High Speed Internet Coming to Space

Using lasers for high-speed communication in space is on the way promising 200 Gigabits per second (Gbps) data transmission. The intent is to replace existing radio frequency (RF) systems that spacefaring nations have used since the dawn of the Space Age.

In the last week, a Toronto-based company, Kepler Communications announced it was working with Airbus and one of the latter’s subsidiaries on a mission to create the Internet-for-Space to grow the future space economy. To do this the partnership is building a low-Earth orbit optical data relay network that uses both laser and RF communications that meets U.S., Canada, and European standards.

Tesat-Spacecom GmbH, a German-based subsidiary of Airbus is joining Kepler to provide the European Space Agency (ESA) with a High Throughput Optical Network (HydRON) that promises a terabit-speed optical network. It will be the world’s first operational optical multi-orbit network offering space-to-space and space-to-Earth communications. Kepler has already put two optical pathfinder satellites with its technology on board in the last year. Future launches are planned to create a constellation of satellites that will deliver 2025 space-based high-speed Internet connectivity for commercial companies and government agencies.

Each satellite will deploy a Tesat-Spacecom SmartLCT scalable terminal to provide connectivity at distances of 45,000 kilometres (28,000 miles). This will facilitate satellite-to-satellite and satellite-to-ground communication. Each SmartLCT can provide data transmission rates of up to 1.8 Gbps. Although impressive, that number falls far short of the ultimate 200 Gbps goal.

What other companies or agencies are in the business of developing optical laser communications for use in space? The obvious one is NASA which has been working on an optical space network for low-Earth-orbit (LEO) and Deep Space.  NASA launched in November 2023, the Integrated LCRD LEO User Modem and Amplifier Terminal (ILLUMA-T). It was installed on the International Space Station (ISS) in Japan’s external-mounted Experiment Module and has been operational since December 2023.

Another optical laser communication system was put into play on NASA’s Psyche spacecraft launched in October 2023. Psyche is on a mission to an asteroid that bears the same name and lies in the Asteroid Belt between Mars and Jupiter. The spacecraft has optical laser communications technology called DSOC onboard. In December 2023, NASA demonstrated its capabilities by transmitting a preloaded high-definition cat video, the tabby used is named Taters. The transmission was sent from 30 million kilometres (19 million miles) away and travelled at 267 Megabits per second (Mgbs). It took less than two minutes to reach the Caltech Palomar Observatory receiver.

Using lasers to communicate from Deep Space is no trivial task. The transceiver has to be isolated from other parts of the spacecraft to eliminate any chance of vibration altering the laser’s trajectory. DSOC also has to compensate for time and distance which changes the position of the receiver. That’s why laser communication from Deep Space is more difficult than that which is deployed in LEO. The distances are much shorter in LEO and constellations of satellites with laser optics communication there can create an interoperable network providing high-speed connectivity.

Another NASA laser optics project is upcoming with the Artemis II mission launching near the end of this year. The Orion capsule includes O2O, an optical communications system. O2O has a terminal created by the Laser-Enhanced Mission Communication Navigation and Operational Services (LEMNOS) Pipeline project. This terminal is designed to send 4K video and high-resolution images, science data, procedures, and flight plans to and from the spacecraft and serve as the communications link to mission control. Transmission rates for O2O are 260 Mgbs.

NASA also has plans to build a lunar Internet using a satellite network and ground-based receivers. It wants to replicate something similar for Mars. RF communications between Earth and the Moon have very short latency, the time gap between when a message is sent and when it is received. The delay is about 2.5 seconds per transmission. A voyage to Mars, however, would have much longer latency gaps. That poses a problem. Astronauts on Mars using RF communications when the two planets align on opposite sides of the Sun (378 million kilometres from each other), would take 21 minutes between each transmission. When the two planets are closest (78 million kilometres) the transmission times each way would be 4.3 minutes.

Developing laser optic communications infrastructure between Earth and Mars would require a network of satellites in place at points between the two planets to ensure transmissions can deal with the changing orientation between the two. A laser-optic network would be faster than RF and would increase the amount of information being sent back and forth.

In 2016, I looked at this subject for connecting Earth and Mars. NASA’s announced aim back then was to achieve a 40-times improvement in data speed and bandwidth rates using a combination of laser-based and improved RF communications with the latter sixteenfold faster.

What is the current speed record for optical laser communications? In 2022, a cubesat with an optical laser system aboard demonstrated transmission rates of 100 Gbps. Called TBIRD, standing for TeraByte InfraRed Delivery, it was 100 times faster than the fastest than most city Internet networks. Transmissions were to an optical receiver in California. TBIRD’s data rate was 1,000 times greater than the fastest RF. As fast as TBIRD was it only takes us halfway to the promised 200 Gbps threshold that I mentioned at the beginning of this posting.

Will private industry, universities or national space agencies from China, Russia, South Korea, and Japan be the first to develop high-speed optical laser Internet services at the 200 Gbps threshold?

China has been advancing the technology of laser optic communication. In June of last year, it demonstrated a growing capability from space.

Russia launched two satellites in the last year with onboard space-based optical laser technology.

South Korea is building satellites with onboard laser optic communication technology.

Japan’s JAXA has been working on laser-optic communication since 1995 and is building the capacity to launch a network of satellites with the technology onboard.

Joining these national projects are a dozen companies developing space optical laser systems or selling technology already available to provide communications between satellites and Earth ground stations. Kepler, the aforementioned Canadian company, is one of these.

Broad-scale deployment for military and non-military constellations of satellites is well on the way to becoming a reality. SpaceX’s latest foray into inter-satellite optical communication using lasers in its recent deployment of Starlink satellites shows that this is already happening.