Report: Computed tomography of PKM and AKM exit cones

In February 1984, two shuttle-launched spacecraft, the Westar IV and Palapa B2 satellites, failed to reach orbit when their perigee kick motors (PKMs) extinguished in a few seconds, instead of burning for 86 seconds. Although the two failed PKMs could not be recovered, a television camera aboard the space shuttle Challenger had observed the premature extinction of the Palapa PKM.