Foreign Military  

~ Moscow ~

Zarubezhnoye Voyennoye Obozreniye

Monthly journal of foreign military affairs
Oct 01, 2001 pp 36-38

Article by Col. A. Fiolentov:
"The American Ballistic Missile Test
Intelligence Collection Platform "Cobra Ball"

~ FBIS Translation ~
Foreign Broadcast Information Service

"The US Air Force has had in its arsenal since the 1960s a platform based on the RC-135 aircraft that is unique in its capabilities for collecting intelligence on strategic and operational-tactical ballistic missile flight tests. Its main purpose, according to the design of the American chain-of-command, is the receipt of objective video information about new missiles, and also the interception of telemetry data in the various phases of the test flight for the purpose of estimating their tactical-technical characteristics.

Initially, the electro-optical device, which was intended for the measurement and video recording of the ballistic characteristics of missiles during their flight testing, was installed on the "Boeing" aircraft JKC-135A, which came to be called the "Nancy Rae". Soon after its modification in 1963, it received the designation RC-135S and the name "Wanda Belle". In January 1967, after the installation of additional intelligence collection equipment, the aircraft was given the name "Rivet Ball". Along its starboard side were situated ten windows of increased diameter to which special optical sensor devices were fastened. With their help and that of a small scanning device mounted in the upper part of the fuselage, motion-picture and photographic intelligence collection was performed. The aircraft's main basing location was at Eielson Air Base in Alaska, and its forward basing location was an airbase on Shemya Island (the Aleutian Islands).

While training and test firings were being conducted at Soviet missile test ranges, the "Rivet Ball" was flying on patrol in the airspace of the southeaster part of the Sea of Okhotsk and the Kamchatka Peninsula, recording intelligence information in the ballistic missiles' final phases of flight.

For more than two years, the "Rivet Ball" had successfully performed intelligence collection missions, when it suffered a catastrophic accident in June 1969 in the region of the Bering Sea while flying from Shemya Airbase to Eielson. Neither the aircraft nor the remains of the 19 members of the crew were ever found. The aircraft's disappearance without a trace prompted many suggestions as to what the true reason for the tragedy was. There was even some political speculation in the foreign media according to which it was asserted that it was destroyed by a missile launched from a Soviet submarine. The American Air Force's chain-of-command, assigning great significance to the information obtained from the airborne ballistic missile testing intelligence collection platform, managed to replace the lost aircraft in a very short period of time. By 1970, two vehicles designed for similar purposes were put into service that were created on the base of the C-135B transport aircraft. In accordance with the program "Big Safari", in particular, work was done for improving its flight handling capabilities and a unique intelligence collection device was installed. These vehicles received the designation RC-135S, and the platform for collecting intelligence on foreign missile flight tests was called "Cobra Ball".

In 1981, one of these aircraft suffered a catastrophic accident while landing at Shemya Airbase in bad weather. Six of the crew members died.

Within two weeks it was decided to re-outfit yet another transport aircraft - a C-135B - for use within the "Cobra Ball" system. Fully equipped with the intelligence collection equipment and the latest satellite communications equipment, it was put into service in 1983.

This was yet another instance that confirmed the significance the American leadership placed on this platform. Over the course of subsequent years, the "Cobra Ball" platform aircraft were brought in for conducting intelligence collection on the testing of not just Russian missiles, but also Chinese, North Korean, Pakistani and Indian missiles, patrolling the airspace above the Pacific and Indian Oceans. Based on the latest scientific-technical achievements, the capabilities of the intelligence collection equipment installed on-board were expanded. According to the assessments of American specialists, the "Cobra Ball" platform supports the detection and tracking of missiles in extended trajectory legs, determining the moment of rocket motor ignition, calculating the missile's launch point and impact point, and obtaining intelligence data on the characteristics of the missile being tested.

At this time, this platform includes three aircraft bearing the designation RC-135S (side numbers 61-2662, 61-2663, and 62-4128). The latter was put into service in 1999. It was created on the base of the RC-135X "Cobra Eye" aircraft, which previously had been used in support of flight tests of American ballistic missiles. The aircraft underwent modernization under the program "Cobra Ball-2" and today, in the opinion of foreign military specialists, it is filled with the latest achievements of American scientists and developers in this field.

TTKh [Tactical-Technical Characteristics] of the RC-135S Aircraft
Take-off weight, tons 124.9
Maximum flight speed (at an altitude of 8000 m), km/h 970
Altitude for performing intelligence collection, m 8000-12000
Maximum flight range, km 11000
Patrol duration (at a flight speed of 780 km/h and one in-flight refueling), hrs up to 30
Crew, persons 6

The placement of the unique equipment on the "Cobra Ball" platform aircraft brought about external characteristics that distinguish them from other modifications of the RC-135. In particular, on the starboard side there are four enlarged windows designed for the performance of electro-optical intelligence collection. On the aircraft modified according to the "Cobra Ball-2" program, there are also such windows situated on the port side. On the first aircraft used for the missile flight test intelligence collection platform, for the purpose of reducing interference (glare and so forth) to the intelligence collection equipment, which operate in the visible and infrared frequency spectrum, the surfaces of the starboard wing and engine pod were painted black. Subsequently, when using the more up-to-date equipment, there was no need for such paint, but this distinctive external feature had already become a tradition and it was decided that it should be kept (fig. 1).

The technical missile flight test intelligence collection system installed on the aircraft is composed of three subsystems: for electro-optical intelligence collection, radio communication, and intelligence data transmission. The team of operator-specialists performing observation and conducting analysis of the data received is made up of from 17 to 24 people.

The electro-optical intelligence collection subsystem contains equipment for panoramic, over-the-horizon scanning (search), as well as for tracking and identification.

The panoramic scanning equipment is part of the MIRA complex (Medium-wave Infrared Array) and is actually two electro-optical devices, which support panoramic surveillance of illuminations in the medium infrared spectrum. In each of these there are six cameras situated in such a way that their overall field of regard images an azimuth surveillance sector of about 180.

The tracking and identification equipment include two electro-optical systems: ROTS (Real-Time Optical System) and LATS (Large Aperture Tracking System). The first one, which consists of eight acquisition sensors and five tracking sensors, records in the visible spectrum.

The second complex, which includes a telescope with a focal length of 30.5 cm, allows for detection and discrimination of small targets. The "Cobra Ball-2" system, housed in the modernized RC-135X aircraft, is equipped with an improved MIRA system. It was designed by the Lincoln Massachusetts Institute of Technology laboratory and it offers a simultaneous panoramic view in three sectors of the infrared spectrum, determining the object's location, its temperature, brightness, and illumination bandwidth. In addition, owing to the aircraft's modernized design, it supports the ability to conduct target observation and tracking not just from the starboard side, but also from the port side (the RC-135S aircraft do not have this capability). An increase in effectiveness of the new platform system (fig. 2), in the opinion of American specialists, should be facilitated by the fact that it uses sensors that have more precise direction-finding and resolution (on average by as much as 15 percent as compared to its existing analogues). The radio- and radio-technical subsystem includes an automated ATS telemetry intelligence collection system (Advanced Telemetry System), radio-intelligence sets and equipment for radar and radio communications direction-finding, and a set of individual aircraft protection equipment.

The ATS supports automatic scanning of the portions of the frequency spectrum used for transmitting telemetric measurement data and digital recording of all the acquired signals for subsequent detailed analysis.

The capabilities of the radio intelligence and direction-finding suites are presumably similar to those installed on the electronic warfare aircraft, the RC-135V and W ("Rivet Joint"). They can support determining the coordinates and characteristics of the enemy's radio-electronic equipment in the 20-40,000 MHz range (interception of radio exchanges between aircraft and ground-based command and control posts). As foreign experts note, at the same time, signals from the missile in flight are intercepted at one of the operator posts, and at another - emissions from ground-based tracking radars are monitored and their location is determined. The set of individual aircraft protection equipment, which is meant for assessing the level of threat to the aircraft in the region for performing the mission, includes radar illumination warning stations and devices for imaging the radio-electronic situation.

The radio-communications and intelligence data transmission subsystem includes equipment that supports the receipt of reports from the Tactical Information Broadcast System (TIBS) [Note: rendered in vernacular text in English as "Tactical Information Broadcast Service"], and the exchange of data in the Joint Tactical Information Distribution System (JTIDS).

Over the TIBS system channels, current intelligence information is received from the highest national chain-of-command, as well as from the TVD [Theater of Military Operations] chain-of-command. Use of the JTIDS system apparatus ensures the secure near real-time exchange of intelligence information from the chain-of-command and cooperating forces.

At this time, according to the assessments of American specialists, the "Cobra Ball" on-board intelligence collection platform ensures the reliable detection and tracking of missiles in trajectory legs at a range of 450-500 km,determination with a high degree of precision of the moment of the missile engine's trust cut-off (shut down), calculation of the launch and impact points (with a deviation of no more than 100 m). As a result of the subsequent (post-flight) processing and analysis of the acquired information, estimates are made of the many important characteristics of the tested missile. So, through an analysis of the spectral components of the illuminated plasma,which forms upon the warhead's entry into the dense layers of the atmosphere, its casing material is determined, and based on an analysis of the tracking data, the speed and maneuvering parameters of the warhead when evading PRO [missile defense] systems are estimated.

In the coming years, the US Air Force chain-of-command plans to update the remaining RC-135S platforms according to the "Cobra Ball-2" program to support the capability of performing electro-optical intelligence collection from both sides. In addition, the intention is to develop and outfit all of the "Cobra Ball" platform aircraft with an on-board multi-functional synthetic aperture radar, which will enhance the effectiveness of intelligence collection - detecting launches and tracking the flight trajectory of ballistic targets under cloudy conditions."

~ End of Translation ~

Kingdon R. Hawes (Webmaster)

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