Engine start on SpaceShipTwo. (Credit: Scaled Composites/NTSB)
The following sequence is extracted from a National Transportation Safety Board (NTSB) document about the loss of SpaceShipTwo last October. The images show the breakup of the vehicle from a camera on one of the tail booms. The premature unlocking of the feather mechanism resulted in aerodynamic pressures deploying the movable tail booms during powered ascent.
NTSB experts did the annotation on the photos and the narrative that accompanies the images. The sequence spans 3 seconds.
Figure 62 (Credit: Scaled Composites/NTSB)
Figure 62 is the last frame exported from the recording that shows the feather in a undeployed and nominal position. A vertical line was drawn at the intersection of the right boom’s leading edge and the contour of the upper fuselage structure to illustrate the feather’s relative position. In every frame prior to this, the feather position is nominal. By figure 62 and forward, the exported images show positive feather movement indicated by the incongruity between the vertical line and the relative position of the right boom’s leading edge and the contour of the fuselage.