VTVL Rocket Platform

Meet Hopper

Hopper is a pressure-fed rocket hopper. It will serve as a development platform for reusable rocket technology. The structure consists of multiple carbon fiber overwrapped pressure vessels, which can withstand pressures of up to 300 bar. The rocket is controlled by a liquid propellant rocket engine and a thrust vector control system.

Height

5 m

Diameter

0.3 m

Propellants

Nitrous oxide/Ethanol

Propulsion

Pressure-fed using N2

Payload capacity

~ 10 kg

Wet Mass

180 kg

Attitude control

2-axis gimbal + 4x N2 RCS thrusters

Max Hover duration

60 s

Our approach

Our goal is the development and production of a rocket hopper that will perform low-altitude vertical takeoff and landing tests. These objectives enable us to focus on the key technological aspects that are essential for advancing rapid reusability in Europe.

Design

Assembly and Testing

Manufacturing

Propulsion System

Liquid-fuel rocket engine

Hopper is powered by our in-house developed liquid rocket engine, Drogon. Cooled by both of our propellants, the engine is able to operate for more than 60 seconds at full thrust. Multiple re-ignitions are possible using a torch igniter system.
‍
+ 0.6-2kN thrust
+ 3d-printed thrust chamber, injectors and valve bodies
+ Storable, non-toxic propellants
+ Throttle using cavitating venturi valves

3d-printed injectors, modular integration

Cavitating venturi valves for mass flow control

Test stand for component qualification testing

Avionics

Achieving stable flight

Our electronics, software and control systems are largely designed from scratch, allowing us to continually improve the quality and performance of our components.

Testing & Mission Control Software

All tests and mission procedures are run by Hopper GCS, our web-based Ground Control Software. This allows multiple users to simultaneously control valves, create mission profiles, and critically survey sensor data. One of the software's main objectives is modularity, providing customizable views for every use case and role. The team provides direct feedback, enabling quick identification and implementation of improvements.

Circuit Design

Our ground station and Hopper is operated by multiple custom-designed printed circuit boards.

+ Flight computer running procedures, attitude control and navigation algorithms
+ Modular Data Acquisition System for tracking sensor data on the ground and on the rocket
+ Valve and motor control boards

Actuators

Steering the rocket for precise landing maneuvers requires high-performance actuators. To perfectly meet the requirements, we developed electric linear actuators for thrust vector control.

+ Reaching up to 400 mm/s
+ Custom 2 kW inverter
+ 3d-printed carbon reinforced plastic casings
+ under 800 g total weight

Live missions

See it in action

Event

Date

Objective

Status

Engine Hot Fire

Jun 2025

First Drogon Engine Hot Fire

In preparation

Our Team

We are embarking on an ambitious project that has the potential to make a contribution to the space industry. We welcome driven and talented individuals to join our team and help us achieve our goal of shaping the future of space exploration.

You share the same mission and are interested in working with us? Check out the job listings!

Open Positions

Partners and support

We are grateful for the generous support of our sponsors and institutions, without which it would not be possible to achieve our ambitious goals.
Would you also like to support the development of one of the most advanced student-built rockets? Please contact us below!