Technology For Space Data Relay Constellation Confirmed
Optical Inter-Satellite Links (OISLs) Established Between Two Satellites in LEO
The successful validation of optical inter-satellite links (OISLs) between two data relay satellites in low Earth orbit (LEO) has been announced by Kepler Communications, a company building Internet connectivity for space.
“The Kepler Network will act as a data transport layer, bringing modern Internet capabilities to space through an interoperable architecture that will revolutionize space communications as we know it.”
Mina Mitry, Kepler Communications
During a commissioning and early operations phase, Kepler established optical inter-satellite links between two Pathfinder satellites equipped with Space Development Agency (SDA) compatible Tesat SCOT80 optical terminals. The pair of satellites were launched in November of 2023 to demonstrate technology for the company’s space data relay constellation, The Kepler Network. Before launching the optical testing campaign in recent weeks, spacecraft commissioning and extensive checkout of Pathfinder systems were performed.
The first file transferred over the optical connection was a recent picture of Kepler’s global team gathered near its headquarters in Toronto, Canada. In the first week of testing, the company successfully sent diagnostic data between the two spacecraft, and the full link performance was demonstrated according to the SDA standard. In addition, multiple acquisition scenarios were tested, and both terminal and spacecraft performed optimally.
“This OISL achievement is a testament to the hard work, determination, and brilliance of our Kepler team,” said Mina Mitry, chief executive officer and co-founder of Kepler. “The Kepler Network will act as a data transport layer, bringing modern Internet capabilities to space through an interoperable architecture that will revolutionize space communications as we know it.”
In addition to initial optical link commissioning, the company has demonstrated Internet Protocol (IP) mesh networking on orbit by communicating with multiple satellites in real time over a single ground link, using standard protocols including Secure Shell (SSH), Transmission Control Protocol (TCP), and User Datagram Protocol (UDP).
Kepler is scaling operations to deploy the first Tranche of its next-generation constellation and expects to offer initial optical services in 2025. The hybrid optical data relay network builds on flight heritage from Kepler’s existing constellation of 21 RF satellites. The Kepler Network provides customers with always-available coverage in LEO, streamlining on-orbit communications with sub-second end-to-end latency, gigabit throughputs, and onboard processing to enable access to space-generated data in near-real time.