs to use some aerobraking while on the Moon everything is propulsive. Research in EDL or supersonic retropropulsion not relevant for the Moon.
- The day/night cycle on the moon is much longer. A base that relies on solar panels would need enormous batteries to last two weeks through the night.
- On Mars you can extract carbon and oxygen from the atmosphere, on the Moon you need to extract it from rocks.
- On Mars you can extract water from various minerals. The availability of water on the Moon is not as clear. If useful ice is found in a permanently shadowed crater you would need to transport it to the base without solar power.

The ITS in particular is built around the idea of generating methane on Mars and SpaceX will have to develop and operate the ISRU infrastructure themselves. Would they really invest in doing the same on the Moon, using different processes?

[guckyfan]

Landing on the moon needs no aerobraking. It needs proulsive landing. Spacex are becoming very good at this. Landing on Mars uses the same.

Day/night cycle. True, but I don't think anyone should expect SpaceX to design a moon base or settlement. Whoever purchases transport to the moon will need to do it.

Same for ISRU. Moon is different and whoever wants to go there will have to tackle that problem, not SpaceX.

For transport it seems fuel ISRU will not be needed. Some calculations I have seen indicate that a significant payload can be delivered and BFS return to earth without refueling. For very heavy single pieces of infrastructure unlike Mars refuelling flights to lunar orbit are quite doable.

[JasonAW3]

There are two things I would not be surprised to see happen:

1. An ITS test landing on Luna. Obviously it is not a perfect practice run, however it does offer an opportunity to do some systems tests and generate interest.

2. NASA contracting with SpaceX for some Lunar landings for scientific research and private corporations doing the same for tourism.

Your second point would be a fairly good idea, as this would generate additional income for SpaceX during the two and a half years between flights.

[CraigLieb]

I would gladly pay to be a passenger on an "Apollo 8" style trip around the Moon.  For me that would be an achievement of a lifetime dream.  Assuming a short trip could hold 200 passengers since there is reduced payload needs. If each could be charged $250k = $50 Million. SpaceX gains risk reduction for longer trips, experience with on orbit refueling, etc.     I made a previous posting about this in another thread some time ago, so enough said.

[envy887]

Space Adventures is trying to book lunar free return tourist flights using Soyuz for $100 million per each of 3 passengers. And LEO tourists are paying $20 million each, so there might be a lot more possible revenue there... as long as people are willing to fly with no LAS.

[TomH]

The Moon and Mars are so different that many of the technologies required only apply to one or the other. This means that treating it as a zero-sum game is not really irrational. Among the important differences:

- Efficient landing on Mars needs to use some aerobraking while on the Moon everything is propulsive. Research in EDL or supersonic retropropulsion not relevant for the Moon.
- The day/night cycle on the moon is much longer. A base that relies on solar panels would need enormous batteries to last two weeks through the night.
- On Mars you can extract carbon and oxygen from the atmosphere, on the Moon you need to extract it from rocks.
- On Mars you can extract water from various minerals. The availability of water on the Moon is not as clear. If useful ice is found in a permanently shadowed crater you would need to transport it to the base without solar power.

The ITS in particular is built around the idea of generating methane on Mars and SpaceX will have to develop and operate the ISRU infrastructure themselves. Would they really invest in doing the same on the Moon, using different processes?

We already know this. Nevertheless, Mars is around 6 months away. When ITS flies, they are going to do a lot of initial testing in LEO, then they will take it to HEO, and likely sis-lunar space for maneuvering practice. And there is a place to test landing, egress, ingress that is only 3 days from home. It is called LUNA. No, it is not exactly like Mars, but it is a place very close by where many systems can be checked. Can all of them? Obviously not. But saying that it differs from Mars and therefore there is nothing to learn or validate and that it should be completely ignored is total folly.

Do you know why Elon changed the name from Mars Colonial Transport to Interplanetary Transport System? Because he wants it to be able to go places OTHER than Mars. ITS is designed to be big, simple (in terms of components), and versatile. It will not be necessary to design a completely different architecture for every celestial target. Well, if you are going to fly it to places other than Mars, and you are able to do it with what you have, where is the closest place, other than just Earth EDL, to start testing the thing?

[Negan]

But saying that it differs from Mars and therefore there is nothing to learn or validate and that it should be completely ignored is total folly.

I would say not acknowledging that testing on the Moon compared to simulated testing on Earth increases risk greatly is total folly. It's a totally unnecessary risk to take when the goal is Mars at least as far as testing goes.

[mikelepage]

I would go further, and say it will be exploration of the Moon, Mars, AND asteroids happening largely simultaneously.  Although they will all have different particular requirements, will also have significant industrial synergies.  I'm thinking less in terms of whether the whole ITS ship (or some variant on it) goes to the moon than that there will be whole groups of companies that have sections dedicated to the Moon project, the Mars project, and/or whichever NEO they have the supply contract for.

Which one happens first is so insignificant in the grand scheme of things.  I even made some youtube videos a few years back called "Settling the Incliptic" (= inner ecliptic), because I think the main limitations on current tech are access to solar power, access to water/minerals, and that the relatively small amount of resources in high inclination orbits around the sun are not going to be mined cost-effectively for some time.

[TomH]

testing on the Moon compared to simulated testing on Earth increases risk greatly is total folly. It's a totally unnecessary risk to take when the goal is Mars at least as far as testing goes.

Firstly, I did not say testing should not be done on Earth. Secondly, landing on Luna mitigates risk in relation to landing on Mars. Landing on Mars is extremely difficult due to the nature of its atmosphere. The atmospheric density on Mars is 0.0059 that of Earth. That is just enough to burn up an inbound craft with no TPS, but low enough that you cannot parachute land. You have to get close to the surface and fly parallel to it to ablate velocity, changing the angle of attack to maintain just enough lift to counteract weight. The majority of Mars landers fail.

Lunar landings offer an opportunity to test SOME of the ITS landing systems in a more benign environment and to work out some possible bugs prior to attempting the far more difficult Mars landing. If ITS did not have the capability for Lunar landing, I would not suggest this. As it is, lunar landing is quite within the robust capabilities of ITS and this would be a prudent test.

[Negan]

testing on the Moon compared to simulated testing on Earth increases risk greatly is total folly. It's a totally unnecessary risk to take when the goal is Mars at least as far as testing goes.

Firstly, I did not say testing should not be done on Earth. Secondly, landing on Luna mitigates risk in relation to landing on Mars. Landing on Mars is extremely difficult due to the nature of its atmosphere. The atmospheric density on Mars is 0.0059 that of Earth. That is just enough to burn up an inbound craft with no TPS, but low enough that you cannot parachute land. You have to get close to the surface and fly parallel to it to ablate velocity, changing the angle of attack to maintain just enough lift to counteract weight. The majority of Mars landers fail.

Lunar landings offer an opportunity to test SOME of the ITS landing systems in a more benign environment and to work out some possible bugs prior to attempting the far more difficult Mars landing. If ITS did not have the capability for Lunar landing, I would not suggest this. As it is, lunar landing is quite within the robust capabilities of ITS and this would be a prudent test.

What landing systems are included in your testing and why can't these tests not be simulated on earth?

[Negan]

Landing on Mars is extremely difficult due to the nature of its atmosphere. The atmospheric density on Mars is 0.0059 that of Earth. That is just enough to burn up an inbound craft with no TPS, but low enough that you cannot parachute land. You have to get close to the surface and fly parallel to it to ablate velocity, changing the angle of attack to maintain just enough lift to counteract weight. The majority of Mars landers fail.

How does landing on the moon remotely equate to testing for what you described above?

Edit: I'll answer my own question. It doesn't. That's what the Red Dragons are for.

[Hotblack Desiato]

I agree with you that the Moon should be a target too.

Let's tackle the problem from a different angle: SX is sending out ITS-crafts to Mars. That happens once every 26 months. So there will be two really busy months and then 24 months with the ITS first stage and the tankers sitting around. Even if Musk is interested in a few other places than just Mars, there will always be the situation with the launch windows and the empty space in between. So if there is another group prepared to go to LEO, Moon or one of the Earth-Moon-Lagrange-points, and if they are paying... why not.

Maybe they develop their own second stage or order a second stage that is better suited to land on atmosphere-less bodies, or they just develop a lander that does the route LLO-surface, with ITS as a supplier of either a LEO-spacestation or a LLO-spacestation (there needs to be another transfer-vehicle for LEO-LLO).

It's just that the worst thing for Musk is: having his fleet sitting around without doing anything, and subsequently not earning any money.

[meberbs]

testing on the Moon compared to simulated testing on Earth increases risk greatly is total folly. It's a totally unnecessary risk to take when the goal is Mars at least as far as testing goes.

Firstly, I did not say testing should not be done on Earth. Secondly, landing on Luna mitigates risk in relation to landing on Mars. Landing on Mars is extremely difficult due to the nature of its atmosphere. The atmospheric density on Mars is 0.0059 that of Earth. That is just enough to burn up an inbound craft with no TPS, but low enough that you cannot parachute land. You have to get close to the surface and fly parallel to it to ablate velocity, changing the angle of attack to maintain just enough lift to counteract weight. The majority of Mars landers fail.

Lunar landings offer an opportunity to test SOME of the ITS landing systems in a more benign environment and to work out some possible bugs prior to attempting the far more difficult Mars landing. If ITS did not have the capability for Lunar landing, I would not suggest this. As it is, lunar landing is quite within the robust capabilities of ITS and this would be a prudent test.

What landing systems are included in your testing and why can't these tests not be simulated on earth?

Everything but the heat shield, the few aerodynamic controls and certain software segments would be tested by landing on the moon. Most of those would be at least partially tested by the return to earth from the moon.

Simulations are always deficient tests in a variety of ways, especially for a system the scale of ITS. A moon landing would test out the integrated system in a way no simulation on earth could. The only reason to not do such a test would be cost, and the cost would not be all that large relative to the project scale and they could almost certainly find a space agency willing to pick up part of the tab in exchange for delivering a science payload. I will be very surprised if they do not do one at some point before the first Mars mission (or at least before the first human to Mars mission)

[MATTBLAK]

Space Adventures is trying to book lunar free return tourist flights using Soyuz for $100 million per each of 3 passengers. And LEO tourists are paying $20 million each, so there might be a lot more possible revenue there... as long as people are willing to fly with no LAS.

For what it's worth (not much) I think $100 million is too much for a circumlunar flight. There haven't been many takers for the Earth orbital $30 million missions. If they priced the Lunar flight at $60 million per seat, they might get more takers. A circumlunar mission would be my life's greatest wish - next to World Peace! At $60 million, you could get somebody like Tom Hanks and James Cameron, who could probably afford such a mission and they could go together; on the pioneering flight with a Cosmonaut. But Cameron might be a bit too tall and a smidgin too old for that flight - not to mention a bit too busy. And Mr Hanks might not pass the physical.

[sdsds]

For many years now, there's been a tension between "Mars first" and "Moon first"[...]

Will Mars-or-Moon be replaced by Moon AND Mars?

Your thinking up to this point is really good!

Is there an opportunity for SpaceX to use profits from higher-frequency Moon flights to subsidize lower-frequency Mars flights?

Uh, did you just fall into the trap you so eloquently described, i.e. did you (essentially) suggest, "Moon first?"

[redliox]

Small problem with debating "Moon and Mars" here: Space X or Elon Musk hasn't really declared an intention to fly to the Moon.  It's the the same problem we have with predicting Donald Trump's space policy, which he hasn't declared either.  Hypothetically, either the Falcon Heavy or ITS could place decent payloads (and eventually people) on the Moon; this may be the case if an International Moon Base (on the Moon itself, not just CisLunar space) is put as a goal.

Probably the only bias Elon might have against the Moon is with fuel production, which is an integral part of ITS reusability.  The Moon has no atmosphere like Mars, and whatever resources you require have to be dug up.  He took much of his Martian ambitions from Mars Direct and Rober Zubrin, who pointed out, in an straightforward-engineering sense, that the Moon is a distraction from Mars.  You could argue his "foundation" inherently leans away from the Moon for better or worse.

I doubt Elon would be against supporting Lunar activity with his rockets, but he isn't likely to spearhead it.  That's all we can deduce.  Of course...Bigelow could arrange a team-up as one scenario...

[envy887]

For what it's worth (not much) I think $100 million is too much for a circumlunar flight. There haven't been many takers for the Earth orbital $30 million missions. If they priced the Lunar flight at $60 million per seat, they might get more takers...

At $100M there isn't much of a market, perhaps a few 10s of people once the viability is demonstrated; but at $10M there are probably a few hundred people who would go, and at $1m several thousand. That's a lot more profit and less risk than $250k per.

Earlier flights would be higher cost and higher risk, if both are high enough then launching on F9R and Dragon 2 might be viable.