Communication systems rely on either radio waves or laser beams to transmit data. As satellite constellations multiply and Earth-observation payloads become more data-hungry, the balance between the two is shifting. Laser communication systems can achieve data transfer rates of up to 10 gigabits per second — roughly five to ten times faster than traditional radio frequency (RF) systems.
Now, the European Space Agency (ESA) is contracting Lithuanian space‑tech startup Astrolight to build the first optical ground station (OGS) in Greenland. The project is part of a broader goal to strengthen Europe’s polar satellite data links, following suspected GPS spoofing incidents near Svalbard in 2025 that exposed the vulnerability of RF‑dependent infrastructure in Arctic regions.
Unlike radio signals, which spread over wide areas and can be jammed or intercepted with relatively simple equipment, laser‑based links transmit data through a tightly focused beam — one that is inherently difficult to detect or disrupt.
Astrolight designs and builds free‑space optical communication systems for satellites and ground stations, including the terminals and adaptive optics hardware needed to maintain stable laser links through atmospheric turbulence.
Interesting Engineering (IE) spoke with Laurynas Mačiulis, CEO of Astrolight, to understand the engineering challenges behind building an optical ground station at one of the most demanding locations on Earth.
What those challenges reveal is as much about the physics of light as it is about surviving the Arctic.
Why Greenland?
Europe’s primary polar satellite infrastructure centers on Svalbard, Norway, where the RF‑based Svalbard Satellite Station tracks all 14 daily passes of polar‑orbiting satellites.
The Svalbard satellite station as of 2023. Credit: European Union, Copernicus Sentinel-2 imagery.
Greenland’s interior town of Kangerlussuaq, also under polar‑orbit tracks, gives similarly frequent, high‑elevation passes ideal for short‑window laser downlinks. Situated further west, it also diversifies polar coverage geographically, and its Arctic-desert interior offers relatively clear skies for much of the year, increasing the number of usable optical downlink windows.
But RF downlinks are bandwidth‑limited. Satellite operators relay less than 30% of the data from modern remote-sensing instruments, a gap projected to widen as the number of Earth-observation satellites rises by 190% over the next decade.
Astrolight’s OGS in Greenland addresses this directly. Operating as a space-to-ground laser receiver, the station will downlink data from satellites during each overhead pass.
The company draws on experience building systems for nanosatellites, where thermal deformation and pointing stability constraints closely mirror those of ground-based optical hardware.
On who the station serves, Mačiulis told IE, “The OGS will support customers in telecommunications and Earth Observation, including space agencies, governments, and commercial satellite operators. It will provide faster, more reliable downlinking of terabytes of data, particularly for optical, hyperspectral, radar, and infrared imaging.”
How the laser link works
At its core, an OGS is a precision telescope system housed inside a protective dome. When a satellite passes overhead, the dome opens, and the telescope locks onto the spacecraft, acquiring the signal, tracking its movement across the sky, and maintaining a stable laser link for the duration of the pass.
On the satellite side, a compact optical terminal transmits the data downlink as a focused laser beam, typically at a wavelength around 1550 nanometers. That wavelength occupies an optical channel — similar to a radio station frequency, but operating at roughly 200 terahertz rather than megahertz. The data is encoded onto the light using modulation techniques — the same spirit as AM, FM, or phase modulation.
The ground station receives that beam with its telescope, focuses it onto a detector, and converts the optical signal back into digital data. Because the laser beam is extremely narrow, multiple laser links can reuse the same wavelength without interference, as long as their beams do not cross paths.
The lasercom link itself is a free-space channel — light travelling through air. From the ground station onward, the data pipeline typically runs over conventional fiber-optic backhaul.
The precise nature of the laser beam also makes it difficult to jam. This is in contrast to RF signals, which radiate outward in all directions.
“A lasercom link is inherently more resilient to jamming because it is highly directional,” said Mačiulis. “To intercept a laser link, an adversary would need to physically interfere with the narrow beam path, which is difficult because the beam is invisible. Even if an adversary manages to get close enough to locate the laser link, it would then be operationally challenging and would likely be noticed fast.”
Engineering the Arctic
The Arctic presents an environment that works against the OGS at every layer.
Atmospheric turbulence
In the Arctic, temperature gradients and thermal convection are the dominant drivers of atmospheric turbulence. These distort the wavefront of the incoming beam and degrade signal quality.
The Arctic environment presents additional challenges to the laser link. Credit: Bernt Rostad/Flickr.
As Mačiulis explained, “There are different techniques, but the classical approach is to measure how the wavefront is distorted by atmospheric turbulence.” Once measured, the system acts fast. “A sensor detects those distortions, and a specialised device known as a deformable mirror is adjusted to compensate for them — the system continuously corrects the beam, reshaping it to a more uniform distribution,” he continued.
Thermal deformation
But turbulence is only one layer of the problem. Once the dome opens, the telescope and its supporting mechanical structures are exposed to extreme cold and sharp thermal gradients.
“These shifts can cause the telescope and supporting mechanical structures to deform, which affects the pointing accuracy that laser communication depends on,” explained Mačiulis. “The system has to be designed so those shifts can be measured and compensated for, allowing the laser to remain accurately referenced and precisely pointed at the satellite.”
The thermal swings are not unlike those Astrolight’s hardware already contends with in space. According to Mačiulis, the company’s systems routinely cycle between about -30 and +60 degrees Celsius orbit to orbit, a design experience that directly informed their approach to the ground station.
Polar day calibration
The Arctic also strips away a tool that optical ground stations elsewhere take for granted: stars. At lower latitudes, star-tracking is the standard method for calibrating a telescope’s pointing reference. During polar day in Greenland, when the sun never sets, that option disappears entirely.
“You cannot rely on stars to calibrate the system,” Mačiulis noted. “That means more advanced methods are needed to maintain precise altitude knowledge and calibration; otherwise, the link cannot be established.”
Together, these constraints define the core engineering problem. Once solved, the data flowing through the station spans optical, hyperspectral, radar, and infrared imaging. For civilian and governmental users alike, that translates to environmental monitoring, disaster response, and Arctic situational awareness.
Beyond Svalbard
The Greenland station is not an endpoint.
“The ambition is not to stop at one location, but to build out a network of OGSs that can provide high-throughput communications to Europe’s satellite networks, such as IRIS², as well as other constellations,” said Mačiulis. “It has the potential to contribute to ESA’s HydRON project.”
Both programmes represent significant bets on optical infrastructure. IRIS² is the EU’s flagship secure connectivity constellation, with first launch envisioned in 2029, while HydRON aims to demonstrate the world’s first all-optical multi-orbit transport network.
Greenland’s value as a starting point is partly strategic and partly practical. If the system performs reliably in one of the most demanding operating environments on Earth, it demonstrates the ruggedness needed for deployment elsewhere. “Greenland is a particularly important starting point because it is one of the more extreme operating environments,” noted Mačiulis.
Europe is not alone in this push. NASA operates optical ground stations in Hawaii and California as part of its Laser Communications Relay Demonstration project. China, meanwhile, completed its first commercially operational satellite-to-ground laser station on the Pamir Plateau in 2024 and has since rapidly scaled throughput — hitting 120 Gbps by early 2026.
The broader implication is resilience. A distributed optical ground network is harder to disrupt than a single RF-dependent node — not just because laser links are difficult to jam, but because the architecture itself distributes the risk.
The Mynaric CONDOR Mk3.1, a production satellite laser communication terminal mounted on satellite to transmit laser beams to ground stations like Greenland’s OGS. Credit: Blervis/Wikimedia Commons.
According to Mačiulis, the key lessons from Greenland will centre on designing systems adaptable to different climates and robust enough to operate across a wide range of conditions — knowledge that will directly inform the next generation of optical ground stations.