The Space Development Agency wants its satellites to be able to easily talk to each other and is considering using optical intersatellite links for communications within its future low earth orbit space architecture.
Now, the organization is looking for industry’s help on what standards should be used for those links.
On Jan. 15, the agency issued a request for information to industry to inform its attempt to establish an Optical Intersatellite Link Open Standard.
Most satellites don’t speak with each other directly. Instead, they utilize radio-frequency communications with a ground station to relay communications between satellites. Some satellites, however, are able to use optical links to provide direct communications between satellites without a ground station acting as an intermediary. The SDA wants to use this technology for what it calls its “transport layer,” the backbone of its plans for a new space architecture in low earth orbit.
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The SDA was established in March 2019 to design the Department of Defense’s future threat-driven space architecture, a setup it has since defined as a multi-layered constellation of hundreds of small satellites providing several capabilities from LEO. The SDA will not be directly responsible for every layer or constellation within the architecture — most notably, the Hypersonic and Ballistic Tracking Space Sensor is being developed primarily by the Missile Defense Agency — however, the SDA will be the agency in charge of integrating those various efforts into a single architecture.
Key to the entire enterprise is the Tracking Layer, a family of satellites in low earth orbit that will facilitate the flow of data between satellites in orbit and between satellites and the ground. The Transport Layer will be essential in connecting the various sensors and capabilities on orbit with weapons systems on the ground or in the air.
In order to build that capability, the SDA plans to use Optical Intersatellite Links. The optical links will also need to provide range estimates of the distance between satellites in orbit and between satellites and the ground to within a meter in order to provide highly precise timing and positional data for the constellation. The SDA also envisions each satellite utilizing a chip-scale atomic clock as well as GPS signals.
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The problem is that there are currently no industry standards for those links. To ensure the interoperability of various vendor technologies used for those links, the SDA wants to establish that standard, and it’s asking industry for help.
Responses are due by Feb. 5. More specifics about what the SDA is considering for its standards is available on beta.sam.gov.
According to the request, the SDA plans to issue a solicitation for Tranche 0 of the Transportation Layer in Spring 2020, with additional solicitations for the other capability layers to follow in the summer. That first tranche, known as the war fighter immersion tranche, will consist “of tens of satellites providing periodic, regional sensing and data transport capabilities, including the capability to detect hypersonic glide vehicles and to disseminate time sensitive targeting solutions over tactical data links.” According to the agency, that initial tranche could be delivered as early as fiscal year 2022