NASA is building optical communications technologies into its networks, using infrared laser links to offer missions higher data rates than comparable radio frequency systems.
NASA’s Low-Cost Optical Terminal (LCOT) will use commercial off-the-shelf or slightly modified hardware to reduce expense and speed implementation.
“We want to build a blueprint for future optical ground stations,” said LCOT Project Lead Dr. Haleh Safavi. “That blueprint needs to be a cost-effective, modular, and easy-to-implement solution that allows more missions to embrace optical communications.”
Procuring commercial off-the-shelf hardware is far easier than building custom optical terminals for missions. It also tends to cost less. However, industry doesn’t offer some of the technologies that NASA needs to fully embrace commercial hardware.
“We want to help industry with identifying gaps and assisting them in expanding their hardware offerings,” said Safavi. “For example: before this effort, there was no commercial receiver telescope that met our needs. NASA developed specifications, worked with a vendor to build one, and now it’s part of their catalogue.”
Until recently, NASA had to create optical communications hardware from scratch or adapt commercial components not meant for the rigors of space applications. Efforts like LCOT seek to change that paradigm, allowing the agency to purchase the components needed for an end-to-end optical system from commercial vendors.
“These offerings also increase the possibility of future commercial optical ground stations, making NASA just one of many optical communications customers in an optical network,” said Safavi.
In addition to being inexpensive and easy to implement, NASA has designed LCOT as a versatile system that can serve a wide variety of users. It will be able to communicate with missions in low-Earth orbit, geosynchronous orbit, and even at lunar distances.
“We consider the LCOT design to be a multi-mission system,” said Safavi. “For example, if there is a lunar mission, we use the optical bench in one side of the telescope, then we can switch to a low-Earth orbit mission using the other side.”
The LCOT team has three upcoming missions they will support to verify the efficacy of their design. The first is the upcoming Laser Communications Relay Demonstration (LCRD), which will be the first end-to-end optical communications relay system. The second is NASA’s Terabyte Infrared Delivery System (TBIRD), a CubeSat developed in collaboration with the Massachusetts Institute of Technology Lincoln Laboratory. The third is the Orion Artemis II Optical Communications System (O2O), which will transmit live, ultra-high-definition video from the Moon during the Artemis II mission.
“LCOT has a 70-centimeter receive optical telescope, so it’s a little smaller than the ground telescopes for LCRD, but comparable to the O2O ground telescope,” said Safavi. “We’re working with them to test our adaptive optics and tracking systems. Our major goal is to test at lunar distances with O2O.”
While LCOT has a 70-centimeter receive telescope, the modular nature of the design will allow for different hardware options without a complete redesign.
“We’re building it in a way that, if the telescope size increased from 70 centimeters to a meter or a meter and a half, it would only require very minor changes to the system,” said Safavi. “We’re considering all the possibilities, from hardware to networking and security.”
Once the LCOT team finalizes and tests their first ground station, NASA will begin to implement the design across its network. With more optical ground stations available, more missions will be able to take advantage of optical communications’ higher data rates, empowering the collection of more science and exploration data than ever before.
