Can we lay to rest a couple more myths about the Carpenter flight.
The astronauts' physician, William Douglas, recognised Slayton's heart problem as early as August 1959. Despite the problem Slayton was slotted to fly MA-7 in November 1961 with Schirra as his back-up.
However, NASA Administrator, James Webb, was not happy with this especially as a review by the Air Force School of Medicine at San Antonio, Texas first said that the condition was "... of no consequence .. " and then changed their mind.
Webb then went to three of America's top cardiologists who came up with the advice that if NASA had an available astronaut with a heart that did not fibullate, then they should be used. This view was supported by President Eisenhower's personal physician, Paul Dudley White. Accordingly, it was Webb who ordered the replacement of Slayton, a decision announced in March 1962.
Douglas and others in the STG disagreed with this decision fuelling a conspiracy theory that suggested that Douglas resigned over the substitution. This is not true. Douglas had indicated that he was leaving NASA some six months prior to the March announcement as he was coming to the end of a three year secondment to NASA from the Air Force.
The decision to use Carpenter rather than Schirra, the original back-up, was made by Walter Williams, the Operations Team Leader. It was made in the light of the delays and the length of training for MA-6. Carpenter, as Glenn's back-up, was the most prepared for what was basically a repeat mission.
In the aftermath, it was claimed at the time that all this was internal NASA wrangling and that Slayton was the victim of a power struggle between the astronauts and NASA Management. Out of this came the suggestion that Carpenter was held responsible for the problems that occurred on MA-7 and that as a consequence never flew again he being an easy target once his close friend, John Glenn, left the programme.
This is not true either. Carpenter went on to play an important role in the early development of the Lunar Lander before losing his flight status due to a motor scooter accident in Bermuda that left him with reduced mobility in his left elbow.
As a postscript to this - I showed my doctor some ECG traces as found in the flight report of Cooper's mission. He looked at them and said, "That's interesting. Technically he suffered a heart attack!" Apparently, the 'P' wave was missing for a couple of beats.