At Area 51, Annie Jacobsen explains (in Area 51), Oxcart pilot Kenneth Collins went by the code name Ken Colmar:
“Same first name because you will instantly respond to it when called,” Collins explains. “Colmar for the C, in case you had something monogrammed.” His call sign was Dutch 21 but most men on base called him the Iceman. The pressure-suit officers came up with the nickname. “I was known to show no emotion or irritation even after a particularly dangerous flight,” Collins recalls. The pressure-suit officers could gauge how tough a flight was by how sweaty a pilot’s underwear was when they helped pilots undress. Collins’s underwear was always remarkably dry.
[…]
Having a stable marriage and family had become a CIA-pilot mandate during Oxcart, something that was not in place during the U-2. It was Gary Powers’s alcoholic wife who’d triggered the change. Some in the Agency believed she put the secrecy of the entire U-2 program at risk with behavior that even they could not control. Once, Barbara Powers got it into her head to visit her husband at his clandestine post in Turkey. She made it as far as Athens before the officer assigned to watch her notified Powers that he would be out of a job if he couldn’t keep his impetuous wife in line. Ken Collins was told this story during his first interview at the Pentagon. Loose lips didn’t just sink ships, he was reminded; loose lips could trigger nuclear war.
[…]
Each Monday morning, Collins left his home and drove to Burbank Airport, nine miles to the southwest. There, he and the other Oxcart pilots climbed aboard Constellation propeller planes and headed to Area 51, never with more than two pilots per airplane—a guideline put into place after the Mount Charleston crash eight years earlier. The deaths of those top Agency and Air Force managers and scientists had set progress on the U-2 program back several months.
[…]
The appearance of a new, moonlike subsidence crater was often a weekly occurrence now that nuclear testing had moved underground. When seen from above, the landscape at the Nevada Test Site looked like a battlefield after the apocalypse.
[…]
During training missions, the papers in Collins’s flight pouch identified him only as a NASA weather pilot. His space-age-looking aircraft was registered to an airfield called Watertown Strip, Nevada. He was never to carry any personal effects with him in the airplane. When the Lockheed Constellation landed on the tarmac at Area 51, security guards took his ID and papers and locked them away in a metal box. Each Friday, before the afternoon flight home, Collins’s identity was returned to him.
Does CIA surreptitiously register its UFOs?