Issue 105

30 Aug: Chinese researchers published “A Review of Space Situational Awareness Satellites: Silentbarker.” The report provides China’s assessment of 4 US space-based SSA programs: 1) Midcourse Space Experiment (MSX); 2) Space-Based Surveillance System (SBSS); 3) GSSAP; and 4) Silent Barker. Report excerpts below. Read full report.

– Space situational awareness satellites have the ability of target identification and target monitoring, which is one of the core capabilities to ensure the safety of space activities.

– Most space situational awareness satellites are equipped with advanced imaging technology, carrying high-performance thrusters and a large amount of fuel.

– In 1996, the United States launched the Midcourse Space Experiment (MSX), which carried the Space-Based Visible (SBV), officially operated since 1998, and officially retired in 2008.

– The only sensor on the MSX, always provides complete metric and Space object recognition coverage for the space surveillance network (SSN) in the geosynchronous belt.

– In 2002 the U.S. military launched the SBSS…The project will eventually build a constellation of low-Earth orbit optical remote sensing satellites with all-weather orbital sensing. SBSS-1 has a 30 cm aperture telescope with a 2.4 megapixel detector.

– SBSS-1 resulted in a fivefold increase in observations and an estimated 66 percent reduction in satellite losses. Compared to ground-based space situational awareness equipment, the SBSS-1 increases SSA performance by three times.

– The United States commissioned the MIT Lincoln Laboratory to develop Operationally Responsive Space5 (ORS-5). It was launched in August 2017. ORS-5 provides space situational awareness at a low cost and fills the gap in the Block 10 mission.

– GSSAP carries optoelectronic sensors that take up a clear, light-free vantage point to perform Rendezvous and Proximity Operations (RPO). RPO enables spacecraft to maneuver near resident space objects of interest by tracking radio emissions from resident space objects as an indicator of satellite identity and activity, while also maintaining flight safety through characterization of noamalic resolution and enhanced surveillance.

– GSSAP is able to approach and observe nearly 600 satellites on GEO, and it is speculated that during the mission of a pair of GSSAP satellites, the satellite drifts to a favorable position above or below the satellite of interest at a relatively low speed by pulse burning.

– GSSAP-4 deliberately approached and accompanied China’s Shijian-20 satellite, with the nearest distance of 29km. The Shijian-20 satellite made a maneuver within 24h and successfully avoided GSSAP-4’s reconnaissance through a maneuverable orbit change.

– Silentbarker is the successor to SBSS. On September 10, 2023, three Silentbarker satellites were lifted into space by a large Atlas-5 launch vehicle. The constellation’s second launch is expected to take place in 2026.

-Silentbarker has the ability to search, detect and track objects from space-based sensors. It will collect real-time satellite data from GEO 24/7, will provide data back to the ground for timely monitoring and event detection, and the results will be communicated to The Combined Space Operations Center (CSpOC) and the National Space Defense Center (NSDC), and other classified users. This data is used for analysis and experimentation as well as integration into the broader space advantage architecture, ensuring that space-based space situational awareness capabilities are responsive to evolving threats.

Through the deployment of space situational awareness satellites, the government can monitor activities in space in real time, and this real-time monitoring capability provides the nation with timely intelligence to help early warning and prevent potential space conflicts and threats. In the field of space situational awareness, the United States is currently leading the way, and its deployed satellites and mature technology provide many learning opportunities for other countries.