NASA to Build Integrated Photonics Modem for Laser Communications

An integrated photonics modem will be tested aboard the International Space Station beginning in 2020 as part of NASA’s multiyear Laser Communications Relay Demonstration (LCRD). The cell phone-sized device incorporates optics-based components, such as lasers, switches and wires, onto a microchip.

NASA laser expert Mike Krainak and his team plan to replace portions of this fiber optic receiver with an integrated photonic circuit, whose size will be similar to the chip he is holding. The team then plans to test the advanced modem on the International Space Station. Courtesy of NASA/W. Hrybyk.

Once aboard the space station, the Integrated LCRD LEO (Low-Earth Orbit) User Modem and Amplifier (ILLUMA) will serve as a low-Earth orbit terminal for the LCRD.

Integrated photonics technology has a range of potential applications in telecommunications, medical imaging, advanced manufacturing and national defense, and offers high data rates that radio frequency-based communications, NASA said.

"Integrated photonics are like an integrated circuit, except they use light rather than electrons to perform a wide variety of optical functions," said Don Cornwell, director of NASA's Advanced Communication and Navigation Division.

Recent developments in nanostructures, metamaterials, and silicon technologies have expanded the range of applications for these highly integrated optical chips. Furthermore, they could be lithographically printed in mass, as electronic circuitry is, further driving down the costs of photonic devices.

NASA’s laser communications system involves a hosted payload and two specially equipped ground stations. The mission will dedicate the first two years to demonstrating a fully operational system, from geosynchronous orbit to ground stations. Once NASA demonstrates that capability, it plans to use ILLUMA to test communications between geosynchronous and low-Earth-orbit spacecraft.

LCRD is expected to transform the way NASA sends and receives data, video and other information, using lasers to encode and transmit data at rates 10 to 100 times faster than current communications equipment, and requiring significantly less mass and power. The technology could deliver video and high-resolution measurements from spacecraft over planets across the solar system, enabling researchers to study in detail the conditions on other planets.

Previously, NASA launched a laser communications payload aboard the Lunar Atmosphere and Dust Environment Explorer (LADEE), which it said demonstrated record-breaking download and upload speeds to and from lunar orbit at 622 and 20 Mbps, respectively, in 2013.

"The technology will simplify optical system design," said Mike Krainak, who is leading the modem's development at NASA's Goddard Space Flight Center. “It will reduce the size and power consumption of optical devices, and improve reliability, all while enabling new functions from a lower-cost system. It is clear that our strategy to leverage integrated photonic circuitry will lead to a revolution in Earth and planetary-space communications as well as in science instruments."

Under the NASA project, Krainak and his team will reduce the size of the terminal, now about the size of two toaster ovens, a challenge made easier because all light-related functions will be contained on a microchip. Although the modem is expected to use some optic fiber, ILLUMA is the first step in building and demonstrating an integrated photonics circuit that ultimately will embed these functions onto a chip, Krainik said.

ILLUMA will flight-qualify the technology, as well as demonstrate a key capability for future spacecraft. In addition to communicating to ground stations, future satellites will require the ability to communicate with one another.

"What we want to do is provide a faster exchange of data to the scientific community. Modems have to be inexpensive. They have to be small. We also have to keep their weight down," Krainak said. The goal is to develop and demonstrate the technology and then make it available to industry and other government agencies, creating an economy of scale that will further drive down costs. "This is the pay off," he said.

Although integrated photonics promises to revolutionize space-based science and interplanetary communications, its impact on terrestrial uses also is equally profound, Krainak said. One such use is with data centers. These costly, very large facilities house servers that are connected by fiber optic cable to store, manage and distribute data. Integrated photonics promises to dramatically reduce the need for and size of data centers, particularly since the optic hardware needed to operate these facilities will be printed onto a chip, much like electronic circuitry today. In addition to driving down costs, the technology promises faster computing power.

In addition to leading ILLUMA's development, Krainak serves as NASA's representative on the country's first consortium to advance integrated photonics. Funded by the U.S. Department of Defense, the non-profit American Institute for Manufacturing Integrated Photonics, headquartered in Rochester, N.Y, brings together the nation's leading technological talent to establish global leadership in integrated photonics. Its primary goal is developing low-cost, high-volume manufacturing methods to merge electronic integrated circuits with integrated photonic devices.

For more information, visit https://gsfctechnology.gsfc.nasa.gov.