CPSS puts significant resources into the design and development of rocket motors. Our Propulsion Team handles the engineering, manufacturing, and testing of these motors. With a dedicated and hard working team, CPSS has the capability to build ever-improving rocket motors to reach our lofty goals.

Test Fire Remote Testing Setup

Our remote testing setup in Cal Poly’s on-site Propulsion Laboratory allows us to safely test our high-powered rocket motors. Safe operations is a critical goal of CPSS, and test procedures are closely followed during every test fire to ensure no members are ever injured.

Test Stand


This test stand gives us the capability to test our smaller hybrid rocket motors conveniently in the Propulsion Lab on campus. It has been used since HM-4 was first tested, and provides us with the data necessary to improve our hybrid motors. We have data acquisition systems set up to measure thrust, oxidizer and pressurant tank weight, and oxidizer and pressurant pressures at key points of the system.

Fuel Production

The fuel production team is responsible for assuring that our fuel grains are consistent and perform optimally.

mixing vats

The mixing vat (left) and vacuum chamber (right) ensure that we get consistent fuel grains every time. The vacuum chamber is used to quickly vacuum the air from the mixing vat after mixing HTPB. The vat is then connected straight to the vacuum pump, where it is brought down to just a few mmHg to vacuum out any additional bubbles.


The shake table, designed by Alec Bluhm and manufactured by Kevin Chouinard, is a newly added component to our fuel production process. A motor runs at a high rpm on a vibrationally-isolated from the ground platform, which shakes all the bubbles in the fuel grain to the top, thus providing a more solid fuel grain. Thanks to the shake table, our fuel grains have less instability-adding bubbles and provides more consistent thrust.