Brief History (cont.)
The oil industry expended considerable effort in the 1970s and early 1980s to develop this technology for monitoring offshore platforms.
Aerospace community began investigating vibration-based damage detection in the late 1970ís in conjunction with the space shuttle.
Since 1987 all orbiter vehicles have been subjected to the shuttle modal inspection system (SMIS).
NASA requires some form of structural health monitoring on all launch vehicles.