Need help with overly ambitious rocket project

[Adoniram]

Hello All, a few friends of mine and I have devised the ridiculous idea that it would be fun to build a rocket that could do something like the popular weather balloon projects which achieve high altitude for cool visuals (via GoPro or similar). But we want to make it better/faster/cooler. The objectives are:

• Rocket is actually swept-wing jet body with retractable wings (in for launch, out for return)
• Rocket achieves high altitude (>50,000 ft is the real goal)
• Uses arduino or similar to maintain both launch and return trajectory
• Flies to specified way points on return
• Takes super cool video

Some strategic goals are:

1. Develop actual mathematical model to explore parameter space of weight and fuel vs max altitude
2. Make simple robotic rocket (plain vanilla Estes with D or E engines) to test and program robotics for upward flight control (point straight up, don't roll, etc)
3. Make simple robotic rocket with retractable wings to test return control
4. Scale up to higher altitudes, eventually use more exotic fuels, etc

I think 2 and 3 will be a fun engineering project, and 4 will be somewhat costly and monumental, but my job is to focus primarily on # 1 for now. It has been a long time since I took CM, so I could use some help... This is what I need to account for (some things are redundant):

• a. Non-constant mass (obviously)
• b. Non-constant air pressure/density/temperature
• c. Drag

I've seen somewhat decently developed EOM for a or c, but never together. Incorporating b should really be something included with c.

If you know of any really well developed models for this, that include all 3, I would really appreciate it! The best I've seen so far, which only has one of those requirements, are here:
http://www.rocketmime.com/rockets/rckt_eqn.html#Method
and here:
http://web.mit.edu/16.unified/www/FALL/thermodynamics/notes/node103.html

Thanks!

ps: yes I know this will require legal hurdles as well, FAA rules, ITAR, etc...

 

[Nugatory]

The only reliable advice you're going to get from the anonymous posters on an internet forum is: Find people who know what they're doing and work with them. Good starting points will be http://www.tripoli.org/ and http://www.nar.org/.

I'm closing this this thread because it's really not something that we can provide actionable advice on, but if anyone wants to suggest other reliable reosurces, please PM me or any of the other mentors so we can add on to this answer.