PTSS Kill Leaves Hole In Missile Defense Sensor Plan

By Amy Butler
Source: Aviation Week & Space Technology

Two Sbirs payloads are in highly elliptical orbit (HEO) on classified host satellites, and the second satellite was lofted into geosynchronous (GEO) orbit in March. Though the GEO satellites are not yet certified for missile-warning messages, Air Force officials brag about their capabilities in detecting targets after launch. And, they are capable of capturing “dimmer” targets, Shelton says. These include shorter-range missiles or other “infrared events,” such as rocket flashes. “Has it been more expensive than it should have been? Absolutely. But, we are getting great operational capability from HEO and GEO.”

The second Sbirs satellite achieved “first light,” and officials expect that it will be certified to warn commanders of ballistic missiles by year-end, says Jeff Smith, vice president of the program for prime contractor Lockheed Martin.

First light means the cover for the sensitive infrared payloads—a scanner and a starer—were removed. The system is now being calibrated.

This satellite was launched March 19 on an Atlas V from Cape Canaveral. GEO-1 was launched in May 2011. Its scanner has yet to be certified to deliver Integrated Tactical Warning/Attack Assessment messages, though approval is expected soon. These ITWAA messages are used to tip off U.S. missile defenses on incoming targets. The Air Force has prioritized use of the scanning sensor, leaving the newer staring sensor for certification later. The Sbirs scanner is faster than the Defense Support Program (DSP), which scans its field of view once every 10 sec.

As a replacement for the DSP, Sbirs will be responsible for providing information on targets—such as launch point, vector and impact point. Its data will be fed into the Missile Defense Agency's Command, Control Battle Management and Communications System, which links to sea- and ground-based interceptors in the field.

Because Sbirs GEO-1 was the first of a new breed of spacecraft, ITWAA certification has been a long journey. Officials, citing security concerns, will not provide details on what, specifically, has taken so long to vet. But, Smith says GEO-1's scanner is in what is expected to be the final, 30-day trial period. “It is a rigid structured process, and we are just checking every box.”

GEO-2 is in en route to its operational location. Once in place, the two GEOs in orbit will be able to provide “stereo” coverage from launches from the Middle East to the Pacific region. “That gives you a much more accurate . . . launch point, state vector and impact point” for targets. Shelton refers to an accurate state vector at booster burnout as the “holy grail.”

Two scanning payloads are also continuing operations on separate, classified satellites in highly elliptical orbit.

Meanwhile, Lockheed Martin has begun work on GEO-3, and HEO-3 is slated for delivery within six weeks. The company has submitted a proposal to the Air Force for production of GEO satellites 5 and 6. A contract award is expected by the end of September, when the fiscal year ends.


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