WASHINGTON — As it prepares to start deploying a mesh network in low Earth orbit, the Space Development Agency is seeking proposals for a demonstration of laser communications between orbiting satellites and aircraft in flight.
The agency on Aug. 4 issued a “special notice” asking vendors to submit by Sept. 2 proposals on how they would conduct a live demonstration of laser crosslinks between SDA’s Transport Layer satellites and a moving aircraft.
An SDA-funded experiment to test out this technology was launched in June 2021 but was unsuccessful. General Atomics Electromagnetic Systems launched two cubesats carrying optical communications terminals to test inter-satellite links but the cubesats never reached their intended orbit and the company was unable to establish contact. One of the goals of the experiment was to establish optical communications between the satellites and an optical terminal on a General Atomics unmanned aircraft.
In the new solicitation, SDA asks vendors to figure out a way to connect one or more of the 20 Tranche 0 Transport Layer satellites — projected to launch in September — with an aircraft that would be chosen by the vendor.
SDA is interested in a live flight demonstration but also would consider a phased experiment, starting with space to ground, space to a moving ground vehicle, and space to an airborne platform.
“This demonstration is concentrated on space to airborne test only to research, design, develop and test,” said the solicitation. “Testing must include successful demonstration of pointing, acquisition and tracking, and the capability to acquire and maintain the link with stability to pass up to 1 gigabit per second test data.”
Experts say optical communications between air and space is a tough technical challenge due to the difficulties of pointing and navigating while maintaining a link to a moving aircraft. It also requires correcting the turbulence in the atmosphere that interferes with lasers.