Late start again

Time is a bit short, so I have to make a quickie post.  By the way, that's the nature of this business.  You have to post something every day.  It gets to be a grind sometimes because there are other things to do, like sleep!

Anyway, I was thinking again about that problem of getting back to the moon, since China is likely to go there.  There doesn't appear to be that much interest in going back there here in America.  However, that may be a mistake.  Or is it?  I think it is if China means to dominate space.  If they dominate it sufficiently, we may not be able to do it even if we want to.  So, we'd better get moving.

The latest idea is to bring an asteroid to the moon and mine it for water and carbon so as to make rocket fuel.

What if there isn't any carbon dioxide on an asteroid?  What if it is just elemental carbon?

You can take elemental carbon and use hot carbon dioxide to make carbon monoxide.  Then, oxidize the carbon monoxide to make more carbon dioxide.  Once you have carbon dioxide and hydrogen, you can then make methane and lox.

Why not just make hydrogen and oxygen?  That's because hydrogen is deeply cryogenic and is a pain in the neck to store for long periods.  For this reason, Elon Musk is going to use methane lox engines in the future.

The long range goal is to go to Mars, where there's plenty of carbon dioxide and water.  You'd better learn to make fuel, or be forced to take it with you.

Carbon dioxide may not always be handy, thus the need to convert carbon back to carbon dioxide.

All of these chemical reactions are going to require energy, so you will need a nuclear reactor.

Anyway, the trip to Mars is going to take a lot of fuel.  Which means you must find a way to get fuel up cheaply by lowering launch costs, or you must use in-situ resourcing and fuel depots, or perhaps both techniques.  If none of this is done, you must use heavy lift vehicles to bring along all that will be needed.

Heavy lift is the brute force way of doing things, but even brute force has its limits.  You can make these rockets just so big.  Big rockets cost big money.

One of the proposed Mars missions requires seven heavy lift launches.  If you don't use nuclear thermal engines, it would require up to fifteen.  No wonder Constellation got canceled.  People may shrink in horror at such a proposition.

It would seem that in-situ resourcing and reusable rockets are the way to go.  But if China pushes things, we may be tempted to go back to the old, big, dumb rockets.  That's would be a mistake.

One way or another, we are going to have to meet the challenge that China is offering.  Or forfeit the position of leadership in space.  Something needs to be decided and soon.