“Bozhe moi!” she murmured, reverently. My God. Can this be real?
She glanced up into the blackness of the sky, seeing for herself that Earth was no longer visible; the Moon was in the way. That also meant all radio signals were blocked.
“Three minutes until ignition,” Michael said. He was loosely strapped in his seat, checklist Velcroed to the panel, eyes intent on the instruments.
“Temps and pressures look good,” Chad responded from the other seat. Without Houston to help monitor, it was up to the two of them to be ready to react to everything.
One of the problems the rocket engineers had to solve had been how to get the fuel out of the tank and into the motor in weightlessness; pumps don’t work without gravity holding the liquid at the pump intake. They’d decided to pressurize the tanks with helium in order to squeeze the fuel through the lines to the motor—175 pounds per square inch, pushing the fuel against the valves, waiting for ignition time to snap open.
They also had to choose fuel that could be relied upon to burn: aerozine 50, a highly flammable, fishy-smelling clear liquid. The oxygen to burn it was waiting in the other tank, in a faintly orange-brown liquid called nitrogen tetroxide. When the two liquids touched each other they instantly exploded into flame. This hypergolic reaction meant they didn’t need the added weight of spark plugs and electrics. As soon as the two mixed, BOOM, the engine would ignite.
Michael tugged on Svetlana’s pantleg and mimed holding on to something. He didn’t want her to be surprised by the acceleration and come tumbling onto them. She nodded and grabbed a handhold.
Chad was watching the clock. “Thirty seconds.”
Michael typed in the command to enable ignition. Both astronauts’ eyes were glued to the gauges, hands clutching emergency checklists, ready to respond instantly if the engine didn’t behave.
The time on the digital clock hit zero. The valves clicked open, the aerozine and nitrogen tetroxide swirled together into the combustion chamber, burst into expanding flame and raced out the exhaust nozzle.
“Ignition!” The urgency of concentration was clear in Michael’s voice.
Floating beside him, Svetlana silently mouthed “Pusk,” the Russian equivalent. She was holding on tightly, but the acceleration was smaller than she expected, like drifting in a gentle, unseen current. She peered out the window and saw the glow of the flame reflected off the flat surfaces of the lunar lander. “Lem,” she said quietly, the sound of the word foreign in her mouth.
“Chamber pressure’s ninety, looks like it’s running smooth.” Chad’s voice was clinical.
Michael was watching the digital displays. “Data looks good. Still in the tight limits.”
Flame poured out the back of the oversized bell nozzle at the back of the ship, the two fluids burning a bright orange, an engine pushing backwards on a capsule with a lander mounted on its nose, slowing gradually to orbital speed around the Moon.
The computers sensed tiny changes in movement and made precise adjustments to the gimbals on the motor, pointing it in exactly the right direction, constantly recalculating speeds. Michael checked the clock.
“Four minutes to go.”
He’d spent the past year learning everything about this ship, this Pursuit. It was his to fly, but it all hinged on this motor. Burn, baby, burn.
If the SPS failed, he’d have to use the engine on the lunar lander to somehow straighten things out and get them safely headed directly back towards Earth. That’s what they’d done on Apollo 13 after the oxygen tank explosion, but they’d barely made it.
Pay attention!
“I show ninety seconds, Chad.”
“Agreed.” Chad had relaxed. In his experience, once an engine lit it would normally keep going. They just had to be sure it shut down on time, and then he could focus on what he was really here for. Getting to the surface of the Moon. He glanced up and shook his head. With her.
“Five, four, three, two, one and . . . cut-off.”
Michael’s eyes flicked anxiously across the gauges, confirming that the engine had shut down properly. He read the digital display carefully. “Looks like small residuals, no correction needed.” In the simulator, as the engine thrust tailed off, it often left some small, undesirable residual rates, and he’d had to manually null them. His fingers threw the switches to safe the system, a grin spreading across his face.
“We’re here!” He held up a hand, and Chad high-fived it.
“Well, that’s just our superior cunning and skill, boy,” Chad said. “And now we can really get down to business.”