The U.S. Air Force plans to launch two new, secretly developed satellites this year to spy on activities in the densely populated geosynchronous orbit belt, according to Gen. William Shelton, who leads Air Force Space Command.

The spacecraft, classified until Shelton revealed their existence Feb. 21, were developed by the Air Force and Orbital Sciences Corp. under the Geosynchronous Space Situational Awareness Program (GSSAP), service officials say.

Their very existence underscores Pentagon leaders' heightened level of concern about advances in so-called space control technologies among potential adversaries, such as China. A major worry for defense officials is deployment of microsatellites that could damage friendly spacecraft, for example. Pentagon procurement chief Frank Kendall listed space protection among the issues that keep him up at night during a question-and-answer session at a conference in Washington last week.

The first two GSSAP spacecraft will be boosted this year, and two more will follow in 2016 to prevent a gap in surveillance on activities in the near geosynchronous belt, Shelton says. This orbit is where most commercial satellite communications are based, as well as critical national security assets such as the Space-Based Infrared System (Sbirs) early missile warning spacecraft and Advanced Extremely High Frequency (AEHF) constellation designed to provide jam-proof communications between the president and military forces even during a nuclear attack.

“One cheap shot” against Sbirs or AEHF would be “devastating” to the Pentagon's capabilities, Shelton said at the annual Air Force Association Air Warfare Symposium in Orlando last month, referring to a potential anti-satellite attack.

The Chinese reportedly aimed a high-powered laser at a U.S. imaging satellite in 2006 but apparently did not damage its delicate optics. Beijing conducted a stunning kinetic-energy anti-satellite demonstration in 2007, using a missile to knock down its own aging weather satellite. This drew ire from the international space community and created a large debris field, much of which is still in orbit.

The two GSSAP satellites will “drift” above and below the GEO belt, using electro-optical sensors to collect information on satellites and other objects in that space, Shelton said. Space Command officials declined to provide details of how the satellites will achieve maneuverability. “GSSAP spacecraft have a standard propulsion and attitude control system that leverage scommercial bus technology and propellants,” they say.

Orbital Sciences declined to discuss the spacecraft due to security concerns. Space Command says the company was selected after a “rigorous source selection process,” without saying whether there was a competition for the work. They will not identify the satellites' cost or say how long they took to design and build.

Information on the technologies used for GSSAP's optics is protected, according to Space Command officials. However, they say that the satellite carries “payloads,” suggesting that the satellites carry multiple cameras. Space Command declined a request for a photo of the satellites.

The spacecraft, described by Space Command as “small sats,” will be maneuverable, allowing them to be “tasked” to collect intelligence on specific targets, much like airborne spy craft, Shelton said. The satellites will provide “accurate tracking and characterization” of satellites, according to an Air Force fact sheet released after his speech. This allows operators to characterize a space object by identifying pertinent information, such as the object's location, orbit, size and status, Space Command officials say.

Deployment of this capability underscores the concern of government officials about the vulnerability of satellites that have become interwoven in government operations at all levels. The GPS constellation is already easily jammable because its signal is relatively weak, but officials worry about more widespread radio-frequency jamming as well as kinetic attacks. Although it is still shrouded in secrecy, GSSAP is described by Space Command as carrying payloads relevant only to the space situational awareness mission; this means it can spy but likely not take action in the event of an attack.

Senior U.S. officials have sought such a capability to help attribute hostile acts in space, denying bad actors the ability to act anonymously there.

Shelton declined to say how much the satellites cost to develop and build or how long they took to design and fabricate. However, they are small enough that two of them will be launched together this year on a Delta IV from Cape Canaveral AFS using the M+ 4/2-booster configuration.

Declassification was cleared by authorities in the U.S. government in part to provide a deterrent to adversaries seeking to conduct hostile activities in space, according to a defense official. The White House also has said it will provide transparency as part of its space policy. Activities, especially of a maneuverable satellite in geosynchronous orbit, are detectable by allies and adversaries. Thus, revealing at least minimal information is a nod toward transparency and, possibly, an attempt to quell concerns that the capability will be viewed as offensive, the defense official says.

GSSAP is, however, likely to be viewed by Russia and China as potentially hostile and could ignite a global debate about appropriate uses of space for military purposes.

The satellites could carry other payloads that have not been disclosed, such as radio-frequency sensors or jammers.

GSSAP is one element of the Air Force's growing space situational awareness family of systems. Also in orbit is the Space-Based Space Surveillance (SBSS) satellite built by a Boeing/Ball Aerospace team and launched in 2010. Carrying an agile, slewable electro-optical sensor, SBSS operates in a low orbit and looks up into GEO; distance likely prevents high fidelity of its imagery product, though. SBSS's design is also complex, as the camera is on a two-axis, gimbaled sensor.

The emergence of the GSSAP program likely explains why the Air Force was holding off on an SBSS follow-on, which Boeing and Ball Aerospace had called for. The GSSAP satellites probably provide more flexibility and higher-fidelity data than SBSS, although officials have not compared their capabilities publicly.

GSSAP “will have a clear, unobstructed and distinct vantage point for viewing resident space objects orbiting Earth in a near-geosynchronous orbit without the disruption of weather or atmosphere that can limit ground-based systems,” the fact sheet says. “Data from the [GSSAP] system will uniquely contribute to timely and accurate orbital predictions, enhancing our knowledge of the geosynchronous orbit environment and further enabling space flight safety to include satellite collision avoidance.”

The Air Force also is expected to announce a manufacturer soon to build a new Space-Fence site in Kwajalein Atoll. And a C-band radar and electro-optical telescope designed for space situational awareness and now located in the U.S. will be moved to Australia to provide better coverage of the Southern hemisphere, where launches from China travel to orbit.

The GSSAP satellites will be operated by the 50th Space Wing at Shriever AFB, Colo.