The next critical event in the Apollo 11 mission was the Trans-Earth Injection burn. The burn involved firing the big service propulsion engine for two and a half minutes on the back side of the moon.
The ascent of the Eagle was strikingly swift compared with the liftoff of the huge Saturn V rocket from Cape Canaveral. Of course for the Moon launch, there was no atmosphere resisting Eagle, and there was only one-sixth gravity to overcome.
Crew training for Apollo 11 was already complicated by the need to master the controls of two different and very complex spacecrafts, as well as the space suit, but now the mission took on new dimensions, principally in learning how to set a 14.5-metric-ton lunar module safely down on the moon.
Armstrong became more and more excited about the prospects of both the Apollo program and of investigating a new aeronautical environment.