New Mars Forums

dryson, this is how I see it.  I won't be offended if you disagree.

This cost is important, because humans in large groups have to make decisions for everyday life before they make decisions for the future of humankind. 

1.)  Who's deciding to spend the money?  If it's government, then the lawmakers have to decide if it's morally right to take the extra cash out of the hands of their people to fund an extremely expensive and risky action that might have no benefit.  If you're telling a working class family that 400 of their $40,000 yearly income is going to send a handful of people to another planet, you should either be absolutely sure that there will be some benefit.
      If not governments, that only leaves individuals.  They can spend all their own money they want and not feel bad about it (and guess what, they are) but that money is limited compared to national governments.  If they an others like them are able to sustain this investment, they must get money for doing what they're doing, because space travel is pretty much the most expensive activity available to mankind.

2.)  It's nice to invoke the brave explorer archetype, and I hope that those people are revealed as humanity makes it's way from this planet, but those explorers are not and were not the individuals or groups paying for things to happen.  That was done by governements.  Not only that exploration was paid for by monarchies that really didn't have to answer to anyone, so it was easy to fund whatever struck your fancy. 

3.)  Explorers in the days of old were using technology not radically different from merchants and traders of those days, just using it a lot further away from home.  This is why people advocate getting an infrastructure in orbit before looking to Mars and further.

Okay, I misread your initial post, Terraformer.

An idea from an old mid 90's paper, by some folks on the Mining side of things.

http://www.annalsnyas.org/cgi/content/a … /822/1/511

Basically, most asteroids have spin to them.  You put a tether down in the main mass, and you send the stuff you want to keep down the tether.  Calculate when you need to release it to sling it toward Earth, and you have a velocity boost requiring very little reaction mass. 

There is lots of other stuff in the paper, but I found that particularly useful from an economic point of view.

Vaguely related:  I remember reading (but I can't remember where I read this, my apologies) that glasses manufactured in space would be far stronger than terrestrial glasses, because of the dryness of hard vacuum.  the water vapor in Earth's atmosphere creates imperfections in glass produced here, weakening it's structureal strength.

Rick,

First off, my apologies, Hb is shorthand for Hemoglobin. 

To answer your first question, there are known forms of Hb with higher binding affinity to O2 (fetal Hb), a mutation has also been observed that increases affinity for O2. 

see http://www.pubmedcentral.nih.gov/articl … id=1220602 for info on O2 binding mutant (albiet based on the embryonic form of Hb).

I don't know of a mutation that increases CO2 binding, so that is more theoretical, but Hb is one of the best understood proteins in the human body and I'd be surprised if one couldn't be rationally designed.  Failing this, designing a CO2 binding molecule based on the deoxy (high CO2 affinity) form of Hb's binding site.  Again, theoretical, but pretty down to Earth as theories go.

This doesn't mean it's going to be easy, of course.  Our proteins behave the way they do because it keeps us alive.  Any changes are suspect, potentially throwing off the biochemical balance.  A huge amount of testing would be necessary to bring this into humans.

To clarify my idea in more detail let me try and describe it better.

    You have a hollow sphere that is divided into 4 quadrants with a hinge at the top of the sphere holding the quadrants together.  The hinge has a CO2 sensor on it that controls whether the bead is closed (a sphere) or open (internal contents exposed).  The internal surface is coated with modified Hb proteins or just CO2 binding sites described above. 
     At high CO2 blood concentrations, the bead opens, exposing binding sites that start binding CO2.  When the blood CO2 drops low enough, the binding sites will start dropping CO2, which is then picked up by normal Hb and carried to the lungs as normal.  Then the bead closes. 
    The important thing is that the CO2 binder has affinity for CO2 less than normal Hb (only binding excess CO2 and not stripping the blood of it).  Also, the sensor needs to activate at a lower concentration of CO2 than the modified Hb binds.  You don't want the beads closing with modified Hb still holding on to CO2, you want to get rid of it when you're back in normal atmosphere.  This rational is for a reusable system, if you want a single use system like Rick described, you want to close the bead when CO2 is still bound.

In all honesty, a single properly designed Hb molecule would do the job, striking the correct balance between O2 and CO2 affinity to deal with increased CO2 concentration.  A much more elegant, but much more difficult proposition.  Another (partial) solution would be to alter the way the body buffers the blood.  If you can reduce the impact dissolved CO2 has on blood pH, then you mitigate some of its toxic effects.

I hope this was clearer,

Michael