[OFF TOPIC] JOwen's Rocketry Shenanigans

[JOwen]

Completed Space Shot rocket concept!


 this design is absolutely NUTS. it weighs only 90 pounds. which is absolutely CRAZY. NINETY POUNDS. GOING TO SPACE. (I'm a little excited). It's a two stage rocket with about 80% of the space in each stage taken up by propellant, the rest being avionics and recovery gear. this rocket is completely re usable.
the launch of the space shot rocket has also been moved up! this rocket could fly to space in as little as 3.5 years.

though skinny and light, this rocket does NOT skimp on the power, flying to an altitude of 378,870 ft above ground level, with a peak speed of mach 5.06 (that's right, its hypersonic), and a peak horsepower of 17,580.

over SEVENTEEN THOUSAND horsepower. can you believe that?!

anyway that's today's ramble for you

A little more information on this rocket:
each stage is powered by a ~4 inch diameter, ~5 foot long rocket motor (266.4s Isp @1000psi, 14.7psi external pressure, 86% solids), each of which produce 1,700lbs of thrust for 4 seconds. the upper stage ("sustainer") of the rocket will fly on its own in an all-systems test flight as soon as next summer, which will go to 25km (82,000ft) and mach 3.41. 

in the flight to space, the booster separates as soon as its motor burns out, and the sustainer coasts for 15 seconds before igniting its rocket motor.

I am SO STOKED about my solution for reliable ignition timing: thermite-based igniters. for those who don't know, thermite is a reaction between a metal (in this case, aluminum) and a metal oxide (in this case, iron oxide) in which the oxygen goes to the less-oxidized metal, releasing heat in the process (in the case of this igniter, this produces aluminum oxide, iron, and a whole lot of heat). the thermite reaction is started using a strip of magnesium ribbon which is heated electrically. the thermite "pouch" will burst, pouring MOLTEN IRON onto the propellant. if that wont start it, i don't know what will. I am not the one who came up with the solution, but I think it is stinking cool.

one problem that still remains to be solved is this:
the sustainer needs to be spinning really fast. we want that thing just absolutely BALLIN so that when it leaves the atmosphere and fins can no longer stabilize it, the flight path doesn't get all wiggly. how exactly we spin the rocket up to ~10Hz is TBD.  here are the options:
a) canted fins - tilting the fins a little bit will generate some roll, but it also increases the drag on the fins, which is not desireable.
b) reaction wheel - having a ring-shaped weight that you spin up generates a roll torque, spinning up the rocket, but this requires fitting that setup in the avionics bay.
c) cold-gas thrusters - forcing a high pressure gas (probably CO2 from a paintball cartridge or similar) through angled nozzles to produce a thrust to spin up the rocket. the main problem with this one is also getting it to be small and fairly light to go in the avionics bay.

anyway, i'll keep you guys updated (if you're interested) and feel free to ask any questions, and I will answer as long as there isn't any legal/safety concerns

also, some aspects of the design I will not share, as the team I am on that is working on this, while we are an amateur team, does have an informal non-disclosure agreement regarding some portions of the rocket(specific dimensions of some parts, avionics, rocket tracking, etc). there are of course some things that I can't tell simply because of legal or safety concerns(exact propellant formula, rocket tracking, etc).