Space traffic under pressure: why data transmission has become one of the key issues of the new orbital economy
The European Space Agency and its industrial partners have in recent days sent into orbit a set of demonstration missions whose shared goal is very concrete: to accelerate, secure, and route more intelligently the data that arrive from space to Earth or travel between spacecraft themselves. At the heart of the story is not just another launch of several smaller satellites, but an attempt to respond to a problem that is becoming increasingly visible as low Earth orbit fills with new platforms and civil society’s reliance on satellite services continues to grow. Weather forecasting, ship and aircraft tracking, forest and crop monitoring, crisis management, secure communications, and the operation of numerous digital services are increasingly linked to how quickly and how reliably data can pass through space infrastructure.
In that context, the SpaceX Transporter-16 mission lifted off on March 30 from Vandenberg Space Force Base in California, aboard a Falcon 9 rocket, as part of the rideshare programme that carries a large number of payloads on a single mission. That particular flight was selected for a series of European technological demonstrations supported by ESA. In practice, this means that eight CubeSats and one additional payload were sent into orbit, distributed across seven separate missions, all of which in different ways are testing how data can travel faster, more securely, and with fewer losses than before.
The main reason for such investments lies in the limitations of the radio-frequency spectrum. Radio frequencies remain the foundation of communication between Earth and satellites, but this resource is limited, congested, and regulatorily complex. As the number of satellites increases, so does the amount of data that must be acquired, processed, filtered, and forwarded. This opens space for technologies that can relieve existing systems, among which optical links, that is, laser communication, and increasingly advanced data processing directly in orbit stand out in particular. In both cases, the idea is similar: not to send absolutely everything, but to send what matters, and to send it to the user who needs the information at the right moment as quickly as possible.
What is actually being tested in orbit
For the wider public, the term “optimised data transmission from space” may sound abstract, but the application is very tangible. If a satellite captures a wildfire area, a flood zone, crop conditions, or a change in water resources, the value of that information often depends on delivery speed. The classic model implies that the satellite must wait for a favourable pass over a ground station and only then download the recorded data. In the case of large amounts of data, this creates a bottleneck. If the same content can be rerouted through another satellite, sent via a high-capacity optical link, or partially processed while still in orbit, the whole system becomes more efficient.
That is precisely why some of the missions on Transporter-16 are testing laser links between satellites and Earth, as well as among the satellites themselves. Laser communication promises higher transmission speeds, lower latency, and a higher level of security, but it requires exceptional precision: satellites move at high speeds, and beam pointing and maintenance must be almost perfect. Another part of the missions is focused on data transmission among satellites located in the same or intersecting orbits, while a third examines onboard data processing in order to reduce the need to send incomplete, erroneous, or redundant information to the ground.
Such an approach is important not only for commercial efficiency, but also for the public interest. In environmental monitoring, early warning, agricultural planning, or communication in crisis situations, the difference between data arriving within a few minutes and data delayed by hours can be very significant. That is why these demonstrations are seen as a step toward a new generation of space networks, in which the satellite is not merely a passive transmitter but an active node that knows how to filter, route, and prioritise content delivery.
Greek connectivity programme: a national technological leap under ESA’s umbrella
A special place in this package of demonstrations is occupied by the Greek missions developed within the Greek Connectivity Programme, which ESA is implementing on behalf of the Greek Ministry of Digital Governance. This programme is politically and industrially interesting because it serves not only individual experiments, but also the broader goal of building domestic capabilities in the design, assembly, testing, and operation of satellites. Following earlier Greek missions, the new group of spacecraft is focused primarily on optical links and the development of infrastructure that should give Greece a stronger position in the European space ecosystem.
One of the key missions is OptiSat, a 6U CubeSat operated by the Greek company Planetek Hellas. It carries the SCOT20 laser communication terminal of the German company TESAT, intended to demonstrate secure and fast optical links from low Earth orbit. In a broader sense, such a demonstration serves as verification of whether a terminal developed for the high demands of secure communications can be successfully adapted to more compact platforms such as CubeSats. If that is confirmed under operational conditions, it opens the door to wider commercial and institutional use of smaller satellites in more demanding communication tasks.
PeakSat follows a different but complementary path. It is a 3U CubeSat developed by the Aristotle University of Thessaloniki, with strong reliance on student and research work. It carries Astrolight’s ATLAS-1 terminal, and the mission is focused on an optical link between the satellite and upgraded Greek ground optical stations. The focus is not only on the transmission itself, but also on creating a realistic picture of how such communication functions under different atmospheric and operational conditions. In other words, the test is not only “can it”, but also “how well”, “how stably”, and “under what constraints”.
Equally important is the ERMIS project, behind which stands a consortium led by the National and Kapodistrian University of Athens. Within that framework are three satellites. ERMIS-1 and ERMIS-2 are focused on 5G Internet of Things connectivity from space and on inter-satellite links via radio frequencies, while ERMIS-3 is focused on high-capacity optical communication to Earth. According to available data, ERMIS-3 is specifically intended to show how capable the system is in precise pointing, acquisition, and tracking of the optical signal, which is one of the most demanding elements of the entire technology. That satellite also carries a hyperspectral camera and is expected to demonstrate rapid transmission of such imagery, which is particularly relevant for precision agriculture and the analysis of vegetation conditions.
In the same demonstration package, ESA had earlier announced the Hellenic Space Dawn mission, which should follow with a separate launch later in the campaign. According to available information, it consists of two 8U satellites managed by the EMTech Space group, equipped with optical terminals intended to verify robust laser links resistant to interference. In this way, the Greek programme is not reduced to a one-off experiment, but is building a series of interconnected demonstrations targeting different levels of the future space communications architecture.
Lasers instead of radio: the advantage is great, but the technical requirements are high too
Laser communication in space is often described as the optical equivalent of fibre-optic cable on Earth. Under ideal conditions, it can offer very large transmission capacities and significantly greater security than traditional radio-frequency channels. But what looks simple on paper in practice requires extremely precise control of orientation, stability, and pointing. Even a minimal deviation is enough for the link to break, especially when talking about small satellites with limited energy, thermal, and mechanical resources.
That is exactly why these demonstrations carry greater weight than a mere “technological showcase”. If smaller European spacecraft show that they can reliably maintain optical links with the ground or with other satellites, that could change the economics of many future constellations. Through other programmes, ESA is already developing broader optical infrastructure and relies on the experience of projects such as the European Data Relay System, which has shown how important reduced latency can be for operational users. What is now happening at the level of smaller CubeSats is in fact an attempt to bring similar logic down to more flexible, cheaper, and faster-developed platforms.
In the Greek case, the additional value lies in the fact that optical terminals and ground stations are being developed in parallel, that is, the entire chain that must function as a whole. Without reliable ground infrastructure, even the best satellite terminal remains limited. That is why these missions cannot be viewed only as individual experiments in orbit, but as part of a broader investment in national capabilities and European competitiveness in the market for secure communications and high-throughput data transmission.
Pioneer programme: from demonstration to market
The second large group consists of missions that emerged through ESA’s Pioneer Partnership Projects framework. The essence of that programme is not only technical support, but also the creation of new space service providers through first operational demonstrations in orbit. In this way, ESA is trying to lower the entry threshold for companies that have the technology but lack “flight heritage”, that is, confirmation that the system truly works in the real space environment. In a sector where investors, public procurers, and commercial users look very cautiously at risk, this is a crucial step.
Spire Global is thus continuing work on optical inter-satellite links through Mission SaaS. Back in 2025, Spire announced that it had successfully established a two-way optical link between two satellites in orbit, highlighting the possibility of data exchange over distances of up to 5,000 kilometres. That demonstration is important because it shows that a network of smaller satellites does not necessarily have to be limited to short communication “windows” with ground stations. If a satellite can forward data to another satellite that is in a better position to downlink content to Earth, the system becomes more flexible and operationally more valuable.
This is precisely important for Spire’s business model, which relies on near-real-time data on weather, air and maritime traffic, and other signals of interest for logistics, security, and risk management. In such an environment, improving data transmission is not only an engineering issue but also a market advantage. Faster acquisition and forwarding of data also means a more useful product for clients who make decisions in hours, and sometimes even minutes.
VIREON and the question of what should actually be sent to the ground
Alongside the communication missions, an important part of Transporter-16 also falls to Earth observation. The British company AAC Clyde Space sent two 16U satellites as part of the VIREON mission, focused on collecting medium- to high-detail multispectral data for agriculture, forestry, and environmental management. The company states that the goal of the constellation is to provide global coverage, frequent revisits, and data detailed enough to monitor crop conditions, forest stands, and water resources, but also accessible enough for sectors seeking operational, not only research, value.
It is precisely in that example that one can clearly see why the topic of data transmission is becoming central. Imaging is only the first step. If you want to refresh data daily for large agricultural or forest areas, you very quickly arrive at large amounts of content that must be transmitted, processed, and turned into a decision-making tool. That is why for missions like this it is equally important both what the satellite “sees” and how what it sees will be turned as quickly as possible into usable information. VIREON is also important because ESA and the UK Space Agency, through the Pioneer programme, are trying to support precisely those systems that should later move from the demonstration phase into the commercial phase.
The company also states that the satellites are aligned with the needs of users who want more frequent and operationally usable data for land management. This means that the market is no longer asking only for a “beautiful image from space”, but for a consistent, fast, and comparable flow of information that can be incorporated into yield assessment models, forest health monitoring, or environmental change tracking. In that context, the problem of data transmission and processing becomes just as important as the optics on the satellite itself.
EDGX: processing in orbit as a way to reduce communication congestion
Perhaps the most interesting element for the future of space networks is not only faster transmission, but the decision to do part of the work before sending anything to Earth at all. Belgium’s EDGX has on Transporter-16 a compact digital processor payload with an emphasis on GPU processing and artificial-intelligence optimisation. The idea is simple: if the satellite can process part of the data locally, recognise relevant patterns, or discard content that is not useful, then a smaller, more valuable, and more operationally useful amount of data is sent to Earth.
This is especially important in Earth observation missions and next-generation communication systems. In its materials, EDGX highlights the ability to process a large volume of tasks in orbit, with adaptive energy consumption management. In space, energy is precisely one of the most stubborn limiting factors. That is why testing such a system is not only a demonstration of computing power, but also a verification of how sustainable advanced processing actually is on small platforms that at the same time must take care of heat, radiation, consumption, and reliability.
If it turns out that processors like these can reliably filter or analyse data before downlink, the consequences could be broad. It would mean less load on communication channels, faster delivery of key information, and more efficient use of satellite resources. In practice, this could mean sending, for example, only changes on the ground, only image segments of interest, or only alerts that exceed a certain risk threshold. In this way, the space system increasingly approaches the logic of “edge computing” that we already know in terrestrial digital networks.
European competitiveness and the question of who will build the next generation of space networks
Behind the technical dimension of these missions there is also a broader industrial story. For years, Europe has been trying to reduce dependence on other parties’ critical technologies in the field of secure communications, space networks, and high-value data transmission. ESA programmes, from optical communications to partnerships with industry, are therefore being ever more openly directed toward creating entire capability chains: from terminals and processors, through operational software and ground stations, to commercial services that can arise from them.
In that sense, Transporter-16 is a good cross-section of what Europe is trying to achieve. The Greek missions show how one country, through cooperation with ESA and its domestic academic-industrial community, is building its own knowledge base and infrastructure. The Pioneer missions, on the other hand, show how young or growing companies are being given a chance to move from demonstration to a sustainable business model. EDGX, meanwhile, illustrates that future competitiveness will not depend only on who can launch a satellite, but also on who can make smarter computational decisions on board it.
It is important to stress that these missions in themselves do not yet mean an immediate market change. They are tests, verification, and the gathering of operational experience. But it is precisely such missions that often determine who, in a few years, will have proven technology, references, and customer trust. In a sector in which technical failure is paid for dearly, every successfully executed experiment in orbit carries more weight than a laboratory demonstration.
As the first results from these spacecraft begin to arrive, it will become clearer how ready laser links, inter-satellite transmission, and onboard data processing are for wider application. Even now, however, it is visible that it is no longer enough simply to “put a sensor in space”. The key competitive advantage is increasingly shifting to the question of how the data travel, who can turn them into a decision the fastest, and how resilient, secure, and economically sustainable the entire system is. That is precisely why these seven missions, although carried out on small platforms, open up the major topic of future space infrastructure.
Sources:- European Space Agency / ESA Connectivity and Secure Communications – overview of the Greek connectivity programme, optical terminals, and the OptiSat, PeakSat, ERMIS, and Hellenic Space Dawn missions (link)- SpaceX – official information on the Transporter-16 mission, launch date, and launch location (link)- ESA Connectivity and Secure Communications – explanation of the Pioneer Partnership Projects framework and its role in commercial demonstrations in orbit (link)- Spire Global – data on the two-way optical link between satellites and the development of optical inter-satellite communications (link)- AAC Clyde Space – description of the VIREON constellation, types of data, resolutions, and applications for agriculture, forestry, and environmental management (link)- EDGX – technical description of the processor platform for data processing in orbit and emphasis on AI/GPU computing (link)- ESA Connectivity and Secure Communications – context of the European Data Relay System and the importance of reducing latency in space data transmission (link)
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