What Happened to Mars Observer?
On Saturday, August 21, 1993, NASA mission controllers lost contact with the Mars Observer spacecraft, one day before it was to enter orbit around Mars and begin a three-year mission to survey and study the Red Planet. Communication was lost after ground controllers had radioed commands to pressurize its fuel tanks in preparation of rocket firings to slow the spacecraft down and allow it to be captured by Mars’ gravity. Initially there was speculation that a problem with the pressurization may have caused the fuel to leak, making the spacecraft tumble out of control, or even explode. After a few days of silence, a second theory emerged: a pair of electronic transistors in Mars Observer’s master clock, the timekeeper for most of the craft’s computers, may have failed, disabling the spacecraft. Researchers found a similar problem in the master clock of the NOAA-3 weather satellite before its launch last June. The faulty transistors were from the same manufacturing batch as those aboard M
