Laser Communication Relay Demonstration

OVERVIEW

NASA’s Laser Communications Relay Demonstration (LCRD) is the agency’s first two-way optical communications relay system and is showcasing the benefits of optical communications.

LCRD launching from Cape Canaveral Space Force Station Credit: NASA

On December 7, 2021, at 5:19 a.m. EST, LCRD was launched as a hosted payload aboard the Department of Defense’s Space Test Program Satellite-6 (STPSat-6) by a United Launch Alliance Atlas V rocket. As a relay satellite, missions in space will send their data over laser links to LCRD, which will then transmit it down to ground stations on Earth.

Using optical communications, LCRD will send data to Earth from geosynchronous orbit at 1.2 gigabits-per-second (Gbps). At this speed and distance, you could download a movie in under a minute.

Since the dawn of space exploration, NASA has used radio frequency systems to communicate with astronauts and spacecraft. However, as space missions generate and collect more data, the need for enhanced communications capabilities increases.

LCRD uses infrared light rather than radio waves to encode and transmit data to and from Earth. The infrared light used for optical communications allows missions to pack more data into each transmission. More data yields more data and discoveries.

Another benefit to optical communications is that it requires less size, weight, and power than comparable radio systems. These capabilities will have broad applications to the future of human exploration and scientific discovery.

LCRD’s first user will be a terminal on the International Space Station. However, prior to mission support, LCRD will test its optical capabilities with a variety of experiments, refining the technology.

Quick Facts

LCRD

LCRD launched on December 7, 2021 on a United Launch Alliance Atlas V rocket. Credit: ULA

LCRD

LCRD is a hosted payload aboard the U.S. Space Force’s STPSat-6 satellite.

LCRD

LCRD communicates with two ground stations in California and Hawaii via laser beams to demonstrate the long-term operational effectiveness of optical communications

LCRD

LCRD is a follow-on mission to NASA’s Lunar Laser Communications Demonstration mission in 2013.

LCRD

Later in its mission, LCRD will communicate with the Integrated LCRD Low-Earth-Orbit User Modem and Amplifier Terminal (ILLUMA-T) on the International Space Station – this will be the first operational optical communications system for human spaceflight!

Ground Segment

Once LCRD receives information and encodes it, the mission sends the data to ground stations on Earth that are each equipped with telescopes to receive the light and modems to translate the encoded light back into digital data.

Optical Ground Station 1 at NASA’s Jet Propulsion Laboratory Credit: NASA

LCRD’s ground stations are known as Optical Ground Stations (OGS) -1 and -2, and are located on Table Mountain in Southern California, and in Haleakalā, Hawaii – a volcano in Maui.

While optical communications can provide more data, atmospheric disturbances – such as clouds and turbulence – can interfere with optical signals. The locations for OGS-1 and OSG-2 were chosen for their clear weather conditions and remote, high-altitude locations.

Optical Ground Station 2 at NASA’s Jet Propulsion Laboratory in Haleakalā, Hawaii. Credit: NASA

To monitor cloud coverage and determine which station should be used, an atmospheric monitoring station observes weather conditions. This monitoring station runs nearly autonomously, 24 hours a day, seven days a week.

While OGS-2 was developed specifically for the LCRD mission, OGS-1 is based at JPL’s Optical Communications Telescope Laboratory and was used for previous laser communications demonstrations. To get OGS-1 ready for LCRD support, engineers had to upgrade the ground station, modifying the system to bring it up to a higher standard. One such upgrade involved replacing the mirrors to have better reflectivity and higher laser thresholds so that the telescope can receive and send laser signals to and from LCRD.

Opportunities for Experimenters

LCRD will spend two years conducting tests and experiments. During this time, OGS-1 and OGS-2 will act as “missions,” sending data from one station to LCRD then down to the other.

LCRD will test laser functionality with experiments from NASA, other government agencies, academia, and commercial companies. These tests will help the aerospace community refine optical technologies, increase knowledge, and identify future applications.

NASA is providing these opportunities to grow the body of knowledge surrounding laser communications and promote its operational use. Some of these experiments include studying atmospheric disturbances on laser signals and demonstrating reliable relay service operations.

The LCRD project seeks partners to propose supplemental experiments to test the functionality of optical communications links. These experiments are selected via the LCRD experiment proposal process.

If you are interested in proposing an experiment for LCRD, please contact us or learn more below.

The LCRD architecture consists of:

A payload in geosynchronous orbit
Dual optical link system
Optical switch
Two optical ground stations
A high-speed radio frequency terminal
A radio frequency ground station
An operations control center
An additional facility for observation and monitoring of LCRD operations and experiments

Optical Infusion

NASA’s Optical Infusion Roadmap. Credit: NASA/David Ryan

NASA is working with the aerospace industry to infuse optical communications into more missions. With optical, missions can generate and send back more data in one transmission than ever before. If your company is developing optical components or systems, connect with our commercialization office at: nasa-commercialsynergies@mail.nasa.gov

LCRD is NASA’s first-ever optical communications relay system. However, there are many missions in development that will demonstrate and test additional laser communications capabilities.

The TeraByte Infrared Delivery (TBIRD) payload will demonstrate laser links at 200 Gbps – a new record– and will allow NASA to test laser communications on a small satellite.
LCRD’s first user will be the Integrated LCRD Low Earth Orbit User Modem and Amplifier Terminal (ILLUMA-T) on the International Space Station. ILLUMA-T will communicate high-resolution images and videos as well as critical data from ongoing experiments to Earth.
The Orion Artemis II Optical Communications System (O2O) terminal will enable an ultra-high-definition video and images between Earth and Artemis II astronauts journeying around the Moon.
In 2026, the Psyche mission will reach its destination – an asteroid over 150 million miles away from Earth. Psyche will carry the Deep Space Optical Communication (DSOC) payload to test laser communications against the distinctive challenges presented by deep space exploration.

Optical communications truly began with the invention of lasers in the 1960s, which made the technology possible. Over the years, there have been many applications of laser technology, but optical communications is one of the most promising.

Technology

Flight Technology:

Both radio waves and infrared light are forms of electromagnetic radiation with wavelengths at different points on the spectrum. Missions encode their scientific data onto the electromagnetic signals to send back to Earth.

LCRD consists of several highly sensitive components. As a relay satellite, LCRD has two optical terminals – one terminal receives data from a user spacecraft, while the other transmits data to ground stations on Earth. LCRD’s modems translate digital data into laser signals, which are then transmitted via invisible beams of light by the relay’s optical modules.

LCRD can both send and receive data, creating a continuous path for flowing mission data to-and-from space. Together, these capabilities make LCRD NASA’s first two-way, end-to-end optical relay.

These are just some of the components that make up the LCRD payload, which all together is the size of a king mattress.

Ground Technology:

The LCRD project developed technology for the mission’s ground stations, which will receive LCRD’s data. These ground stations each contain modems to translate encoded light back into data.

Despite the usually clear weather at the ground station locations, NASA engineers must still work to reduce the effects of atmospheric turbulence on the data. To do this, both stations leverage the power of adaptive optics.

An adaptive optics system uses a sensor to measure the distortion to the electromagnetic signal that's coming down from the spacecraft. If NASA can measure that distortion, then engineers can send it through a deformable mirror that changes its shape to take out those aberrations that the atmosphere induces. That allows the system to produce a pristine signal.