He had to stay conscious long enough to push his speed past Mach 4.8, raising the fuel-injector strut temperature of the scramjets to the 3,000-degree-Fahrenheit regime and establishing full ignition. If the scramjets failed to stabilize and initiated auto shutdown, he would flame out—at almost twenty-five hundred miles per hour.
You are now experiencing nine G's, the female voice continued, emotionless as ice. Pilot will confirm vision periphery.
The fucking computer doesn't believe I can still see, he thought.
Most men, of course, would have been functionally blind by then. Prolong the experience of ten G's and you went unconscious: the event.
Confirm, Petra's voice insisted.
"Thirty-eight degrees." He read off the video screens inside his helmet, temporarily quieting the computer. But now he had a demand of his own. "Report scramjet profile."
Inboard tridents at eighty-two percent power. Outboard tridents at sixty-eight percent power, the voice responded.
Get ready, Petra. Spread your legs. I'm coming home.
The velocity scrolling on the right side of his helmet screen was about to pass through the barrier. Strut temperature was stabilizing. With engines in the scramjet mode, the vehicle should be able to push right on out to Mach 25, seventeen thousand miles per hour. From there it was only a short hop to low orbit. If—
Inboard tridents at eighty-eight percent power. The voice came again. LAC compression nominal. The liquid air cycle equipment would be using the cryogenic hydrogen fuel to chill and liquefy the rush of incoming air; oxygen would then be injected into the scramjets at pressures impossible to achieve in conventional engines.