Standing on the surface of Pad 39B, I thought about the events and forces that had previously occurred in the space I was currently occupying and on the cement I was standing on.
Sir Isaac Newton's First Law of Motion - the law of inertia - states that an object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force. To create the unbalanced force to propel Space Shuttle missions away from Earth, three main engines worked together to create almost 1.2 million pounds of thrust and two solid rocket boosters created a total of 6,600,000 pounds of thrust. The total thrust at launch, on this pad surface, was about 7.8 million pounds.
Pad 39B was first used for Space Shuttle missions. The first launch from it was the fateful Challenger STS-51-L on January 28, 1986, that broke apart 73 seconds into its flight, killing all seven crew members.