The advancing developments in space technology mean that it is now possible for a wide range of public and private institutions to develop their own satellites and place them in orbit. A common problem in all satellite projects, but especially for smaller ones, is the provision of power to all systems. A second common challenge is to distribute the radio frequencies for communication with the increasing number of objects.
The DISCO One project is developing and deploying a technology called Modular Retroreflectors (MRR) designed specifically for micro-satellites that addresses these 2 issues. By using the MRRs, the downlink of data can be done without radio transmission. To transmit the data, a ground-station directs a strong laser at the passing satellite. This laser beam hits the retroreflectors, which throw the light back in the same direction. Due to the modulators, the reflected laser beam can be influenced in intensity, in the simplest case, binary switched on and off. The reflected beam is detected by an optical telescope at the ground station and the transmitted data is determined. The modulation requires by orders of magnitude less energy than the transmission by radio and no radio channel is occupied for the downlink. Due to the high focus of the laser beam, it is virtually impossible for other satellites or ground stations to experience crosstalk or interference.
The aim of this project is to build a fully functional satellite-based setup with MRRs and ground station with laser and telescope, and to use the experience gained to develop a module that can be easily integrated into other satellite projects. For maximum compatibility, the finished module should not occupy more than 0.5U of a cube.
The TU Wien Space Team is not only concerned with the development of space-capable hardware and software and the mechanical components, but also with the simulation of environmental conditions at start and in orbit, with the construction of the optical communication signal and the legal requirements.[01.12.2019]:
At the moment a new DISCO One website is under construction! We will publish it as soon as we are ready – stay tuned!
An overview of the frequency bands is available at this website (Public Domain, United States Department of Commerce).
Basic principle of the satellite communication
https://technology.nasa.gov/patent/TOP2-248 (Public Domain, NASA)
Latest CAD models of the CubeSat DISCO One