This month, the Space Development Agency issued a draft solicitation for the Tranche 1 Demonstration and Experimentation System (T1DES), which is to consist of up to 12 satellites to explore future communications features for the National Defense Space Architecture’s (NDSA) Transport Layer.

The several hundred Low earth Orbit (LEO) Transport Layer satellites, which are to be optically linked, are to be the foundation for Pentagon Joint All Domain Command and Control.

The 12 T1DES satellites would launch in the spring and summer of 2025 as rideshares aboard four rockets dedicated to lofting Tranche 1 NDSA  Tracking Layer satellites into orbit. T1DES would “demonstrate and evaluate new mission payloads for proliferation in future tranches of the Transport Layer,” per the May 16 T1DES draft solicitation.

“The Tranche 1 (T1) architecture will deliver comprehensive capabilities designed to support a stressing regional conflict,” the draft solicitation said.

“The constellation will be interconnected with Optical Inter-Satellite Links (OISLs) that have significantly increased performance over existing radio frequency (RF) crosslinks,” per the draft notice. “LEO orbits in conjunction with OISLs will reduce path loss issues but more importantly offer much lower latencies with higher throughput which are deemed critical to prosecute time sensitive targets in today’s wartime environment with a peer competitor. The Transport Layer will operate over Ka band RF up and downlinks, optical up and downlinks, as well as in-plane and cross plane optical links, and be dynamically networked for simpler hand-offs, greater bandwidth, and fault tolerance. T1DES will leverage T1TL [Tranche 1 Transport Layer] services to enable the LEO Integrated Broadcast System (IBS-L), and other Tactical Satellite Communication (TACSATCOM) missions.”

SDA plans to field 28 satellites in Tranche 1 of the Tracking Layer to allow the U.S. to detect and monitor any hypersonic missile launches by China and Russia (Defense Daily, March 15).

In apparent recognition of that potential, Congress added $550 million in the fiscal 2022 omnibus spending bill for an upcoming satellite demonstration in U.S. Indo-Pacific Command.

President Biden signed the bill into law on March 15.

SDA said that it has been working with industry to resolve COVID-19 electronic board supply disruptions for optical cross links and radios for the hundreds of satellites destined for the Tranche 1 Transport Layer.

The agency has said that it has collaborated with companies to find alternate parts suppliers and designs and will use part of the congressionally added $550 million to do the same for Tranche 1 of the Tracking Layer.

SDA is to become part of the U.S. Space Force by Oct. 1 and to be overseen by Frank Calvelli, the assistant secretary of the Air Force for space acquisition and integration.