Microgravity Techniques

RX31 – CREATE (Carbon REinforced Additive manufacturing Technology Experiment)

Technische Universität Braunschweig

Launch Date: March 2024

The application of continuous fibres in composites enables the production of materials with improved material properties, such as increased specific tensile strength. An ongoing area of research is the production of fibre-reinforced composites through additive manufacturing. Recent studies have shown that during the in situ impregnation process, voids can form at the fibre-matrix interface. This is disadvantageous as materials with higher void fraction have reduced material properties. Manufacturing under microgravity could potentially influence the void fraction. The aim of the Carbon REinforced Additive manufacturing Technology Experiment (CREATE) is to gain an improved understanding about the influence of gravity on fibre-matrix impregnation in additive manufacturing of fibre composites. In the experiment, polylactide (PLA) is co-extruded with a continuous carbon fibre. The nozzle temperature as well as ambient pressure and temperature are recorded. The experiment is conducted under both Earth gravity and microgravity conditions utilizing a REXUS sounding rocket to achieve the microgravity environment. In the evaluation, the samples are examined microscopically and the tensile strength is measured. A comparison with the samples produced on the ground shows the influence of gravity on the fibre-matrix impregnation and the material properties.


RX29 – ECRIDA (3D Printing by Curing Resin In-orbit using UV Digital Light Processing Apparatus)

University Politehnica of Bucharest, Romania

Launch Date: 01 April 2023

During supply missions, objects may get broken or damaged and this can cause extra costs and delays for on-going space missions.
Additive manufacturing techniques may have a great impact on future space applications. Sending in orbit raw materials that can be transformed into useful objects can reduce the cost and the duration of space missions.
The main goal of the ECRIDA experiment is to design and test a DLP printer for manufacturing 3D objects on-board of the REXUS 29 rocket. Digital Light Processing (DLP) is a 3D printing technology based on curing UV sensitive resin with the help of a UV emitting LCD display and a moving build plate. Each layer is printed by lightning up the pixels of the display in a desired shape and waiting until the resin solidifies and sticks to the build plate. Then, with the help of an actuator, the build plate is risen with the next layer’s size and the process is repeated until the object gets fully printed. We aim to manufacture test specimens with a thickness of 1mm during the reduced gravity period and to compare them with specimens printed in terrestrial conditions by performing material analysis procedures.

RX27 – AIMIS (Additive manufacturing in space)

University of applied Science Munich, Germany

Launch Date: 5 November 2022

The core of the AIMIS team’s experiment consists of the extrusion and subsequent curing of a photoreactive polymer with UV light under space conditions. The first step on the path to this goal is a technology demonstration of the manufacturing process. For this purpose, in the preface of the experiment, the team will generate simulations of the process and verify them by monitoring the process. Additionally, the team will conduct an analysis of the material science properties of the samples after the flight. The (autonomous) fabrication of components in space has not yet been attempted, so the experiment is the first of its kind. The results of the experiment could serve as a basis for future experiments, for example, by a finer definition of requirements for the polymer, possible fiber reinforcement or creation of complex 3-dimensional structures. Expected results include self-supporting polymer rods and a stable manufacturing process for photoreactive polymers.

RX11 – ADIOS (ADvanced Isolation On Sounding-rockets)

FH Aachen, Germany

Launch Date: 16 November 2012

The goal of the ADIOS experiment is to further develop and optimise the VibraDamp system which was successfully flown on REXUS 7 in 2010. ADIOS is primarily a passively damped experiment module that isolates the external forces that may negatively impact on experiment performance. The contactless damping system operates under the eddy current principle, and is sized to fit into a REXUS standard module. To verify the damping quality, the residual accelerations acting on the rocket structure and inside the isolated experiment container shall be measured using a tri-axial accelerometer, during the reduced gravity phase of the flight. All components shall be as light as possible, so as to further reduce the mass of the structure. To aid this process, a complete working knowledge of the mechanical loads acting on the structure is important. Therefore, the second goal of the ADIOS experiment is to measure structural static and dynamic loading during the flight. A third tri-axial accelerometer with a wide sensitivity range shall be used to measure the dynamic load during flight. The static loads onto the structure shall be determined using at least twelve one-dimensional strain gauges. Respectively, four strain gauges shall be located at different positions in one cross-section of the rocket structure. Using this knowledge, it should be possible to optimise material selection and the associated mass of the structure, and therefore enhance the design of sounding-rockets.

RX07 – VIBRADAMP (Damping system for an experiment module)

FH Aachen, Germany

Launch Date: 2 March 2010

The goal of the VIBRADAMP experiment was to investigate whether it is possible to improve the microgravity quality of the REXUS rocket, by means of a passive experiment isolation system based on the eddy current effect. During the free fall phase of a REXUS flight, the induced microgravity can often be affected by externally produced vibrations, negatively influencing experiment performance. VIBRADAMP aimed to combat this effect by developing a lightweight, passively damped experiment module for REXUS which would isolate a major part of the forces acting on the system. During the free fall period, the only connection between the damped module and the rocket structure would be small beam-springs. The contained experiment would be isolated further by the counter movement of opposing magnetic fields generated by a permanent magnet passing over an electrically conductive plate. It was anticipated that the experiment would create a system with an Eigen frequency below 1 Hz which could isolate approximately 95% of the forces acting on the damped system. To verify the system two accelerometers were used to measure and compare the accelerations acting on the damped system and the surrounding structure.

VIBRADAMP Conference Paper

BX09 – reel.SMRT (Balloon microgravity platform)

‘Erasmus Mundus’ Space Masters course

Launch Date: 11 October 2009

The purpose of reel.SMRT was to investigate the feasibility of a balloon based microgravity research platform, capable of conducting multiple drop tests in a s ingle mission. The system consisted of a small capsule, which could be dropped or lowered from the main balloon gondola and then returned, using a fishing reel and motor connected to the capsule by a high strength line. Complex mechanical, electrical and data acquisition systems were implemented to monitor the low gravity performance during operation. The vision was that this microgravity platform could be scaled up to cover drop distances on the order of hundreds of meters, thereby providing cyclical, extended periods of freefall, and a viable alternative to parabolic flights and drop towers. During the BEXUS flight, a payload tethered to the reel.SMRT system was dropped and decelerated using an internal braking system. As the payload came to a halt, it was reeled back up to the gondola and re-released. This cycle was to be repeated several times, in order to measure the microgravity quality during the free-fall phase.

reel.SMRT Conference Paper