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Silentbarker (sometimes also spellt Silent Barker) is a classified space situational awareness program conducted jointly by the Air Force Space Command is partnering with the National Reconnaissance Office (NRO).

The program aims to improve satellite threat intelligence and space situational awareness, although no details have been specified.

The Space-Based Space Surveillance (SBSS) Block 10 satellite was launched September 2010 with a design life through 2018 and an extended operational capability through 2020. The SBSS Follow-On (SBSS FO) program will develop and deliver a system to continue providing space object surveillance from space post SBSS Block 10 End-of-Life. AFSPC and NRO have signed a Memorandum of Agreement partnering SBSS FO with an NRO program based on overlapping requirements. The new partner program is called SILENTBARKER. SILENTBARKER requirements are based on a Statement of Capabilities and upon the current Space Situational Awareness (SSA) Initial Capabilities Document architectural requirements focused on protecting High Value Assets. SILENTBARKER will provide the capability to search, detect, and track objects from a space-based sensor for timely custody and event detection. Surveillance from space augments and overcomes existing ground sensor limitations with timely 24-hour above-the-weather collection of satellite metric data only possible with a space-based sensor and then communicates its findings to the Combined Space Operations Center (CSpOC), National Space Defense Center (NSDC), and other classified users. This program element includes efforts related to SILENTBARKER, its integration into the broader space superiority architecture, and analysis and experimentation to ensure space-based space surveillance capabilities against the evolving threat.

Three satellites were to be launched in 2022 on an Atlas-5(551) rocket from Cape Canaveral. During launch preparation an issue was discovered and the payload was returned to the manufacturer. The launch was then rescheduled for August 2023.

Two more launches of Silentbarker spacecrafts are planned within this program. Full operational capability (FOC) in is planned to be achieved in 2026.

Note: The NROL designations refer to the launch, not to the payload.

Nation: USA
Type / Application: Space surveillance
Operator: Space and Missile Systems Center (SMC), NRO
Satellite COSPAR Date LS Launch Vehicle Remarks
Silentbarker 1 (USA 346, NROL 107) 2023-140A 10.09.2023 CC SLC-41 Atlas-5(551) with Silentbarker 2, 3
Silentbarker 2 (USA 347, NROL 107) 2023-140B 10.09.2023 CC SLC-41 Atlas-5(551) with Silentbarker 1, 3
Silentbarker 3 (USA 348, NROL 107) 2023-140C 10.09.2023 CC SLC-41 Atlas-5(551) with Silentbarker 1, 2
Silentbarker 4 (NROL 118) - 2025 CC SLC-41 Vulcan Centaur VC6S with Silentbarker 5, 6
Silentbarker 5 (NROL 118) - 2025 CC SLC-41 Vulcan Centaur VC6S with Silentbarker 4, 6
Silentbarker 6 (NROL 118) - 2025 CC SLC-41 Vulcan Centaur VC6S with Silentbarker 4, 5


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