[time-brightcove not-tgx=”true”] It was a very big deal on Sept. 14, 1966, when astronauts Pete Conrad and Dock Gordon flew their Gemini XI spacecraft to a never-before-attained altitude of 850 miles. It’s still a big deal 58 years later, since that record for a crewed spacecraft in Earth orbit remains. But that will change later this month, when the crewmembers of the Polaris Dawn mission—set for launch on Aug.