The Night Before the Launch – (A True Story)
It was a late night, in the Spring of 1989, before an important missile launch, but at last all the work and the check-lists had been completed. Finally, a tired bunch of engineers and technicians were now home tossing in their beds. The launch the next morning was designed to test the ability of the missile to: 1) successfully release from the aircraft, 2) navigate all the way to a designated location some distance from the target, 3) visually locate a laser spot being aimed on the target by a remote designator, 4) and then lock onto the target and use the laser spot to guide the missile to impact the target on the ground. The distance from the launch position to the target was long enough to require that two solid fuel rocket engines be fired in sequence in order to maintain sufficient airspeed and altitude to reach the point where the missile would be able to see the laser spot.
It was well after midnight, when one of the engineers woke violently from his sleep. He and a fellow engineer had wired the rocket motor firing circuit that evening, and through a miracle, he now realized that he had installed the two wires to the circuit BACKWARDS. Leaping from his bed, he quickly dressed and drove from his home in Pasadena, California, to the assembly area 50 miles away. Using his access card, he entered the building and turned on the lights. The missile was sitting on the transport trailer just as it had been left that evening. As he quickly worked to fix the reversed wires, he felt gratitude that he had realized the problem, thereby preventing a test failure the next day, costing the company well over a million dollars. With a sigh of relief, he slowly turned off the lights, and made his way back to his car. He would be tired the next day, but he felt that it was well worth it, having saved the company from an embarrassing failure, not to mention the idea that he was the one that had made the mistake.
Getting on the freeway, he headed back towards Pasadena, and a well needed sleep. The freeway was wide enough, and the night was dark enough, that he failed to notice that his fellow engineer passed him going in the opposite direction on the other side of the freeway. He also had received similar inspiration about the two wires in his sleep and attributed it to a personal miracle. He also felt fortunate that he had realized the mistake and was now going to be able to correct the error by swapping the two wires and connecting them correctly.
Entering the building with his access card, he made his way to the missile, which was still sitting quietly on the trailer. He reversed the two ignitor wires, and even considered leaving a note for the test engineers, who would probably be waking up within the hour. “I’ll document the change tomorrow,” he said to himself as he walked quietly back to his car in the dark parking lot. They would soon be transporting the missile to the launch site in the Mojave Desert, several hours away and a short distance north of Edwards Air Force Base.
The next morning, an F-4 Phantom jet aircraft with a modified pylon was loaded with the 2000-pound test missile. The weather in the Mojave Desert was cold but the sky was clear and it was perfect weather for the launch. A small airplane flew over the test range to certify that it was clear before the F-4 pilot started the engines and took off. He was followed immediately by another jet that would serve as the chase plane and would be responsible to observe and video tape the launch and photograph as much of the flight as possible. The F-4 flew a designated oval flight path twice, as part of a “dry run” before the actual launch of the missile. Finally, the clearance was given and the small red cover to the “Master Arm” switch was raised. The count-down began. High-speed cameras were started and everyone on the ground tried to focus their binoculars on the smoke trail from the old F-4.
The 2000# test missile is hanging on the right side of the F-4. A small white camera pod can be seen on the left side.
At the instant the “Fire” command was given, the missile was released from the wing pylon and cleanly separated from the F-4. The missile’s autopilot maintained a slight nose-up angle as the 2000-pound missile headed towards the point where it expected to be able to see the laser spot being shined on the target. As the speed decreased and the missile continued its descent, the autopilot finally realized that it needed to increase its speed. At a designated minimum airspeed, the autopilot sent a rocket motor “fire” command to the first of the two solid fuel rocket engines. Nothing happened. Engineers on the ground, who were monitoring the telemetry data and signals coming from the missile, soon became concerned that something was wrong. Meanwhile the autopilot increased the angle of attack in order to maintain the designated altitude. Airspeed continued to drop and soon it was apparent that even the second of the two motors had failed to fire. Engineers, managers and company executives watched in amazement as the missile continued to pull up its nose to a higher and higher angle of attack. Finally, the aft end of the missile touched the ground. It almost appeared that the missile might actually try to land on the sandy surface of the dessert floor. Immediately upon touching the ground, however, the rear end of the missile disintegrated, releasing internal components, wings, fins and the two full rocket motors, still waiting for the command to “fire”.
Once the dust had cleared, a disappointed team of engineers began the cleanup, and a thorough investigation of the cause of the failure was started that afternoon. A review of the telemetry data showed that while a “fire” command had been sent to the rocket motors, they had failed to ignite. The two engines were located in the desert, a short distance from where they separated from the missile, and were basically intact. A forensic analysis was performed on the ignitors and no problems were noted. At one of the subsequent meetings, the two engineers sat next to each other as the test failure investigation now focused on the electrical signals to the ignitors. The telemetry data clearly showed that the “fire” signal had been sent at the designated altitude and airspeed.
For the first time during the meeting, one of the two engineers spoke, revealing that there had been an issue with the polarity of the “fire” signal. He began to explain what had happened during the night, but before he could get the words out of his mouth, the other engineer, who was sitting next to him joined his voice, as the two of them finished the sentence in perfect unison…” but I fixed it the night before the launch.”
Simultaneously, the two engineers spun around in their chairs and looked at each other in amazement. Again, they spoke in unison.
“You fixed the problem!?” they said to each other.
The room went silent as it now became clear to everyone sitting at the long conference room table, including them, what had happened. The two of them had independently reversed the wires, and canceled out their intentions to fix the problem. Perhaps the most serious mistake, however, was a failure to communicate their correction. If only they had documented their work and at least left someone note.
