Further research indicates that the "Go for at least seven orbits" line from capcom was to inform Glenn that the Atlas rocket had injected him into an orbit that would be stable for at least seven orbits, not that he was approved to stay up that long. This has led to an often repeated but historically inaccurate notion that Glenn's flight had been cut short by a problem, when in fact he was never intended to stay up for more than three orbits. The fact that Scott Carpenter's flight was also for only three orbits should indicate that the first two manned orbital flights were only intended to fly for three orbits, being our first initial baby steps into the cosmos.
see http://www.thespacereview.com/article/550/1 and http://www.spaceflightinsider.com/space-flight-history/our-spaceflight-herit...
Dan Schultz N8FGV
------ Original Message ------ Received: Mon, 09 Jan 2017 06:30:09 PM EST
This leads to the interesting question of why Glenn was told that he was "Go for at least seven orbits" by his capcom
(page
- when there was absolutely no possibility of his flight lasting that
long.