Date: April 2, 2020 | Outlet: Air Force Magazine | By Rachel S. Cohen

The Space Development Agency has released its draft request for proposals for an initial batch of 20 data-relay satellites known as the “Tranche 0 transport layer.”

Pentagon officials see the transport layer as a way to unify the various space-based sensors that are part of the Air Force-led joint all-domain command-and-control vision, SDA Director Derek Tournear told reporters April 2.

SDA will accept feedback on its draft RFP through mid-April, publish the final solicitation May 1, and issue contracts to at least two companies in August. The agency aims to launch a functional transport layer for test and training purposes at the end of fiscal 2022.

“There are two major outcomes of [Tranche] 0,” according to the draft RFP, published March 26. “The first is to experiment and demonstrate the capability of the system to integrate and provide interoperability with other warfighting entities. It will be the first opportunity for the warfighter to develop the necessary tactics, techniques, and procedures towards movement to a more digitally enhanced warfighting capability. The second outcome is to serve as a baseline for future tranche development.”

Tournear wants to demonstrate that the network can pull data from sensors in space, like the Air Force’s Overhead Persistent Infrared missile-warning system, and deliver it directly to service members on the ground. He also hopes to show limited battle management functionality and improve on that capability in 2024, to share information typically transmitted through Link 16 to warfighters without that datalink, and to maintain a common time so the military can still have its own timing reference if GPS satellites are unusable.

“These goals, as envisioned, will become a significant enabler for [JADC2], which will connect distributed sensors, shooters, and data from all domains [maritime, land, air, space, and cyber] to all forces,” the draft RFP said. “The major functional team elements from JADC2 map directly to the space layers of SDA. For example, the JADC2’s sensing layer maps directly to SDA’s custody and tracking layers.”

While the services try to prove they have the technical means to share more combat information with each other, SDA has a similar role in ensuring its ideal network of satellites can spread data more effectively. Tournear said SDA is collaborating with the Army on its mobile Titan ground station that aims to pull in fires targeting data from every level from space to land.

“That would allow our transport network to tie into Titan, and Titan could rebroadcast our information over [ultra high frequency] or any other means to get directly to Soldiers that do not have Link 16 connectivity,” Tournear said.

The Army has run some tests on Titan in Europe, and will hold other demos on the same timeline as SDA’s Tranche 0. SDA plans to see whether Titan is compatible with the transport layer during those demonstrations.

On the Air Force side with the Advanced Battle Management System concept, Tournear said the GatewayONE datalink that may fly on an aircraft like the notional Skyborg drone could also plug into the transport layer.

Transport layer development is expected to start at the end of fiscal 2020 and last into summer 2021. Test and integration would then run through the end of summer 2022.

One experimental launch to try out optical inter-satellite links (OISL), seen as an elusive but key technology to pass information between satellites, is already scheduled for December with the firms Astro Digital and SA Photonics. OISL is one of the main challenges SDA faces in designing a large architecture of interwoven satellites, along with antennas, networking, size, weight, power considerations, and supply chain issues.

SDA plans to work with the Space and Missile Systems Center’s Orbital Services Program-4, designed to carry payloads heavier than 400 pounds to orbit, and Mission Manifest Office to launch its satellites. Those systems will work with pieces of six other satellite layers under development at the fledgling agency, which eventually plans to move under the Space Force.