The near-infrared seeking eye in the Guidance and Control Group (GCG) Serial Number 1, from 1956.

Modern Sidewinder missiles are still in use by most Western Air Forces, and one recently shot down the Chinese spy balloon that drifted over the U.S. In a surreal historical note, the first use of the Sidewinder in combat was also against the People’s Republic of China, by Taiwan in 1958.

It uses an innovative reticle seeker, and astronaut Wally Schirra remembered his first encounter with the “dome-shaped device, made of glass…a man-made eyeball. I was a cigarette smoker in those days, and I had one in my hand. As I crossed the room, I noticed that the eyeball was tracking me.” Shirra was the first Sidewinder project test pilot, and once had a Sidewinder circle back on him during a test flight but fortunately managed to outrun it.

Under the glass dome, a parabolic mirror spins gyroscopically at 4,200 rpm. The distance of an infrared blip’s reflection from the axis of spin indicated its angle-off and current from the centrally mounted lead-sulfide detector kept the “eye” on target via electromagnets around its rim and controlled the missile’s canard guide fins. A cross-hatch pattern in the spinning mirror solved the problem of discriminating a moving point source of light against a stable backdrop of bright clouds.

With just 14 tubes and 24 moving parts, the seeker aims for where the target is going, a “near-biological intelligence” that baffled the Soviet weapon teams at the time. They obtained one from that first battle between China and Taiwan; it was lodged in the airframe of a MIG that survived the dogfight to return to China.

This particular GCG, S/N 1, was presented to Dr. Charles P. Smith (who went by Chuck), the Assistant Technical Director and head of the Naval Weapons Center Systems Development Department, on his departure in 1976. The body is signed in ballpoint by 76 of his scientists at the Naval Air Weapons Station (NAWS) at China Lake. Dr. Smith eventually became the country’s recognized expert in guided missiles, optical lasers, and infrared technology, and is responsible for developing the Sidewinder and Maverick missiles. It is now in the Future Ventures Space Collection.

From the book Sidewinder: “The AIM-9B belongs in a special class as one of the great weapons of all time; it changed the nature of air warfare. Chuck Smith, a junior member of the Sidewinder 1 team, became the program manager. Afterward, until 1976, he filled a variety of important roles in designing, leading, and managing Sidewinder development efforts” (p.173)

5 responses to “The First AIM-9B Sidewinder Heat-Seeking Missile Head”

  1. jurvetson Avatar
    jurvetson

    The missile head end on a custom stand, with S/N 1 prominently displayed: It has four fins and umbilical cable, standing 25.5" tall, measuring 14" across the fins, and the optical seeker ‘eye’ 4.75″ in diameter. The forward fins function as all-moving canards, powered by a hot gas generator with a 20-second burn time.

    The full Air-to-Air Missile (in museum), for context: Looking under the glass eye, the sensor-mirror array pivots on a spring loaded gimbal, like a reflecting telescope: Looking further in, the circular sensor looks to have a fresnel lens surface treatment:Diagram:The electronics inside: The GCG (Guidance and Control Group) body houses the gyro and guidance system for the missile. The crowning touch, however, was wiring the seeker to aim not where the target was, but where it would be. It did this with proportional navigation, keeping a constant angle to the target on the spinning seeker head:

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  2. jurvetson Avatar
    jurvetson

    Zooming in on that umbilical… it connects to the aircraft and serves many functions: "The missile’s umbilical cable is also attached to the guidance and control section. A shorting cap/dust cover must be installed on the umbilical connector at all times when the missile is not electrically connected to the LAU-7 launcher. The umbilical cable provides the necessary path for the exchange of electronic signals between the missile and aircraft before missile launch. It also provides a connection to the launcher-mounted cooling gas supply, which prevents the electronic components of the guidance and control section from becoming overheated during operation before missile launch. The umbilical cable is sheared off at missile launch." (source)"The gas system consists of a gas receiver assembly, seal valve, and control valve.
    A cooling switch in the cockpit manually operated by the pilot energizes the control valve. This allows gas to flow to the missile through a tube in the missile umbilical cable." (source)

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  3. Ro-bot-tens Avatar
    Ro-bot-tens

    Wow I had no idea it was that old. What a story

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  4. jurvetson Avatar
    jurvetson

    I had the same reaction!

    The missile head came with Chuck Smith’s hardcopy book Sidewinder in which he is mentioned several times:An essential element of the success of the Sidewinder project over competing efforts was a iteration and test cycle time. They rigged up a radar mount to take tracking input from their heat-seeker in development. At one facility, they had integrated development and test in the field. The competitors “had nothing like this. Nichols suspected that the inferior reticle on the Hughes Falcon was attributable to their long cycle of design and testing.” (p.55)

    Each of the open engineering problems were assigned to small teams, sometimes in competition. Chuck Smith called them “hobby shops” and “at least four groups worked on the Sidewinder seeker. This parallel teams approach provided ‘strategic flexibility’ [whereby] the program would not be forced into a corner or become locked in too early into a single approach.” (p.59)

    In describing the maestros of the Sidewinder team, “Chuck Smith could accomplish the seemingly impossible in terms of organization and management.” He was an “implementer and problem solver” (p.232)

    “Chuck Smith, who headed the Sidewinder project during AIM-9D, used weekends to solve the problems his team had accumulated during the week. Smith had an intuitive grasp of the technology and its operations. Usually, his interventions got his group back on track.” (p.233)

    Chuck describes the culture at China Lake: “There was a feeling, not that you worked at a big naval test station, but that you were part of a closed-knit group, a university like atmosphere. And whether it took you eight hours a day or whether it took sixteen hours a day to get it done, you worked until you got your part of it done — so your part didn’t lag anyone else’s part.” (p.69)

    And some further color of Shirra’s role:
    “Wally Shirra was essentially the first Sidewinder test pilot.” (p.95)
    “Shirra was the group’s Sidewinder test pilot from the early days up to the first successful shot. Frustrations could run high, but Shirra and his successors were committed. He knew the importance of getting the attack angle and position correct, and worked hard to get the firing plane in exactly the right position.” (p.102)
    “Shirra had been virtually the sole Sidewinder test pilot until October 1953.” (p.122)

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  5. jurvetson Avatar
    jurvetson

    Looking though Chuck’s paperwork, I see a list of the people on his team that signed it. There was a culture of respecting the technicians as you can see in the laudatory comment about Foust below: And I count a dozen women on the list, which reminds me of a wild claim in the Sidewinder book: "China Lake had about half the female technical professionals employed by the United States government" (p.236)

    And a handwritten note:

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