On September 29, 1962, NASA announced its third group of astronaut candidates — fourteen men, all military test pilots, all white. The year before, thirteen women had completed the same physiological screening tests as the Mercury astronauts and met all the qualification criteria. One of them, Jerrie Cobb, had higher scores than John Glenn on several of the tests. The program testing them — the Women in Space Program — was canceled in 1961. The women were told the requirements had changed.

The new requirement was that astronauts hold jet test pilot certifications. Military jet test pilot programs did not accept women. The loop was closed.

The thirteen women — known informally as the Mercury 13 — continued their careers. Cobb spent decades as a missionary pilot in the Amazon. Gene Nora Stumbough became a professional pilot and aviation writer. Jane Briggs Hart, who had also been tested, testified before Congress in 1962 alongside Cobb, arguing directly that the exclusion was irrational. The committee did not act.

Sally Ride became the first American woman in space in 1983 — twenty-two years after the Mercury 13 had qualified on the same physical criteria as the male astronauts. She died of pancreatic cancer in 2012 and was posthumously revealed to have been in a long-term relationship with a woman — a relationship she had kept private, she explained in her posthumous statement, because she valued her privacy and the state of lesbian rights in America.

Wally Funk, the youngest of the Mercury 13, finally reached space in 2021 at age eighty-two on a Blue Origin suborbital flight.