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SILENTBARKER ‘watchdog’ to be ‘exponential’ leap in US DoD monitoring of Chinese, Russian sats


Jun 19, 2014
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United States
United States
WASHINGTON — The Defense Department’s next-generation, classified space monitoring constellation, called SILENTBARKER, will provide an “exponential” leap in America’s current capability to keep tabs on potentially threatening Russian and Chinese satellites once it reaches full operational capability in 2026, according to senior officials.

Jointly developed by the National Reconnaissance Office (NRO) and the Space Force, SILENTBARKER will be a “watchdog” in geosynchronous Earth orbit (GEO), NRO Director Chris Scolese said in a press conference on Monday. GEO, some 36,000 kilometers in altitude, is where the bulk of DoD satellites, as well as commercial telecommunications birds, now reside.

“What SILENTBARKER is going to do is provide … indications and warnings so it can inform decisions about what we do or don’t need to do in terms of maneuver or awareness. So, it’s a great increase in our understanding of what we’ll be able to do and will greatly improve our ability to to determine future courses of action,” Scolese said.

Lt. Gen. Michael Guetlein, head of Space Force’s Space Systems Command, agreed, characterizing the expected improvement in space domain awareness as “exponential” — including boosts in the capabilities for “maintaining all weather day night capability and being able to maintain 100 percent custody those objects as they maneuver around in GEO.”

The spy satellite agency and the Pentagon have been tight-lipped about SILENTBARKER since its inception in December 2017, but Monday’s press conference provided a bit more insight into the program.

For example, Scolese and Guetlein would not disclose how many SILENTBARKER birds will join the five operational Geosynchronous Space Situational Awareness Program (GSSAP)satellites currently undertaking on-orbit inspections to augment US Space Command’s ground-based radar and telescopes for monitoring the heavens. But in response to reporters’ questions, Scolese said that there will be “multiple payloads” in the first launch and at least two more launches with one or more payloads to meet full operational capability in 2026. He did not clarify whether those payloads planned for the first launch actually are multiple SILENTBARKER satellites, or only one accompanied by payloads doing other things.

Answering a question about who is actually going to operate SILENTBARKER, Guetlein revealed that while data will go into the Space-Track.org “catalog” of space objects maintained by US Space Command’s National Space and Defense Center, which coordinates Intelligence Community and military space operations, “the satellite itself will be maintained by NRO.”

That first launch was planned for Tuesday on a United Launch Alliance Atlas V, but was scrubbed due to Hurricane Idalia bearing down on Florida’s west coast. ULA’s CEO Tory Bruno told the press conference that due to further forecasts for bad weather, the “next opportunity on the range is a few days off.” (An August 2023 launch for SILENTBARKER is already months behind at least the original initial request for proposals in January 2018, which targeted launch in 2022.)

On Satellite Flybys, China Accuses And UN Debates​

The NRO and the Space Force argue that the need systems like SILENTBARKER and GSSAP, which can move close to spacecraft of concern and take detailed images of them, are needed to counter the threat from Russian and Chinese satellites that can themselves maneuver close to US birds and possibly do harm.

China and Russia, however, have pointed out that GSSAP satellites are similarly shadowingtheir satellites (and those of others). Among the latest rhetorical volleys, a study published by the Chinese Optical Society in the April edition of its monthly technical journal, “Infrared and Laser Engineering,” charges that GSSAP close approaches and detailed imaging of Chinese GEO-based satellites presents a “serious threat.”

The study alleged that on at least two occasions, GSSAP sidled up to around 10 kilometers to China’s SJ-20, a heavy, high-thrust propulsion satellite. While that is very close in terms of distances in space, it does not necessarily come with a high risk of collision, according to experts, because there are a lot of other factors at play — including how much margin of error is involved regarding measuring the exact spatial trajectory of the target satellite.

SPACECOM does publish data about GSSAP satellites positions, if often somewhat after the fact, but not about maneuvers or its close approaches to other satellites. And it is unclear how accurate the Chinese study is, given that there isn’t another database that does so.

A SPACECOM spokesperson, in response to Breaking Defense questions, said only that GSSAP operations were conducted in a safe way.

“USSPACECOM operates the GSSAP satellites in accordance with international law and long-standing military operational practices. This includes operating in, from, to, and through space in a safe and professional manner, as well as maintaining safe separation and safe trajectory, which includes equipping GSSAP satellites with appropriate collision avoidance systems and following trajectories that allow other space objects to maneuver in a safe manner,” the spokesperson said.

But the problem is that there aren’t any hard and fast rules for how close is too close when undertaking such rendezvous and proximity operations (RPO).

Back in 2020, then Space Force chief Gen. Jay Raymond told Time magazine that a maneuver by a Russian satellite that brought it about 160 kilometers from a US spy satellite was “unusual and disturbing.” A 2022 report by the Center for International Security Studies’ Aerospace Security Project noted that the US Space-Track catalog shows the median distance in GEO is about 207 kilometers. The DoD’s 2021 “tenets” of responsible behavior in space only advise US military operators of the need to “maintain safe separation and safe trajectory.”

The question of whether there should be a limit on close approaches, especially between military satellites, has been raised at the ongoing UN discussions on voluntary norms to prevent conflict in space.

Jessica West, of Canada’s Project Ploughshares, told Breaking Defense that the need for constraints on RPO activities was championed by a number of countries, including Japan and Germany, during Monday’s meeting of the UN Open Ended Working Group on Reducing Space Threats in Geneva. That said, she added, a number of countries, including China, oppose the idea.

In fact, it is unlikely that the working group coming to any consensus agreement about new norms when it wraps up Sept. 1, given the geopolitical polarization between the US and its key rivals Russia and China. Diplomats nonetheless are hopeful that a follow-up effort, based on the foundation laid by the discussions that began in 2022, will be approved by the UN General Assembly.

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