Re: Space Policy: Why Mars should be our top priority.

Marvin the Martian <marvin@xxxxxxxxxxxx> wrote:

:On Fri, 24 Apr 2009 19:14:47 -0700, Fred J. McCall wrote:
:
:> Marvin the Martian <marvin@xxxxxxxxxxxx> wrote: :
:> :Energy wise & rocket wise, Mars is closer than the moon, :
:>
:> You've said this before. I've pointed out that the source you gave
:> doesn't agree with your claim. Go add it up for yourself.
:
:Yes, I've said it before.
:
:You didn't point out anything.
:

Yeah, I did. Let me point it out again.

:
:Let's go here:
:http://en.wikipedia.org/wiki/Delta-v#Delta-vs_around_the_Solar_System
:From LEO to the moon surface is 4.1 km/s + 1.6 km/s.
:
:So the KE from LEO (Low Earth Orbit) to the moon is 1/2 m v^2 = 16.24 kJ/
:kg.
:
:From LEO to Mars is 2.5 + 0.7 + 0.6 = 3.8 km/s The red arrows indicate
:the opportunity to Aerobrake; using the planet's atmosphere to slow down
:rather than needing rocket energy. So the KE from LEO to Mars is 7.22 kJ/
:kg, less than half the energy of the trip to the moon.
:

You're reading it wrong. Let me point out an example of what the way
you're reading it implies. Look at "Lunar Orbit". If your reading is
correct, one can assume one can get from lunar orbit down to Earth's
surface purely on aerobraking.

Of course you can't do that. Neither can you disregard the entire
velocity change required from Mars Transfer to Mars Surface by
claiming you can do it all by aerobraking.

:
:What I said is true, and what you said... yeah. right.
:

What you said is poppy***. But then we just need to consider the
source.

--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn
.

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