In the noisy exhibition halls of CES2025, we stumbled upon the emerging world of optical (laser) satellite communications. As the space economy grows, the “pipes” used to send data back to Earth—traditional radio waves—are becoming congested. In the above interview, SangHoon Oh, Ph.D., Research Director for SpaceBeam, explains how their new optical ground stations unlock a new form of space to earth communications: a fiber-optic cable to the stars.

The “Sprinkler vs. Hose” Shift

For decades, spacecraft have communicated via radio frequency (RF) waves. As NASA depicts, this is like a sprinkler: it sprays data in a wide wave, effective for broad coverage but inefficient for power and speed.

Laser communication, or Free-Space Optical (FSO), is like a nozzle on a hose. It shoots a tightly focused beam of light directly at a target. This precision allows engineers to pack 10 to 100 times more data into a single transmission, securely and with lighter hardware.

Enter SpaceBeam: Korea’s Optical Pioneer

While NASA tests these systems on the ISS and missions to the asteroid belt, South Korean startup SpaceBeam is bringing this technology to the commercial sector. SpaceBeam has successfully demonstrated the transmission of 4K HDMI video via laser over a distance of 20 km using commercial 10 Gbps SFP+ module and media converter.

This experiment allowed them to “identify the requirements for an optical communication ground station necessary for space communication at distances exceeding 1,000 km.” This is a critical proof-of-concept for replacing slow radio links with “ultra-high-speed data highways,” specifically designed to link small satellites to the ground. SpaceBeam has also launched the nation’s first commercial Optical Ground Station (OGS) in Osong to receive these signals.

Tale of the Tape: SpaceBeam vs. Starlink

While both companies utilize similar physics, their engineering goals differ. SpaceBeam is optimizing for Satellite-to-Ground links (punching through the atmosphere with compact hardware), while Starlink has perfected Space-to-Space links to create a mesh network in the vacuum of space (see this ViodiTV video for a depiction of how this is creating a new world wide web). Google Gemini and xAI Grok summarize the distinctions between SpaceBeam and Starlink in the table, below.

Feature	SpaceBeam	Starlink (SpaceX)
Primary Use Case	Satellite-to-Ground & Inter-Satellite for Nano/Micro-sats	Inter-Satellite Links (ISL) (Backbone Mesh)
Data Rate	10 Gbps (Demonstrated)	200 Gbps (Internal Backbone) / 25 Gbps (Commercial “Mini”)
Aperture Size	30 mm (Optical Terminal)	~15 cm (Estimated; Proprietary)
Range	Tested at 20 km (Ground-to-Ground proof of concept)	4,000 km+ (Space-to-Space)
Key Hardware	Fast-Steering Mirrors (FSM) for atmospheric stability	“Starlink Mini Laser” module (for 3rd party satellites)

The Starlink Connection: A Mesh Network in the Sky

The timing of SpaceBeam’s rise is no coincidence. The arrival of Starlink in South Korea is a pivotal moment for the industry. Starlink isn’t just a satellite internet service; it is the world’s largest operational proof of laser communication.

Recent data reveals that Starlink’s laser interconnects are fully operational and carrying massive loads:

• Volume: As of early 2024, the system was already transmitting 42 million GB (42 Petabytes) of data per day across the fleet.
• Reliability: The laser mesh has achieved a 99% link uptime, effectively creating a “fiber-optic network in space” that allows data to hop between continents without touching the ground.
• Expansion: Third-party operators like Muon Space have begun integrating “Starlink Mini” lasers into their own satellites. This low latency free space optical network, combined with data processing on its satellite (think mini-data centers in space) will improve the applications of their existing customers. For instance, FireSat indicates that “incident commanders and first responders will receive near instant alerts of new ignitions – enabling rapid mobilization while fires are still small.”

Starlink’s entry into the Korean market validates the technology SpaceBeam is building. While Starlink uses lasers to move data between satellites, SpaceBeam is perfecting the critical link between those satellites and the ground.

Why It Matters

This technology effectively “closes the circuit” for the next generation of the internet.

• Speed: Downloading a movie or a terabyte of scientific data takes seconds, not hours.
• Security: Unlike radio waves, which can be intercepted by anyone in the “sprinkler’s” path, laser beams are pinpoint narrow and incredibly difficult to jam or tap.
• The Future: As South Korea aims for 6G leadership and lunar missions, the optical technologies pioneered by SpaceBeam and popularized by Starlink will be the backbone that makes it possible.

[Note: Google Gemini and xAI Grok assisted with this post.]