[OFF TOPIC] JOwen's Rocketry Shenanigans

[SlimeJime]

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

dude all this is amazing i wish you good luck in your endeavors

[Benvisions]

You're going to do good in the project.

[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).

[JOwen]

Time to make some composite rocket parts!

the most common composites used in rocketry are fiberglass and carbon fiber. they are similar weights, carbon fiber being a bit lighter, and similar strengths. fiberglass is a bit cheaper, and it is transparent to radio frequencies (unlike carbon fiber), allowing you to send telemetry from the rocket to the ground station.
carbon fiber is great for body tubes, but fiberglass is better for nose cones since you can send radio signals through it. the very tip of the nose cone is made of chunk of solid aluminum, since that takes the brunt of the aerodynamic heating at higher Mach numbers.
for the purpose of the current rocket i'm working on, the entire airframe will be fiberglass since it's cheaper. some future high performance rockets will have CF body tubes though.

This rocket is called "risky business" and it'll be my first rocket to go over twice the speed of sound. it has a top speed of just about 1,700 mph. it is mainly being used to test avionics and structures under extreme G-forces, as this rocket accelerates at almost 95G on takeoff (peak thrust/weight for this rocket is 91.2).

the body tube will be pretty simple to make - I put about 1.5 wraps of 4mil Mylar around a cylindrical mandrel, which is given a thick coat of laminating epoxy. while the epoxy is workable, i add 4.5 wraps of 6oz fiberglass cloth, making sure to let the epoxy soak through the cloth. finally, 2 wraps of PeelPly (release cloth) is added to remove the excess epoxy and make for a smooth surface finish. the epoxy is allowed to cure at 80 degrees fahrenheit for 24 hours. once the epoxy is cured, the PeelPly is peeled off, the rough ends of the tube are removed with a miter saw, and the tube is sanded with 180 grit, 220 grit, and then 320 grit sandpaper, with the tube being cleaned between each sanding.

the nose cone will have a 3D printed mold for everything except the very tip, which is given 4 wraps of 6oz fiberglass cloth and one wrap of peel ply.. the nose cone tip is also the anchor for the kevlar shock cord, and is added later. once the peel ply is removed and the nose cone is sanded and cleaned, the shock cord is attached to the eye bolt, which is stuck through the forward end of the nose cone, and the aluminum tip screws onto that.

the fins are tacked onto the body tube with JB-Weld steel reinforced epoxy, after which they are given a fillet at the root using thickened West Systems epoxy. then, after sanding and cleaning the surface of the fins, they are given a 2-layer tip-to-tip fiberglass layup (with the 6oz fiberglass cloth rotated 45 degrees between layers), followed by a layer of peel ply. as usual, the epoxy cures for a day at 80 degrees F, the peel ply is removed, and it is sanded with 180, 220, and 320 grit sandpaper, being cleaned between rounds of sanding.

the method for making this rocket if you made it from carbon fiber instead of fiberglass would be the same, assuming you used similar density carbon fiber cloth, and a high quality epoxy.

[JOwen]

hello, its been a bit since i updated on this thread, as i've been quite busy and haven't been able to do much.

as of late, i have developed 2 rocket propellants, "cookie dough" and "hot sauce".

cookie dough is a slow-burn propellant, which makes for longer run times at the cost of less thrust. this is ideal for second stages, but sub-optimal for booster stages.

hot sauce is fast. it burns hot and at high pressure, making lots of thrust but not for very long.

the "risky business" flight has been postponed until january 2024 (original launch date was november 2023), but the performance has also increased. the rocket will be powered by a motor named "HS886," or "Hot Sauce 886" as it uses the hot sauce propellant and produces a peak 886 horsepower.

the rocket will accelerate at a peak of 92.3G and reach a top speed of Mach 2.38, as it is extremely light for the amount of power in it.

i also recently cracked a tough problem that had been plaguing my for a while, and this will allow me to break the 1,000hp milestone in the next couple months.

that's all for now, let me know if you have any questions i will happily ramble at you about rockets

[MoonlightTheStupidTouhouFan]

I feel like we should add The Great Strategy to this rocket of yours.

[JOwen]

I finally got back to launching rockets!




the latest launch was a relatively small rocket that packed a punch, as it did 0-60 mph in 0.043 seconds (i like to compare the rockets to cars with car stats because it shows how much of an unfair advantage rockets have over traditional engines)
it produced a peak horsepower if 813hp, but it only weighed about 5 pounds excluding propellant.

the top speed acheived was 1,748 mph, or about 2.3 times the speed of sound, at a perigee of just 1500ft AGL, and apogee was at just shy of 3 miles AGL.

the motor that powered this rocket was one that i designed, built, and tested myself named the "EX-J414_G" (lovely name, i know but these names help me keep the motors organized in the simulation software and also tells me some info about the motor at a glance).

the rocket itself was a Carbon Fiber COPV (Composite Overwrap Pressure Vessel) body with a Carbon-glass composite fin can and an RF-transparent composite nose cone. surface heating was around 450 degrees F above ambient. peak G-force was around 94.8G and the peak drag deceleration was -14G (slowing down about 16 times harder than a road car slows down when you slam on the brakes all the way)

let me know any questions you may have and i'll do my best to answer!

[Fireguyy27]

just hear me out what if you attach water ballon bombs

[--Polaris--]

wowzers

[DaviousDingle]

oh my DAVE!!!!!

just be sure not to become dave gehehe