Various industries employ myriad consumables for vacuum operations. These consumables may cost anywhere from a couple of hundreds to lakhs of rupees. This gives rise to the question: Are low cost consumables lesser in importance to high cost ones? Is that the reason why they cost less? I’ll give you a case in point. Then YOU decide. On January 28, 1986,the cause of the Space Shuttle Challenger disaster was determined to be the failure of an O-ring seal ………NASA has gone through considerable transformation after the accident.(Source: Wikipedia)