Intercept Ground Optical Recorder (IGOR)
| Type: | Missile-tracking telescopic camera |
| Focal length: | 96/192/298 inches |
| Main optic diameter: | 16 inches |
| Data recorder: | 8-120 frames per second |
| Event recorder: | 500-3,000 frames per second |
| Tracking: | Manual |
| Number of units: | 15 |
| Years active: | 1951-1965 |
The Intercept Ground Optical Recorder, pronounced “Eye-gor” was one of the early tracking telescopes used during missile testing at White Sands Proving Ground. The IGOR was developed by Clyde Tombaugh, who discovered Pluto, and the Ballistic Research Laboratory. IGOR was originally designed to support the Nike and Talos missile programs being developed for use in the early years of the Cold War. However, variants of the IGOR were active for decades and its descendants are still in active use today.
The IGOR is a three-piece system composed of a Navy modified 5-inch gun turret mount, folding Newtonian telescope, and a high-speed 35mm Mitchell camera, capable of operating at up to 2,500 frames-per-second. A three-man crew, comprised of two operators and a section chief, was required. One operator would control the telescope’s azimuth while the other controlled its elevation. The two operators were placed on opposite sides of the IGOR and needed to work together to keep its optical crosshairs on the missile in flight. The section chief was on-hand to take environmental readings, operate the camera, and generally provide instructions and directions for the two operators.
As range operations grew in complexity through the 1950s and into the 1960s, the need for advanced optics, telemetry, and other range support infrastructure also grew. The intent during this period was to establish an entire chain of range instrumentation from the launch complexes near WSMR Main Post to the north end of the range, around 100 miles away. This chain was to have the capability of tracking a missile from launch until impact in the 30-mile, 50-mile, 70-mile, and 90-mile impact areas.
Lessons learned and improving technology enabled the creation of a 96-inch telescope known as the Modified IGOR, or MIGOR. MIGOR’s improvements included a wider field of view and automatic controls to compensate for exposure and temperature variations. Further developments on MIGOR led to the Medium Focal Length Mobile Tracking Telescope (MFLMTT), which was carried on a mobile trailer and towed out to wherever it was needed. Many of the instrumentation devices used on WSMR were protected inside astrodomes and other structures. Many of these “golf balls” can still be seen on the peaks of higher elevations all over the range.