New Mars Forums

In response to the initial post by SpaceNut:

I am sure we will be able to grow a range of salad vegetables.

Lettuce has shallow roots - good for a layered farm hab.  Tomatoes have surprisingly deep roots. But I have seen them in relatively shallow pots producing good fruit (I think technically tomatoes are fruits).

I think that's an interesting approach Tom.  And the concept can be proved with much smaller craters can't it?  You could gradually scaled up.

Just a thought - is there some sort of gel material that needs to be loaded at the joins to create a seal?  Perhaps there is some sort of organic material that would do the job?

In response to post #15 by GW:

Hi GW -

I had composed a fairly lengthy response replete with references - but I managed to lose it (duh!) and so this is a less full summary:

1. Refreshing my memory on the tonnages issue it appears we need 7 units of fuel in tonnes for every tonne unit delivered from LEO to LMO. However, with ballistic capture we can reduce that by 25% (so 4.3 units).  However, for the human landing we want to stick with the 7 units (as I assume we want the shorter journey time afforded by HTO).  Robot loads can be delivered in smaller separate loads like Viking with ablative shields, parachutes and a small amount of propellant.

2.  I base the human lander on a dragon which can ferry up to 7 people. I assume 5 crew members for the Mars Mission to allow for extra supplies.

3.  Delivering 30 tonnes to the surface (say 24 tonnes in useful supplies) would be more than adequate.

4.  I allow 10 tonnes for a transit hab and supply module. So with the 6 tonne Dragon, that is 16 tonnes in all to go on the human mission. All other supplies go as robot landings.

5.  Total tonnage to launch:

          16 + 16x7 = 224 tonnes

          30 + 30 x 4.3 = 258 tonnes

Then add something for the return voyage - let's say 150 tonnes? 

And maybe a contingency of 100 tonnes.

Total = 732 tonnes x $2 million per tonne = $1.46 billion for the launch.

6.  30 tonnes of supplies at the surface would be a huge amount for five people. 

7.  A key requirement would be to use dried food as much as possible.  Add water.  We take water with us but can recycle that easily - we can have several recycling units - so as to make it failsafe. The average American eats about a tonne of food per annum.  Our crew won't need that much I expect, but let's assume that. With food having a water content of something like two thirds or more on average, a dried food supply of say 2.5 tonnes would scale up to 7.5 tonnes of food with added water.  Add another 2.5 tonnes of complete food supplies e.g. frozen, vaccuum packed, pickled food, energy bars and so on...That would give you 10 tonnes of food (more than sufficient for two years with 5 people). So in terms of tonnage to Mars that would be 5 tonnes of mass. We could probably get by with one tonne of water being delivered to the surface, giving a wide margin of safety. Perhaps it could be less.

8.  So out of the 30 tonnes delivered 6 tonnes would be food and water.  The remaining 24 tonnes could include: 5 tonnes of PV panel equipment (including storage batteries); 3 tonnes for a pressurised rover; 1.5 tonnes for a robot digger; 0.5 tonnes of medical supplies; 1 tonne experimental farm hab; 1 tonne of scientific experiments; 3 tonnes for a number of robot rovers; 1 tonne for spare space suits - there is still lots of slack to take up. You might use some of the slack for rocket fuel production or ISRU experiments like 3D printing, brick manufacture; solar powered steam engine etc etc.

9. So far on cost we have $1.5b or thereabouts spent on the launch.  I maintain there has already been huge sinking of development costs (rover design, rocketry, Bigelow style habs, retropulsive rockets etc etc). This will not be an Apollo style mission where you are inventing nearly everything from scratch. Of course there has to be Mars-specific development, coms improvement and implementation through tests and trials (e.g. in a lunar setting).  I know Curiosity cost $2.5 billion - on that basis you might justify a $100 billion price tag but I would counter (a) launch costs have declined dramatically (b) in terms of what goes on at the Mars surface for the human mission, we can keep things reasonably simple. The complicated machinery can stay "indoors".  (c) Space X have a record of being able to deliver at a fraction of the cost of NASA.

10. I think we need to ask what costs would be involved in development?  A final price tag of under $20 billion seems reasonable to me. But that cost could be shared between several space agencies e.g. NASA, ESA, Jaxa and the Space Agencies of and India and Canada, say. Furthermore if the mission was commercialised at least half that cost could be covered through sponsorship, television rights, regolith sales, and sale of scientific services.

In response to post #14 by GW:

GW, I agree with most of what you say but I think your price tags are grossly inflated.  Even with NASA's "wish list" pricing, I don't think we ever got higher than $400 billion back in the 80s or 90s (though I guess, one has to allow for RPI increases).

As regards the costs now, well at $2000 a kg,  you could launch 50 MILLION - yes million - tonnes to LEO for $100 billion!!!

Obviously launch costs are only a proportion of overall mission cost, but let's say we wanted to get 50 tonnes to the Mars surface, and we applied a multiplier of 4 to the $2000 a kg cost (the multiplier would reflect transit and return costs), then launch and transit would cost only $400 million - not even half way to one billion.

Remember also we have sunk a lot of the development costs already for a Mars mission - e.g. development of life support technologies on the ISS, Mars Rover exploration, development of communications with Mars, development of the Falcon 9/Heavy, Red Dragon and now Space X returnable rocket.

Putting it all together for a Mission will still cost a huge amount but I very much doubt it will cost more than $20 billion over ten years , and if we seek to commercialise the mission, we could get a lot of that back in sponsorship, TV rights, regolith sales and other revenue raising options. Overall net cost needn't be more than $10 billion.

Sounds like that episode in the Simpsons where Springfield went under a dome!

Is such a dome feasible?  I doubt it - without supports that is. I am guessing in any case that at its highest point the dome - if it is to look like a dome - would be at least 3-4 kms tall at its highest point.

However, I could imagine an area that size being enclosed with discrete pressurised areas of perhaps a sq. km. You'd enter air locks to pass from one discrete area to the next. Might be a kind of assembly of domes or a combination of domes, cubes and skyscraper pressurised areas.

Yes I recall all the fertile fields below Vesuvius! 

As you say, one issue to be settled is the extent to which the volcanic material on Mars is similar to that on Earth.

I think these are interesting ideas Void, but I don't think they can be the first port of call.  I guess I would put lava tubes in the "intermediate zone" - maybe 10-20 years after the initial landings. This is the sort of thing we need to explore: how do we create big living spaces without having to invest infeasibly huge resources in construction.  There are other contenders as well: ice caves and (my favourites) natural gorges that are then artificially covered.

I like your approach, that you can create different environments through influencing the ambient conditions e.g. soil - that could equally apply to covered gorges.

Yes, a good point about the outward bound waste stream, SpaceNut...I would think that could be something like 600-700 Kgs for a six person mission.  However, that is 600 Kgs plus that you have to land safely on the surface and that has its own costs in terms of fuel and storage!

Thanks for removing the duplicate-kind-of post.

1,2, and 4 shouldn't require too much energy if you have the right location. No. 3 would of course - grinding it down to soil size particles.

I don't think it's too difficult overall - but I am just interested to hear other people's views on what might be required. 

I have come round to the view that soil trays in enclosed farm habs are probably the best way to go (compared with say hydroponics) - simply in terms of being less labour intensive. The amount of labour required is a key consideration for the early Mars colony.

Lest we forget: crops aren't all about food.

I'd like to fly the flag for bamboo -

"Bamboos are the fastest-growing plants in the world, due to a unique rhizome-dependent system. Certain species of bamboo can grow 91 cm (3 ft) within a 24-hour period, at a rate of almost 4 cm (1.5 in) an hour (a growth around 1 mm every 90 seconds, or one inch every 40 minutes). Bamboos are of notable economic and cultural significance in South Asia, Southeast Asia and East Asia, being used for building materials, as a food source, and as a versatile raw product. Bamboo has a higher compressive strength than wood, brick, or concrete and a tensile strength that rivals steel."

https://en.wikipedia.org/wiki/Bamboo

The bamboo plant has a wide range of uses including in construction.  It can be used to fashion utensils and tools, provide flooring, and make furniture. It can even be used as piping for water. 

It would be a lot easier to start producing bamboo on Mars than steel. So I would suggest that it is a serious candidate for one of the early crops. 

I've often wondered about bamboo's qualities at v. low temperatures.  Does anyone know?

Tito's Inspiration Mars mission seems to have slipped to 2021.  I don't really expect it to happen myself.

The reference in the first link to the NASA conference gives the game away. NASA has no focus on settlement. It is still trying to address all its interests with references to "geologically interesting regions".  The whole of Mars is "geologically interesting" for heaven's sake! Stop letting scientists with special interests dictate the course of Mars exploration. "Settlement first" should be the watchword.  Science and discovery can wait - we will be able to plenty once we have established a viable settlement.

My guess would be that Musk is fully aware of NASA's deficiencies in this regard and has his own settlement plan which we will find out more about in 2016.

I can't claim to be an expert in this area. I just suspect it will throw up all sorts of problems you haven't thought about.  For instance, one that occurs to me is that here on Earth we can say "Oh yeah, New York is five hours behind London time" or whatever. But how does that work (on Mars)) when you have a 39 minute hiatus in the clock?  I'm thinking that there will be variations during the day - so sometimes it will be whole hour differences and other times it will be hour plus minute differences for different longitudes on the Mars globe.  But I must admit my limited numeracy means I quite envision how that works. However, it is clear it is far more complex than on Earth in such circumstances.

It is an interesting debate...I must say I am quite attracted to your proposals of the "vacant lot" of 39 plus minutes each sol. But of course once you have a complex economy that sort of "lacuna" in the sol will throw up all sorts of legal problems (about being paid by the hour and so on).  So on balance I do prefer Mars minutes for Mars's natural time - and let scientists keep Earth minutes as SI.

Regarding the discussion of festive periods - my proposal of four festive periods dedicated to Exploration, Terraformation, Earth and Family are not in any way culturally specific and I think those are the sorts of festivals we need if we are starting a new civilisation on Mars.

No doubt recent arrivals on Mars may wish to continue celebrating the festivals of their ancestors but the Mars community should make every effort to ensure those celebrations are "drowned out" by a very strong Mars-based tradition that all Mars residents can take part in.