Otto Koudelka, Rainer Kuschnig, Manuela Wenger
Graz University of Technology
Institute of Communication Networks and Satellite Communications
TUGSAT-1 / BRITE-Austria, the first Austrian satellite was launched together with its sister satellite UniBRITE in February 2013. They are part of the world’s first nanosatellite constellation to measure the brightness variations of massive luminous stars. Five nearly identical nanosatellites from Austria, Poland and Canada are in continuous operations since 2013. Each spacecraft carries a small telescope with CCD sensor as the scientific payload. Although designed for a lifetime of two years, the Austrian BRITEs are now in operations for more than five years and and show an excellent health status. None of the components are space-qualified, although critical components were radiation-tested. The CCD naturally has accumulated radiation damage, resulting in hot pixels and warm columns. A method called “chopping” was introduced to overcome the radiation impairments by image processing. Thus, the mission can be extended for at least two more years. This impressively demonstrates that challenging scientific requirements can be fulfilled by a low-cost nanosatellite mission .
In another project called OPS-SAT  TU Graz has developed an advanced on-board processor payload, a software-defined radio receiver and an optical payload with partners in Austria and Germany. These subsystems use selected industry-grade (non-Space-qualified) electronics components, such as system-on-chip modules, mixed-signal chips and single-photon counter modules. They were radiation-tested at ESTEC in 2015 up to 20 krad and showed no degradation.
The presentation will discuss the radiation effects identified in the BRITE mission and the countermeasures taken. Also the results of the OPS-SAT radiation tests will be shown.
 Pablo, H.; Whittaker, G. N.; Popowicz, A.; Mochnacki, S. M.; Kuschnig, R.; Grant, C. C.; Moffat, A. F. J.; Rucinski, S. M.; Matthews, J. M.; Schwarzenberg-Czerny, A.; Handler, G.; Weiss, W. W.; Baade, D.; Wade, G. A.; Zocłońska, E.; Ramiaramanantsoa, T.; Unterberger, M.; Zwintz, K.; Pigulski, A.; Rowe, J.; Koudelka, O.; Orleański, P.; Pamyatnykh, A.; Neiner, C.; Wawrzaszek, R.; Marciniszyn, G.; Romano, P.; Woźniak, G.; Zawistowski, T.; Zee, R. E., The BRITE Constellation Nanosatellite Mission: Testing, Commissioning, and Operations, ,in Publ. Astron. Soc. Pac., 128, 970, 2016.
 Koudelka, O., D. Evans, The OPS-SAT Nanosatellite Mission- A Flexible Platform for On-Board Experiments, Proc. 11th IAA Small Satellite Symposium, Berlin, 2017
BRITE-Austria/TUGSAT-1 is funded by the Austrian Aeronautics and Space Agency within the ASAP program. OPS-SAT is funded by the ESA GSTP program.