Risk Assessment: Tools, Techniques, and Their Applications

Chapter 9

Failure Mode and Effects Analysis

When an analyst begins to perform a risk analysis, he/she must first determine what exactly is being analyzed. For this, we must first determine what we consider a failure. Is a failure the total loss of a spacecraft, aircraft, ship, or chemical plant? Or is it the failure to ensure there are enough funds in an account before using a debit card? On November 2, 2006 the NASA Mars Global Surveyor last communicated with Earth. Up to that point, the spacecraft that had been launched in 1996 had operated four times as long as the design life and sent back huge amounts of geographical data on the Red Planet. Therefore, the mission was a great success. However, on November 2, 2006 after the spacecraft was directed to perform a routine adjustment of its solar panels, it sent back that it had experienced a series of alarms. The spacecraft then indicated that it had stabilized. However, that was its final transmission. Next, the spacecraft reoriented to an angle that exposed one of two batteries carried on the spacecraft to direct sunlight. This caused the battery to overheat and ultimately led to the loss of both batteries. The communication antenna was not oriented correctly and kept the orbiter from telling controllers its status. The system's programed safety response did not include making sure the spacecraft orientation was thermally safe and it failed (1).

However, since it had already outperformed its original mission, had it truly failed? ...