School Project

[William]

Hello,

Ideas have changed since this initial post see post number 6.

I am not sure if this should go here or in the "scratch built" section so it will probably get moved.
I have been given a school project (an EPQ) that allows me to do pretty much anything and I have decided to design and launch a rocket! I would quite like an original fuel or material not used before (but that I can actually get hold of).
This is still very much in the preliminary stages but I had an idea to do a Space Shuttle. It would have 3 motors, one in each SRB and one where the three SSMEs would be. The two SRBs would jettison and the orbiter engine would burn for a bit longer then and ET would jettison and the orbiter would glide back as a remote controlled glider. The trouble is jettisoning the SRBs and ET. I was thinking the back-thrust normally used to deploy the parachute could be directed inwards to push the SRB or ET away from the orbiter although that depends on just how powerful that thrust is as if it is too weak then the SRBs will not be able to be held to the ET, and the ET to the orbiter, strongly enough and still be able to separate by that method. Also this would mean the ET and SRBs could have no recovery device but I have been informed if they are light enough that is OK.
Shaping the Orbiter could be quite awkward to do from scratch, possibly a balsa tube for a simplified fuselage shape, balsa carved wings, and maybe some very difficult balsa carving for the cockpit area. The SRBs could just be basic tube rockets and the ET a similar idea (but no motor).
What motors should I use (bearing in mind the proposed separation method above (if indeed that method is any good) so the time between burnout and jettison would have to be timed correctly and the Orbiter engine should burn for a bit longer then separate the ET almost immediately)?
Also any ideas for computer programs that could model this (bearing in mind I have no programming skills). I would also quite like to attach some instrumentation such as an altimeter, transponder, accelerometer etc.

I seek your superior knowledge!

Deadline is Christmas time this year.

Thanks,
Will

[rockets4kids]

Everything you want is completely do-able, but you really want to plan on 18 hour days seven days a week if you want any hope of achieving those goals by xmas. I have been at it for about four years now, and I am only *just* getting there...

My suggestion is to go out and build and launch a few Estes kits at your local rocketry club, preferably an HPR one with people launching electronics, and talk with them about your plans.

[JStarStar]

It can be done, because it HAS been done:



However bear in mind this model was built by George Gassaway, one of the true master builders of model rocketry, and it took him several years to get it to work.

Essentially to do this you have to be a wizard in both model rocketry (including middle and high-power) and R/C airplanes.


The Space Shuttle is very very difficult to get to fly correctly (or even non-disastrously) because it is a very asymmetric and non-aerodynamically stable design. To get it to simulate the real flight profile (jettisoning SRB's, then the ET, then glide recovery of the orbiter) is much tougher.

Most Shuttle kits feature large non-scale model add-on fins for aerodynamic stability.

[Marc_G]

Sounds like a fun project but I agree you should get some basics down first.

One thought is to give up on designing your own fuel. It's difficult, dangerous, may involve significant regulatory and liability issues, and should be outside the scope of this project.

That said, it's still a significant challenge (though certainly doable) to design a shuttle stack that launches, deploys the boosters, and pops the shuttle off as a glider. Making it an RC glider with the added weight involved could easily turn this into a project requiring HPR certification. But RC isn't my thing so I'll let others comment.

Get ye to hobby lobby and pick up some starter materials!

Marc

[William]

Thanks for the advice,
A Shuttle with full staging, glider recovery etc will probably nigh impossible for a beginner to do by the end of this year. As such, we (I have enlisted a minion) will probably go for a three stage Saturn V but I still plan to do something a bit different, maybe a semi-controlled landing of the CM (though I'm not too fond of that as it seems a bit of a gimmick). A potential problem is chute deployment on the CM as it won't have a motor. Perhaps a small pin or something could be set to activate after a set time and deploy the chutes? What computer programs are there that could model this?

I have been to a rocket club twice and launched a small kit-build rocket a few times to get a feel for things.

[William]

We have been doing some thinking and thought it might be interesting to find an old/untried/theoretical rocket design and see how it would perform. We will make calculations/simulations and compare these to the actual flight data (we will cram the rocket with instruments such as an altimeter, accelerometer, ASI etc). We will have to use a motor with equivalent thrust/Isp to the fuel the rocket would have used (scaled down of course). We have looked on the internet but despite how easy I thought it might be we can't find any old designs. Any ideas?

Thanks (again),
Will