The_Hound – Sustainer near Apogee (Background Source: wikipedia/Thunderstorms_over_the_Pacific_seen_from_Earth_orbit_on_STS-64.jpg)












Short Description

Simulation details (OpenRocket)

Two stage rocket with commercially available motors to achieve highest possible altitude.

  • Booster: Cesaroni Pro 98 N5800
  • Sustainer: Cesaroni Pro 75 M2245
  • Peak Altitude: > 100km (Sustainer)
  • Peak Velocity: > Mach 5 (Sustainer)


The Project

the_houndThe objective here is to build a two-stage rocket based on commercially available motors, which is optimized to achieve highest possible altitude within the limits of materials and manufacturing techniques available to our team.

The selected motors have a combined total impulse of about 30000Ns. For comparison purposes, this would be enough to accelerate a motor cycle to about 400kph (250mph). Because our rocket is much lighter, it will accelerate to about 5500kph (3400mph). At this speed, a marathon race would be finished in less than 30 seconds. Our simulations indicate that, dependent on actual aerodynamic parameters, an altitude of more than 100km (62mi) above ground could be achieved.

These numbers present quite a challenge in various aspects. On one hand, we need to build different parts as light and small as possible to be able to obtain that speed and altitude. On the other hand, those values raise the requirements e.g. for toughness and heat resistance, demanding more special materials and manufacturing techniques. All in all this is a tricky multi-variable optimization problem.

Other challenges include:

  • Ignition of upper stage motor
  • Determination of apogee altitude
  • Apogee detection and barometric altitude detection for two stage parachute deployment
  • On board video recording
  • Radio transmission of sensor data and – most importantly – landing coordinates.

All that said, the biggest challenge for Europeans is to find a launch site with an appropriate altitude waiver and safety radius. Thus far the only viable option would be to attend a launch event in the Black Rock Desert, Nevada, USA.

Nevertheless, up until now anything above 32.3 km (current record holder HyEnD/Stuttgart) would set a new “european university amateur club record” – and that is what we want to go for!

Key Components

  • Flight Computer: inertial measurement; GPS-data; liftoff-detection, separation, upper stage motor ignition and recovery initiation; telemetry
  • Central Ground Station: direct connection between operator and rocket, visualizes relevant parameters in real time
  • Autonomous Ground Stations: multiple distributed RF repeater extend reception area of central ground station. Autonomous logging of received data.
  • Airframe: Nose cone manufactured out of high temperature resistant fiber glass reinforced plastics. Rocket motors are structural parts of the airframe.
  • Staging Adapter: Integrated into sustainer tail cone: lightweight, stiff and compact.
  • Recovery: two stage design based on aramid drogue parachute and Nylon main parachute.
  • Fincan: Lightweight but full-metal design manufactured by Direct Metal Laser Sintering (DMLS), for heat dissipation and high strength. The interior isogrid-spar structure enables a superior strength-to-weight ratio.

Presentation of the project “42km – The Hound”

A presentation by former project manager Christian Plasounig, detailing the current status of the project as of May 2018, can be found here.

Further details about the project are included in the following videos:

Milestones as of 2020

  • In August 2016 the Space Team attended a rocket launch event in Manching, Germany, where the Space Team’s first ever two staged flight took place. A motor with low thrust was intentionally chosen in order to be able to easily observe the sequence of the two staged flight from the ground. This flight served as a successful proof of concept for the two stage flight.
  • Not long afterwards the teams very first supersonic flight took place. With a maximum acceleration beyond 30g, the rocket was accelerated to a velocity of 390m/s (Mach 1.14)within 1.4 seconds. Despite aerodynamic disturbances, that affected the barometric sensor while passing the transonic speed region, the flight computers apogee detection worked without a hitch
  • After many hours of construction, The Hound began to take its final shape. In May 2017, the upper stage of The Hound celebrated its maiden flight in Roitzschjora, Germany. The goal of this launch event was to test the new recovery system, the automatic apogee detection, the attitude estimation, and the radio modules with configurations almost identical to planned final configuration, that will be used for the European record attempt.
  • In early 2018 final tests were conducted in Roitzschjora, Germany, before the rocket was shipped to the US.
  • The first attempt to reach space was performed in 2018 in Nevada, USA. Read more about the results in the news.

Because the launch in the fall of 2018 was not successful, the TU Wien Space Team decided to extend the project for another attempt in 2019. Notably, two rockets will be used this time: “The Hound 2018” with only minor changes and an updated version of “The Hound” with a adapted concept based on previous experiences:

  • Improved telemetry integration including new antenna design
  • Iridium satellite communication system for redundancy
  • New upper stage ignition concept
  • New on board video cameras

With both rockets, our chances should increase for successfully reaching our goal: to boldly go where no student has gone before. (Update: In Spring 2019 a US based student team successfully passed the Kármán line and established a new record for university teams. The current European record still stands at 32,3 km.)

The launch in September 2019 unfortunately did not go as planned. Despite several delays The Hound 2 was launched, however, the upper stage only reached an altitude of about 2.5 km. Unfortunately, the avionic unit broke apart shortly after the launch, the data recording failed and neither of all four on-board cameras could be found afterwards. Additionally, the radio communication to the booster was interrupted midflight, which is why the booster couldn´t be recovered. A more detailed final report can be found at final report 2019.


During 2020 work on an update is ongoing: The Hound 3.  The most important changes are:

  • We are working on an avionic unit inside the coupler between the two stages which contains a camera, an autonomous GPS tracker and a GPS independent tracker (“bird finder”).
  • A new backup-device inside the booster because the one that was used up to now probably caused The Hound 2 to crash.
  • The top will be built from titan, instead of aluminum.
  • The electric connection of the headend ignition will be built more robust as just before the start of The Hound a cable broke and had to be fixed in a short amount of time right at the launch pad.
  • A change in the starting procedure in order to be more independent from the quality of the radio communication near ground.
  • More tests and test flights are supposed to make the platform “The Hound” more reliable, get rid of possible difficulties and give the team the possibility to further bring the starting procedure to perfection.

Update November 2020

We did not get another attempt to break the European record since Balls 2020 — like many other events — got cancelled due to the global COVID-19 pandemic. However, we were still able to implement all updates and improvements, planned for The Hound 3. Thanks to Portugal Space we even got a great opportunity to test all that on European soil: EuRoC 2020. With the sustainer reaching a max. altitude of about 9km the launch in Portugal marked our team’s highest rocket flight in Europe and a great success overall. The new and updated avionics worked flawlessly and, for the first time, we were able to watch five onboard videos after the launch (2x booster, 2x sustainer, 1x interstage). Despite all those achievements there is still work to be done since the main parachute of both stages did not deploy. We are, however, very confident that we can resolve these issues till next year when we can hopefully attempt another launch in the Black Rock desert at Balls 2021.

True to the motto “all good things come in threes”, the Hound-Team is optimistic that The Hound 3´s flight in 2021 in Nevada will be a great success.

Simulation Results

The software packages OpenRocket and RASAero were used to perform flight simulations. The results for “The Hound 2” are presented below:

Project team

Past and present team members (in alphabetical order)

  • Christian Plasounig (Projektleiter bis 2018)
  • Christoph Fröhlich (Projektleiter ab 2019)
  • Andreas Bauernfeind
  • Tobias Bauernfeind
  • David Birschitzky
  • Florian Guggi
  • Alexander Hartl
  • Michael Hauser
  • Thomas Hirschbüchler
  • Patrick Kappl
  • Peter Kremsner
  • Benjamin Luxbacher
  • Ulrich Meisl
  • Simon Neumüller
  • Moritz Novak
  • Julian Präsent
  • Reinhard Rath
  • Stefan Schaffer
  • Stefan Schindler
  • Manuel Schleiffelder
  • Benedikt Stingl
  • Silvia Tirler