Last November, Derek Tournear, the director of the U.S. Space Force Space Development Agency (SDA), said that SDA was working to resolve delayed deliveries of microelectronics and space system components for Moog, Inc. [MOG-A]-built satellite buses for L3Harris‘ [LHX] four Tranche 0 Tracking Layer satellites to allow a launch of those satellites this spring.
The first Tranche 0 launch–of eight York Space Systems Transport Layer communications satellites and two SpaceX Tracking Layer satellites for missile warning and tracking–occurred on April 2. At the time of that first launch, SDA said that it expected a second launch this summer would include the remaining 18 satellites in Tranche 0–another two SpaceX Tracking Layer birds, the four by L3Harris, 10 Transport Layer satellites by Lockheed Martin [LMT], and the two remaining Transport Layer ones by York Space Systems.
The manifest for the scheduled Aug. 31 SDA Tranche 0 launch from Vandenberg Space Force Base, Calif., however, does not include all 18, but rather 13 satellites–the 10 Lockheed Martin Transport Layer ones, the two remaining SpaceX Tracking Layer satellites, and another Transport Layer bird by York Space Systems. SDA said that it is using the remaining York Space Systems’ Tranche 0 Transport Layer satellite as a ground-based testbed.
Tournear told a National Security Space Association webinar last November that, due to the COVID-19 shutdown, SDA had faced supply chain problems with microelectronics and space components for the buses for the L3Harris satellites but that SDA believed there was a “good chance” of launching the four L3Harris Tracking Layer satellites this spring (Defense Daily, Nov. 10, 2022).
SDA said on Aug. 30 that the reduction in five satellites on tomorrow’s manifest from SDA’s plans this spring are the result of several factors, including a top level decision to conduct a third Tranche 0 Tracking Layer launch this year in concert with the Missile Defense Agency (MDA).
“The reduction of the five–one of those is attributed to the York satellite that we left on the ground as a satellite testbed so that was a concerted effort there to leave that on the ground and get some additional lessons learned,” Mike Eppolito, SDA’s Tranche 0 program director told reporters on Aug. 30 in a pre-launch audio question and answer session. “That’s a concept that we’ve incorporated into future tranches where we leave a testbed on the ground. That was a good lesson that we got out of Tranche 0.”
“As far as the L3Harris satellites go, that will be part of that integrated effort with the Missile Defense Agency,” he said. “It was a decision made at the leadership level to have a demonstration of both the MDA and SDA satellites in the same plane to see the same targets demonstrating both medium field of view and wide field of view tracking payloads. There will be a tremendous benefit to having those satellites on that launch together with MDA.”
Asked whether there was any technical issue with the L3Harris satellites or whether it was just a leadership decision to schedule a third Tranche 0 launch to collaborate with MDA, Eppolito said that “it was the timing of those satellites and the ability to have this joint effort with MDA–a little from both columns, I guess.”
A SpaceX Falcon 9 rocket is to launch the 13 Tranche 0 satellites at 10:30 a.m. Eastern time on Aug. 31 in what is to be the 50th SpaceX launch from Vandenberg.
Lockheed Martin and York Space Systems received contracts for the 20 Tranche 0 Transport Layer satellites–10 by each company–in August 2020, while L3Harris and SpaceX received contracts for eight Tranche 0 Tracking Layer satellites–four by each firm–in October 2020.
Airbus and RTX [RTX] protested the Tracking Layer awards, but SDA, buttressed by Government Accountability Office (GAO) findings, resumed work on the initial awards in January 2021.
The Tranche 0 Transport Layer is to demonstrate the optical linking of satellites and space-based Link 16 beyond line-of-sight transmission to accelerate targeting by military forces, while the Tracking Layer is an initial SDA stab at monitoring threats from hypersonic and other advanced, maneuverable missiles able to change their impact point during flight. SDA said that each Tranche 0 satellite will have two optical communications terminals. Telesat Corp. [TSAT] and CACI International, Inc. [CACI] are the contractors for the optical links, SDA said.
SDA plans to field the first operational Proliferated Warfighter Space Architecture satellites in low Earth orbit late next year in Tranche 1. Tranche 1 is to include 126 Transport Layer satellites, 35 Tracking satellites, and 12 tactical demonstration satellites.