# Re: [PSAS] Fwd: staging designs, code inspection

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```the code is aero model independent: plug in stages and delta v for
each stage, isp and fif, and it spits back masses. Aero modeling
should inform delta v apportioning.```
```
delta v for leo is like 7500 (?) m/s, so there's a fat ol' margin in
those examples. I'd like to discuss aero modeling at the next meeting
(what it gets us, what we can engineer around, extreme values, max q
and whatnot.
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Yes, aero, indeed.
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Realistically, I don't think we want to move through the atmosphere at 3000 m/s (need max q figures). Further, we'll likely find (in simulation) that trying to do so is less than optimal in terms of fuel consumption ;)
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I have some questions about masses as defined as well. If the proposed numbers mean anything, I'm not sure our final mass can be 1.22 kg. We need weight of last stage tanks, motor(s), etc. with the 1kg cube-sat.
```

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```On 1/31/11, David Harris <dharris...@gmail.com> wrote:
```
```Hi Ben,

What aero model are you using and how are you calculating the gravity turn
and angle of attack losses?

Or at this point are you just adding some margin to the delta v target
figure and just approximating?

David

On Sun, Jan 30, 2011 at 6:03 PM, Benjamin Kaplin <bkap...@pdx.edu> wrote:

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Ex:
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```- m_i1  Mass of 1st stage only, including fuel
- m_f2  Mass of 2nd stage only, excluding fuel

```
```This comment pointed out to me that the script was really only useful for
designing a particular stage. So, to provide a more general tool, I
rewrote
the script. It should be a lot more user-friendly now. It allows for cool
things like specifying the supportmass/fuelmass ratio on a per-stage
basis.
Enjoy!

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