HyFIVE-1: First Hot Fire Tests of STERN II Project

Our Hybrid Fuel Investigation and Verification Engine (HyFIVE) was tested for the first time on September 2nd, 2020. Since then, three cold flow tests and six hot fire tests were conducted. All engine hot fires had an operational time of 5 seconds and were successful. The goal of the tests was to evaluate different fuel parameters such as regression rate and combustion characteristics. Two different fuel compositions have already been evaluated and we are currently preparing the next tests to further enhance the fuel composition. In a future design stage, the engine will be used as propulsion unit of the demonstrator rocket. For this purpose, we will optimize combustion efficiency and thrust as well as using a lightweight combustion chamber casing. We would like to thank the DLR Institute of Space Propulsion in Lampoldshausen for their help and support even in this challenging times. Stay tuned for more test footage!

STERN 2 participation on track

Although our Preliminary Design Review (PDR) of the DLR STERN Project is being rescheduled due to the outbreak of the corona virus, all HyEnD members are working hard (and from home) in order to bring the project forward. We think this is a great opportunity to give you an update of the current state of the project.

Propelled by its powerful HyLIGHT Hybrid Rocket Engine, our project rocket N2ORTH will fly to an altitude of 20km or higher and will be fully recovered. The engine will provide a nominal thrust of 10kN over an operation time of minimum 15 seconds. It will use a new type of in-house developed polymer-based fuel in combination with nitrous oxide. The whole rocket is designed from the ground up using the experience gained with the previous HEROS rockets. In order to test the different systems of the rocket in advance, we will build a subscale demonstrator rocket which will be launched next year. Currently, HyEnD is focusing its work mainly on this demonstrator. In the following, we will give you an overview of the different systems of the rocket.

Structure and oxidizer tank:

The structure team evaluates different design approaches for several lightweight rocket structure elements. One of the most challenging parts is the oxidizer tank, which is planned to consist almost entirely of composite materials. Several design and manufacturing approaches are investigated, including designs without the use of an aluminum liner. This is challenging since nitrous oxide usually causes problems in a hydrocarbon-based environment.


The propulsion team has already started fuel evaluation tests back in fall 2019 and has built a completely new engine called HyFIVE-1 in order to continue these tests. The first test was scheduled for March 2020 but was canceled due to the corona virus. Currently, the team is working on the design of the demonstrator flight engine, which will use a carbon fiber reinforced plastic (CFRP) combustion chamber hull in order to reduce weight. First design studies for the larger HyLIGHT engine are currently in progress as well.

Fluid System:

In the last weeks and months, the fluid system team has developed a simulation model for the self-pressurizing behavior of nitrous oxide inside the tank. This is crucial in order to determine the required tank size and resulting engine performance. Also, three design studies for every valve were carried out, emergency and relief valve prototypes are currently being manufactured. For the main valve, a pyro charged slider valve is considered.


Since the rocket shall be required entirely, the rocket will be equipped with a two-stage parachute recovery system.  The recovery team has carried out different concepts and decided that the following mechanism will be used. First, the drogue will be ejected with a motar placed between the oxidizer tank and engine. The main deployment mechanism is located near the top of the rocket. It includes the main chute and a pilot chute. The drogue and pilot chute are deployed using pyrotechnical charges. First tests to verify drag coefficients and shock loads for the demonstrator rocket were already done in October 2019.


The Avionics team is currently focused on developing the individual systems. Choosing the right components to implement in the design is crucial to keep the systems as compact and space efficient as possible. For each systems a schematic containing all the used components as well as the connections in between them are designed.

Ground Support Equipment:

Members of the ground support equipment team are working on a custom launch rail for the demonstrator rocket. For N2ORTH, the MRL in Esrange will be used. Also, different concepts for the arm mechanism (responsible for fueling the rocket) were carried out and it was decided to use a rotating arm. Tasks also include the development of an antenna tracking platform, which will enable a life video feed during flight.

Announcing our second STERN participation

Hybrid Engine Development is proud to announce its second participation in the STERN* (STudentische Experimental RaketeN) program of the German Aerospace Center DLR! During the first participation, HyEnD was able to set a new World Record for student-built Hybrid Rockets and we are looking forward to new possibilities in the next three years.
HyEnD will design, build and launch a new Hybrid Rocket in the 10kN thrust range during the program. We are currently in the preliminary design phase and so there is still the chance that some of the key parameters will change, but we will share with you more information once we are ready to do so.

It is also planned to build a smaller demonstrator rocket to test some of the technologies necessary. This demonstrator will be based on our previous project EXPLORE, although the oxidizer will be changed from liquid oxygen to nitrous oxide. In addition, tests during the last few months have shown the potential benefits of a completely new kind of polymeric fuel which will be further investigated and likely be used in both rockets.

We would like to thank the Deutsches Zentrum für Luft- und Raumfahrt (DLR) and the Institute of Space Propulsion of the University of Stuttgart for their support.

*The STERN Program is supported by the German Federal Ministry for Economic Affairs and Energy (BMWI)

EXPLORE is taking shape

EXPLORE is taking shape! During the last few weeks we have worked hard and started the manufacturing of the first components of flight hardware, including the structure, recovery system and tanks. Prototypes of the fluid system and the main valve are also in construction. While the engine is still in its test phase, we have managed to reduce combustion instabilities and improved the design of the engine multiple times. However, tests will continue in order to improve stability, efficiency and burn time.


We’re now one month into the new year! Roughly one year ago we decided to go for EXPLORE, a demonstrator propelled with liquid oxygen (LOx) and solid paraffin-based fuel. Here is an overview over the current status:

The development of the avionics hard- and software is running in high gear. For the first time in HyEnD history, a self-made flight computer shall take control of the most critical functions during flight. First prototypes of many electrical subsystems are already built and about to be tested thoroughly. As for the structure, we have manufactured the tip and have a prototype of a CFK-tank for the LOx. After its ascent, the rocket shall be recovered via a recovery system containing a main parachute and a smaller one for pulling out the first one. It’s now in its final design stage. While some components are already ordered others are being prepared to be manufactured soon. Also, a wind tunnel test campaign is currently being planned, which will finish the development process of the new recovery system of EXPLORE. Very challenging is the design of the fluid system because the oxygen will have gaseous and liquid phases when being transferred to the tanks before the launch and then to the combustion chamber during flight. Safety measures like a mechanic and electronic release valve as well as a burst plate need to be included. Those components are still in a design and re-design process. Gaseous nitrogen under high pressure will deliver the LOx to the combustion chamber. Because of the high pressure, there needs to be a pressure regulator. We already tested a sophisticated design at 50 bar but currently re-designing it to make it lighter and qualify it for 300 bar. At the moment we are looking for suitable sensors for checking the pressure and temperature. Also time-consuming is the development of the engine. A whole thesis concentrated on its first design steps and main parts like the showerhead-injector and pre-combustion chamber are already manufactured. Current stage is the preparation of the test bench. We hope that tests in March will give us promising results on its performance. We also hope that you had a great start in 2019!

EXPLORE – HyEnD’s First LOx Hybrid Rocket

HyEnD is proud to announce that the development of its first ever liquid oxygen hybrid rocket EXPLORE (Experimental Paraffin Liquid Oxygen Rocket) is in full gear. EXPLORE is intended to be a stepping stone for a bigger project, using a variety of new subsystems to prove their sustainability.

The rocket will be able to reach a maximum altitude of 4500m while continuously transmitting telemetry data. Data will be recorded using a TeleMega and an Arduino. We will manufacture the structure out of carbon fibre composites, in order to not surpass the targeted launch weight of 19kg. EXPLORE’s dual parachute recovery system will be radially ejected, as this has been proven feasable with the successful recovery of our CanSat Launcher. Besides our usual paraffin mixture, we will utilize liquid oxygen as oxidizer. As liquid oxygen doesn’t possess the same self-pressurisation capabilities as nitrous oxide, which has been used as oxidizer in the past, an external pressurisation system for it’s tank is being developed. Passive stabilisation is achieved using four fins attached to the rear end of the rocket.

The preliminary definition phase of the project has been completed and detailed designs for the different subsystems are currently being developed.

More updates will follow soon!

CSL Maiden Launch

Great News! Our CanSat Launcher has been launched successfully. CanSat and parachutes were deployed flawlessly and the rocket landed softly in the fields near Lampoldshausen. It is completly intact and can be launched again using a new motor. Below you can see a video of the launch, recorded with several ground cameras and a drone.

CanSat Launcher Progress

Recently, great progress has been made in the development and production of the electronics subsystem. By now there’s a complete hardware package made of an Arduino, a TeleMega and the primary batteries which are mounted on a platform in the nose cone. The software and hardware will be tested soon. The testing of the electronics involves drone flights and a vacuum chamber to make sure the software will trigger the deployment of the CanSat and the parachutes after reaching the apogee.

Lately the fins were attached to the lower end of the rocket. To lower production and development time two identical compartments were produced. One will be used for the CanSat, while the other will contain the main parachute.

Shortly after reaching the apogee, the software will trigger a cable cutter to cut the string used to keep the door of the CanSat compartment closed to the rocket. By releasing the compartment door the CanSat will be ejected immediately via a block of foam material. An ejection mechanism based on foam sounds like a simple solution, but has two main advantages: During the ascent the CanSat is kept in its position in the compartment and the ejection doesn’t need an extra trigger by the software.

CanSat Launcher (CSL) Announcement

HyEnD is teaming up with student group KSat Stuttgart e.V. for a cooperative project. „CanSat launcher“ is a small platform developed to carry K-Sat’s CanSat satellite to an altitude of up to 500m. Equipped with a drogue and a main parachute, the solid motor based rocket can be recovered and reused. It is made out of CFRP, with a GRP nose and aluminum for structural elements. We will use a TeleMega to deploy the CanSat and the parachutes with pyro charges and an Arduino for flight data acquisition. As of now, we are finalizing the design and will soon start the production of the rocket parts and testing of all subsystems. While this project does not have the scope of HEROS, it is used as introduction and practice for our many new member.

HEROS 3 On Display

Three months after its record flight, HEROS 3 made its long trip back from Northern Sweden’s tundra to the exhibition at the German Aerospace Center (DLR) Lampoldshausen site! It is easy to see that HEROS 3 is one of the tallest exhibit in the museum. Here HEROS has found its place next to famous rocket engines and rocket parts like Vulcain 2, Viking, Ariane 5 Upper Stage etc… It’s really a nice place to visit, now even more. Next to HEROS 3 there are some posters and the demonstrator rocket MIRAS.