High-power lasers ensure a robust optical link
NKT Photonics’ Koheras single-frequency fiber laser platform is the heart of the system, built around an ACOUSTIK sub-rack with seed laser, pre-amplifier, modulators, and a custom timing module. The signal is split and boosted by five high-power amplifiers, based on core technology, and each amplifier delivers up to 2 kW with less than 10 microseconds’ switching time.
The system’s precise pointing technology uses star cameras and fine-steering mirrors to pinpoint the kilowatt beams in the night sky with incredible arcsecond accuracy. This is equivalent to hitting a 1-mm target at 1-km range. The method, known as blind-pointing, is particularly challenging because it relies only on the calculated location of the spacecraft. Real-time feedback from the spacecraft was not possible because the time taken for the light to travel this vast distance and for the return telemetry to be received was approximately 30 minutes.
This type of optical link with spacecraft offers a glimpse into the future of deep space communications, including manned and unmanned missions to the Moon, Mars, and beyond, and highlights the importance of collaboration between agencies and industry in advancing Europe’s optical technology.
First-attempt success within tight test window
We had a limited window for testing. The Psyche spacecraft is on a long journey to investigate a metallic asteroid and can’t slow down simply because our equipment isn’t ready. The equipment was delivered to the installation site just four days before the first trial, so the timeline for installation and testing was extremely tight. But thanks to an incredible team effort, the optical link worked on the first attempt.
In the weeks that followed, three additional trials were carried out, each more successful than the last with higher data rates, longer distances, and more data downlinked and decoded. In the final link with the spacecraft at more than two earth-sun distances, a sustained link was obtained with a data rate of 1.8 Mbps that allowed a high-definition video of “Tatters” the cat chasing a laser pointer to be received from the spacecraft, which has been widely shared on social media.
For NKT Photonics, it’s not just about building the biggest or the fastest communication channel. It is about pushing the boundaries of what is possible with lasers and photonics. We take pride in being a technology-driven company, and this achievement is a groundbreaking milestone for us.
The laser links are proving themselves, pushing data rates far beyond what was once thought possible for deep space. The result? Spacecrafts fitted with laser links can be built smaller and lighter. Every gram of weight saved can be used for scientific instruments, exploration tools, or fuel to reach farther.
Future exploration
What’s next? More lasers for space comms? Talking to the moon or maybe even Mars? Or using lasers to locate, track, and possibly even maneuver satellites and space debris? Whatever the future brings, NKT Photonics is excited to see how this will develop over time and proud to play our part pushing the boundaries.