The events on this day in history for our heritage companies are noted below.
Military and Classified Programs:
1987 – LAUNCH FAILURE: FLTSATCOM-6, GD Atlas G/Centaur, LC36A, CCAFS – hit by lightning
2020 – LAUNCH: LM AEHF-6, ULA Atlas V 551, LC41, CCAFS
Exploration and Interplanetary Programs:
NONE
Earth-Monitoring and Civil Weather Satellite programs:
NONE
Commercial Programs:
1976 – LAUNCH: RCA Satcom2, Delta 3914, LC17A, CCAFS
Test, ICBM, FBM programs:
1965 – Last MM Titan I ICBM taken off alert status, Lowry AFB, Colorado
1965 – LAUNCH: GD Atlas D, 576-A1, VAFB
1980 – LAUNCH: Lockheed Trident C-4, SSBN655, ETR
Other:
NONE
The photo today is a lightning strike back to the pad from the launch of A/C-67 in 1987. This culminated a nearly two-year across-the-board series of disasters for American launch vehicles (Titan 34D7 in August 1985, Challenger in January 1986, Titan 34D9 in April 1986, Delta/GOES-G in May 1986 and A/C-67 in March 1987). Here’s the story of A/C-67:
On 26 March 1987, A/C-67 failed to launch a Navy FLSATCOM satellite. Weather conditions were poor that day, with thick clouds and “moderate to heavy” precipitation. The weather conditions violated one launch criteria (“The flight path of the vehicle should not be through mid level clouds 6,000 feet or greater in depth, when the freezing level is in the clouds.”), the weather team reported it as an icing issue, not a lightning risk. After discussions about the risk posed by ice, the NASA program directors gave the go-ahead. The Atlas was struck by lightning around 38 seconds into launch. Control of the booster started to fail and it broke apart from structural loads at T+50 seconds. The Range Safety Officer sent the destruct command, but there was no evidence that the booster ever received it. Debris rained out of the clouds onto the pad area, the shoreline, or in shallow water just off of it and was easily recovered. A section of the payload fairing was found to have multiple small holes burned in it due to repeated lightning strikes. The key piece of evidence was Atlas’s flight computer, which was recovered intact and examined. It was discovered that the last command issued was a signal to gimbal the booster engines hard to right, caused apparently by lightning induced Electromagnetic Pulse (EMP) altering a single word in the guidance program.
The launch caused significant reappraisals of weather guidelines at Cape Canaveral. The 45th Weather Squadron uses rules developed after the incident to determine if weather conditions allow a launch. Ironically, this failure occurred AFTER the Apollo 12 incident in November, 1969, when that Saturn V launch vehicle was hit more than once during ascent.
