Big ups to the MIT Rocket Team team for posting this and sharing their experience. We can all learn from this, but most importantly no one was hurt or injured. A testament to having good safety protocols in place.
Looking forward to seeing the issues resolved, and future testing carried out.
Video Caption: At T+ 2.9s a combination of insufficient grease, poor polyurethane application, and inconsistent assembly technique lead to a catastrophic burn through of the thermal liner in the middle of grain 4.
The motor self extinguished at the catastrophic loss of pressure, but the propellant which remained in the motor reignited several seconds later due to residual heat.
This test did not endanger any people. Always use care when testing rockets.
As reported earlier, this test happened at the end of February, this is the full video of the days activities.
Video Caption: On Feburary 23, 2018 the MIT Rocket Team burned our first P-Motor. The motor delivered full impulse, despite ejecting parts of the thermal liner for the first and second grains, which burned out early as intended.
Higher than expected combustion efficiency yielded a faster burn and higher pressure than expected. Details here: http://rocketry.mit.edu/2018/02/p-190…
The MIT Rocket Team recently tested their first ‘P’ class rocket motor (Wikipedia has a good table on the class ranges) at the end of February.
… This test produced 65,077 Ns at a peak pressure of 1440 psi and 22,970 N of thrust.
For all my imperial unit readers, that is 5163lbf of thrust, but the test did not go entirely to plan with the motor ejecting several thermal liners during the burn.
The team states,
…As the design pressure and thrust of this motor were greatly exceeded, we think it likely that aluminum combustion (triggered by the increased residency time in a longer motor) lead to the unplanned increase in burn rate, the increase in combustion pressure, and then triggered the cascade of failures.
The motor did well to hold up, of which I look forward to the next test. This size motor will propel the teams Hermes rocket to 80,000ft in June at Spaceport America.
You can read the team’s full update here.
Ignition! The teams first monolithic finocyl motor set team records for highest thrust and highest efficiency, peaking at 6800 N of thrust and 224.2 s of isp.
The team is really pushing forward with their work on solid rocket motors, great to see so many frequent tests on variously sized motors.
I expect to see good things at this rate of progress!
Pc: 816 PSI (5.6 MPa)
Thrust (max): 5221 N (1173.7 lbf)
Follow the team here.
Updated 17/1/2018 with YouTube video
More team details can be found here.
MIT Rocket Team are aiming high, 80,000ft high in fact, with Project Hermes which they plan to launch from Spaceport America next year as an exhibition flight for IREC 2018.
The rocket, builds upon previous flight-proven designs will use an in-house built ‘P’ class solid rocket motor. Having a propellant mass of ~85lbs (38.5kg) and a liftoff mass of 175lbs (79.4kg), the rocket will reach Mach 3.5 on its way up to 80,000ft.
The team have an extensive range of information on their Wiki Page about the project but also loads of info on designing and building rockets, from composite tube layup to picking the right video camera for that awesome footage!
The team placed 2nd in this years IREC Competition for COTS solid rocket motor powered rocket to 10,000ft and also flew a rocket to 31,850ft at the same competition.
Am looking forward to seeing Project Hermes lift off and to see that 100km barrier broken in the not too distant future.
Make sure to follow progress on,