BEXUS 22/23 – testing new technologies in the atmosphere with research balloons
On 5 October 2016 at 15:33 CEST, the research balloon BEXUS 22 took off from the Esrange Space Center, near Kiruna, Sweden, en route to the stratosphere. BEXUS 23 is scheduled to be launched on 6 October. On board the balloons are eight scientific experiments from teams made up of students from Germany, Poland, the Czech Republic, Belgium, Italy, Spain and Portugal. The experiments are part of joint missions of the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) and the Swedish National Space Board (SNSB) and address satellite communications and navigation, as well as astrophysics and technology testing.
BEXUS 22 – testing satellite communications and navigation using stratospheric balloons
BEXUS 22 carried two German experiments on board:Lotus-D (Laser Optical Transmission experiment of University Students - Data) and TDP-3 (Technology Demonstrator Platform 3). With Lotus-D, students from Dresden University of Technology are hoping to establish a communication link using light from Light Emitting Diodes (LEDs) between a small, mobile ground station and the research balloon. Depending on the LED power, the distance of the balloon and weather conditions at the launch site, this connection will determine the maximum transmission rate achievable, measured in bits per second.
By means of a modulated LED – directed from a telescope to the balloon gondola – it was planned to transfer data. At the gondola the light beam was intended to be detected and recorded. By comparing the received data sequence with the original data sequence sent to the balloon, and depending on the weather conditions and distances, a resulting bit error rate should have been determined immediately.
TDP-3 – a new system for data processing
High altitude research rockets and balloons are used for atmospheric research. The experiments are limited by the size of the balloons and rockets, and therefore require compact data processing and control systems that consume little power. Remote control of the experiments, as well as science data transfer, also require a compact, yet high-performance, communications system.
As part of their TDP-3 experiment, students from the Technical University of Munich have developed a new data processing system that fulfils these conditions and can be adapted for other experiments and platforms. This should significantly reduce the development time for future experiments. The team has also integrated a new kind of particle detector into their experiment, to test the functionality of the data processing system during flight.
In addition, two further experiments from Italy and Poland were on board BEXUS 22: the STRATONAV experiment, from Sapienza University of Rome and the University of Bologna, tested the accuracy of a navigation system during the BEXUS flight to the stratosphere. When the system is more mature, it will be able to be used for position determination during space missions. Students from the Warsaw University of Technology developed the BuLMA experiment and aim to capture mini meteorites and dust particles during the mission, to be studied in a laboratory. Parts of the experiment can be adapted for Mars missions.
BEXUS 23 – experiments for astrophysics and the testing of new technologies
Four experiments will be tested on the BEXUS 23 balloon gondola. Students from the University of Hasselt in Belgium have developed the OSCAR project. During the mission, carbon-based optical solar and sensor cells will be tested for their potential application in the aerospace industry. In addition, the performance and stability of organic solar cells will be tested under extreme conditions, such as radiation and high temperature differences. Furthermore, the researchers have developed an optical magnetometer prototype for measuring weak magnetic fields, which will be tested under stratospheric conditions.
The aim of the PREDATOR experiment by Czech Technical University in Prague is to measure the differences in the flying altitudes of aircraft using a cost-effective system, and to test this as an additional reference system for the correction of errors. To achieve this, pressure on the gondola will be measured in two locations. As the distance is already known, it is possible to establish the exact height of the balloon.
A team at the University of Porto in Portugal is predominately focussed on navigation information, which can be transmitted via radio and television signals during the BEXUS flight. To this end, the SIGNON experiment will process the signals received and determine the distances in order to measure the balloon's flight path. These navigation methods can be used on small satellites, at altitudes of 450 to 550 kilometres.
The ACORDE experiment, led by students from the University of the Basque Country, will test a cost-effective and lightweight particle detector, which is capable of detecting traces of cosmic radiation. Using this detector, students will be able to measure the quantity and type of radiation present during the flight.
BEXUS 23 – experiments for astrophysics and the testing of new technologies
The German-Swedish BEXUS programme (Balloon Experiments for University Students) enables students to gain practical experience in the preparation and implementation of space projects. The proposals put forward this year by the DLR Space Administration in Bonn, as well as the European Space Agency (ESA) and the Swedish National Space Board (SNSB) are BEXUS 24/25, for the autumn of 2017, and the rocket project, REXUS 23/24, both of which are already under way.
New experiment proposals can be submitted until 17 October 2016. Half of the balloon payload is being made available for experiments undertaken by students from German universities and higher education facilities. The Swedish National Space Board (SNSB) has also opened up their programmes to students from other ESA Member States. The German team of students will receive technical and logistical support from the Centre of Applied Space Technology and Microgravity (ZARM) in Bremen. The flights will be carried out by EuroLaunch, a joint venture between DLR's Mobile Rocket Base (MoRaBa) and the Esrange Space Centre of the Swedish Space Corporation (SSC).