Project Liquid

Who Are We?

We are a small but dedicated group of undergraduate students looking to push the boundaries of engineering excellence at Yale. We sponsor an iterative and action-oriented approach to solving problems, which we believe facilitates the best learning approach. We welcome anyone with an interest in our short-term and long-term mission, regardless of personal experience, to join our project!

What Is Our Mission?

We aim to pioneer liquid propulsion technologies at Yale.

Our immediate goals are ambitious. That is, to create a bi-propellant, pressure-fed liquid engine by mid-2022 and to build a liquid rocket compete in IREC’s 10k-foot Student Research and Developed (SRAD) liquid/hybrid rocket competition in mid-2023.

Our longer term mission is to expand opportunities in important aerospace technologies for Yale undergraduates in science & engineering, which we believe can be facilitated through liquid propulsion technologies.

What Are Liquid Propellant Engines?

In rockets, there are usually two types of propellant systems: solid propellant engines and liquid propellant engines.

Solid propellant engines have solid propellant called “grain.” This solid propellant is shaped into a cylinder with a hollow center leading to the bottom of the rocket. When ignited, the grain combusts into exhaust gas which feeds from the hollow center to the bottom of the rocket.

Liquid propellant engines have liquid propellants, one being a liquid fuel and the other being a liquid oxidizer. This liquid fuel and oxidizer are stored in separate tanks, where they pushed down into a combustion chamber. The propellants are ignited in a combustion chamber, where exhaust gas feeds through the bottom of the rocket.

Liquid and Solid Propellant Rocket Engines Diagram Diagram | Quizlet

Why Is Liquid Propulsion Important?

Liquid propulsion technologies are highly sought after in modern space industries. While solid propellant engines are powerful, they aren’t throttable, restartable, and efficient like liquid propulsion engines are. In an industry starting to optimize for efficiency, reusability, and turnaround time, liquid propellant engines serve as a must-have technology for future space industries.

An example of this is in seen in SpaceX’s Falcon 9 and upcoming Starship. These two rockets take advantage of liquid propellant systems by modulating thrust during takeoff, re-entry, and landing. Liquid propellant rockets are also seen in other key organizations such as Blue Origin, ULA, Rocket Lab, etc.

Starship prototype flies to 32,000 feet and sticks the landing in  third flight test | TechCrunch
SpaceX’s 10th Starship prototype test launch and landing
Blue Origin: Rules should change in Air Force rocket contracts race
Blue Origin’s liquid propellant BE-4 engine

Leadership Team

Leader: Ryan Smithers (