Help with Feb 1996 LR #11

[uwofresh]

Building a space station, in which astronauts would live for a considerable time, is essential even if the space station project were to contribute no new knowledge about space or earthe that could not otherwise be obtained.  For future missions to explore mars, we will need the medical knowledge that the space station project will give us about the limits of human capacities to live in spacecraft for an extended time.

the argument makes the assumption that

a.) the exploration of mars will be carried out by people traveling in spacecraft and not by robots alone.

b.) the capacities of astronuts are typical of those of ordinary human beings.


Ok, I know that A is right and this is the one I picked on the real test.  However, I don't know how to eliminate B.  If I were to negate B, wouldn't it destroy the argument?  If the capacities of astronutes were not Typical of those or ordinary human beings, this wouldn't really give any medical knowledge about the limits of human capacities to live in spacecraft for an extended time wouldn't it?
Can someone explain this?  Thanks in advance.

[theo]

Building a space station, in which astronauts would live for a considerable time, is essential even if the space station project were to contribute no new knowledge about space or earthe that could not otherwise be obtained.  For future missions to explore mars, we will need the medical knowledge that the space station project will give us about the limits of human capacities to live in spacecraft for an extended time.

the argument makes the assumption that

a.) the exploration of mars will be carried out by people traveling in spacecraft and not by robots alone.

b.) the capacities of astronuts are typical of those of ordinary human beings.


Ok, I know that A is right and this is the one I picked on the real test.  However, I don't know how to eliminate B.  If I were to negate B, wouldn't it destroy the argument?  If the capacities of astronutes were not Typical of those or ordinary human beings, this wouldn't really give any medical knowledge about the limits of human capacities to live in spacecraft for an extended time wouldn't it?
Can someone explain this?  Thanks in advance.

It's because even if astronauts are unusually well-suited to extended space existence, it would still be information about "the limits of human capacities". 

"The limits of human capacities" would obviously refer to the limits of unusually well-suited humans, not the limits of invalids with one lung and half a liver.

That is, any astronaut attempting long term space travel would of course be pre-selected for fitness, anyway.  And even if we were planning to send off average slobs into deep space (now there's an idea), how much better-suited are astronauts?  10%?  40%?  You'd still gain plenty of medical insight from the fit astronauts.

[Atlas429]

With B negated, astronauts could have capacities that are very much above average or very much below average. Whatever the case may be, this would still test "the limits of human capacities to live on a spacecraft for an extended period of time". You'd just be testing the limits of one extreme group.

So B negated doesn't destroy the argument.