[ExI] new heavy lifter

[spike]

>. On Behalf Of John Clark
Subject: Re: [ExI] new heavy lifter

 

On Apr 5, 2011, at 1:14 PM, spike wrote:

 

>>.This caught my attention because I have long thought of this approach as
compelling:

 

http://cosmiclog.msnbc.msn.com/_news/2011/04/04/6409132-spacex-shoots-for-ne
xt-big-thing

 

.

spike

 

>.I hope the claims made for this prove to be more accurate than those made
for the space shuttle. There is more and a promotional video at:

 

http://www.foxnews.com/scitech/2011/04/05/powerful-rocket-world-ready-2012-s
pacex-says/

 

  >John K Clark

 

 

Hmmm, John there is a subtlety here I hope to up-clear.  

 

I often hear the comment that the space shuttle's capability was exaggerated
(30 tons to LEO, 12 tons return.)  It never came close to either, but it was
*theoretically* capable of both of these goals in its final configuration.
The original design specs called for carrying the Hubble Space Telescope to
orbit and returning it to the deck for periodic maintenance and relaunch.
The shuttle was never used for this purpose, but that was for a good reason:
it's dangerous as all hell to carry that much payload either direction.  In
either scenario, it stresses everything to the maximum.  We saw one shuttle
come apart on re-entry.  Carrying the maximum design load greatly increases
the risk of a structural failure resulting in the loss of vehicle and crew.

 

Also note: if they were to attempt a maximum payload re-entry, they need to
go to every level of heroics to get the human payload down.  It isn't just
the weight of the apes, it's the weight of all the associated life support
equipment, and the risk of a failure that may give the astronaut several
minutes forewarning of impending doom, with nothing to do about it but tell
her family and the whole world her final words.

 

One can imagine a single occupant aboard during an attempted landing, or
even none, since it would be inherently high risk.

 

Back in 1989 we returned a very valuable payload, the LDEF.  That one
weighed about 5 tons, and we were aaaaaallllll sweating blood in huge red
droplets until that payload rolled to a stop.  Nooooobody wanted to even
think about trying to return a 12 ton payload, nobody.  But I would estimate
a good ~85% chance the shuttle could have done it and landed safely, maybe
90%

 

spike

 

 

 

 

 

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