SDA architectureWASHINGTON: The Space Development Agency (SDA) plans to issue a request for proposals this summer for some 150 satellites to provide “initial warfighting capability” for communications and missile tracking, says SDA Director Derek Tournear.

The new satellites, to be launched in September 2024, will comprise what SDA calls “Tranche 1” of its planned seven-layer National Defense Space Architecture. They will follow-on the 20 Transport Layer satellites for porting data to users and the 10 Tracking Layer missile warning and tracking sats planned for launch in March 2023 to demonstrate capabilities, Tournear told the SmallSat Symposium today.

According to the slides Tournear presented today, the Tranche 1 satellites will allow “persistent regional access” for warfighters on the ground. “Tranche 1 is going to be a big deal,” he said.

“The news from SDA is fantastic!,” enthused Steve Nixon, president of the SmallSat Alliance. “They are demonstrating the kind of rapid space innovation that is possible when acquiring smallsat capabilities. The pace and scale of this effort would simply not be possible if SDA approached space in the traditional manner.”

The overall goal of SDA’s National Defense Space Architecture is to enable resilient beyond-line-of-site targeting for time-sensitive ground and maritime targets, and to provide hypersonic/advanced missile threat warning and tracking, Tournear explained.

In other words, the idea is to provide a backup network to DoD’s current satellite constellations — for everything from military communications; to positioning, navigation and timing (PNT); to missile warning and tracking; and to imaging of targets on the ground  by using a multitude of small satellites based in Low Earth Orbit (LEO, up to 2,000 kilometers in altitude.)

Current constellations, by contrast, are each made up of handfuls of large, extremely expensive (some in the billion-dollar-apiece range) birds based in Geosynchronous Orbit (some 36,000 kilometers) which, — in the immortal words of Gen. John Hyten, now the Vice Chair of the Joint Chiefs of Staff — make “big, fat, juicy targets” for adversaries.

SDA Tranche 0 teamThe Transport Layer constellation, which will comprise 300 to 500 satellites, is designed to form the “backbone” communications network that eventually all DoD command and control (C2) systems will link into, under a May order by former Defense Secretary Mark Esper. The aim of Esper’s mandate was to set up the SDA Transport Layer as a key space node to enable Joint All-Domain Command and Control (JADC2).

“That’s the backbone. That’s how we tie everything together to make sure I can have high bandwidth, low-latency communication directly to the end user on the ground,” Tournear said. (Low latency means a minimum delay caused by the fact that satellites are far away from their ground receivers.)

More specifically, the Transport Layer is a “mesh network of hundreds of satellites, all optically interconnected, that provides a low-latency data comm network, and also provides connectivity directly down to existing tactical data links — notionally Link 16 — which is one of the tactical data links that the department uses to be able to talk to weapons systems,” Tourner told the symposium. “So, we’re not fielding new equipment to the user on the ground, we’re going over their existing tactical data links from that Transport Layer.”

When the Transport Layer Tranche 1 satellites are up and working, they will provide “low latency data connectivity; data directly to weapons; and data disseminated to the theater,” Tournear’s slides elaborated.

SDA awarded Lockheed Martin and newcomer York Space Systems contracts to build 10 data relay satellites each for the Transport Layer’s Tranche 0, to be orbited by 2023. Lockheed Martin’s contract is worth $187.5 million; York’s is worth $94 million.

The Tracking Layer satellites are one of three sensing constellations included in SDA’s architecture, along with a “Custody Layer” of ISR satellites for detecting and tracking ground targets, and, eventually, a Deterrence Layer of space domain awareness satellites that could include a constellation monitoring cislunar space.  

The missile warning/tracking satellites included in Tranche 1 will provide “detection of HGVs [hypersonic glide vehicles] and other advanced missile threats; targeting quality data; and communication directly with C2BMC,” Tournear’s charts show.

SDA in October awarded SpaceX $149 million and L3Harris $194 million to each build four satellites for the agency’s Tracking Layer Tranche 0. And the Missile Defense Agency awarded L3Harris and Northrop Grumman contracts to each develop a prototype satellite to carry the medium field of view Hypersonic and Ballistic Space Sensor (HBTSS) for the Tracking Layer. L3Harris’s contract worth $121 million was awarded on Jan. 14; and Northrop Grumman’s $155 million on Jan. 22. Those satellites also are all expected to be on orbit by 2023.

SDA near term experiments timetableRegarding the Custody Layer for ground targeting, Tournear explained that this will involve figuring out how to link existing satellites — both commercial imaging satellites and spy satellites operated by the NRO — into SDA’s Transport Layer. SDA has no plans to build its own imaging satellites, he said.

More immediately, SDA’s work this year and next will focus on the Tranche 0 demos of various capabilities for the Transport and Tracking Layers, as well as some ground system elements. There are four SDA-contracted on-orbit demos planned in the near term, he said:

  • Prototype Infrared Payload (PIRPL): a joint effort with the Missile Defense Agency (MDA) and being developed by Northrop Grumman, to develop a “medium field of view, multispectral imager for OPIR to be able to demonstrate the feasibility and use of that for some of our models.”
  • Mandrake II: a joint effort with DARPA and Air Force Research Laboratory (AFRL) to build two experimental satellites to “demonstrate optical cross links between two satellites, optical cross link to the ground, and optical cross links to airborne systems.” The two Mandrake II sats, built by Astro Digital and Photonics, are part of DARPA’s Blackjack program. They were supposed to fly on SpaceX’s Transporter 1 mission in January, but the sats were damaged in an accident at the launch facility; Tournear said they are now expected to launch in June.
  • Laser Interconnect and Networking Communication System (LINCS): two optical cross-link demo sats being developed by General Atomics.
  • XVI: an experimental satellite being developed by AFRL and Viasat, with SDA as a “transition partner,” to demonstrate connectivity with Link 16 on the ground.

In addition, Tournear said, SDA is working closely with DARPA on the overall Blackjack program, with DARPA planning to launch up to 18 demo sats, starting this year and running through 2022/2023.

At the moment, SDA is most interested in industry help to develop autonomous and real-time processing capabilities. “That’s a big deal … “We need a lot of algorithm development work to make sure that we can actually autonomously tip and queue,” he said, as well as to process and fuse data.