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Old April 19th 18, 01:06 AM posted to sci.space.policy
Jeff Findley[_6_]
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Default Space X 2nd stage recovery

In article ,
says...

"JF Mezei" wrote in message news

On 2018-04-17 20:05, Jeff Findley wrote:
In article ,
says...

https://www.space.com/40313-spacex-r...y-balloon.html


By "party balloon" are we talking helium or Hydrogen filled balloons
that will "lift" the stage to slow its descent? (and I assume provide
drag initially).


I'm guessing nitrogen myself. I don't think lift is nearly as important at
this point is as drag over as large a surface area as you can manage.


I heard helium, because while lift isn't important, mass most certainly
is. And at the same volume and pressure, helium masses less than
nitrogen. The mass of the molecule doesn't enter into the ideal gas
law:

P*V = N*R*T

Jeff
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