C’mon, baby, we scientists are ready! Time for all you engineers to do your stuff. Get that crazy monstrosity off the ground!
——
The Saturn V’s F-1 engines were beasts with a power the world had never seen. Five of them waited at the bottom of the rocket, sleeping in suspended animation, their blood vessels dry, their hearts and bellies empty. Hungry and ready for the fuel and spark that would bring them to life.
Ten minutes before launch three valves had clicked open, allowing the first of the kerosene and chilled oxygen to gush down from the tanks, high above. This potential explosive power now waited to be mixed, just one valve away from exploding into the barely controlled hellfire that would push the massive weight up and away from the Earth.
Luke was aware that the pre-valves were open; he knew the entire sequence by heart. The giant dragon beneath them was awakening. He’d wondered how he would feel just before launch. Not afraid, he observed. Good. Either this thing was going to work or it wasn’t. He felt . . . ready.
Movement on his right caught his eye. Michael’s left knee was bobbing up and down, an unconscious release of pent-up emotion and energy. Luke was glad both of his knees were still.
He glanced at the clock. One minute to go. Sixty clicks of the second hand and the games would truly begin. He watched Chad reach and push the button to align the gyros, giving the rocket a final snapshot of orientation for accurate steering. It was the last crew step prior to launch.
Luke turned the page of his checklist and put his thumb next to the top of the table. Chad and Michael would be watching lights and instruments, but he’d be looking at height versus speed. The whole 11 minutes and 39 seconds was laid out in the table. When his thumb got to the bottom, they’d be 93 miles up, going 25,599 feet per second. 17,500 miles per hour. Five miles a second.
22
Launch Pad 39A, Kennedy Space Center
Starting the world’s most powerful engine wasn’t easy. It took about nine seconds to crank one up—the time an Olympic sprinter could run 100 yards. The time it takes to tie one shoe.
The most dangerous nine seconds of the whole flight.
The amount of fuel needed to push the Saturn V off the pad was staggering: 3,400 gallons every second. That required fuel pumps with their own jet engines, just to spin them fast enough. The rocketship had five of these jets pumping the kerosene and oxygen into the rocket chambers, where it would mix, explode and storm out the 12-foot-tall exhaust nozzles in a 5,800-degree, 160-million-horsepower inferno.
The crew’s eyes were glued to the engine instruments as the clock counted down into single digits.
“T minus ten, nine, and we have ignition sequence start.”
Four fireworks ignited inside each engine: two to spin up the fuel pump, and two to burn any flammable gases lurking in the exhaust nozzle.
“Six, five, four . . .”
Two big valves opened, and liquid oxygen poured from its high tank down through the spinning pump and into the rocket, gushing out the huge nozzle under its own weight like a frothy white waterfall. Two smaller valves clicked open, feeding oxygen and kerosene to fuel the jet engines, spinning the pumps up to high speed. The pressure in the main fuel lines suddenly jumped to 380 psi.
Conditions were set, with everything ready to ignite the rockets. Just needed some lighter fluid.
Two small discs burst under the high fuel pressure, and a slug of triethylboron/aluminum was pushed into the oxygen-rich rocket chambers. Like the ultimate spark plug, the fluids exploded on contact.
“Three, two . . .”
The middle engine lit first, followed quickly by the outer four; if all five had started at once, they would have torn the rocketship and launch pad apart. Two more big valves opened, and high-pressure kerosene poured into the growing maelstrom.
Luke felt the rippling vibration through his back and heard the deep, rumbling noise from 300 feet below. Different than the simulator! He glanced left to where Chad’s eyes were focused. The five engine lights had gone out, confirming full thrust.
“One, zero, and liftoff, we have liftoff, at 7:32 a.m. Eastern Standard Time.”
Hell, unleashed, creating 700 tons of thrust in each of the five engines—enough total power to lift more than 7 million pounds straight up. The ultimate deadlift.
The last of the ground umbilicals feeding the rocket disconnected and snapped back. The four heavy hold-down arms that had been clamping the base to the pad hissed in pneumatic relief and pivoted away.
The Saturn V was free.
Chad’s eyes clicked around his instrument panel, confirming. The small, square Lift Off light was glowing, he could feel the vehicle moving, and the digital mission timer was counting upwards.