Apollo 8 and the Astronauts Who Made Man's First Journey to the Moon (2018)
At T minus 5 minutes (time before launch), the access arm and loading area pulled away and retracted from the Saturn rocket and the spacecraft. At T minus 3 minutes at 6 seconds, computers took over the full checkout of the Saturn rocket. At T minus 60 seconds, all three stages of the Saturn rocket were fully pressurized, and Borman’s left hand was gripping the abort control, ready to twist it to the left in case of a catastrophic problem during the launch. As the countdown reached zero, Borman loosened his grip of his left hand to avoid twisting the abort control by accident during lift-off, and then Apollo 8 started its lift-off at Cape Canaveral.
Finally, the astronauts were barely able to hear the “Tower Clear” call from Launch Control, 13 seconds into the flight, and at that point, Mission Control in Houston was in charge of Apollo 8. “How do you hear me, Houston”, Borman said, and CapCom (Collins) answered “Loud and Clear”, and as the Saturn rocket ascended, everything was a go at Mission Control. One minute into the flight, Apollo 8 reached 767 mph at 24,000 feet altitude, traveling so fast that the sounds of the rocket couldn’t catch up to the command module, so the cabin became pretty quiet for the three astronauts.
In less than 20 seconds, the spacecraft would reach max Q, the moment when the maximum aerodynamic pressure was exerted on the ascending rocket/command module. Max Q was reached at 1 minute and 19 seconds after lift-off at 44,062 feet altitude at a speed of around 1500 mph; if the spacecraft was going to break apart, this was the most likely time for that catastrophe to occur - Apollo 8 continued to soar into the sky.
A few seconds later, Borman prepared to get rid of the 34 foot tall spire-shaped escape tower and conical boost protective cover, which was at the very top of the spacecraft. Its purpose was to rocket the command module away from the Saturn 5 in case of emergency. If an abort was still necessary, after jettisoning the escape tower, Apollo 8 would use the propulsion systems built in the command and service modules. By this point at 300,000 feet altitude, the astronauts could see the curvature of the Earth. Two minutes later at 100 miles altitude, Apollo 8 was almost high enough to enter orbit.
The second stage engines shut down, and the stage separated, and then the single engine on the third stage ignited, with the push to full thrust more gentle this time. After reaching 95% of the speed necessary for orbit, it would take just over a minute to reach the required speed without flying into space. The third stage’s engine was shut down at 17,425 mph at 11 minutes and 25 seconds into the flight, and Apollo 8 was orbiting the Earth. The third stage was not separated from the spacecraft yet, since it would be the engine of that stage that would reignite again in 2 hours 45 minutes in order to send Apollo 8 to the Moon.
Apollo 8 orbited the Earth every 88 minutes and 10 seconds, with the closest point of the orbit to the Earth’s surface (perigee) at 113 miles, and the furthest point (apogee) 119 miles. The three astronauts were in zero gravity, which was new to Anders, but familiar territory to Borman and Lovell. Technically, zero gravity isn’t the lack of gravity in this instance, in that orbiting the Earth meant that they were in constant freefall, not moving forward.
Almost immediately, Lovell felt nauseous, since he was actually moving around in zero gravity; during Gemini missions, he was strapped to his seat. Lovell warned Borman and Anders to not turn their heads when they first left their seats in zero gravity. The three astronauts were allowed to remove their helmets and gloves 25 minutes into the flight, which made everything they needed to accomplish much easier. Apollo 8 started to orbit the dark side of the Earth 45 minutes into the flight, and at about that time, Lovell accidentally activated his inflatable life vest, which was inflated with CO2. Now the challenge was to figure out what to do, since the CO2 could not be released in the cabin. In just a few seconds, Anders offered a solution: deflate the vest using the uring dump.
To escape Earth’s orbit, Apollo 8 had to increase its speed to almost 24,250 mph from their single engine in the third stage. By doing so, the shape of Apollo 8’s orbit would change from a circle to an ellipse, one that would stretch all the way to the Moon and back. However, that third stage engine burn had to occur at the perfect moment and last for a precise time frame, taking into consideration slingshotting around the Moon; only 25 minutes remained until the scheduled burn.
At just over two minutes into the burn, Lovell reported a speed of 20,000 mph, which was the fastest speed that humans had ever moved to that point. Over the next three minutes, Apollo 8 would exceed 24,000 mph in order to achieve the desired trajectory towards the Moon, and the G-Forces continued to increase. With 40 seconds to engine shutdown, Apollo 8 had reached 98% of its target speed. When the third stage engine cutoff, the astronauts and Mission Control looked at their instruments: Apollo 8 was 215 miles above the Earth traveling at 24,208 mph, which was perfect for TLI (Trans Lunar Injection). Immediately, the Earth answered, using its gravity to pull back on Apollo 8, but it wasn’t enough gravity to overcome Apollo 8’s speed and momentum.
Gene Kranz, who was the flight director at Mission Control for Apollo 7, left the control room and broke down in tears at the significance of the moment. Kranz was the flight director for the odd-numbered Apollo missions, meaning he was the flight director for Apollo 11 and Apollo 13. Chris Kraft resisted the urge to temporarily take over for CapCom in order to congratulate Apollo 8, seeing it as a breach of protocol as well as causing unnecessary confusion. Instead, Kraft spoke to the entire room, saying “You’re on your way, you’re really on your way now” . . .