The Moon is NOT a stepping stone to Mars

[TakeOff]

My hypothesis here is that the Moon cannot work as a stepping stone to Mars. I think that the huge differences between those two destinations have very few synergies. For sure, it is true that any big space mission helps every other big space mission in some general ways, but I think that the synergies Moon/Mars are much smaller than the impression one sometimes gets from the Moon/Mars debate. Or even from NASA mission plans like Constellation.

What equipment designed for use on the Moon could be useful on Mars?

- Not the spaceship because of the difference between 2½ days travel time and 6-8½ months travel time.

- Not the EDL (landing system) because of the different gravity and Mars' atmosphere.

- Not the (solar) electric power system because of Mars greater distance from the Sun and atmosphere, and the different diurnal cycles (25 hours on Mars, eternal sunshine on Lunar poles). Same for the communication system since practically real time communication with Earth is possible from the Moon.

- Not the physical constructions, like human habitats, because of the differences in surface gravity and atmosphere and types of regolith and the degree of radiation threat from Solar eruptions and differences in temperature variations. Same for all vehicles and probably the space suites too. Hopping ballistic spacecrafts are more feasible on the Moon than on Mars. Would probably wouldn't want to use the same 3D printer or ventilation systems either.

- Not the in situ resource utilization systems. The Moon's eternally shadowed craters are very different from the CO2 in the Martian atmosphere. The abundances of elements are different.

- Not the market for the resources produced, since the Moon is in the middle of cis-Lunar space where there's a potential market for fuel, while Mars sometimes is on the other side of the Sun. One wouldn't even do the same science on the two destinations.

So, going to the Moon and going to Mars will be two separate projects. Travel to Mars might be supported by fuel from the Moon, which would be yet another big difference since colonization of the Moon would be supported directly from Earth! Is see that there are good reasons for the debate about Mars OR the Moon. They are not located on the same road.

[alk3997]

So, what in your opinion is a stepping stone to Mars?  How do you develop the technology to get to Mars? 

It's easy to say something isn't a good idea, but it is much harder to then come up with the actual good idea.

I don't agree with you, but I'm willing to listen to other ideas.

Andy

[TakeOff]

So, what in your opinion is a stepping stone to Mars?  How do you develop the technology to get to Mars? 

The best way to Mars is to go there directly! A useful stepping stone would be a space station in LEO which is built like a prototype spaceship to Mars would be built. With artificial (rotating) gravity and a fully recycling life support system. And even simulated communication delay with Earth. A crew which has spent 6 months there would be well prepared for a real trip to Mars. It would also help selecting the most suitable crew members.

And of course pre-placing assets on Mars, not on the Moon.

I don't agree with you, but I'm willing to listen to other ideas.

Great! I want to learn. I am no expert, I just use secondary sources. If you can point out any major synergies between going Mars and the Moon, I'd be happy.

[pagheca]

The problem with your approach, TakeOff, is IMO to see a station on the Moon as a test-drive to Mars.

The point is that while doing some science and exploration on the Moon you would also have an opportunity to develop and test most of the technologies required to go to Mars (or to other celestial bodies), but with reduced risks and costs.

You designed your list to systematically forget or underline the commonalities between the two missions.

And I see another problem: how would you justify exploring Mars if you haven't yet explored the Moon? Put a flag, do some science for a couple of weeks and go for the next 50 years, Apollo like or stay for longer time? If the second, why going to Mars when you haven't done that on the Moon? If is the first, I really don't see the point for repeating that approach another time.

[SF Doug]

I agree with TO.

The Moon is no longer a stepping stone to Mars.  It was once.  We stepped on it.

The Shuttle was a shoe.  We wore it.

The Space Station is a stone throne firmly in place. We step on it often and look further into the stream.

An asteroid is not a stepping stone.  It is a loose rock.  Skip it.

It is time to launch a boat and ride it downstream to a good landing on that other shore.

Mars is just a stepping stone.

[Lee Jay]

I disagree.

Design a spacecraft to go to Mars and test it by going to the Moon.  If things go wrong, you're a lot closer to help and a lot closer to getting back home.

[eric z]

    I'm just a dolt that has been a huge space fan since I was a kid in the late 50s/early 60s. But I am honestly so sick and tired of these endless, getting us nowhere fast debates: manned vs. unmanned,military vs. civilian, government vs. private, you-name-it. But the silliest one of all, IM not-so-humble O is this one. The moon is sitting right up there; let's stop screwing around and get on with it already. I will trust John Young's views on this! Yes I want to see the Old Glory and the meatball on mars and Titan as soon as anyone else - but first things first! If we can't walk and chew gum at the same time we are pretty pathetic.

[SF Doug]

A spacecraft designed for Mars could not go to the Moon.  The propelled delta-V to the Moon's surface, or even low lunar orbit and back is too large.  The MCT thread discusses possible free-return orbit shake-down flights and tourist trips.

[TakeOff]

The problem with your approach, TakeOff, is IMO to see a station on the Moon as a test-drive to Mars.

The point is that while doing some science and exploration on the Moon you would also have an opportunity to develop and test most of the technologies required to go to Mars (or to other celestial bodies), but with reduced risks and costs.

You designed your list to systematically forget or underline the commonalities between the two missions.

I honestly do not see how "most" of the equipment developed to go to the Moon could be used to go to Mars. Feel free to give some examples! I think it would be wasteful to use artificial gravity while going to the Moon, but necessary for going to Mars, to repeat one of my points. Going to the Moon with equipment designed for Mars, would be lethal!

And I see another problem: how would you justify exploring Mars if you haven't yet explored the Moon? Put a flag, do some science for a couple of weeks and go for the next 50 years, Apollo like or stay for longer time? If the second, why going to Mars when you haven't done that on the Moon? If is the first, I really don't see the point for repeating that approach another time.

I don't have a problem with exploring Mars directly. I realize that the Moon will happen before Mars will (as in permanently manned base, ISRU and so on) because the Moon is so much more accessible and useful in our lifetime. Actually, a Lunar base might preferably be semi-permanently manned because its ease of accessibility makes that feasible. But if I could ignore the practicalities, I'd prefer exploration of Mars instead, for romantic reasons.

My bottom line here is that they are on a crossroad. One has to choose, or do both as two separate parallel missions. They are like Sahara and the Antarctic.

[The Amazing Catstronaut]

The moon is a stepping stone to the moon, and mars is a stepping stone to mars, I agree.

They are different value prizes - it's easier to get to the moon but the moon also has significantly less long-term uses. Also, reality is gearing up for martian targets rather than lunar targets; it's easier to win support for something humanity hasn't done than something humanity did.

I think driving for the harder goal (mars) will get us to Lunar quicker than if we simply tried to go for Luna alone. Remember; Luna has been a proven dead-end stop for manned exploration before, we don't want another Apollo dead end in our lifetimes.

Mars is less of a dead stop. You either pull all the stops out or you don't get your flags and footprints. The very nature of the mission forces you to think bigger than flags and footprints regardless.

Mars is realistic and mars will happen. However, any spacecraft that can readily get to mars can also readily drop sizeable payloads onto Lunar. So which would you prefer to gun for? With one, you by rational default get the other, either pre-mars, during mars or post-mars. Compare with the other, where you just get the moon.


Edit: One of the problems with space travel is that we assume that we cannot build a craft that can do just about every role we envision for it. Not so; Apollo did everything it was required to do, Soyuz and Progress have done everything it was required to do, and the Shuttle did everything it was required to do. I'm sure mission planners for lunar colonisation wouldn't complain about having too capable a spacecraft to get the job done with.

[Kansan52]

IMHO, this is an either or question. We shouldn't choose one over the other, we should do both. A Penny for NASA should allow for both.

But if forced to choose, it's the Moon. There is so much more left to do.

Of course, if you can revive NERVA as a fast vehicle to Mars, that would change everything.

[DanielW]

This argument only makes sense is humanity were old pros at moving about and living in space, and getting to Mars was only a matter a resource allocation. As it is we don't really know what we would learn from a trip to the moon. Issues with ECLSS, toilets, which movies to have in the on board library. Who knows. In any case going to the moon has a lot more in common with going to Mars than endless planning here on earth.

So no it is probably not a direct stepping stone as in 100% common hardware and procedure but it would be useful for getting a feel for long duration spacefilght in general. The same way that tooling around the neighborhood for a couple years in a car would better preparation for jumping behind the wheel of a Mac truck for a cross-country haul than not knowing how to drive at all.

[clongton]

I am all for human settlements on Mars, provided they are properly planned, staffed and allowed to create their own economy. But I do not expect to actually see anything even approaching that in my lifetime.

I am a dyed-in-the-wool Moon-Firster. There is an entire world only 250,000 miles away, just sitting there waiting to be settled and exploited. Would it be easy? No. Would it be cheap? No. Would it pay off? Yes. We would end up with a 2-planet economy.

Mars, as exciting as it is, can wait a couple hundred years. We have a much closer world to develop.

[redliox]

So, what in your opinion is a stepping stone to Mars?  How do you develop the technology to get to Mars? 

The best way to Mars is to go there directly! A useful stepping stone would be a space station in LEO which is built like a prototype spaceship to Mars would be built. With artificial (rotating) gravity and a fully recycling life support system. And even simulated communication delay with Earth. A crew which has spent 6 months there would be well prepared for a real trip to Mars. It would also help selecting the most suitable crew members.

And of course pre-placing assets on Mars, not on the Moon.

Regarding the Moon's place in Martian schemes, you are quite correct in 2 ways:
1) Totally different body from Mars, namely gravity environment, and light.
2) Huge delta-v differences to get from one or the other.  The Moon you have to fire your engines constantly to go anywhere, and if you're going to Mars after a surface landing it's like making 3 round-trips to Mars fuel-wise.  Best way to go to either body is directly.

Mainly the only use the Moon has, at least if you go by NASA's current PR charts, is an orbital parking lot either in Distant Retrograde Orbit or its Lagrange points.  Better than LEO or Lunar orbit, presuming you're launching elements to near-escape speed and needing them somewhere easy to leave Cis-Lunar from.

Hypothetically Martian vehicles could be tested on the Moon, but they need to be made-for-Mars, not the Moon since a Lunar vehicle wouldn't support it's own weight on Mars to put it one way.

Regarding the two destinations, I'd suggest a separate-but-interchangeable path, though it's doubtful we'd be visiting both simultaneously anyway.

[TakeOff]

Regarding the two destinations, I'd suggest a separate-but-interchangeable path, though it's doubtful we'd be visiting both simultaneously anyway.

The willingness to go to Mars might compensate for the relative easiness of going to the Moon. And because going in the both directions at the same time would be the most irrational thing to do, I bet that is exactly what will happen once the ketchup effect comes to space flight.

[Warren Platts]

An upgraded, ACES-style lander could land on Mars as well as the Moon--fully propulsively.

Also, there are at least 6 billion tonnes of relatively pure water laying around in the northern polar region of the Moon alone. Vast majority of Mars missions will be propulsion and other "dumb" mass. These can be got from the Moon for a fraction of the cost of launching from Planet Earth.

[nadreck]

From a 'testing' standpoint, almost every technology you need for a human mission to Mars orbit can bet tested in LEO. Radiation shielding isn't going to experience a realistic level in LEO. In terms of landers and rovers those need to go to Mars for any meaningful tests, however several technologies have been tried there so far.

If you are only doing an Apollo style 'there and back again' HSF mission to Mars then really the moon should play no part in it at all.

However if we are talking about permanent presence, meaningful exploration and exploitation, and most importantly keeping the cost of this down enough to make the activity sustainable, then it makes sense to have that presence start in LEO expand to include the Moon, and then Mars. However that doesn't mean 'waiting' for a bunch of milestones and gating lunar activity to a lot of LEO activity or activity on Mars to activity on the moon. 

Lets say the 'long term plan' is a permanent human presence on and around Mars to explore it and both for the sake of making life better for cheaper on and around mars exploitation for resources that will be needed to support the people and activities there. Lets also presume that we are going to have a permanent presence in LEO (maybe MEO/GEO) and certainly the moon.   Synergies between developing a permanent exploration and exploitation activity at and around the moon and at and around Mars is a communications network. So lets set the constellation up for Lunar communications first. We gain experience by doing that, it also means that from day 1 of that constellation on, even unmanned probes could take advantage of the network. Certainly though you want to plan and launch your Martian network not too much later though as it also reduces costs and increases effectiveness of all future probes.  Habitat technology will definitely be iterative, and some of that technology, especially as relates to the use of plant life and maybe fish farming, will have some cross over. However, it makes sense to have projects that run independently and simply exchange people and ideas so that new ideas propagate quickly to benefit both projects.

If it is practical to harvest lunar water then launching and returning larger Mars transports to lunar orbit Lagrange point may make more sense than to LEO, however a LEO transfer point for cargo and personal is essential then and some lunar fuel has to make it there.

However the benefits of a permanent human presence in LEO, in and around the Moon have far more elements than simply supporting activity that relates to Mars or systemic exploration in general. By the same token the benefits of systemic exploration go beyond putting cities on Mars. Possibly Mars is the most desirable living space off Earth, there are still places that may be for more important to explore and exploit.

[A_M_Swallow]

The inside of the Moon and Mars habitats are likely to be similar. I suspect that airlocks will be similar as well, including the docking ports to rovers.

[gbaikie]

I am all for human settlements on Mars, provided they are properly planned, staffed and allowed to create their own economy. But I do not expect to actually see anything even approaching that in my lifetime.

I am a dyed-in-the-wool Moon-Firster. There is an entire world only 250,000 miles away, just sitting there waiting to be settled and exploited. Would it be easy? No. Would it be cheap? No. Would it pay off? Yes. We would end up with a 2-planet economy.

Mars, as exciting as it is, can wait a couple hundred years. We have a much closer world to develop.

I think NASA should explore Mars before human settlement. Though against government inhibiting in any fashion any attempt at Mars settlements. Instead, rather than stop or discourage, the US government needs to get it's butt in gear.

And not of opinion that we use the Moon regardless of the costs [and will be worth whatever is spent]
in my opinion is quite the opposite.
Or I think US should spend a lot money exploring the Moon and a lot of money exploring Mars.
And purpose of exploring the Moon is to determine where and if there is minable water on the Moon.
And purpose of exploring Mars is to determine where and if there could be Mars settlements.
And I don't think the purpose of exploring Mars should be to find alien life. But part of exploring Mars
should include determining if there water which can gotten from beneath the Mars surface [hundreds of meters [or perhaps as deep a km or two] and such exploration could find alien life on Mars.

So my idea of spending a lot of money on exploring the Moon is 40 to 50 billion- preferably 40 billion or less. And my idea of spending a lot of money exploring Mars is +100 billion dollar- preferably more than 100 billion.

So have NASA spend less than 10 years exploring the Moon and with budget of 4 billion per year. Have NASA explore Mars and be about 5 billion per year and more than 2 decades [+100 billion].

Now after spending 40 billion on exploring the Moon, I don't think it is unreasonable expectation that NASA could determine if and where there could be minable lunar water. Nor do think it's an unreasonable expectation that within 1 decade of exploring Mars, that NASA has some clues about the possibility of a future which has Mars settlements. Or anyone who wants to go to Mars could begin to get some good ideas of how this could be done.

Once NASA has spent 40 billion on exploring the Moon, then it starts it's 100 billion Mars program. And
by this point in time, NASA can provide information about where one could do commercial lunar water
mining. Though NASA should as part of lunar exploration have returned samples, and these may develop more information about the Moon, as NASA goes to Mars.

Having NASA going to Mars and having already explored the Moon, will allow investor to consider and formulate an investment plan which involves mining lunar water. It's possible one get commercial lunar mining starting before NASA is finished exploring the Moon. If so this should be HUGE CLUE to NASA to Stop exploring the Moon and get to the business of exploring Mars. Or it might require say 5 years after NASA has finished exploring the Moon before any commercial lunar water begins.
NASA should not wait for commercial lunar water mining before going to Mars. Or should not plan to have commercial lunar water mining as on the critical path of their Mars exploration program.
Instead commercial lunar water mining should be considered important to long term duration of Mars exploration and perhaps a critical path of future Mars settlements.

So generally speaking whatever the conditions on the moon, these are not solely the issue of whether lunar water is minable, but these conditions are required to be known before one can mine.
Other factor of whether lunar mining is viable, could related to the condition of economy on Earth- how tight is money?
Maybe something else is very hot to invest in, and sucking out investment dollars.
Other things could be related to laws passed by governments. And etc.

[KelvinZero]

Essentially any HSF in space can be a stepping stone to Mars. The only real proviso is that you actually do it.

I could strongly argue the moon is a great stepping stone:
*Differences in ISRU and dust mitigation are like different doormats on your mansions. Most of the complexity is inside and concerned with the precise requirements of human life support.
*Difference in gravity shouldnt be a problem. Design it to work on earth and on the moon, and probably only minor issues will be discovered on mars.
... However at this moment in time I think the political support for the moon is fraudulent, so I wont. I see no interest in funding a lander, let alone a base. When there is three times more funding for the elements to go on top of the launcher than for the launcher itself, I may begin taking them seriously.

The smallest and most obvious stepping stone at this moment would be a DSH. At first it could be attached to the ISS, later it could be pushed to higher orbits cheaply with SEP (unmanned). If you cannot get this funded Its probably silly to talk about more extravagant goals. With sufficient confidence in your DSH, multiyear missions to all sorts of destinations can be considered.