Martlet IV

Hybrid built to break the UK Amateur Record

The Story Behind Martlet IV

After the rapid unscheduled disassembly of Martlet III mid-flight due to a problem with the only off-the-shelf part, the solid rocket motor, CUSF embarked on the journey to launch a rocket using only custom parts. The first step of that was the design, build and test campaign for Pulsar, a bespoke Nitrous-HDPE hybrid engine, delivering 5kN of thrust, culminating with a successful 2019 hot fire at Airborne Engineering in Westcott. To date, Pulsar is one of the biggest Nitrous hybrids fired in the UK. The next stage is our best rocket yet – Martlet IV. Designed to break the UK altitude record in July 2022 and consisting of over two years of our work, Martlet IV is guaranteed to be a show-stopper.



Wet Mass




Top Speed



Friends of Amateur Rocketry


Spaceport 1 Consortium


Langanes Peninsula


Machrihanish Space Cluster

The Life-Saver

A two-parachute system deployed using an automatic burst of CO2 from a canister, codenamed the Falcon recovery system.

The Brains

Altimetry, flight-control, telemetry and control of recovery through an Arm Cortex-M4 chip powering Strix, Martlet IV’s flight computer.

The Soul

Pulsar, an ablatively-cooled 5 kN HDPE-Nitrous Oxide hybird engine providing more than 50,000 Ns of total impulse.

The Body

Standing tall at over 6m, the steel and aluminium airframe was designed to hold strong under massive accelerations.

The Heart

An oxidiser tank holding 53 litres of Nitrous Oxide at a design pressure of 45 bar. Designed and built to the highest safety standards regarding the handling of Nitrous Oxide.


The most powerful Nitrous Hybrid Engine in the UK.

Fit for Purpose

Worked on by over 40 students over the past 2 years, Martlet IV has been built from the ground up by undergraduates. From the airframe from our Aerodynamics Team, to avionics from the Electronics Team, the single-stage rocket has been rigourously designed to utilise every last bit of performance from the Pulsar engine.

Thorough analysis of parachute snatch-loads, engine performance and aerodynamic effects, coupled with a fully-featured in-house trajectory simulator, gives us every confidence in the ability of Martlet IV to reach an apogee of over 20 kilometres, before deploying its recovery system for a safe landing.

Project Strix

Did I Hear Custom Electronics?

Something Caught Your Eye?

Get in touch! Reach out to contact[at] to find out more.