Stafford, Cernan, and Young were the first Apollo astronauts to be free from illness during the mission, although Cernan experienced a slight vestibular disturbance. Like all their colleagues who had flown before, once they unbuckled from the couches they had a stuffy feeling in their heads. This lasted for 8 to 10 hours for Stafford and Young; Cernan gradually lost the sensation over the next two days.

Episode 193 on SRH

After a shaky but successful S-IVB burn Apollo 10 was on the way to the Moon. Now the first order of business was for John Young to move to the command module pilot seat.

At first stage cutoff the astronauts expected to encounter a single pulse of negative G and the crew would be thrown forward in their straps before the Second stage ignited and recommenced the acceleration. However, they actually encountered a form of pogo which continued for 4 cycles, during which they were “slammed forward, back, forward, back, forward, back, and forward, back. At this point the instrument panel was so blurred the astronauts could not read it.

https://spacerockethistory.com/?p=3313

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.

https://spacerockethistory.com/?p=3275

With the passing of John Glenn last week, I thought it would be appropriate to pause my coverage of Apollo 10 for a week and create an episode that celebrates the life of the American Icon, John Glenn.  I covered John Glenn’s Mercury flight in episodes 30-31.  I am going to re-release those episodes over the next 2 days.  So I won’t spend a lot of time on his Mercury flight in this episode, that will be covered tomorrow.

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).

Thomas P. Stafford was the first member of his Naval Academy Class of 1952 to pin on the first, second, and third stars of a General Officer. He flew six rendezvous in space; logged 507 hours and 43 minutes in space flight and wore the Air Force command Pilot Astronaut Wings. He has flown over 127 different types of aircraft and helicopters and four different types of spacecraft.

Although the contractors had shipped excellent spacecrafts, preparations at Kennedy did not go quickly from the assembly building to the launch pad. Testing was delayed several days in order to stay out of the way of Apollo 9 pre-flight activities. Also during maintenance to the Launch Control Center, the electrical power was switched off to replace a valve. The Apollo 10 launch vehicle’s pneumatic controls sensed the power outage, opened some valves and dumped 20,000 liters of fuel on the launch pad.