Expensive hardware was the reality of space communication for decades; heavyweight, hardware-dependent, and incredibly expensive. But developers have been reshaping this scene and fundamentally changed how we take to spacecraft.
Today, that same communication capability can potentially fit on a laptop, thanks to Software-Defined Radio (SDR) technology. This transformation is a fundamental shift in how we approach space communication infrastructure, and offers an unprecedented flexibility and efficiency in satellite operations.
The implications of this shift are profound, especially as we enter an era of increased commercial space activity and complex multi-satellite missions. As Alexander Spaniol, RF Engineer at Terma, notes:
"We try to get as much as possible into software to get all the benefits from there and try to rely as less as possible on the actual hardware itself."
Software-Defined Radio basically reimagines how we handle space communication signals. Instead of requiring specialized hardware components for each function such as modulators, demodulators, frequency mixers, and signal processors, SDR systems capture the raw radio signal and perform these operations digitally.
This approach offers remarkable flexibility. When mission parameters change, whether it's orbital adjustments, varying data rates, or shifting frequency requirements, updates can be made through software modifications rather than hardware replacements. For space missions, where physical access to equipment is impossible post-launch, this adaptability is invaluable, and something we ourselves have worked hard to secure in our own SDR-solution from Terma.
"With software defined radio, you can change it like you want to," explains Spaniol. "Different modulation schemes have different advantages and disadvantages. So you always have to deep dive into your specific application, what suits the best for you."
→ LISTEN TO THE FULL INTERVIEW WITH SPANIOL AND STREN HERE
The huge difference here is the fact that you’re not stuck with with you choose. You can change your mind and chance the system – from the ground.
Perhaps one of the most revolutionary aspects of SDR technology is its role in enabling virtualized ground station operations. Traditional ground stations required extensive physical infrastructure and constant on-site personnel. Now, with virtualization, the software stack – including digital signal processing and mission control – can run in the cloud or on edge servers, paving the way for Ground Station-as-a-Service (GSaaS) models.
This shift has profound implications for space mission operations. Ground station capabilities can be orchestrated, scaled, and accessed from anywhere over secure, low-latency networks – enabling 24/7 monitoring without the need for permanent physical presence. More importantly, multiple organizations can share the same digitized infrastructure, significantly lowering operational costs and reducing entry barriers for emerging space players.
The democratizing effect of these technologies is already visible in the educational sector. As Andreas Stren from the University of Applied Sciences Wiener Neustadt shares:
“For our mission, we cannot operate our ground station 24/7 with manpower. So, we use this new technology to be able to access it from anywhere, anytime.”
While SDR technology offers numerous advantages, it also presents unique challenges. Digital systems react differently to radiation than traditional hardware ones, and requires new approaches to ensure reliability in the harsh space environment, Stren explains. This is something satellite builders and space companies must tackle in the systems they build.
“It’s fairly easy for the strong radiation in space to flick a 0 to a 1, and surely easier than changing anything in a traditional hardware system,” Spaniol adds.
To solve this, extensive testing and development is needed, and even so, the solution most often involves redundancy with multiple SDR systems operating in parallel to ensure continuous communication even if one system is compromised.
Relying on software rather than hardware also introduces cybersecurity as another critical consideration. As more communication functions move to software, protecting these systems from unauthorized access becomes paramount.
"If someone hacks into your system, then we will have a big problem because they can easily speak and hijack your satellite," notes Spaniol. “The systems must be secure by design, and must be updated with security patches and updates when vulnerabilities are discovered. This is true for our own SDR products and solutions, as well as for everyone else.”
Satellite communication should be considered a part of a country’s or a company’s critical infrastructure, and hence the cyber-security measures match accordingly.
No doubt, the future of space communication appears increasingly software-defined and virtualized. The industry trends point toward more sophisticated parallel communication capabilities that enables simultaneous transmission and reception across multiple frequencies and protocols.
Ground station as a service (GSaaS) models are gaining traction, allowing organizations to access communication infrastructure without massive capital investment. This democratization of space communication technology is both making operations more efficient and it's enabling entirely new business models and mission possibilities.
As we seek deeper into space and launch more ambitious missions, the flexibility and adaptability of SDR technology will become increasingly crucial, because it allows for i.e. changing communication frequencies over the course of the satellite’s life, for better reception or less crowded and noisy frequency bands.
One thing is for sure: the developments in satellite communication will shape the future of space exploration and commercialization for decades to come.