Previous Bipod Foam Losses

NASA knew of four previous cases where foam had fallen off of the left bipod for unexplained reasons - STS-7, STS-32, STS-50, and STS-112. After the Columbia accident an intense study of all of the available film from previous missions showed that there were two additional cases - STS-52 and STS-62 - where much smaller amounts of bipod foam was lost.

Thumbnail for DSC00769 umbilical door.jpg An exclusive animation of the External Tank falling away from Atlantis on the STS-112 mission. The frames were taken by an automatic camera mounted within Atlantis's belly. The final shots show the left bipod with a piece of foam missing.

Computer generated views of the amount of foam lost on each of the four previous known cases of bipod foam loss.
On the CD-ROM each photo can be clicked for a larger photo.

Thumbnail for As presented by Marshall.jpg Thumbnail for As it should have been presented.jpg Thumbnail for Actual data.jpg
These three pie charts show the statistics for bipod foam loss on previous missions. The first figure shows what the Marshall Spaceflight Center (MSFC) presented at the STS-113 Flight Readiness Review - only four losses out of 111 missions. The second figure shows what they should have presented - four losses out of 73 missions with adequate photography to determine whether or not foam was lost. The third chart shows what was determined after the accident - two additional cases where bipod foam was lost and not discovered, for a total of six cases of bipod foam loss before the STS-113 launch. The actual numbers were over twice as bad as what Marshall had presented.

Thumbnail for foam loss summary.jpg This final chart shows the total statistics after the Columbia accident. 67 missions without any known bipod losses, seven missions with bipod foam losses (including STS-107), and 39 missions with no way to determine whether or not any bipod foam was lost.

On the average of one out of every 11 missions foam was lost from the left bipod.

Columbia after it arrived on Launch Pad 39A in December 2002. The red arrow indicates the bipod where a piece would fall 81 seconds after Columbia's launch, fatally damaging the left wing.

STS-112 External Tank animation and charts by author Philip Chien.
Photos from NASA and the CAIB.

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