Hey guys,
I'm having some rather painful migraines which are leaving me doubtful that
I'll attend tonight's propulsion meeting. AFAIK Nathan is still going, so
tonight would be a good time to actually compare designs in open rocket.

Keep in mind that changing the fin dimensions or adding ballast to the nose
cone is fair game if your design isn't stable in flight (recall that
stability is a function of the positions of the center of mass and the
center of pressure, both of which are changing dynamically with time,
velocity, angle of attack, altitude, and also with reynolds number and mach
number among other things). It's okay if its not totally stable for the
first half second or so right off the launch rail (assuming that it doesn't
ruin your simulation). If somebody is able to get a legit design to 100 km,
take the burn time and rocket dry mass to get the mass ratio, and plug that
back into the rocket equation to compare with our super simple 1.4 km/s dV
estimate. My bet is it will be 1.5X-2X as high.

I'm guessing the 100 km rocket with steel tanks isn't doable for us in a
single stage. But I'm curious if we can pull it off with aluminum. We also
assumed a pressure fed rather than pump driven propellant feed system,
which is good because if anything this means our current numbers will be
pessimistic (because we are using a design calling for heavier, high
pressure tanks). I'm hoping this whole exercise will give you an intuitive
appreciation for how ridiculously parameter sensitive rocket design is.

Ad astra,
Erin Schmidt
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