New Mars Forums

We'll be taking plenty of nitrogen with us, in the form of food, and human waste. A lot of this nitrogen is in the form of urea in urine. Undiluted urine is an excellent fertilizer, I recommend you try it on your garden. Go on, pee on your peas, it'll do them good.

If you're worried about the health effects, the World Health Organization guidelines are that if a household's urine is being used on that household's food crops, it can be used immediately. Processing faecal matter takes longer because of the pathogens it contains.

If you want something based on fact, you have to acknowledge the reality that manned space-flight beyond LEO, like supersonic travel, is a thing of the past.
Nobody has been beyond LEO in the lifetime of most people currently alive. Is it any wonder that so many of them don't believe it happened in the first place. After all, why would we stop going to the moon?

If you get a chance to see the program do so. It is entertaining and contains input from proper scientists (not simple engineers like me).

The plastic sealant is a good idea. What happens in some liquid retaining structures is that when the concrete is poured channels are formed in the surfaces at predetermined distances. These channels are where the cracks will from. After the concrete has set, a sealant (either silicone or tar based) is fixed into the channel.

An alternative method is to include an impermeable membrane in the concrete to intercept your designed cracks.  Some of the modern geotextiles are impermeable to liquids and gasses. Particularly those used to protect us from the leachate and gas produced by landfill sites. The gas can be used for fuel, but that's a different matter.

My idea for using water as a sealant relies on using it in its liquid state to penetrate cracks in the rock that our dome will be built on. Then when it freezes, it will, I hope, form an impermeable barrier. As with the concrete the problem will be cracking as the water freezes. Of course, there is the added matter of the water expanding.

Ed

This is just a quick note. I haven't had a chance to study the details, but research my current dissertation has thrown up a few things that may be relevant.

Human urine can be used for irrigation. As well as the water content, it contains phosphates and organic nitrogen, good for growing plants. You don't use it on root crops, of course, but other crops will benefit. Similarly greywater can be used for irrigation.

Almost all of the vast wastewater treatment structure in the developed world is to deal with faecal matter. This is the stuff that contains all the potentially nasty things. The problem is increased by the large amounts of water we use to deal with (typically 130 litres per person per day, and rising). By using composting toilets the "output" of six people can be easily dealt with. This compost can be used to grow fodder for animals, or air cleaning plants. Unfortunately, as a solid it is more suitable for soil-based solution than for hydroponics.

To be honest I need to have a more thorough look through the details at the top of the page. Then I may well write some more. Nonetheless it would be good to see other people's ideas.

Somehwere along the way, the line was crossed between "looking after" and "mollycoddling".

My parents gave me a lot of freedom when I was a kid, and nothing bad ever happened (unless you can't hospitalization with second-degree burns, or falling face-first over a 20 ft cliff, to be bad things

I had a similar problem. I went off to do voluntary work and didn't log on for some time. When I came back I couldn't log on.

To make it worse, when I tried to re-register I couldn't revive the user name, or use the same e-mail address.

Ed,

(used to be canalbuilder)