UCLA Rocket Project

Summary

The University Rocket Project (URP) at UCLA is a student group in AIAA that works on sounding rockets for self-training and educational competitions. URP often competes at the Experimental Sounding Rocket Association's Intercollegiate Rocket Engineering Competition (ESRA's IREC).

About the Rocket

Over the 2012-2015 years, URP worked on their HyPE rocket (Hybrid Propulsion Experiment). HyPE used a paraffin wax fuel-grain with nitrous oxide as the oxidizer. Helium was used to maintain pressurize in the oxidizer tank as the nitrous was used.

HyPE was designed for around 25,000 ft AGL, but had limited success due to its complexity. HyPE had a lengthy assembly and filling process. Fueling the rocket required chilling the oxidizer tank through evaporative cooling and subsequent venting of the gaseous oxidizer. The team had several successful cold flows and hot-fires in the desert, but at IREC in 2013 the desert heat kept the tank warm for too long. High wind gusts eventually broke a launch lug and caused the rocket to fall from the launch rail.

The separated ingredients and lack of pressure (no helium was loaded at the time) made the hybrid rocket relatively safe, but damage to the nozzle from the fall prevented any further attempts at that year's competition.

Hot Fires

The team regularly set up the HyPE rocket in a static test fire to practice procedure, refine methods, get testing data, and have a bit of fun.

Hybrid rocket test at FAR in Mojave using a commercial hybrid rocket motor
Hybrid rocket test at FAR in Mojave using a commercial hybrid rocket motor; this test used the remaining oxidizer and was a shorter burn as a result

Downrange Tracking

URP wanted a tracker to help recover the rocket after it landed. Additionally, any tracker was supposed to be able to feed back into a Main Engine Cutoff (MECO) program that used Kalman filtered accelerometer data and GPS (when available). Last, many GPS chips cut off above 18km or at velocities greater than 515 m/s (due to COCOM).

While HyPE was not at risk of violating the altitude constraint, some manufacturers impose both restrictions. After creating a tradespace and looking at our options, we selected the BigRedBee 70cm model. Other options (like the Tracksoar) are now on the market, but weren't available when we conducted the trade. Given new products, URP may have chosen differently.

Since the majority of the rocket body is carbon fiber, the GPS and transmitter were placed in the molded fiberglass nosecone. We built a dipole antenna for the BigRedBee in the nosecone, and a quarter-wave vertical on the ground. Unfortunately, the MECO system was descoped due to time and complexity.

We set up with a fairly standard packet receiving setup, and got solid telemetry from our tests. The BigRedBee even gave us decent performance when when "landed" on the ground across a flat lake bed. Unfortunately, I never got to fully test the GPS. However, during our IREC attempt I observed a slight altitude drop when the launch lug broke and the rocker fell. Position reporting worked.

HyPE Hot Fire test
Image of a HyPE Hot Fire at Lake Lucerne north of the Transverse Range near Los Angeles. The combustion chamber is laying on the ground and staked down; the white tank holds nitrous oxide; the upper pressure tank holds helium.

Resources

Rocket Project at UCLA

I'd be remiss not to include a link to URP's website. I was only involved for a short time, but the current members continue to do awesome things.

ESRA

ESRA is the aforementioned non-profit dedicated to educational sounding rocket experimentation. They host IREC , formerly at Green River, UT, and now at Spaceport America in New Mexico.

FAR

Friends of Amateur Rocketry (FAR) is a test site out in the Mojave desert. They have a well-equipped facility and helpful staff. URP a few hot-fires and launch attempts at FAR.

Big Red Bee

I didn't get enough experience with the Big Red Bee in a real recovery situation to feel comfortable endorsing it. It is one possible option for those looking for High Altitude Balloon or Amateur Rocketry position reporting.

TrackSoar

TrackSoar is an open source APRS beacon project with an integrated GPS. I haven't used their product and can't endorse it, but I'm happy to see open source / open hardware options on the market.