http://www.openminds.tv/will give anyone who registers access to a free pdf manuscript of a Philip Corso book.
http://www.openminds.tv/corso-notes/Corso, like Edgar Mitchell, held a position of trust in the USA military establishment. Both Corso and Mitchell claimed to have proof of extraterrestrial biological entities.
Mitchell's IONS can be found at:
http://www.noetic.org/So two highly trusted men claimed EBEs are real.
Neither showed any obvious sign of derangement.
Neither appeared to be motivated by fame or publicity.
Neither made any significant money off the deal.
It could be a disinfo op - someone high up at the Pentagon might have said, "There really are no EBEs, but we must lie, and we must use highly trusted men to lie for us."
It could be true.