And their orders were clear.
Alarms hooted, and with the firing sequence initialized, all three cruisers executed their mission as one.
Within seconds, an Aegis antisatellite SM-3 missile roared from each ship, smoke billowing from its rocket engines as the kinetic-kill warhead arrowed into a counter-orbital trajectory to intercept the International Space Station.
Almost instantly, each cruiser launched another Aegis Standard Missile-3. However, one of the missiles exploded almost immediately after it cleared its pad, raining flames and debris over the ship.
As the cruiser’s damage control crew moved to suppress the fires and clear the wreckage, a total of five ASAT missiles locked on to their preprogrammed, counter-orbital trajectories and headed upward on their mission.
Thirty-seven seconds after the last missile launched, the captains received an urgent message to belay their launch orders and stand down.
CENTRAL POST, INTERNATIONAL SPACE STATION
Kimberly stayed in Central Post, diligently watching the laptop screens for any sign of the approaching ASATs. She was breathing pure oxygen through a portable mask. Her symptoms of the bends were becoming gentler, bearable. She felt thankful that the BME—the biomedical engineering team—had recommended the pure oxygen treatment as she switched out her nearly depleted bottle of oxygen for a fresh one while keeping an eye on the screens she’d set up.
Normally, the station’s changes in altitude would be controlled by TOPO in mission control, and coordinated days in advance with the Attitude Determination and Control Officer, the desk responsible for the station’s four control momentum gyros. But now as Kimberly prepared to engage in a last-second maneuver, she knew that she’d have to respond by instinct, she wouldn’t have time to validate her decisions through Houston, or have them confirmed by the flight center at Goddard.
She scanned the laptops, not fully trusting the timing alarm she’d programmed into the tracking system’s software. TOPO, the mission control center desk responsible for tracking the ISS’s orbit, had an open line with NASA’s Defense Department liaison, and was able to pass along the status of the approaching warheads, despite such information being highly classified, since it referred to ongoing military operations. But she didn’t rely only on that intelligence for situational awareness. So as she floated in front of her bank of laptops she kept shifting her eyes to as many feeds as she could.
She started to query CAPCOM for another update when one of the laptop screens started blinking red and a raucous clanging noise reverberated from its built-in speaker. As she moved to cut off the ear-splitting alarm, Kimberly wished that the ISS had approach radar—but only incoming spacecraft had that capability. She couldn’t even eyeball the missiles: it was virtually impossible to see them until they were only about two to five kilometers away, much too close for her to react. NASA’s ground-based radars had picked up the incoming warheads, and from the timing numbers scrawling across one of the laptop screens they were zeroing in on her at incredible speed.
A cold chill enveloped Kimberly as she gaped at the dizzying numbers. The missiles were racing toward her in a counter-orbital direction at 17,500 miles per hour. Add that to the station’s own 17,500 mph velocity in the opposite direction around the Earth and you got a head-on collision at 35,000 mph—over 51,000 feet per second—enough to tear the ISS apart.
Her heart pounding against her ribs, her hands clammy, and her throat dry, Kimberly pecked swiftly as a madwoman at the graphical display. She’d integrated NASA’s tracking data with her own algorithm to show a crude visual image of the incoming missiles. Another object appeared on her screen, then another one—and then two more.
They had launched not three, but five warheads, all of them speeding toward her.
Kimberly poised her finger over the icon controlling the thrusters’ fuel line, ready to start the flow of fuel that would engage the engines. Not too soon, she told herself. Steady … steady. Inanely, she remembered a line from her school days: Don’t fire until you see the whites of their eyes.
The warheads were not converging on the station, she knew, but on a future spot in the ISS’s projected orbit, where the ASATs’ computers calculated the station would be located a mere few seconds from now.
NASA’s feed showed the five warheads flying in graceful shallow arcs, neither jinking nor otherwise behaving like anything except dogged, determined cheetahs utterly fixated on their prey. They moved in undeviating trajectories across the screen, their positions updated by her estimated timing program.
Kimberly knew that her software was automatically updating the incoming warheads’ position and velocity. The laptop was using that data to instantly project each ASAT’s impact point. Simultaneously, the software she’d written predicted when her thirty-second window would open for her to engage the thrusters and maneuver the station out of the warheads’ way. She’d know within seconds if the ASATs would go ballistic or if they would continue to home in on the ISS, making last-second course corrections right down to the moment of impact.
Silently, she prayed that the warheads would all go ballistic and converge on their predicted target all at the same time. That would mean that in their final thirty seconds they would not be able to maneuver.
But if the missiles didn’t go ballistic, her biggest fear was that she’d engage the thrusters too soon, giving the warheads enough time to change their velocity and intersect her new orbit. Then they’d impact the ISS, no matter what she did.
Seconds count, Kimberly told herself. Microseconds count.
Steeling herself, she watched the ASAT warheads converge on their calculated future location of the ISS’s position. Each warhead showed on her laptop screen as a tiny oval at the end of a dotted line. In less than a minute the station would be at that point in space unless she engaged the thrusters. But if she started too soon the ASATs could adjust their velocity to converge on the new impact point.
The longer she waited the more they’d have to change their momentum. She hoped that their final stages were designed more for finessing rather than making any large orbital change.
It was a waiting game. Seconds stretched into eternities. The tension in Central Post ratcheted up unbearably. Kimberly wanted to scream, wanted to shout for help from somebody, anybody. But there was no one except her. She was alone. The thought flashed through her mind that this wasn’t only her own life on the line. The next few moments would also determine the fate of 150 billion dollars’ worth of space infrastructure—and most likely the future of the entire human space program.
The blips showing the five approaching warheads jumped closer to the ISS’s future location with every second as their final-stage rocket engines accelerated them. Kimberly held her breath as the digital clock on the laptop screen counted down the time to her thirty-second window.
Two of the warhead blips turned green. They were within the window.
Kimberly started to engage the thrusters as a third blip went green. Three of the warheads had gone ballistic.
She froze her finger above the console as a burden of fear slammed into her. The other two warheads were making small, last-second course corrections! CAPCOM had said they might have throttleable divert and attitude control systems. Time seemed to hang suspended as she glanced at the clock: twenty-six seconds to impact.