COBRA BRASS

Cobra Brass Schematic

Cobra Brass (CB) will provide space-based multispectral data for the GEO and HEO components of SBIRS. The Cobra Brass sensor employs a focal plane array (FPA) and a multiposition filter wheel that can be rapidly changed from one band to the next. The CB staring, fast framing, multi-spectral electro-optical sensors represent a significant departure from the traditional approach of scanning, slow framing, single band sensors which have traditionally been used for Tactical Warning and Attack Assessment (TW/AA). A major emphasis of this program will be to increase the timeliness of sensor tasking and reporting. This will allow CB data to be processed in real-time through the existing theater infrastructure.

COBRA BRASS is designed to demonstrate the utility of multi-spectral, fast-framing, staring sensor technology. It will provide space based multi-spectral data to the National Air Intelligence Center (NAIC). This data may also have some application to the Space Based Infrared System (SBIRS) missions of missile warning, missile defense, battlespace characterization, and technical intelligence. The system is divided into two major components, the COBRA BRASS payload and the COBRA BRASS Ground System (CBGS).

COBRA BRASS is an experimental, multi-spectral, fast-frame, staring sensor on a classified host vehicle. The sensor employs three focal plane arrays, each featuring a multi-position filter wheel for viewing in various bands. This approach, combined with extremely high-frame rates and higher sensitivity than previous iterations, allows for a full characterization of a number of targets and backgrounds. COBRA BRASS will interface with the host spacecraft's power, thermal, structure, command, control, and telemetry subsystems. The COBRA BRASS Ground System (CBGS) is co-located with the host spacecraft mission ground site and interfaces with the existing site command and control uplinks, high-speed data downlinks, and high-speed LAN.

The COBRA BRASS optical subsystem consists of a twelve-inch diameter, two-axis steerable telescope and associated transfer optics, beam splitters, filter wheels, flip mirror, and image forming optics. This telescope system has a 0.25 field-of-view (FOV) and is capable of pointing and tracking within its field-of-regard. The telescope design utilizes two motor driven gimbal systems mounted in an elevation over azimuth configuration. The sensor subsystem consists of three multi-element mosaic array sensors with associated filter wheels for band selection as well as scan, bias, and readout electronics to operate the sensor.

The downlink subsystem collects real-time data feeds from the digital, processor, sensor, pointing, and state of health subsystems for transmission to the ground. Taken together, the payload subsystems are capable of producing data at aggregate burst data rates up to 192 Mbps. The downlink system collects, compresses, buffers, encodes, and transmits this information over two 12 MBPS synchronous data links. The payload design allows for periods of high data rate collection when the total data rate from all sensors greatly exceeds the downlink bandwidth. To meet this requirement, sensor data is buffered on-board prior to forwarding to the ground. Sufficient storage capacity is available to buffer all sensor data at a peak 192 MBPS rate for 100 seconds. Data buffering takes place in the payload solid state recorder (SSR). This memory also permits the storage of an equivalent number of single channel data collects.

The COBRA BRASS Ground System (CBGS) will collect and process data from, and provide command of the COBRA BRASS payload. Principal CBGS functions include payload command and status monitoring, telemetry de-commutation, mission data processing, data storage and display. Post-collection data review and analysis, and support for payload diagnostics and anomaly resolution are also included in the CBGS. Selected data will be sent to NAIC for further processing, analysis, and reporting. Selected data will be sent to Sandia National Labs (SNL) as needed to support diagnostics, troubleshooting, and evaluation. In order to minimize development and maintenance costs, as well as schedule and technical risk, the CBGS will use commercially available technologies, standards, hardware, and software to the extent practical while achieving mission objectives. Moreover, CBGS development and deployment will be evolutionary in nature with two defined development phases. Phase I will provide the core functionality needed to support initial payload operations and collect data for analysis and algorithm development. Phase II will augment those capabilities based upon on-orbit experience to enhance the utility of COBRA BRASS.

The COBRA BRASS program is a Defense Intelligence Agency/Central MASINT Office Research and Development program. The program was combined into the SBIRS Program Office as part of the February 1995 Defense Acquisition Executive Review. It is a pathfinder program for bringing SBIRS on-line because it is designed to demonstrate advanced capabilities to extract data from transient low-intensity infrared events and their applicability to battlespace characterization. Previous CB sensors have demonstrated the ability of this technology to contribute to both the Theater Missile Defense (TMD), Technical Intelligence (TI), and Battlespace Characterization (BC) missions. Some initial space-based multispectral data from the Cobra Brass program were presented by the National Air Intelligence Center in April 1995. CB was combined into the SBIRS program as a result of the Feb 95 DAE review.

CB was developed by Lockheed Martin Sandia National Laboratory, Albuquerque, NM. The Cobra Brass multispectral staring sensor system--consisting of a complex satellite payload and its associated ground-based command, control, and data processing system--was delivered to the Air Force customer. Delivery of this innovative R&D system, which will provide unique capabilities, marked the culmination of an aggressive 30-month development effort by a large number of Sandia organizations. (5700, 6500, 2300, 2600, 9300).

The flight history of this program remains obscure. Initially it appeared that COBRA BRASS payloads were launched using the Satellite Launch Dispenser, co-hosted on the SLDCOM communications System spacecraft, launched most recently in May 1996. It is reliably reported that a CB payload was launched in early 1998, which almost certainly corresponds to the first SDS-III launch of 29 January 1998. This currently operating Overhead Nonimaging Infrared R&D System has demonstrated its utility to military operations and Technical Intelligence, while providing technical support to the Space Based Infrared System program. With these improvements, SBIRS will provide vastly improved MASINT data for the characterization of strategic and theater ballistic missiles and other threats.

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