Author Topic: A real application for human space flight  (Read 7448 times)

Offline AS-503

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Re: A real application for human space flight
« Reply #40 on: 01/25/2011 02:48 am »
Oh, DarkenedOne...

Thou has ignorantly drifted into shark infested waters with a chum suit.

More facts and less conjecture will serve you better in these dangerous waters that are unkind to opinion.

Jim is merely showing you the light.


Offline JohnFornaro

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Re: A real application for human space flight
« Reply #41 on: 01/25/2011 02:49 am »
... where as a Shuttle mission could be arranged in under a year.
Wrong. 
A.  A shuttle mission can not be arranged in a year.
B.  Aside from MPLM, it would take the same years to build a payload for the shuttle.
Please provide some references for this info.

You do need to do some more reading on this site and more reading on the subject matter in general.  For example:

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Even then most satellites are lost because they run out of fuel.

From Space Mission Analysis and Design (SMAD), 3rd Ed., p. 208:

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Heating due to extreme UV radiation and its solar cycle variation has the greatest effect on satellite lifetimes.

And thank you again, Jim, for the recommendation.  I'm up to page 241; it's been slow going, and I don't fully understand it all, but this is a great book.

But back to the OP: 

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A real application for HSF

All that we have right now is tourism, the way I read the word "application" in the thread title.  So I expected to see an economic activity suggested:  You poo-poo'd exploration.  Manufacturing?  Gambling?  What?  You don't quite say. 

The robotic solution for exploration has been discussed a zillion times on this site.  The general consensus is that you use them now, because you have to; ultimately humans will discover the really interesting stuff, later on, when mining and construction activities become more common place, humans will operate robots.  Sometimes the humans will be on the surface, other times in orbit, and in the case of the Moon, sometimes the humans will operate the robots from Earth.  It simply isn't an either/or decision.  Eventually humans will live on other celestial bodies, as well as in orbiting stations.

There is a very real chance that we may be compelled to stay on planet. 

But what do you think would be a real application for human space flight?
Sometimes I just flat out don't get it.

Online ugordan

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Re: A real application for human space flight
« Reply #42 on: 01/25/2011 12:05 pm »
Secondly it clearly costs more to transport something to the L2 point than it does to LEO. 

Exactly, and you have to make a choice between making that telescope serviceable by humans to justify HSF in your mind OR launching it to an orbit that scientists (the ones who are supposed to use the telescope in the first place) prefer. Prefer over something where at any given moment half of the sky is blocked by a big, bright object imposing nontrivial pointing, thermal and power restrictions. I'm sure atomic oxygen in LEO is a real doozy as well.

You appear to not be aware of all these issues human-serviceability imposed on Hubble and why future big telescopes (especially IR ones which are now preferred) prefer L2. Or do you think JWST is going there just because it's more expensive?

Offline JohnFornaro

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Re: A real application for human space flight
« Reply #43 on: 01/25/2011 01:29 pm »
And speaking of atomic oxygen, again from SMAD, P211:

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Atomic oxygen - the predominant atmospheric constituent from ~200km to ~600km - is another importan part of the upper atmoshpere's effect on space systems.This form of oxygen can react with organic films, advanced composites and metallized surfaces [Visentine, 1988] resulting in degraded sensor performance.

It's not like I know all this by heart; I just read it the other day.
Sometimes I just flat out don't get it.

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