Update 10/26/2015: Zombie Control Valves

Starting out with an exciting change this week, our test stand team has been renamed this week to the launch team! We also ran a pressure test at 500 psi this weekend and rearranged all our valves to match our procedures. Problem? Our control valves work, but popped again. On the bright side, our actuator didn’t break this time either. For future testing, we’re looking into a wireless design so our team members won’t have to be plopped down by the board the whole time during testing.

Working on the Control Box 1

We’re finalizing a design for our engine that is feasibly machined. All is beginning to come together again for another round of testing.

Copy of Regenerative Cooling Coil


Member Spotlight: Paige Owens

Hello! My name is Paige Owens. I am a sophomore in Chemical Engineering. I joined LPRD Rocketry because I thought the project was really cool and I wanted to be a part of a team to work toward something awesome! I am also a part of Society of Women Engineers and Science and Engineering Student Board. In my free time I love to read and eat! As far as what I want to do in a future career, I would love to work in a research and development role or a quality engineer!

-Paige Owens


Over these past couple of week, the test stand team has been super busy! In particular, we broke one of our control valves during testing a few weekends ago, but we opened it up this week, took a look inside, shifted some parts around, stuck it back together, and apparently it works.

None of the gears inside are structurally damaged, so we believe a gear slipping out of place was the reason for the popping noise and subsequent actuator failure.

Taking apart the CV Actuator 2

The slip likely occurred due to an incomplete re-engaging of the gear box after manually changing the position of the valve.

Working on the Control Valve 2

This means that the valve/actuator assembly itself had no issues (other than its incredible slowness), so we went ahead and ordered new, faster moving actuators! They cost a bit ($220 each), but we think they’ll finally give us the responsiveness we need to fully fire our engine.

Of course, we’re also taking a look at the future and have two big projects lined up. The first is the creation of some composite tanks for our kerosene, nitrogen, and oxygen storage. The commercial, off the shelf piping has worked well so far, but if we’re ever to bring the weight of our system down far enough to put it into an actual rocket, we’ll need to shift to making our own tanks. This will be a year long project, and hopefully we’ll have some beautiful carbon fiber tanks ready for testing by Spring!

The second project is a shorter (we hope) project to incorporate force measurement into our test stand. We already have a Vernier brand force plate from our earlier excursions into testing solid propellant motors, but we need to find a way to incorporate it in.

This should be a fun several months!

20151017_184634 TSOM (1)

-David Deng


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Update 10/19/2015: An Ode to the Hammer

Before we resume our regularly scheduled programming, here is a quick eulogy in remembrance of our loyal hammer, who broke during pressure testing last weekend:

Hammer, you treated us well,

Thanks for all the nails you hit

and the parts you fit,

We are apologetic for the the way you went.

You may not have lasted long

but you did what you were meant.

All of us today are joyous,

for you have served us well.

You may be broken at the neck,

but you will be remembered in our hearts……


Sweet hammer rest your soul,

released from your wooden handle,

be free, stay true, and good bye.

~Anna Koene

IMG_0451 (1)

Our designing process is undergoing a bit of an overhaul. Instead of solely looking into regenerative cooling, the team is now also looking into the idea of using film cooling as well, possibly in correlation with regenerative cooling. Film cooling applies a thin layer of propellant on the outside of the chamber wall or injector rather than the channels or tubing used in regeneratively cooled engines. This week we’re also looking into what went wrong at our testing last weekend. Other than our faithful hammer breaking, we’ve looked into some of the parts that were busted post-testing and determined if they were still functional. It turns out the control valve is still in tact! We also compared some new valves to what we already had and planned to call tech specialists about their ideas.

~Jessica Wettstein


Member Spotlight: Jessica Wettstein


Sitting on the edge of Sugarloaf Mountain in Arkansas

My name is Jessica Wettstein and I’m a junior in the Materials Science program here at the University of Minnesota. I am the social media manager as well as a member of the test stand subteam for LPRD Rocketry. I currently have a co-op at American Engineering Testing in St. Paul, so I’m taking a semester off of classes for my internship.


Equipment for internship

I like to hike, especially in Arkansas by my grandmother’s house. This summer, a friend and took a road trip to Atlanta. It was a lot of time in the car, but it was a great experience nonetheless.

~Jessica Wettstein


Subteam Spotlight

This week, the sensors subteam is rearranging tangled wires after first testing this semester. We found there were some problems with our current circuit during the testing. Glen and Gaurav are testing and fixing our circuit.


After a couple tests and discussions, we found we did not hook up the wire correctly between the inverter and batteries in between the three way switches. Gaurav made a new design to adjust for the changes in our circuit.


We are planning to use a new bigger board to build our control panel. We will put more LED lights on the board to keep track of the activation of the switches.


~Zicheng Li


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Update 10/12/2015: Pop Goes the Actuator

The pressure testing this Saturday went by with varied success. We were able to get everything from Akerman to the East River Flats without having to use stairs! Thank goodness we didn’t have to carry the off balanced test stand around again. We even got the pleasure of taking the test stand and a couple members of our team through the finish line of the Eagle and Anchor 5K finish line.!

Maddie's Encroachment Across the Army 10 Miler

We also made a list of things to bring with us next time we run testing, like a fire extinguisher in case the battery goes up in flames and paper towels to clean off grease on something other than your shirt.

Working on the Control Box 1

For the testing, the 200 psi test was a success! It wasn’t too eventful, but in this case, that was good. However, when it came around to our 500 psi test, there was a “pop” sound. The worrisome plastic pieces from our control valves were not the culprit though. We decided to try and test to see if the pop was due to built up pressure. The problem was, when we ran our test again, we heard nothing. After some investigation, it turned out that it was the actuator that was busted. We had to pack up and call it a day.

~Jessica Wettstein


Member Spotlight: Riley Hilstrom

Copy of 2015-02-20--Raw Aluminum and Riley-

Hello, and welcome to LPRD’s first member spotlight! We’re introducing member spotlights so that you can get to know our team members rather than just knowing them as happy worker bees. We realize our team members have lives outside of rocketry, so we decided to share that side  with you all. We want to create a connection between each individual on our team and our mentors or others who are interested in our project. How ’bout it! First up, Riley.

My name is Riley Hillstrom, a sophomore double majoring in Aerospace Engineering and Entrepreneurial Management. I enjoy working on projects that push my personal abilities and require a lot of design considerations and critical thinking. That being said, building a liquid fueled rocket fulfills these needs and more. This is such a cool project to work on and I’m thrilled to be a part of it. When I manage to squeeze out a bit of free time from my schedule, I enjoy writing short stories, exploring the cities, freestyle snowboarding, boardercross, fencing, soccer, and long distance running. Last weekend I finished my first marathon and I can’t wait to run the next one! Another student group I’ve started to get involved in is Design U. This group works on various design based projects to solve problems here in the cities, like designing new metro bus stops, to social entrepreneurship projects in Africa.


If you were to ask me about my dream job, I would tell you that it’s not a career I’m shooting for, but a lifestyle. My eventual goal is to work as a freelance consultant in the aerospace and high tech industries, managing and consulting for engineering projects, and working with disruptive technologies that are having a hard time breaking into the market. Heck, I might even start a company myself. I work best when I get to manage myself. I need a flexible enough job that will allow me to choose to travel, raise a family, work, and enjoy my hobbies whenever I want. I enjoy both the engineering and business sides of the tech industry and I believe that my degrees here at the U will give me an edge in these competitive fields.


Projects like LPRD get me excited for my personal future and the future of technology. I can’t wait to help develop world changing technologies and help humanity shoot for the stars, literally. I have some pretty big ambitions going forward, but right now I’m keeping myself grounded with all the studying and hard work it’s going to take to get there.

~Riley Hilstrom


Subteam Spotlight: Engine Team


With the beginning of the school year already far behind us, the engine subteam is getting ready to manufacture a new engine model this coming spring. Currently, the engine subteam is working on scaling up our first engine model, replacing the combustion chamber with copper, and adding a regenerative cooling system to replace our old hose-cooling method. Once we are able to create a self-contained cooling system, our engine will be much, much closer to becoming flight capable.


The biggest challenge we are currently facing with or engine design is how to manufacture the regenerative cooling system. Because of the shape of our combustion chamber and throat, we will have to make the coolant jacket in two or more pieces in order to fit around the indented throat area. Another design consideration we are trying to address is having all copper coolant tubes but without making the jacket out of expensive copper. We are looking into copper plating or simply not having a coolant jacket and instead creating the coolant system without of copper tubing twisted around the combustion chamber in a helix.

Copy of Regenerative Cooling Coil


There are countless directions we could be taking this engine design, and with the collaborative research of the subteam, we hope to decide on a design by next Friday. Although there is still a lot of work we have to do with the regenerative cooling system, we are almost ready to start manufacturing our scaled up engine. We have had trouble finding a machine shop to work from since the old shop is getting remodeled, and we may have to work from a private workshop. The exciting work starts soon, so look out for our project updates in the near future!

~Riley Hillstrom


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Update 10/05/2015: Revved up and Ready to go

First off, here’s a link to our new Facebook page, fresh of the presses!

Our subteams are starting to crunch some numbers and sketch some designs. Getting up and started this year, we’ve been working on improving our designs from last year.

2015-02-06--Engine Schematic - 2-

Last Semester’s Early Engine Schematic

2015-02-06--Whiteboard Engine Picture-

Last Semester’s Early Propellant Schematic

We’re scaling up the size of our engine to make machining a regeneratively cooled engine possible without outsourcing ants to manufacture our parts. We’ve been pulling out all the equations and information we can from what we have from last year to make our lives just a little bit easier.

We decided on using an alternating current converter in the circuit for our design. The board is in progress, and we hope to finish the control board by the end of the week for our pressure testing at the west river flats. There was a minor hiccup in getting the wrong switch, but it will be an easy fix. Did I mention we’re pressure testing this Saturday?

We’re hoping this year to improve the business side of our project by reaching out to student groups interested in the collaboration between business and engineering. By creating a connection between business and engineering students, we can expand the application of the project beyond just the mechanical aspects. This connection can  aide us in appealing to a wider breadth of students with different viewpoints on our project.

Test Stand Subteam Spotlight

We used to describe the structural integrity of LPRD Rocketry’s test stand as “charmingly fluid.” For those of you who don’t remember, the student machine shop was closed to non-course projects last year just before we managed to place the final touches on the test stand, and we were left with a stand of questionable stability. I’m proud to announce that’s no longer the case! After about an hour with a power drill, we now have a test stand that is fully stable thanks to four new angle brackets and four new bolts.

Stable Test Stand

We also managed to get in a bit of a workout carrying 50 lbs of metal up and down flights of stairs (hurry up with the construction in the Mechanical Engineering building!), but we had plenty of fun doing it.

2015-09-26 TSOM Selfie

Over these next couple of weeks, we hope to finally integrate the control valves that will let us throttle the engine!

Belimo CCV 1

We originally thought we would need to spend over $6000 on a set of globe valves and actuators, but Belimo offers these “Characterized Control Valves” for less than $100 each. They’re rated to 400 psi and have a 200 psi shutoff pressure (which shouldn’t ever be an issue due to our fail-safe ball valves), but that thin piece of plastic is awfully concerning. Once we’ve incorporated them into the test stand, we’ll be running a series of pressure and flow rate tests to see if they’re really up to par. The plan is for this next Saturday (October 10th). Fingers crossed!

-David Deng


Hopefully all these components will come together for a successful pressure test and possible flow rate test Saturday, October 10th! Feel free to join us at the University of Minnesota east river flats to watch the testing. The team will be meeting in Akerman at 9:00 am and we hope to be set up on the flats ready to go by 10:00. We’ll be testing until past noon so feel free to drop by anytime and check us out!

-Jessica Wettstein


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