Welcome to an incredibly special and momentous update for LPRD Rocketry! We are finally celebrating our transition from “some random kids who want to make liquid propellant rocket engines” into a group which has proven its ability to design, build, and operate liquid propellant rocket engines. Few people can claim this feat, so for those of you who have been through the crucible with me, I congratulate you.
(Full test video is at the bottom of this post)
For those of you who haven’t heard of us before: We are LPRD (“leopard”) Rocketry. We work with the belief that dreams should be pursued fervently and pursued now. We are a group of students at the University of Minnesota – Twin Cities and other Minnesota colleges, and our dream is a dream we think is shared by the human race. Ever since people have been able to look up at the heavens, the stars have been a source of wonder. We want to contribute to the engineering body of work that will allow humanity to expand to that final frontier. Specifically, we aim to use the engineering skills of students to design, manufacture, and test liquid propellant rocket engines, and we invite you to join us.
In the beginning…
When we started about a year and a half ago, we were just three people with a little curiosity. Hobbyists build model rockets all the time; some even make their own rocket engines, but they always use solid propellants. Why don’t amateurs build liquid propellant rocket engines? We decided to find out.
We started small. Fall of 2014, we started by building some out-of-the-box hobby rockets and designing a test stand which would let us practice handling commercial-off-the-shelf (COTS) solid propellant rocket motors.
And then there were 20…
Then the real work. We expanded to a team of about twenty and began the task of designing and building our own little rocket engine and test stand. Rocket engine design and manufacture progressed quickly. Laborious, yes, but straightforward. We hammered out a few dozen hours in the machine shop, and out came an engine.
But the path was hard…
The delay occurred in the test stand. Piping, plumbing, and valves are hard. Not sexy, but hard. We made some poor hardware choices, and that set us back. I won’t lie, the delay frustrated me. Some of our operations were scary. Pressurized gases are scary things to a college kid who’s never dealt with them before and is suddenly figuring it out on his own.
And we struggled…
When summer came, we still had no real product. Just an engine and a partially functioning test stand we could use for cold flow rate and pressure testing. Safety approval became an issue as well. Professors wanted nothing to do with it, since no one at the University of Minnesota specializes in rocket engines. The UofM College of Science and Engineering wanted nothing to do with some kids playing around with trying to light a home-made, untested, highly risky rocket engine.
Many people dropped out, and I don’t blame them.
And then there were 5…
The believers (or those of us stupid and stubborn enough to keep doing this) spent the summer working doubly hard in reduced numbers to pressure test the engine and make sure it would withstand the structural strain we would eventually put on it.
Then, we caught a break. We talked to Orbital ATK‘s TPG (back then, it was ATK’s ATPG) about using their facilities to conduct test firings since the University wouldn’t have anything to do with it. The project excited them, and they wanted to help us to a test firing.
The only problem? Our test stand setup wouldn’t let us fully fire the engine. The test stand wobbled, only had on-off control, and the valves moved painfully slow. We couldn’t do any more than an ignition test, but school started in a few weeks, and if we didn’t have anything to show for 6 months of work, how would we recruit for a dying project? We either had to create something out of nothing, or die as a project.
And so we created something out of nothing.
Something, but barely a result.
That day, we made mistakes. Many of them. In front of professional test technicians whose job it was to not make mistakes as they set off explosives.
As soon as we got there, we accidentally shorted together our batteries and set our lines on fire. Two, twelve volt, lead-acid ATV batteries designed to output more than 300 Amps of current shorted together. Thick clouds of pungent smoke roiled out of our battery box. Luckily, the fire burned out, harmed no one, and the proving grounds had a backup power source into which we hooked our control panel. Regardless, we made mistakes and made barely any progress when Orbital ATK donated their time to help us fire a rocket engine, so we knew we had to do better.
So we came back…
We hyped the video, recruited and expanded our team again. We purchased new valves, we tested those valves, and we discovered those valves were the wrong valves. And then we did it again until we found acceptable valves.
Concurrently, we began designing a second generation engine which would be regeneratively cooled, meaning we wouldn’t have to pump water to it to keep it from melting.
And suddenly, things started happening…
Our team grew. We built our first high power (solid propellant) rocket as a testbed for our avionics.
We contacted Protolabs about 3D printing our regeneratively cooled engine, and they decided they would like to donate the piece.
We started designing and testing our own, custom injectors.
We talked to the Minnesota Space Grant Consortium and received some workspace and some funding.
But none of this matters if we don’t have anything to show for it.
So we scheduled a second test with Orbital ATK at the proving grounds and began preparing. Hours and hours of dress rehearsals consumed our time and brainpower as we found issues, fixed issues, discovered new issues, and fixed those issues.
We ran dress rehearsal nine days from testing day, and we were nowhere near ready. The ignition system was not assembled, the engine was under modification, and the procedure had flaws. This is the time when Dreamers fall away and Doers pull through.
We pulled it together. We showed up, we delivered, and we ran the first successful liquid propellant rocket engine in Minnesota.
We are a group of students, not professionals. We attend a school with no aerospace propulsion lab. We are a group of dreamers, of believers, of doers. We are LPRD Rocketry. We look up at space, and we see endless potential. We look around us at the other students, and we see endless potential. We don’t want to wait for a diploma to do real engineering and create something real. We don’t want to hear that we’re too young, too inexperienced, to naive, because we know we are. We also know we always will be thus unless we go out and learn by doing.
So we did.
Sound like you identify with us?
There’s a long path yet to tread. There’s work to be done, and it will be hard. Some of it will be tedious, even boring. Some of it will be exciting and experimental. Some of it may even be dangerous, but I can guarantee you that all of it will be hard. That’s what sets us (and maybe you) apart. We choose to do this not because it is easy, but because it is hard. We do this because we are LPRD Rocketry.
When we come out the other end, we will be more experienced, smarter, stronger, and more ready to help solve the engineering challenges the world currently struggles with.
Still identify with us? Then I’d like to invite you to join us in our journey.
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