Milt Windier’s team at mission control quickly reviewed the status of the remaining four engines, ran the computations for the new engine cutoff times, and passed them to the crew.
As they passed behind the moon, they had just over 8 minutes to go before the burn. They were super-careful now, they checked and rechecked each step several times. It had to be perfect. Just one digit in the computer out of place could send them into a lunar mountain or turn them and send them into orbit around the sun.
What do we call this strange region between earth and moon? Cislunar space is the most common term, Is it day or night? Humans generally define night as that time when our planet is between our eyes and the sun, so this must be considered constant daytime, But it looks like night out of Command Module’s windows.
“Hey, Apollo – Houston, this is Apollo 10. Look, I know you ran some studies, but by golly, we can see Snoopy, and he isn’t too far away! He’s catching up with us. Can you talk to the FIDOS? He’s right down below us. We can occasionally see him tumbling end-over-end down below there, and he’s coming in closer each pass. That’s Snoopy’s descent stage. We can see him right down below us now, and he’s right – I thought he was a little out-of-plane, but now he’s looking more in-plane with us.” Tom Stafford Apollo 10
As the lunar module approached, Young saw it through his sextant at a distance of 259 kilometers. Stafford and Cernan got a radar lock on the command module shortly after the insertion burn and watched with interest as the instrument measured the dwindling gap between the vehicles and demonstrated the theories of orbital mechanics in actual practice. Cernan especially liked the steady communications that kept both crews aware of what was happening.
On May 18th 1969, a king, some congressmen, other distinguished guests, and a hundred thousand other watchers waited at scattered vantage points around the Cape area. At 49 minutes past noon, Rocco Petrone’s launch team sent Apollo 10 on its way to the United States’s second manned rendezvous with the moon.
John Young enjoyed the longest career of any astronaut thus far. Over the course of 42 years of active NASA service he made six space flights and is the only person to have piloted, and been commander of, four different classes of spacecraft: Gemini, the Apollo Command/Service Module, the Apollo Lunar Module, and the Space Shuttle.
On Cernan’s second space flight, he was lunar module pilot of Apollo 10, May 18-26, 1969. Apollo 10 was the first comprehensive lunar-orbital qualification and verification flight test of an Apollo lunar module. Cernan was accompanied on the 248,000 nautical sojourn to the moon by Thomas P. Stafford (spacecraft commander) and John W. Young (command module pilot).