Strike Force

After the tanker departed the area, Hunter reconfigured the bomber’s computers for the next phase of flight, then began checking all of the engine and flight systems carefully. Patrick steered the Black Stallion north, then began a slow climb and gradually began applying full throttle. At full afterburner power at forty thousand feet about a minute later, they were at Mach 1.8, or about fourteen hundred miles an hour. “Airflow has stabilized and is in the green, lasers ready — we’re ready to spike the leopards, General,” Boomer reported.

“Let’s see what this thing has under the hood,” Patrick said. He hit a small control stud on the side-stick control and spoke, “Spike engines.”

“Engines spiking, stop spike,” the female computer-synthesized voice responded, adding the command to stop as a reminder. The airspeed slowed to Mach one point six, enough to tug at their shoulder harnesses. On the front of each engine, heat-tolerant vanes extended across the engine inlets, diverting airflow around the fan blades and compressor section of the engines. As the air was turned it was also mixed with tiny amounts of jet fuel and compressed. As the air-fuel mixture was squeezed, several diode laser emitters in each engine ignited it, and the jet exhaust was forced out of the back. The airspeed almost immediately jumped back up to Mach one point eight and quickly rose, exceeding Mach two, three, four, and even began approaching Mach five. The vertical velocity readout was equally as impressive — as the airspeed increased, the pitch angle became steeper and the Black Stallion climbed faster.

The LPDRS, or Laser Pulse Detonation Rocket System, nicknamed “leopards,” was Boomer’s engine design that would change the face of high-speed travel. The LPDRS engines were a new generation of advanced rocket engines that used instantaneous, pulsed detonation of jet fuel using blasts of laser energy, producing fifty percent more thrust than the conventional chemical rocket engines. Patrick was squished back into his seat as the “leopards” engines began their high-frequency hammer-like pulsing and the spaceplane rapidly picked up speed.

Finally, the engines began to throttle back and the pitch angle decreased, until they were straight and level again. The curvature of the Earth began to become apparent, although a few thunderheads on the horizon seemed to reach their altitude. “All engines stabilized and running perfectly at Mach four point five-one,” Boomer reported a few minutes later. “We’re level at flight level eight-zero-zero — eighty thousand feet. Incredible,” Patrick breathed. “Simply incredible. Almost five times the speed of sound.” He glanced at the engine readouts. “And I don’t even detect any fuel burn at this speed.”

“The lasers are hot enough to ignite the compressed air, but we use a few hundred pounds of fuel an hour to help the process along,” Boomer said. He checked some position readouts, then said, “We can turn eastward now and I can have you in Washington in about forty minutes, sir.”

“You could…but that’s not why I came on this ride, Boomer,” Patrick said. “Besides, we have a job to do too — this isn’t just a taxi ride. Let’s do it.”

“Yes, sir,” Noble said excitedly. He checked some more readouts; then: “Ready for suborbital burn, sir.”

“Roger that,” Patrick said. He took one last sip of water from a canteen, then flipped his oxygen visor back in place, tightened up all of his straps, and situated himself in his seat. “Here we go,” he said. “Computer, commence suborbital insertion burn.”

“Commence suborbital insertion burn, cancel suborbital insertion burn,” the computer responded. When the countermanding order was not received, the computer said, “LPDRS engines activated…ignition in three, two, one, zero.”

At that moment they heard four distinctive and rather unnerving “BAARRK!” sounds reverberating through the fuselage, and the XR-A9 suddenly accelerated so fast that a puff of air was forced out of Patrick’s lips. Patrick’s vision blurred and tunnel-visioned as his eyeballs were squished against his skull, but the last thing he saw clearly was the airspeed jumping past Mach five, less than a minute after main engine start. As the airspeed increased, the flight control computer nosed the XR-A9 higher and higher, until their climb rate now exceeded one hundred thousand feet per minute. At that point the readouts switched to thousands of feet per second — two, five, then ten thousand feet per second. The Mach numbers, or times above the speed of sound, were approaching double digits.