From The Editor | November 14, 2024

Revolutionizing Deep Space Comm With Lasers

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By John Oncea, Editor

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As research continues and technology matures, laser communications are set to play a pivotal role in expanding our capabilities for deep space exploration and scientific discovery.

Yes, space lasers are real. And also yes, they’ve been a topic of scientific research and conspiracy theories in recent years. We’ll leave the conspiracies for others to write about and, instead, focus on the research and how it has helped advance deep-space communication.

The development of space lasers has been a gradual process spanning several decades. The foundation of space-based laser technology was laid in the 1960s when Theodore Maiman invented the first laser.

According to NASA, Goddard Space Flight Center achieved the first successful satellite tracking using a laser in 1964, marking the beginning of the use of laser applications in space technology. During the 1970s and 80s, various types of lasers were developed, including gas lasers and semiconductor lasers, which would later be crucial for space applications.

The development of quantum cascade lasers, ideal for remote sensing of gases in the atmosphere, came in 1994 and, in 2001, NASA began exploring laser communications for space applications more seriously. The 2010s, according to NASA, saw several breakthroughs, including:

In 2021 NASA launched the Laser Communications Relay Demonstration (LCRD) to test a two-way laser relay system and, later the same year, the TeraByte InfraRed Delivery (TBIRD) mission demonstrated a burst-like laser downlink of 200 gigabits-per-second from a small satellite. A year later, the Psyche mission launched, carrying the Deep Space Optical Communications (DSOC) payload to test laser communications in deep space.

Throughout this timeline, space lasers have evolved from experimental technology to practical tools for satellite tracking, communications, and scientific research. The development continues, with ongoing efforts to improve data rates, reduce size and power requirements, and extend the range of laser communications in space.

Lasers In Space

The Advanced Topographic Laser Altimeter System (ATLAS) on ICESat-2 uses lasers to measure the distance between Earth’s surface and a spacecraft. NASA’s Space Communications and Navigation (SCaN) program is using laser communications technology in various orbits, including the Artemis II mission. The Department of Defense (DOD) is developing space-based laser weapon systems for various tactical and strategic missions.

And while the scientific, industrial, and defense communities have differing opinions on whether current laser technologies can support an effective and affordable constellation of space-laser weapons, they’re not letting that stand in the way of continuing the development of this technology.

Recently, NASA Jet Propulsion Laboratory released a video explaining why space lasers aren’t just science fiction – but their reality may be different from what you’d expect.

More specifically, Dr. Angel E. Velasco and Dr. Joe Kovalik, members of NASA’s DSOC team, shared how data transmission via laser (also known as optical comms) has the potential to revolutionize deep space communications by enabling ultra-high-definition video and complex science data transfer across the solar system.

The two focused their presentation on a technology demonstration that launched aboard NASA’s Psyche mission in October 2023. That experiment successfully assessed high-bandwidth laser communications for the first time beyond the Moon and recently achieved another milestone by transmitting data from Mars orbit.

According to the Jet Propulsion Laboratory, “With data rates 10-100x higher than radio frequencies, laser communications could support robotic spacecraft throughout our solar system and even future astronauts exploring Mars.”

Optical Communication: A Background

The development of space laser communication technology has seen significant progress globally, with major powers investing heavily in its potential for terrestrial internet, aircraft connectivity, secure high-speed communications, and deep space communications.

Russia pioneered free-space optical communication in the 1960s, with early links established in Moscow and other Soviet cities. Initially plagued by stability issues, the technology became more feasible in the 1990s with the introduction of automatic tracking systems. Today, laser communications are widely used in Russian telecommunications.

China, despite a late start, has made remarkable advancements in recent years. Key milestones include the first dynamic in-flight space laser communication test in 2007, achieving transmission rates up to 10 Gb/s. In 2013, China completed a long-distance laser communication test between aircraft, surpassing similar demonstrations in Europe and the U.S. The country has successfully conducted satellite-ground laser communication experiments, with rates reaching 5.12 Gb/s in 2017.

Terrestrially, Free Space Optical (FSO) equipment is being integrated into 4G LTE and 5G network infrastructures, offering seamless compatibility with major communication protocols and rapid deployment capabilities.

In space applications, laser communication is crucial for supporting crewed space activities, enhancing data transmission in remote sensing systems, improving deep space communications, and enabling efficient communication in satellite constellations. It’s particularly valuable for addressing the exponential growth in global data traffic, which is expected to increase 100-fold by 2030.

Additionally, laser communication holds promise for providing high-speed internet to aircraft, potentially increasing current data rates significantly beyond the current 20 Mbps limit.

As terrestrial networks face increasing congestion, space-based laser communication systems are poised to play a vital role in supporting 5G networks and providing connectivity in areas where ground-based infrastructure is unavailable or inadequate.

Transforming Space Comm With Lasers

Recent advancements in laser communication technology are poised to transform deep space communications, offering unprecedented data transfer rates and efficiency. NASA's Deep Space Optical Communications (DSOC) experiment has made significant strides in this field, demonstrating the viability of laser-based communication over vast distances.

In October 2024, NASA reported a groundbreaking achievement: the DSOC technology demonstration successfully sent a laser signal from Earth to the Psyche spacecraft, approximately 290 million miles away. According to Jet Propulsion Lab, this distance is equivalent to the maximum separation between Earth and Mars, showcasing the potential for high-speed communications with future Mars missions and beyond.

The DSOC system utilizes near-infrared light to encode data, allowing for much higher data transfer rates compared to traditional radio frequency communications. At closer distances, the system achieved transmission rates of up to 267 megabits per second, comparable to broadband internet speeds. This capability could revolutionize space exploration by enabling the transmission of high-definition imagery, complex scientific data, and even video from deep space missions.

The technology’s success is not limited to deep-space applications. In July 2023, the U.S. Naval Research Laboratory’s Space Wireless Energy Laser Link (SWELL) experiment surpassed 100 days of continuous operation on the International Space Station, notes Space Operations Command. This experiment, while smaller in scale, demonstrates the reliability and efficiency of laser-based power beaming in space, achieving an end-to-end efficiency of around 11%.

These advancements in laser communication technology are crucial for supporting future space exploration endeavors, including crewed missions to Mars and beyond. As Dr. Jason Mitchell, director of NASA’s SCaN Advanced Communications and Navigation Technology division, stated, “Laser communications will not only return more data from science missions, but could serve as NASA’s critical, two-way link to keep astronauts connected to Earth as they explore the Moon, Mars, and beyond.”