Sometimes that is not enough: In this rocket malfunction, a part was installed upside down. It had arrows indicating the direction and only fit in its place in

Sometimes that is not enough: In this rocket malfunction, a part was installed upside down. It had arrows indicating the direction and only fit in its place in one orientation. Still, on finding that it didn't immediately fit a technician forced it in: http://www.russianspaceweb.com/proton_glonass49.html#culprit http://www.russianspaceweb.com/proton_glonass49.html#culprit By July 13, investigators simulated the improper installation of the DUS angular velocity sensors on the actual hardware. As it turned out, it would be very difficult to do but not impossible. To achieve that personnel would need to use procedures and instruments not certified either by the design documentation or the installation instructions. As a result, the plate holding the sensors sustained damage. Yet, when the hardware recovered from the accident was delivered to GKNPTs Khrunichev, it was discovered that the nature of the damage to the plate had almost exactly matched the simulated version.