The Pegasus satellite was named for the winged horse of Greek mythology.  Like its namesake, the Pegasus was notable for its “wings”, a pair of 29 meter long, 4.3 meter wide arrays of 104 panels fitted with sensors to detect punctures by micrometeoroids at high altitudes.  In its stored position with panels folded inside the Apollo service module, the Pegasus was 5.3-meters high, 2.1 meters wide, and 28-cm deep.

The key to high-energy stages was to use liquid hydrogen as the fuel.  Liquid hydrogen fuel appealed to rocket designers because of its high specific impulse, which is a basic measure of rocket performance. Specific Impulse is the impulse delivered per unit of propellant consumed.  You might think of it as the efficiency of the rocket.  Compared to an RP-1 (kerosene) fueled engine of similar size, liquid hydrogen fuel could increase the specific impulse or efficiency of an engine by 40 percent.  The combination of hydrogen and oxygen for propellants made the moon shot feasible.

At various stages of lunar module design, mockup reviews were conducted to demonstrate progress and identify weaknesses. These inspections were formal occasions, with a board composed of NASA and contractor officials and presided over by a chairman from the Apollo office in Houston.

The Lunar Lander originally had two docking hatches, one at the top center of the cabin and another in the forward position, or nose, of the vehicle, with a tunnel in each location to permit astronauts to crawl from one pressurized vehicle to the other…

Since the lunar module would fly only in space (earth orbit and lunar vicinity), the designers could ignore the aerodynamic streamlining demanded by earth’s atmosphere and build the first true manned spacecraft, designed solely for operating in the spatial vacuum.

A few seconds after liftoff, a fin-vane at the base of the booster stuck and started the 13-meter-tall spacecraft-booster combination spinning like a bullet. Twenty-six seconds into the flight the vehicle started coming apart. The abort-sensing system signaled the launch escape tower rocket to fire and pull the spacecraft away…

Saturn 1, SA-6 was the first orbital launch of an Apollo Spacecraft by a Saturn Launch Vehicle and also the first flight utilizing an active ST-124 Stabilized Platform.

Max Faget’s position was that considering the difficulty of the job,  if each mission was successful half the time, it would be well worth the effort.  But Gilruth thought that was too low.  He want a 90% mission success ratio and a 99% ratio for Astronaut safety.  Walt Williams who was currently running the Mercury program believed that astronaut safety needed to be limited to only 1 failure in a million which was 99.9999%.

…From the information they gathered on the existing technical problems, Disher and Tischler concluded that prospects were only one in ten that Apollo would land on the moon before the end of the decade….

“The contractor role in Houston was not very firm. Frankly, they didn’t want us. There were two things against us down there. Number one, it was a Headquarters contract, and it was decreed that the Space Centers shall use GE for certain things; and number two they considered us (meaning GE) to be  Headquarters spies.”  Edward S. Miller of General Electric.