Cavalier innovation provides cutting-edge space surveillance

by Staff Sgt. Craig Gantt
10th Space Warning Squadron

10/9/2012 - CAVALIER AIR FORCE STATION, N.D. -- Driving on North Dakota's Highway 5, some perceive a behemoth 12-story radar building standing in the distance as a relic of the Cold War. However, unbeknownst to the passing public, the 10th Space Warning Squadron has undergone rigorous upgrades and modernizations as a culmination of necessity and innovation.

The radar at Cavalier Air Force Station is no stranger to innovation. In 1973, massive rooms in the radar were dedicated to providing the space necessary to house one of the first multiprocessor computers in the world. Considered an engineering marvel at the time, the 48 large metal cabinets have now been replaced by a modernized computer that can fit in a room no bigger than a small storage closet. Extremely complex hardware systems stand idle as emulation software suites now silently provide far superior capabilities.

The Perimeter Acquisition Radar Characterization System is a vital component of the Integrated Tactical Warning Attack Assessment System. Once a stalwart of the Army's Safeguard program, PARCS is now one of the most advanced ground-based radar sites in the world. The primary mission of PARCS is to provide early warning and attack characterization of submarine launched or intercontinental ballistic missile attack on the continental United States and Canada. PARCS is the only missile warning sensor that can provide attack characterization and assessment, and determine the number and types of missiles entering its radar coverage. Additionally, PARCS has the capability to provide earliest and next time of impact metrics for the continental United States.

PARCS is also a collateral space sensor. Its secondary mission is to support the Air Force's space surveillance mission by providing tracking, reporting, and Space Object Identification data on Earth satellite vehicles. PARCS accounts for nearly 40 percent of the Air Force's phased array radar observations, collecting up to 100,000 observations per day. As the workhorse of the space surveillance mission, PARCS has been the primary contributor for timely space event resolution for more than five years. It is also a major contributor to the conjunction assessment program, searching for lost objects and ensuring collision avoidance for the International Space Station and a wide variety of other orbiting assets. PARCS is an incredibly powerful radar. Its 16 transmitters are capable of producing 25 megawatts of power cumulatively. The radar is able to track 75 percent of all catalogued space objects on orbit today. Recent innovations to specific hardware and computer components have resulted in extensive advancements in promoting longevity and cost effectiveness of the system.

Two of the most recent innovations to the radar are upgrades to Central Logic Control and the Traveling Wave Tubes. The CLC is the heart of the radar's data processing system. It performs calculations, makes decisions and directs the operation of interfacing subsystem components. Recent upgrades have dramatically increased the efficiency and lifespan of the CLC. The old legacy system was replaced by emulation software which is more reliable and greatly increases system memory. Not only has this innovation increased system performance, but it has reduced maintenance costs.

Currently, Cavalier AFS uses more than 100 Traveling Wave Tubes that are essential to radar operations. The TWTs are linear electron accelerators capable of producing 200 kilowatts peak power of pulsed RF output. This power output results in the creation of the RF radiation PARCS uses to carry out its mission. This process can heat the TWTs up to temperatures of 1,100 degrees centigrade, resulting in damage to the TWT components and a shortened service life. At approximately $130,000 per TWT, heat damage can make system operations extremely expensive. Through improvement, Air Force and Navy studies produced new TWT filament regulators. The installation of these new regulators resulted in a change to TWT operating temperatures extending the service life of these components by up to 25,000 hours. Additionally, vacuum ion pumps have been added to prevent damage to TWTs. The historical consistency of innovation at Cavalier AFS has saved the Air Force millions of dollars.