BX24 – DREX (Deployable Reflector EXperiment)
University of Padova, ITALY
Launch Date: TBD 2017
Solid dish antennas are a widespread technology and nowadays they are used in many communication systems. Despite this, there exist even more applications that could take advantage of this type of antennas but, at the same time, are unable to use them because of strict constraints imposed by the characteristics of the system and of the operating environment. In this case, devices must be small and light and solid dish antennas are often unable to meet all of the requirements. Deployable antenna structures seem to offer a promising solution to this problem combining an optimized structure with the same features of a solid dish. Their use could spread to various fields, creating a completely new range opportunities. The purpose of this project is to design, test and verify the performance of a stratospheric deployable reflector named DREX. The current technology is a further development of an existing deployable antenna for space: it is a prime-focus radial opening antenna that combines inherent redundancy with a reliable deployment mechanism. It weights less than a solid dish of the same size and, since the deployment occurs in the stratosphere, it would be less subjected to atmospheric drag during the flight. In addition, the central fixed hexagon guarantees operativeness also in the event of unexpected behavior of the deployment system, overcoming the necessity of other antennas for redundancy on the balloon system. This kind of technology could be used, for instance, to implement an aerial high-data-rate microwave radio links (UHF/SHF/EHF). Il could also be used for interception of communications and radar signals (P-band and X-band) for military and intelligence, Earth observation in low and midrange-frequency radar (from P-band to C-band), deep space observation (MF to EHF) and remote sensing. Aside antenna applications, a wide scale DREX reflector could be functionally relevant as a solar concentrator for the balloon power supply system.
RX21 – DIANE (Dipole Inflatable Antenna Experiment)
Technical University of Dresden, Germany
Launch Date: 15 March 2017
The DIANE experiment is focused on developing an inflatable antenna with application in space. Inflatable structures attract for its unique characteristics. Low mass and superior volume packaging efficiency – those are not all, but the most significant advantages of such structures. Extremely light constructions can be fabricated out of thin films or gas-tight textiles, with any form, limited only by imagination.
An enormous long dipole inflatable antenna and will be deployed in microgravity environment within the upcoming REXUS campaign. The whole antenna with its storage, deployment mechanism and gas generating system, transmitter and control board should fit a CubeSat 4U module, showing direct application for tiny satellites. During the deployment process of the antenna structure will be observed by a camera to investigate and study the dynamical behaviour.
RX21 – UB-SPACE (University of Bremen – Image Processing for Determination of relative Satellite Motion)
University of Bremen, Germany
Launch Date: 15 March 2017
Space debris is a growing challenge in spaceflight. Yet, no promising solution has been implemented to remove the amount of debris surrounding our planet. By using systems which are able to navigate autonomously, it is possible to realize a camera-based detection and removal of space debris, such as defective satellites. To enable an optimal preparation for these systems to fulfill such tasks, images of the approach of uncooperative objects in the real space environment, as well as related data describing the motion of the objects are essential.
To this day, mainly visualisations are used instead of real images for the purpose of testing systems to approach other satellites, since real images are rare and not freely accessible. The experiment shall provide such a series of images, showing the approach to a satellite. Therefore, one CubeSat is ejected and will be observed from the rocket via a 360° camera view. In addition, motion data from the CubeSat will be sent to the rocket module. By means of image processing, the relative motion of the satellites can be determined.
The recorded images, the measured data and a reconstructed relative motion will be published, so they are generally accessible and thereby allow everyone to work towards solutions to this global problem.
RX19 – PICARD (Prototype Inflatable Conical Antenna – REXUS Deployment)
University of Strathclyde and University of Birmingham, United Kingdom
Launch Date: 17 March 2016
The PICARD experiment aims to demonstrate the viability of partial surface metal-polymer rigidisation based structures in a miligravity environment; the structure deployed will be a conical helix antenna designed for wideband Ionospheric Radar measurements, a precursor to the WISCER mission. Detailed measurements shall be taken during the experiment to verify the success of and to characterise the dynamics of the deployment.
BX21 – InTex (INflatable TEXtile based antenna systems and structures)
TU Dresden, Germany
Launch Date: 7 October 2015
The InTex experiment aims at developing a novel technology for inflating antenna structures in space. Instead of using planar foils and thus limiting the geometry to piecewise developable surfaces, textile fabrics can be manufactures in virtually any shape. Even more conductive filaments, which are needed for the actual antenna structure, can be introduced into the fabric with very high precision. This can be done during the knitting or weaving process or afterwards by stitching. One of the major drawbacks of inflatable structures is the risk of deflating, which leads to a structural collapse. This could be even more catastrophic when e.g. the deflated antenna wraps around a solar panel. In the InTex experiment the textile fabric is soaked with an uncured polymer. It is cured after the inflation of the structure by UV light originating from the sun and an internal UV light source. After curing, the antenna consists of a stable textile-polymer compound, which ensures mechanical integrity even in case of pressure loss. To validate our approach, the inflation will be visually monitored by video cameras and the electrical performance of the antenna will be measured after inflation, curing, simulated pressure loss and compared with simulation results as well as lab measurements.
RX18 – SMARD (Shape Memory Alloy Reusable Deployment Mechanism)
TU München, Germany
Launch Date: 18 March 2015
The scientific objective is to verify the functionality of shape memory alloy actuators. The technical ojective is to test a prototype of the solar panel deployment mechanism for the CubeSat MOVE2, the successor of First-Move. In addition we will use the CERESS platform for data handling. After recovery the data will be analyzed and used to further optimize the satellite. The deployment mechanism is supposed to secure the panels backlashfree during launch and deploy the panels in orbit. The device shall be operated by elements made of shape memory alloy. These elements must be heated electrically to function as actuators. This concept allows a very small size and weight as improved simplicity and reusability of the system.This effectively removes one of the major disadvantages of the First-MOVE mechanism, which is partially destroyed during each test.
RX13/RX15 – StrathSat-R/StrathSat-R2 (Investigation into the use of two Cubesat-based deployable inflatable structures, including: a solar sail and a dynamic structure that adapts to varying conditions)
University of Strathclyde, United Kingdom
Launch Date: 9 May 2013, Launch Date Reflight: 29 May 2014
Space vehicle size is mainly governed by launch vehicle dimensions. The use of deployable structures became necessary due to their low stowage and high in-orbit volume. For the success of future space missions involving large space structures, the development of new deployable structures and the improvement of current designs are of great importance. StrathSEDS, a sub-division of UKSEDS at the University of Strathclyde (Glasgow, UK), developed StrathSat-R therefore to validate different inflation deployment techniques in space conditions. The StrathSat-R experiment consists of two distinct sections that are based on a 1U cube satellite (10x10x10 cm3) outline. The primary objective of both satellites is to deploy a structure in micro-gravity by using inflation. After inflation, the two free-flying units have different specific objectives: The aim of the first cube satellite, FRODO (Foldable Reflective system for Omni-altitude De-Orbiting ), is to deploy and then rigidise a large reflective sail from a 1U cube satellite sized pod. The concept of the passive solar radiation pressure (SRP) de-orbiting system is rooted in the research undertaken by the University of Strathclyde’s Advanced Space Concepts Laboratory. The ERC funded project is investigating highly non Keplerian orbital dynamics and applications. The passive SRP de-orbiting concept is using solar radiation pressure and the J2 perturbation to increase the eccentricity of an initially circular orbit until the perigee is affected by drag and the spacecraft de-orbits. This technique is particularly effective in MEO but can be applied to even higher altitudes. After the deployment of the reflective sail, the de-orbiting manoeuvre takes place completely passively. This research could open up new high altitude orbital regimes for future pico- and nano-satellite missions. The scientific objective of the second cube satellite, SAM (Self-inflating Adaptive Membrane), is to serve as a technology demonstrator for the residual air deployment method with a novel hexagon element design approach. The big advantage of the hexagonal element approach is that a structure can be obtained which is simultaneously stiff and flexible due to the stiff pillow elements and the flexible seam lines. The second goal of this endeavour is to develop a structure that can adapt itself to various environmental conditions. For example, the structure could serve as a substructure for a solar concentrator and adjust its focal point autonomously by changing the curvature of the entire structure. Both cube satellites will be recovered after impact with the ground.
BX16 – iSEDE (Inflatable Satellite Encompassing Disaggregated Electronics)
University of Strathclyde, United Kingdom
Launch Date: 8 Oct 2013
The goal of this project from students of the University of Strathclyde, is to design and build an initial prototype of an all-inflatable satellite with disaggregated electronics for deployment on-board a BEXUS balloon as proof of concept. The idea is to use cellular structures as support for all the subsystems composing a typical nano-satellite. Each subsystem and component is mounted on a different cell. Cells are both individually inflated and individually controlled. The aim is to design and build a prototype for this new type of satellite, demonstrating the deployment and wireless communication among components. Furthermore, the inflatable satellites have the ability to change their shape to prove a smart structure concept from the bio-inspired mechanism that plants are using to follow the sun.
RX14 – EDoD Spacesailors (Experimental Deployment of a Dragsail)
RWTH Aachen, Germany
Launch Date: 7 May 2013
The launch of Sputnik, the first artificial satellite on 4th of October 1957 introduced the era of spaceflight. Unfortunately with this great event the problem of space debris was also born. Now, after nearly 55 years of human activity in space a constantly increasing amount of space debris represents a tremendous problem for actual and future space missions. Therefor it is necessary to develop new de-orbit technologies for disused satellites. By using a dragsail at the end of life of a satellite the aerodynamic drag of the earth’s atmosphere can be increased which causes an acceleration of the satellite’s reentry. Unfortunately there are not many experiences in the domain of the deployment of such large lightweight structures in microgravity conditions until now. With our Experiment EDOD we hope to enhance the comprehension of the deployment kinematics of a dragsail and to qualify a deployment mechanism for future CubeSat missions. We also want to qualify a self-constructed camera module which will monitor the deployment of our 5 m² kapton sail. The deployment will take place on the nosecone adapter part of the rocket and in an altitude of nearly 100 km.
RX12 – Suaineadh (The controlled deployment and stabilization of a space web)
University of Glasgow & University of Strathclyde, UK, KTH Royal Institute of Technology, Sweden
Launch Date: 19 March 2012
The objective of the Suaineadh experiment is to prove the concept of deploying and stabilising a space web under microgravity conditions, by means of the centrifugal forces acting on the spinning assembly once it is ejected from the nosecone of a REXUS rocket. Controlled web deployment and stabilisation will be achieved by an active control method, which has the potential to drastically simplify the design of a Furoshiki net, whilst further enhancing its stability. The experiment will provide an enormous scientific return on the behaviour of centrifugally deployed and stabilised structures in space. The experiment can be split into two distinct sections; the ejectable section CHAD (Central Hub and Daughters) and the data storage section DAST (Data Acquisition and Storage) onboard REXUS. The CHAD carries out all mission operations, including web deployment and stabilisation, and consists of the central hub, a square web (2m x 2m) and four corners masses attached to the web. Prior to deployment; the web and corner masses will be wrapped around the central hub and ejected at an altitude of approximately 62 km. The web deployment phase will then be monitored by several cameras, to assess its dynamic behaviour during flight.
RX10 – SQUID (Spinning QUad Ionospheric Deployer)
KTH Royal Institute of Technology, Sweden
Launch Date: 23 February 2011
The main objective of the SQUID project was to design, implement and test a miniaturised version of a wire boom deployment system called SCALE, which could also conduct electric and magnetic field measurements of the lower magnetosphere. Research of this kind is often conducted using sounding rockets, from which multiple ‘daughter payloads’ can be ejected to collect multipoint measurements. However the rapid payload deployments associated with this platform can often result in residual oscillations and instabilities, which can complicate the correct interpretation of the acquired data. The SCALE system aims to combat this effect. The SQUID experiment consisted of two parts; a Rocket Mounted Unit (RMU) and an ejectable Free Flying Unit (FFU). The FFU carried four wire boom deployment mechanisms which were released upon ejection of the FFU. The fast deployment then followed a pre-programmed stabilisation scheme which reduced the residual oscillations of the wire booms, thus stabilising the payload itself. Each boom end-mass incorporated a sensor which measured the electrical and magnetic field properties of the atmosphere, as well as the in-flight dynamics of the wire boom system. The RMU contained a video camera, which captured the moment of deployment for later analysis. Post flight data from the wire boom deployment was used to further refine the SCALE system and improve the deployment routine.
RX09/RX11 – Telescobe/Telescobe-2 (Demonstration of a new telescopic boom system)
Dublin Institute of Technology, Ireland
Launch Date: 22 February 2011, Launch Date Reflight: 16 November 2012
The goal of the Telescobe experiment was to design, build and test a carbon fibre, telescopic boom system capable of being used to deploy E-Field and Langmuir probes for use in upper atmospheric research. Electric field, or E-Field, probes are used to measure the magnitude of the electric fields in the atmosphere. Langmuir probes are used to measure the ionisation energy and electron temperature of plasma. Since stowage space and mass are often at a premium in spacecraft, a telescopic boom system offers a much more efficient and desirable method of boom probe deployment. During flight the boom was extended out to a length of 1.6 m. Two pyrotechnic guillotines activated and finally jettisoned the spring actuated boom, which was monitored by a number of cameras and an accelerometer, to ascertain the performance of the boom during the flight. Images from the cameras determined the deployed length of the boom to within an accuracy of 5mm. The data from the accelerometer was used to monitor vibrations in the distal end of the boom after it was deployed whilst data from the accelerometers in the REXUS Service Module was also used to determine the effect of boom deployment on the entire payload.
RX07 – BUGS (Boom for University Gravity-gradient stabilised Satellites)
University of Bologna, School of Aerospace Engineering, University of Rome, Italy
Launch Date: 2 March 2010
The purpose of the BUGS experiment was to perform a microgravity deployment test of a boom, in order to study its dynamic behaviour in spaceflight conditions. The proposed use of the boom was for passive gravity gradient stabilisation of small satellites, and was based on a new concept exploiting the excellent rigidity properties of tape coiled springs. The idea was to record the boom deployment process, and any associated flexural vibrations, using dual video cameras. This data was then compared with a system finite element modal analysis, and used to further improve simulations of boom deployment dynamics. Moreover the collected data was also used to model real perturbations introduced by the booms deployment, thereby giving an accurate idea of a satellites attitude motion in orbit. By doing this it was hoped that the BUGS system could be utilised for future low-cost Earth observation satellites as a means of providing simple passive nadir pointing and attitude control.