With the start of the Apollo program in 1960, a wide range of technologies and techniques needed to be developed to mount advanced missions beyond Earth orbit. Among these was figuring out how to safely return the Command Module (CM) to Earth from the Moon. At this point in time, NASA and branches of the military had practical experience with spacecraft and warhead-laden reentry vehicles hitting the Earth’s atmosphere to speeds as great as about 7,000 meters per second. But Apollo would be reentering the Earth’s atmosphere at a much higher 11,300 meters per second involving kinetic energies over twice that of a spacecraft returning from low Earth orbit.
While one could extrapolate from current experience to estimate the heat loads involved, there were different results depending on the methods used. The uncertainties in this new environmental regime needed to be addressed in order to ensure the spacecraft (and its passengers!) were properly protected without an undue mass penalty. In order to resolve these issues, NASA started Project FIRE (Flight Investigation Reentry Environment).
Origin of Project FIRE
In September of 1960, NASA personnel at Langley Research Center (which had responsibility for Project Mercury – see “The Origins of ...