When an employee of NASA or one of its contractors participated in a major milestone, they were often sent a thank you letter from their manager. Here’s one my grandfather got from his boss, Dr. Kurt Debus.
In this case, my grandfather got a letter from his boss, Dr. Kurt Debus, congratulating him for his participation in helping to launch America’s first satellite, Explorer 1. The satellite was not only the first for the nation, it was also the first to carry scientific instruments designed to make measurements in the new frontier of outer space.
One of the measurements that the satellite made was cosmic rays — a form of high-energy radiation that constantly bombards the Earth, and originates from outside our solar system. The expected count was thirty strikes per second on the instruments aboard Explorer 1, but periodically, it would drop to near zero. Analysis of this data showed that zero counts were occurring when Explorer 1 was at an altitude of 2,000 km above Earth, but it would rise to the expected level of thirty. This in turn led to more experimentation on later satellites, and as a result, the Van Allen Belt was discovered — a geomagnetic phenomena where highly changed particles are trapped in the magnetic fields surrounding the Earth.
Debus’s letter to my grandfather:
