The Drake Equation
NASA was created by the National Aeronautics and Space Act signed by President Eisenhower on July 29, 1958. At the time NASA was born the U. S. Government was well aware there was an extraterrestrial presence engaging the Earth.
The creation of NASA stimulated much speculation among scientists who may or may not have been aware of the ET reality. Giuseppe Cocconi and Philip Morrison published an article in Nature with titled “Searching for Interstellar Communications” in September of 1959. Noted Harvard astronomy professor Harlow Shapely publicly talked about the potential number of inhabited planets.
In early 1960 Frank Drake began looking for signals, created Project Ozma, and produced the Green Bank conference from which the Drake Equation was spawned.
Almost certainly some of those attending at Green Bank knew there was an extraterrestrial presence and the Drake Equation was an anachronism from the day it was born. But that was ok as the national security backed truth embargo on the ET reality was accepted by all in the know.
The Extraterrestrial Equation
On August 9, 2014 Paradigm Research Group presented an updated version of the Drake Equation. The Extraterrestrial Equation aimed to bring the Drake Equation into the 21st Century by utilizing hypotheses based on the vast research done since 1960. The equation is as follows:
E = S * P * Z * L * I
E = Number of planets with sentient life that have existed in the galaxy
S = Number of stars in the galaxy [100 billion]
P = Number of planets per star 
Z = Fraction of planets in the life zone [.20]
L = Fraction of life zone planets that develop life [.50]
I = Fraction of life planets developing intelligent life [.50]
E = 100 Bn * 5 * .20 * .50 * .50 = 25 billion
The Contact Equation
But an even more advanced equation was presented by PRG at Contact in the Desert: The Contact Equation.
This is the equation scientific academics should be engaging, if they weren’t cowed by the U.S. Government imposed truth embargo. It was created in service to the unnervingly vast number of contactees, most of whom continue to remain in the closet regarding their experiences cowed by the ridicule generated by this embargo.