You don’t need a government budget to do meaningful science in space.
Interesting questions come from interesting places. Sometimes they come from social media. Sometimes, they’ll land directly in your email inbox.
But sometimes, you get someone close to you who asks an interesting question.
“So…uh… what are you doing with that old satellite dish anyway?”
Ask a good question, receive an interesting answer.
Why The Dish?
With the internet powering much of the modern world, it’s easy to forget that behind the scenes, much of the infrastructure exists thanks to the broad-reaching impacts of the electromagnetic spectrum.
In layman’s terms, satellites talk. Constantly. Weather data, navigation signals, telemetry, imagery downlinks, and communications relays mean that the electromagnetic spectrum around us is anything but quiet.
SIGINT (Signals Intelligence) is the discipline of listening to that noise and extracting meaning from it.
For decades, this was the exclusive territory of nation-states and well-funded agencies with the infrastructure and budget to match.
It would require large dish arrays, dedicated receiving stations and classified processing pipelines that would keep the discipline firmly out of civilian reach.
That changed when the cost of cheap consumer electronics went through the floor right at the time that the internet would democratise access to information.
That Hardware You Already Have
The RTL-SDR would pack a cheap radio receiver into a USB dongle that would work effectively on nearly any computer, providing a way to visually assess the spectrum, all at a price point that would be almost trivial in comparison to previous systems.
The barrier to entry would be reduced to little more than a laptop with USB ports and an RTL-SDR. This was a pretty cool evolution for nerds, but the real story wasn’t about the hardware. It was about what people were connecting it to and what it was pointing at.
Foxtel dishes would be pulled off rooftops and repurposed for weather satellite imagery and SIGINT, while consumer hardware that enabled legitimate civilian science to occur would start to hit the market.
Over time, the civilian SIGINT community has quietly built a culture of hardware repurposing that turns consumer cast-offs into functional receiving infrastructure. A dish that spent a decade pointing at a broadcast satellite can, with the right feed and a cheap SDR, become a legitimate ground station.
Part of the reason that civilian hardware would play such a key role would be the implementation of quality communication systems at consumer price points. As the world of satellite television would grow and then decline in popularity, a wide variety of hardware would filter down into the market that could essentially be acquired for free.
No longer were the nerd gangs limited to a 90cm TV dish for their satellite reception, and more importantly, a wide variety of dish styles would unlock even better performance.
Now, you could go big at home. A 3-metre dish repurposed for Hydrogen line exploration for under $100. Too easy.
Real Programs, Real Results
Talk is cheap, so let’s look at three real-world programs that have naturally played into the strengths of this evolution.
SatNOGS:
The Satellite Networked Open Ground Station network is perhaps the best example of what an organised civilian effort can achieve. SatNOGS is a globally distributed network of ground stations, built and operated by volunteers, that collectively provides satellite tracking and signal reception coverage that rivals dedicated institutional infrastructure.
Anyone can build a SatNOGS station. Anyone can contribute observations. The data is open.
The community is active. And you can build your own station in this previous tutorial.
GNU Radio & The SDR Community
GNU Radio is the open-source toolkit that underpins much of what the civilian SDR community does. It provides the signal processing framework that lets a cheap receiver and a laptop decode satellite telemetry, capture weather imagery, or analyse unknown transmissions.
The broader SDR community that has grown around tools like GNU Radio, and platforms like RTL-SDR.com and even our own Radio Hackers publication represents a collective knowledge base that is freely shared, constantly updated and increasingly sophisticated.
A standout example is the community-developed decoder for the now-retired NOAA weather satellites.
This was a complete, documented workflow that let anyone pull live satellite imagery from orbit with nothing more than an RTL-SDR and a basic antenna. All developed by people who simply took an interest.
Amateur antenna farms in rural areas can be large and elaborate, covering huge parts of the radio spectrum. The radio-quiet nature of some rural areas is also very helpful for those interested in Deep Space communications. Source: Wikipedia.
The Wildcard: AMSAT
If SatNOGS gives us the ground station while GNU Radio gives us the processing pipeline, the Radio Amateur Satellite Corporation (AMSAT) closes the loop entirely by sending civilian hardware directly into space.
Since 1969, AMSAT has been designing, building and launching amateur satellites. These are real spacecraft, built by volunteers, carrying real payloads, transmitting real signals that anyone with modest equipment can receive.
The existence of AMSAT provides a real-world pedigree to civilian science projects that can’t easily be achieved by passive listening alone. Actually launching satellites with targeted scientific goals and secondary payloads enables civilian science to carry out research with real-world consequences.
Let’s just pause to consider this angle for a moment longer. There is a network of objects in orbit specifically designed to be received, tracked and communicated with by the public.
Science is fun.
The Security Research Angle
It’s a little-known fact that many legacy communication protocols we’ve relied on for years carry inherent vulnerabilities that were often never disclosed by the companies that implemented them.
Back then, it was assumed that the equipment needed to receive them was expensive enough to act as a natural barrier. Obscurity, in other words, was the security model that would be relied upon.
That assumption has aged terribly with time.
It was civilian researchers using cheap, consumer hardware who would help to highlight the fact that Iridium satellite traffic would be passing commercially sensitive and operationally relevant data via its satellites in clear text.
The messaging system called ACARS, which underpins the global aviation network, would not avoid scrutiny either. Its L-band satellite traffic has been decodable for years, providing researchers with an intricate look inside the global aviation network.
None of this required classified tools or nation-state resources. It required curiosity, cheap hardware and open-source software.
It’s worth pointing out that despite the hype that often occurs in the media, these aren’t hacks. They are responsible disclosures that have pushed real-world security patches into effect and helped shine a light on some of the problems that exist in legacy protocols.
The bug bounty industry provides real-world solutions to companies that need them while giving security researchers the chance to monetise their research skills. The incentives, for once, actually aligned.
Over To You
The world where governments have a monopoly on space has long ended. The civilian contributions around responsible disclosure and actually being involved in legitimate space programs are well-documented and only expected to increase in the future.
At the end of it all, the protocols that govern how satellites communicate with the ground were not all built with adversarial scrutiny in mind.
The fact that the people providing that scrutiny today are often doing it from a shed, with a dish someone threw away and a laptop running open-source software, is pretty damn cool.
The sky is talking. Will you listen?
Investigator515 explores the RF spectrum, cybersecurity, and the hidden tech behind modern espionage.
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