COBRA DANE: A piece of history transitions to AFSPC

Published March 3, 2014
By Lt. Col. Jennifer Jeffries

CLEAR AIR FORCE STATION, Alaska -- It has often been said that history repeats itself and if you wait long enough you can watch as things change back to the way they once were. The AN/FPS-108 COBRA DANE radar system, the 21st Space Wing's newest weapon system, represents a case in point where mission and ownership have come full circle.

COBRA DANE is a large ground-based, L-band phased-array radar located on the northwest corner of Eareckson Air Station on Shemya Island, Alaska. The system was fielded in 1976 by Raytheon Equipment Division Laboratories under contract through Hanscom AFB Electronics System Division as the 16th Surveillance Squadron, an Air Force space asset. The contract was awarded in June 1973, and initial operational capability was achieved by July 1977. Aerospace Defense Command was given the operations and maintenance responsibility in October 1977.

From the beginning, COBRA DANE supported three critical Air Force missions: technical data collection for ballistic missile treaty verification (primary), early warning (corollary), and space surveillance (secondary). COBRA DANE has endured many mission changes and mission owners throughout its 37-year history. It supported its original missions from inception until spring of 1994, after completing a four year, major system modernization between 1990 and 1993 by Raytheon EDL for the COBRA DANE system modernization program. CDSM replaced the original mission computers, peripherals and radar displays, all of the operational software (approximately 300,000 lines of code), and several unsupportable radar hardware subsystems. The entire radar front end was retained.

In April 1994, Air Force Space Command ceased operation of the COBRA DANE System, and the corollary and secondary missions of early warning and space surveillance were terminated. COBRA DANE continued supporting its primary intelligence mission without interruption, and the early warning and space surveillance mission capabilities were retained within the software for the possibility of future need.

When AFSPC left Shemya, Raytheon Technical Services Company was tasked to solely operate and maintain the system under Air Force management but without Air Force presence. As a cost savings measure following the discontinuation of early warning and space surveillance missions, COBRA DANE was operated at limited duty factor during periods of no missile activity or data collection opportunity. A capability was implemented to enable the radar to maintain a reduced number of surveillance fences at limited duty and to respond to any tracked missiles by running the transmitters up to full power in time for data collection. In April 1994, Pacific Air Forces withdrew blue-suit support from Shemya and transitioned to contractor support. Shemya AFB was decommissioned to Eareckson AS. The Pacific Regional Support Center (formerly 611th Air Support Group) and the 3rd Wing Contracting Squadron at Elmendorf AFB, Alaska, are now responsible for administering base operations support at Eareckson AS.

During 1994-1995, Riverside Research Institute was tasked to study the feasibility of implementing a field of view expansion. The azimuth coverage increase was to enable data collection on additional new foreign launches, provide increased time in track on routine missile events and to expand collection opportunities. RRI and RTSC conducted tests on the COBRA DANE phased array in April 1995 to establish maximum beam scan angles that could be safely steered. One month later, the FOV expansion was implemented through firmware and software modifications.

Then in 1998-1999, COBRA DANE participated in space surveillance demonstrations to AFSPC and NASA. It demonstrated unrivaled performance in orbital debris tracking, which coincided with the heightened interest in protection of the International Space Station, which was under construction. Increased demand was placed on sensors that could track hazardous orbital debris, and this commenced COBRA DANE's participation in the annual International Debris Assessment Campaigns. In October 1999, following the series of successful demonstrations, COBRA DANE's historic secondary mission of space surveillance was restored at limited duty factor, on a non-interfering basis with the radar's primary mission. A dedicated data link between the radar and Cheyenne Mountain Air Force Station was re-established for automatic data transfer and satellite tasking. In March 2003, with additional funding from AFSPC, COBRA DANE resumed continuous full power operation for space surveillance.

Under Presidential Directive PD-023, COBRA DANE Upgrade development began in 2001 for a new missile defense radar mission that supplanted its original corollary early warning mission. This mission was implemented largely as a software modification. None of the system hardware was changed, but a new communications processor was added to enable COBRA DANE to accept sensor tasking from, and report threat missile data to, the Ground-based Mid-course Defense Fire Control component for target engagement support. CDU was completed in 2004 in a limited defensive operations capacity and is now in a sustainment phase. In 2003 amidst this upgrade, COBRA DANE's continuous full power operation resumed. In 2009, the CDU sustainment and Missile Defense mission responsibilities were transferred from MDA to the Air Force operating community. Finally, in 2013 COBRA DANE's complete mission, program management, and ownership was transferred back to AFSPC as a space unit, where it is now an operating location of the 13th Space Warning Squadron.

Despite its many mission and ownership evolutions, one thing regarding COBRA DANE has remained constant. It has continued to be a low-density, high-value asset that performs a vital national interest mission for North America.