13. June 2022
Testing software for a new computer system

Smart­phone tech­nol­o­gy pro­vides satel­lites with in­creased com­put­ing pow­er

OPS-SAT research platform
OPS-SAT re­search plat­form
Image 1/3, Credit: ESA

OPS-SAT research platform

ESA's OPS-SAT Cube­Sat has been in low-Earth or­bit since the end of 2019. It can be used as a re­search plat­form for hard­ware and soft­ware de­vel­op­ment. The func­tion­al­i­ty of ScOSA was suc­cess­ful­ly test­ed us­ing this satel­lite.
ScOSA computer
ScOSA com­put­er
Image 2/3, Credit: DLR (CC BY-NC-ND 3.0)

ScOSA computer

Pre­lim­i­nary in­te­gra­tion of a ScOSA com­put­er for the up­com­ing DLR Cube­Sat mis­sion. The satel­lite mea­sures 30 by 10 by 10 cen­time­tres.
One high-quality image and two low-quality images
One high-qual­i­ty im­age and two low-qual­i­ty im­ages
Image 3/3, Credit: ESA

One high-quality image and two low-quality images

The soft­ware on­ly rat­ed the first im­age (left) as high qual­i­ty, the oth­er two were dis­card­ed and would not have been sent to the ground sta­tion. This ex­per­i­ment was suc­cess­ful.
  • DLR is developing distributed and heterogeneous on-board computers for future space missions.
  • These combine radiation-hardened and commercially available processors that monitor one another and redistribute tasks in the event of an error.
  • A successful experiment has been conducted on board an ESA research satellite, processing Earth observation data.
  • Focus: Space, Earth observation, technology

Reliable and powerful computers play a central role in spaceflight – for example, computer systems in satellites enable sophisticated Earth observation missions. The German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) is developing a new computer architecture that will provide On-Board Computers (OBCs) with more power as well as enabling them to repair themselves. Distributed heterogeneous OBCs are being created in the Scalable On-Board Computing for Space Avionics (ScOSA) flight experiment project. They feature different computing nodes that are connected to form a network.

A general challenge for computer systems in satellites is that cosmic radiation can interfere with their operation. "If a radiation particle impacts a digital memory element, it might turn a zero into a one," explains Project Manager Daniel Lüdtke from the DLR Institute for Software Technology in Braunschweig. Ultimately, the system can even fail or deliver incorrect results. For this reason, radiation-hardened processors are available for use in space. However, these are very expensive and have only limited computing power. On the other hand, processors such as those used for smartphones are very powerful and also much cheaper. They are, however, much more vulnerable to space radiation. ScOSA integrates both types of processors in one system.

Testing on the OPS-SAT satellite in low-Earth orbit

Special software detects errors and failures, and manages the computers. "In this process, programs running on a faulty processor are automatically transferred to other processors via the network," explains Lüdtke. Meanwhile, the satellite continues to function normally. The software then restarts the processor and re-integrates it into the system.

An experiment on the European Space Agency (ESA) OPS-SAT satellite has now shown that this works. "The satellite, which is 30 by 10 by 10 centimetres in size and contains an experimental computer, has been in low-Earth orbit since the end of 2019. OPS-SAT is available to researchers as a fully equipped and open platform," explains David Evans, ESA Project Lead for the mission.

The DLR researchers installed and successfully tested the ScOSA software on OPS-SAT together with ESA. To do this, the satellite acquired Earth observation images, then processed and evaluated them using artificial intelligence. The satellite then only transmitted the viable images to a ground station. "Sensors with increasingly high resolutions and complex algorithms require more and more computing power," says Daniel Lüdtke, summarising the requirements for software and hardware. A larger ScOSA system consisting of radiation-hardened and commercially available processors will soon be tested on a dedicated DLR CubeSat. This small satellite is expected to be launched at the end of 2023.

Development of software for space missions

The Onboard Software Systems Group of the DLR Institute for Software Technology is involved in several national and international space missions. A central research topic in this context is the development of fault-tolerant and resilient software that can react to errors and failures. In addition to the Institute for Software Technology, the DLR institutes of Space Systems and Optical Sensor Systems, and DLR Space Operations and Astronaut Training are also involved in the ScOSA flight experiment project.

  • Katja Lenz
    Ger­man Aerospace Cen­ter (DLR)

    Cor­po­rate Com­mu­ni­ca­tions
    Telephone: +49 2203 601-5401
    Linder Höhe
    51147 Cologne
  • Daniel Lüdtke
    Ger­man Aerospace Cen­ter (DLR)
    In­sti­tute for Soft­ware Tech­nol­o­gy
    Soft­ware for Space Sys­tems and In­ter­ac­tive Vi­su­al­iza­tion
    Lilienthalplatz 7
    38108 Braunschweig


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