Reports that Matter

Columbia Accident Investigation Board Report, Volume I

SPACE SHUTTLE PROGRAM

Section 55 of 106

SPACE SHUTTLE PROGRAM

Space Shuttle Projects Office (MSFC) NASA Marshall Space Flight Center, Huntsville, Alabama

STS-112/ET-115 Bipod Ramp Foam Loss Date

  • Issue

  • Foam was lost on the STS-112/ET-115 –Y bipod ramp (~ 4" X 5" X 12") exposing the bipod housing SLA closeout

  • Background

  • ET TPS Foam loss over the life of the Shuttle Program has never been a "Safety of Flight" issue

  • More than 100 External Tanks have flown with only 3 documented instances of significant foam loss on a bipod ramp

many of the managers who would be actively involved with STS-107, including Linda Ham, the Program Requirements Control Board ultimately decided against such classification. Instead, after discussions with the Integration Office and the External Tank Project, the Program Requirements Control Board Chairman assigned an "action" to the External Tank Project to determine the root cause of the foam loss and to propose corrective action. This was inconsistent with previous practice, in which all other known bipod foam-shedding was designated as In-Flight Anomalies. The Program Requirements Control Board initially set December 5, 2002, as the date to report back on this action, even though STS-113 was scheduled to launch on November 10. The due date subsequently slipped until after the planned launch and return of STS-107. The Space Shuttle Program decided to fly not one but two missions before resolving the STS-112 foam loss.

The Board wondered why NASA would treat the STS-112 foam loss differently than all others. What drove managers to reject the recommendation that the foam loss be deemed an In-Flight Anomaly? Why did they take the unprecedented step of scheduling not one but eventually two missions to fly before the External Tank Project was to report back on foam losses? It seems that Shuttle managers had become conditioned over time to not regard foam loss or debris as a safety-of-flight concern. As will be discussed in Section 6.2, the need to adhere to the Node 2 launch schedule also appears to have influenced their decision. Had the STS-113 mission been delayed beyond early December 2002, the Expedition 5 crew on board the Space Station would have exceeded its 180-day on-orbit limit, and the Node 2 launch date, a major management goal, would not be met.

Even though the results of the External Tank Project engineering analysis were not due until after STS-113, the foam-shedding was reported, or "briefed," at STS-113ʼs Flight Readiness Review on October 31, 2002, a meeting that Dittemore and Ham attended. Two slides from this brief (Figure 6.1-5) explain the disposition of bipod ramp foam loss on STS-112.