RX32 – BOOMERANG (nonBOOM-deploying Experiment with a Return-to-launch-site Automated Non-propelled Glider)

KTH Stockholm

Launch Date: March 2024

The comprehensive objective of BOOMERANG is to demonstrate an autonomous return to launch site (RTLS) functionality of disc-shaped free-falling units (FFUs) used to perform electric field and plasma measurements in ionized space. However, the measurements in near-Earth space will not be performed in this experiment, which implies that the RTLS functionality shall be modular – i.e. fit any future experiments regardless of their objectives. The return functionality of the FFUs is novel (in contrast to the parachute landings of FFUs in previous KTH REXUS experiments) and features a high-altitude subsonic glider solution. This exposes the BOOMERANG team to challenges within controls, structures, aerodynamics, flight safety, electronics, mechanics and more. By using an autonomous solution that returns the experiment equipment after being ejected from a sounding rocket, one of the potential benefits is that resources and time would be saved since a manual retrieval procedure would be unnecessary. The expected results of the experiment will contribute to future technology development of sounding rocket free-flying payloads for research in space plasma physics and potentially other scientific areas.

RX32 – GAMEon (Glider for Atmospheric measurements and Experiments)

Ernst Abbe Hochschule Jena

Launch Date: March 2024

GAMEon is short for “Glider for Atmospheric Measurements and Experiments”. The “on” stands for the continuation of a REXUS predecessor of our university. The team consists of 15 students of the Ernst Abbe University of Applied Sciences Jena from different departments.

We want to build on the results of our predecessors and take the next step by developing an independent platform for atmospheric measurements.

In the GAME experiment, it has already been proven that a glider dropped from a sounding rocket can transition into stable gliding flight. We want to make progress in the mechanical strength of the glider as well as in the communication with the glider. In addition, by installing an attitude control system, we would like to achieve that the glider can transition more quickly from free fall to stable flight and head for a given target coordinate.

After the jettisoning of the rocket tip, at an altitude of about 70-90km, our glider should also be ejected. After a certain period of free fall, the glider will enter a spiral dive. During this phase, it will be actively controlled to return to a target coordinate – the ground station in Kiruna.

The newly designed glider is to maintain contact with the ground station during the flight and thus exchange data that it collects during the flight. This data will be used to control the glider’s approach to the ground station. The basic idea here is to build an experimental platform from which successors can benefit.

RX31 – TRACE (TRAnspiration Cooling Experiment)

RWTH Aachen University

Launch Date: March 2024

TRACE (TRAnspiration Cooling Experiment) is a project developed by a team of students from the Space Team Aachen e.V., an association of the RWTH Aachen University. TRACE aims to develop a transpiration cooling system for a re-entry vehicle and investigate its performance. The free flight experiment is intended as validation of the transpiration cooling concept for heat protection systems under real flight conditions.

The transpiration cooling effect is achieved by blowing a cooling gas through a porous surface into the boundary layer surrounding the structure of the vehicle to reduce the thermal loads acting upon it. The reuse of the system can simply be achieved by refilling the cooling fluid tank.

The TRACE free-flight experiment will be carried in the nose cone of a REXUS rocket and jettisoned at an altitude between 70 and 90 km, after which the TRACE capsule will fly back to earth independently. The experiment’s shape allows for passive aerodynamic stabilization during entry into the lower atmosphere, as TRACE reaches speeds of up to Mach 3.5. At an altitude ranging between 30 and 10 km, the high velocity leads to strong heating of the outer structure. Part of the surface is equipped with new transpiration cooling elements, enabling a comparison of the surface temperature and heat transfer with reference surfaces, resulting in measurements of the effectiveness of the cooling effect. At an altitude of about 8 km, a parachute sequence for recovery will be activated.

The generated data will be used to guide future designs and to validate assumptions, simulation tools and flight predictions.

RX31 – SHEAR (Supersonic Heatshield Experiment Aboard REXUS)

TU Delft

Launch Date: March 2024

SHEAR (Supersonic Heatshield Experiment Aboard REXUS) is an experiment of the Parachute Research Group (PRG) of Delft Aerospace Rocket Engineering (DARE) that aims to flight-prove the alginate and montmorillonite nanocomposite foam, a self-developed heat shield material. From prior on-ground testing, this material is known to withstand high thermal loads, which makes it suitable as a thermal protection system for sounding rocket flight conditions. The upgraded heat shield aims to expand the flight envelope of existing and future DARE sounding rockets.

The mission aims to increase the technology readiness level (TRL) of the self-developed composite foam by integrating the heat shield into a flight-ready configuration. The experiment module is composed of two heat shield samples attached to the outer surface and two thermocouples per sample. One thermocouple measures the temperature on top of the heat shield and the other measures the temperature on the inner surface of the rocket skin behind the heat shield. Another pair of thermocouples is used to measure the temperature of the outer and inner surfaces of the rocket for reference.

The experiment will gather temperature data measured on both the heat shield and the rocket skin during the descent phase and this data will be compared with on-ground tests and simulations during post-flight analysis.

RX29 – DAEDALUS 2

Julius Maximilian University of Würzburg, Germany

Launch Date: March 2023

Daedalus2 is the follow-up to the Daedalus Project on REXUS 23. The goal is to improve the “Free Falling Unit” developed by its precursor. This vehicle, also called “SpaceSeed”, implements the auto-rotation principle seen in the slow fall of maple seeds and employs this to decelerate its descent. Daedalus2 aims to improve and upgrade this purely passive system. For a more stable flight, the body of the Daedalus2 SpaceSeed will be decoupled from the rotor and the whole flight will be monitored by control systems. In addition, the use of landing controls will enable the transportation of a possible payload safely without the need for a parachute.

RX28 – SPEAR (Supersonic Parachute Experiment Aboard REXUS)

Delft University of Technology, The Netherlands

Launch Date: October/ November 2022

The REXUS experiment SPEAR (Supersonic Parachute Experiment Aboard REXUS) of the Parachute Research Group (PRG) in Delft Aerospace Rocket Engineering (DARE) will test the in-house developed Hemisflo ribbon drogue parachute in supersonic conditions. The mission aims to validate supersonic functioning of the drogue parachute and to gather a full validation set for the PRG tools ParSim and TumSim and falls under the area of investigation of “Re-entry Systems”
To do so, a separate SPEAR test vehicle will be jettisoned from the REXUS nose cone at apogee. The test vehicle will descent and deploy the Hemisflo drogue when travelling Mach 1.5 or higher. During its descent the test vehicle will gather data on the atmospheric pressure, accelerations of the vehicle, loads on the drogue parachute, heat loading on the vehicle and video footage of the parachutes.
The vehicle includes two main parachutes and a location system to retrieve the vehicle safely. Next to this it houses deployment systems for all parachutes and a telemetry system to send a selection of data back to the ground.

RX27 – HADES (Hayabusa capsule Active Dynamic re-Entry Stabilisation)

HES-SO, Switzerland

Launch Date: October/ November 2022

HADES (Hayabusa capsule Active Dynamic re-Entry Stabilisation) is a project developed by a team of students from the University of Applied Sciences Western Switzerland (HES-SO). The experiment aims at studying the dynamic stability of an atmospheric re-entry capsule, and is based on two previous HES-SO Bachelor theses: one on the aerodynamic study of a capsule’s oscillations and the other on a regulation control system for an inverted pendulum on a cart.
In the vicinity of transonic and subsonic re-entry phases, spacecrafts are known to show a rather unstable behaviour even if not perturbed by external factors. If this instability is not constrained, it can lead to persisting high amplitude oscillations resulting in undesired behaviours, which can even lead to the loss of the spacecraft.
A system of actively controlled moving weights will be placed inside a capsule to damp oscillations and ensure dynamic stability during re-entry. A secondary goal is to allow a limited manoeuvre of the spacecraft by centre of gravity positioning.
The HADES experiment aims to demonstrate that an active stabilisation system is a viable solution to suppress any oscillation that might occur during an atmospheric re-entry. The real flight profile will be compared with flight predictions, both accounting and not accounting the active mass control. And future bachelor and master theses at HES-SO will analyse the data obtained during the mission and propose further improvements to the system.

RX25 – GAME (Glider for Atmospheric Measurements and Experiments)

Ernst-Abbe-Hochschule Jena, Germany

Launch Date: 11 March 2019

GAME stands for “Glider for Atmospheric Measurements and Experiments”. We are a team of 14 people from the University of Applied Sciences Jena (faculties Space Engineering, Precision Engineering as well as Electrical Engineering). We plan to eject a glider at the apex of the rocket’s trajectory. First we wanted to eject our experiment from a normal rocket module but after the Selection Workshop we are now located in the nose cone.

The glider will be placed in a transport box to protect him from vibrations and to avoid damages to its structure. The transport box will have a negative imprint of the glider to guarantee perfect protection during the flight preparation as well as the flight itself. The glider electronic will be supplied via the rocket’s supply system during that time. While flying the electronic will be powered by batteries.

When the nose cone is split off the transport box shall open and release the glider. Then the glider will descend in free fall at first and shall enter a stable flight independently. During the stable flight the glider will gradually descend in a spiral motion.

We want to maintain contact to the ground station constantly and gather data on temperature, position (GPS) as well as physical alignment (sun sensor). This data can be then used to provide a proof of concept for a glider that can enter and hold a stable flight and can further be used to develop gliders with different tasks (e.g. carry another experiment and prolong its time in high altitudes or an automated glider).

RX23 – DAEDALUS (Research of an Atmospheric Reentry of a Glider)

Julius Maximilian University of Würzburg, Germany

Launch Date: 4 March 2019

Daedalus’ goal is to build and successfully test an alternative form of a descent mechanism for drops from very high altitudes. Since parachutes are not always useable there have to be new and innovative ways to descent through an atmosphere without using any propellant at all. Inspired by the bionic design of the maple seed, which gently falls to the ground due to its ingenious natural design, Daedalus builds a “SpaceSeed” which is applying the same idea of a gentle descent for aerospace mission.The range of applicationsfor the “SpaceSeed” are numerous, for example could designs like this also have a terrestric use like weather probes which would be able to withstand harsher winds then a parachute could. This design is directly usable for turbulent atmospheres like on Venus or even Jupiter. Also sample returns from LEO could be actualised with similar designs, again removing the challenges one would face with a parachute or an actively propelled landing system. Daedalus wants to prove that this alternative is usable for real life applications on Earth and other planets, too.

RX19 – MIRKA-RX (MIkro-RückkehrKApsel 2 – REXUS)

Universität Stuttgart, Germany

Launch Date: 17 March 2016

The REXUS experiment MIRKA2-RX (Micro Return Capsule 2 – REXUS) by the small satellite student group at University Stuttgart (KSat e.V.) is going to examine the aerodynamic stability and general functionality of a micro return capsule and its separation mechanism, with which it is to be ejected at the apogee of the rocket. This process will be monitored with video cameras. After separation the capsule will communicate to the ground station via a commercial satellite service, transmitting data about its position, attitude, pressure and other relevant parameters. The data will also be stored on an SD-card in case the capsule is retrieved. The unique characteristic of this experiment is the size of the capsule, which measures only about 10 x 10 x 10 cm, wherein all the sensors and electronics need to be accommodated. This requirement is set by the wish to use the capsule in a Cubesat project called CAPE (Cubesat Atmospheric Probe for Education) by the Institute of Space systems at the University of Stuttgart. There, the capsule will experience a controlled re-entry with the help of a powered three-unit Cubesat in order to gain data about the behaviour of the ablative heat shield material. Therefore the MIRKA2-RX experiment, besides the possibility for students to engage in a space program from the beginning to the end, acquires scientific and technical data for its follow-up project.

RX09 – REMOS (REcession MOnitoring System)

University of Stuttgart, Germany

Launch Date: 22 February 2011

The goal of the REMOS project was to develop a system enabling in-situ measurements of ablative heat-shield regression rates, by monitoring the materials electrical properties during re-entry. Ablative cooling is a popular means of thermal protection, and usually consists of ceramic or carbon phenolic materials which char, melt and sublimate through the process of pyrolysis; subsequently diverting the excessive heat loads of re-entry away from the spacecrafts sensitive payload and subsystems. During the free-fall phase of the REXUS flight, REMOS deployed a probe consisting of ablator material which was exposed to the re-entry flow. Its thermally induced recession was then monitored using electrical and optical systems. As the probe material is ablated, the electrical properties of the sensors are altered, thus indicating how much of the heat-shield is lost. The collected data was verified using visual data collected via two autonomous video cameras. It was hoped that the results of this study could be used to optimise future ablative shield design processes.

REMOS Conference Paper

REMOS Final SED

RX08 – LAPLander (Light Airbag Protected Lander)

KTH Royal Institute of Technology, Sweden

Launch Date: 4 March 2010

The objective of the LAPLander experiment was to design, build and validate a prototype of an inflatable re-entry system for recoverable scientific payloads. For high altitude atmospheric research, multi-point measurements are often collected by ejecting recoverable payloads from sounding rockets. Storing data onboard these sub-payloads removes the radio link bandwidth limitations and allows storage of large quantities of data, with the system being scalable with the number of sub-payloads. The LAPLander was optimized in terms of size and mass, and measured ~24 cm in diameter, 8.4 cm in height and 3 kg of mass. As no standard off-the-shelf recovery system exists for such a small, fast-spinning payload, the LAPLander made use an inflatable structure both to decelerate the fall, and to serve as protection at the moment of impact. To assess the re-entry systems performance the experiment was equipped with sensors for in-flight diagnostics, with a redundant radio-beacon and satellite transmitter for post flight recovery. To demonstrate the systems applicability for future ionospheric research, the payload also contained a miniaturised SMILE magnetometer and 4 dummy boom deployment units for an E-field instrument.

LAPLander Conference Paper