2017 - 2018 Propulsion Subteam Recap - MIT Rocket Team

Mixing over 290 lbs of propellant for 236,380 Ns of Impulse, the MIT Rocket Team has one of the premier student propulsion teams on the planet, and we'd like to recognize the countless hours they've put into their work.
Producer: Sam A.

[@mojaverockets]

They say bigger is better...why we're doing an 18" after our 12" motor

[@lakshyaagrawalhub9821]

Which song is it in the background??

[@vendright]

Love it, thanks for sharing

[@HomeGrownPyrotechnics]

also, what is it costing you in fuel? im guessing its apcp? that can be pretty costly.

[@AstroCharlie]

The cost of the propellant varies with formula. Somewhere between $10 and $25 per lb.

[@mayanksharma7354]

Woah what a video keep it up guys

[@pestypig]

Crude music! Nice rocket!

[@deldrise9169]

0:12 What are the grain Spacer O-rings used for

[@harrys2k]

The space that they leave between the grains ensures that all grain faces will be lit on ignition and that they don't inhibit themselves. This would cause complications during the burn, like the Kn range getting thrown off. Alternatively, you can make a concave face on the grains like CTI does, but doing that on 5" diameter grains sounds less than fun :-)

[@HomeGrownPyrotechnics]

how are you guys sealing the nozzle to the casing? press fit or o-ring?

[@AstroCharlie]

There's a double o-ring shaft seal to both closures

[@mojaverockets]

@@AstroCharlie Have you thought about including a 'compression O-ring' that fits between your nozzle and nozzle retainer? Doesn't risk getting cut when sliding nozzle past O-ring groves or bolt holes and seals better as the pressure increases.

[@AstroCharlie]

@@mojaverockets We don't have seals around our retainer, so we'd need to change a lot. We've had our seals survive to 1550 psi hot and over 2k psi hydro, so we're pretty happy for now.

[@mojaverockets]

Just looking at the triple O-ring setup at 1:49 in the video. We use to do two and three and have reduced that to none or a single floating compressional and one traditional and found a large weight and space savings in the motor. The O-rings don't go around the retainer, it sits between the retainer and the bulkhead or nozzle in a slight cut in either and gets compressed when the motor fires. Never had a leak doing that method provided the ends are a good fit. Just a suggestion if you need to save some weight.

[@christaylor4864]

@@mojaverockets @Charlie Garcia Have either of you or your classes made any hybrid motors?