Combat

by Stephen Coonts

  Diane inhaled deeply. This was a mistake. A terrible mistake. Closing her eyes, she briefly prayed that nothing went wrong with the approach. Although HEP had a long safety record and was very unlikely to go off accidentally, Diane didn’t want to add more risk to their mission. A subsystem could explode if the laser hit the wrong spot on the orbiter. Having explosives on board could create secondary explosions if the initial blast happened to be close to the charges.

  “Endeavour, Houston, Confirm orders.”

  Diane shook her head as she said, “I want it on the record that I disagree with the orders, but I will execute them. I will secure all objects in preparation for the OMS burn.”

  “Roger, Houston out.”

  Slowly, Diane turned around, only to be welcomed by Colonel Frank Ward wearing a headset. The plastic oxygen mask floated under his square chin. The UNSC colonel had been listening to the conversation. McGregor stood in the back, flanked by two of Ward’s men. The short F-16 pilot looked quite helpless next to the large and muscular soldiers in all-black uniforms.

  “All set?” Ward asked.

  Diane Williams nodded and turned back to her instruments. “We’re about to start an orbital-change maneuver. Everyone take your seats.”

  Ward floated toward the back of the flight deck and disappeared through one of the interdeck hatches. The two soldiers followed him.

  McGregor approached Diane as she strapped herself to her seat and put the headgear back on.

  “Diane, are you—”

  “Is the airlock secured, Gary?”

  “Ye—yes. It’s secured.”

  “Good. Strap in. We’ve got work to do.”

  Diane refused to let her emotions surface more than they already had. She was a professional. She was Endeavour’s commander. She would behave as such for as long as the mission lasted.

  Before starting the final approach to the ISS, Diane had to realign the Inertial Measurement Units—three all-attitude, four-gimbal, inertially stabilized platforms that provided critical inertial attitude and velocity data to Endeavour’s General Purpose Computers—to maintain an accurate estimate of orbiter position and velocity during the orbital flight.

  She did a quick radio check inside the orbiter to make sure all was secured. Satisfied, she reached for an overhead panel and enabled the Star Tracker system. Talk-back lights on the same panel told her both Star Tracker doors just forward and to the left of the front windowpanes had fully opened, exposing the two sophisticated bright object sensors to the cosmos. In addition to the nose attitude-control rockets, the Star Tracker system was another reason why the segmented mirror could not cover the orbiter’s nose section.

  The Star Tracker system measured the line-of-sight vectors to the two brightest stars within the system’s field of view. The data was fed to the GPCs, which calculated the orientation between the selected stars and Endeavour to define the orbiter’s attitude and relative velocity. A comparison between the calculated attitude and the attitude measured by the Inertial Measuring Unit provided Diane with the correction factor necessary to null the IMU error.

  The newly adjusted position and velocity vectors, or “state” vectors, were then compared to the International Space Station’s state vectors fed to Endeavour’s GPCs via S-band telemetry communications relayed from Houston. Both sets of state vectors, updated once every millisecond as both Endeavour and the ISS orbited the Earth, were fed to the Guidance, Navigation, and Control software running in the GPCs, which in turn fired the Orbital Maneuvering System thrusters.

  Diane’s eyes drifted to the OMS helium pressure and hydrazine propellant indicators as the engines came to life, unleashing twenty-six thousand pounds of thrust for fifteen seconds, directing a tail-first Endeavour toward its planned delivery orbit, nicknamed Delta. The mild deceleration force pressed her against the back of her flight seat as the southern portion of South America flashed across the top of the front windowpanes before disappearing behind the edge of the segmented mirror frame. In her mind, however, flashed the armed charges shifting inside their containers.

  Focus!

  A scan of control panel F7, where three five-inch-by-seven-inch green-on-green CRTs displayed the status of Endeavour’s vital systems, showed nominal. The array of talk-back indicator lights between CRT#1 and CRT#2, and directly above CRT#3 also showed no warnings. The OMS helium pressure indicator to the left of CRT#3 marked 3,700 pounds per square inch, matching the digital readouts on CRT#1 directly above.

  “ETA to Delta Orbit, fifteen minutes,” said McGregor, typing a few commands on the right keypad of the center console beneath control panel F7, while checking the readouts of the rendezvous radar measurement, which provided range and range rate to the station. Unlike the late nineties rendezvous radar systems, which could not be used until the orbiter got within fifteen miles of the target, the new system gave them ranging information from as far away as nine hundred miles.

  Diane barely acknowledged it, her eyes switching back and forth between the mission event timer and CRT#1. At Delta Orbit, Endeavour would have achieved the necessary translational velocity to maintain an orbit six miles behind the ISS.

  The GPCs stopped the OMS engines. “Burn complete,” she said as the software programmed the aft and forward Reaction Control System verniers to turn the orbiter without disturbing its translational velocity, positioning the mirror toward the ISS. The moment the inertial system detected that the orbiter achieved the desired attitude, the GPCs fired the RCS thrusters in the opposite direction to counter the rotation.

  She briefly glanced at McGregor before using a secured S-band radio frequency and speaking into her voice-activated headset. “Houston, Endeavour.”

  “Go ahead, Endeavour.” She heard Jake’s voice coming through very clear. Audio and video communications, as well as telemetry-data transfer, were established through the S-band frequency. Information from Endeavour traveled to one of three Tracking and Data Relay Satellites (TDRS) in geosynchronous orbit, where the signal was amplified and relayed to White Sands Tracking Station in New Mexico, before arriving in Houston. Although the link had been established nearly thirty years before, it still remained the best and most reliable way to establish clean, secured, and uninterrupted communications during a mission.

  “Houston, OMS burn complete. ETA to Delta thirteen minutes, twenty seconds, over.”

  “Endeavour, you’re confirmed.”

  “Will be within firing range in one minute,” Diane said while checking the leftover pressure on the OMS helium and propellant tanks, which told her that Endeavour now had enough fuel left for two more orbital maneuvers besides the deorbit burn at the end of the mission.

  Diane glanced at McGregor, who brushed his mustache with a finger while frowning slightly, obviously feeling as nervous about this whole ordeal as she did.

  “We’re in range,” McGregor said, while releasing his restraining harness and heading to the aft station, where he could make adjustments to the RMS arms if necessary.

  Diane turned around and gave McGregor a glance. The Mission Pilot already had planted himself in front of the aft station, his right hand on the RMS hand controller, which was currently set to control the starboard mechanical arm.

  As the orbiter quickly reached its orbital position behind the ISS, Diane prayed that the mirror would hold in place and that the soldiers kept the HEP safe.

  Seven

  His feet secured to Velcro attachments in front of the crew support station of the Habitation Module, Sergei Viktor Dudayev heard the proximity alarms disturb the peaceful whir of the airrevitalization system inside the International Space Station.

  He checked the timer on the support station before pulling free of his Velcro anchor and propelling himself across the twenty feet that separated him from the Unity module, which connected to the aft section of the cylindrical module.

  His Chechen contacts had been right in assessing the Americans. They were sending a shuttle his way in an attempt to re
gain control of the station before Sergei could release any of the warheads.

  But they do not know what kind of enemy they are facing.

  Floating cleanly through the hatch connecting the Hab Module to Unity, Sergei kicked his legs against the padded wall to his right and cut left to snug his short frame through the opening leading to the GPATS module. The screen of the proximity radar, which filled the space three hundred miles around the station with energy, showed an approaching space vehicle. The computers had already identified it as the Space Shuttle Endeavour.

  Eight

  At Houston Space Center, Jake Cohen watched the image displayed on the huge projection screen in the front center of the Flight Control Room on the third floor of the Mission Control Center. The telescopic lens of the camera McGregor had attached to the starboard edge of the segmented mirror captured the image of the ISS in the distance. It looked like a white dot with multiple white lines extending like tentacles. The dot was the core of the station, where all the modules interconnected. The lines were the sections of the scaffoldlike booms supporting the gigantic solar panels. At this moment those panels were not powering the station because the Earth was now positioned between the ISS and the Sun.

  Jake clenched his jaw and simply waited for the laser attack that he feared would follow soon.

  Nine

  “We’re here, Colonel. Stay in your seats until we’re safe,” Diane said over the intercom while still strapped to her seat. Her left hand was glued to the Rotational Hand Controller (RHC), the center stick located in between her legs, which controlled the attitude verniers on the nose and the OMS engine pods. By simply moving the RHC as she would an airplane control stick, vernier rockets in the nose and rear of the orbiter would fire to move Endeavour in the desired direction.

  A backward glance and she saw McGregor still in front of the aft crew station, right hand on the RMS controller.

  “We’re gathering our equipment,” Ward said over the intercom from below.

  “No, no. Stay in your seats. Keep your equipment secured.”

  “We can’t. There isn’t enough time.”

  “But there is no telling how the orbiter is going to take the lase—”

  A blinding flash, followed by a powerful jolt. The orbiter suddently went into uncontrollable gyrations.

  Dear God!

  “Keep that mirror taut against us, Gary!” Diane screamed, realizing a moment later that the laser had either partially struck the nose of the orbiter, or its energy level was far greater than Los Alamos had predicted. Endeavour’s nose was not only blackened, but a number of heat-protection tiles were missing while the rest appeared charred. The laser had damaged the nose’s rotational verniers. Two of them were firing sporadic bursts of—

  A second laser flash engulfed the orbiter, this time without the direct protection of the mirror as Endeavour tumbled across space.

  An explosion rocked the orbiter, followed by an even larger blast that sent powerful stress waves across the entire fuselage. Warning lights came alive on the control panel as a second explosion rocked the shuttle. The laser must have sliced through the exposed skin of the orbiter, damaging subsystems.

  “Smoke! We’ve got smoke down there!” screamed McGregor from the aft crew station.

  Diane turned around and watched black smoke coiling up from the crew module. The smell of cordite assaulted her nostrils.

  “The HEP!” she screamed as her fears became reality. “A charge must have gone off!”

  “Jesus, what are we going to—” said McGregor.

  “Remain at your post!” she commanded, while her right hand applied forward and right pressure to the RHC to get Endeavour’s upper side facing the station again. The orbiter, however, would not respond, as the nose verniers continued to fire at random, making it impossible for her to offset their thrusts with the aft verniers.

  “Colonel Ward? Colonel Ward? Do you copy?” she said over the intercom.

  Nothing.

  “Colonel? Colonel?”

  No response.

  “Let me go down there and check it out,” McGregor said.

  “Remain at your post!”

  The smoke was now beginning to fill the flight deck, but it was not as thick as it first looked. Most of it was already being sucked out by the airrevitalization subsystem, which was still operational after the explosions.

  But smoke was the least of Diane’s problems. Endeavour was still dangerously exposed to the ISS, and she could not bring it back under control.

  “Houston, we have a problem.”

  “We’ve heard, Endeavour,” came Jake’s voice. “You’re showing multiple failures of the payload-bay door system, rotational verniers, and—”

  “Houston, I’m having a hard time correcting the orbiter’s attitude,” Diane said, as she began to move her hand toward an overhead panel, where she planned to switch from General Purpose Computer control, to manual control of the Orbital Maneuvering System engines. But her hand never made it. Instead both arms got thrown forward from the fierce explosion that followed the intense light of a laser beam that caught Endeavour broadside.

  In a blur, Diane saw a cloud of thermal-protection white tiles bursting off the orbiter’s starboard wing. Several crashed against the front and side windowpanes.

  “The mirror is loose!” screamed McGregor.

  Diane looked up, through the upper windowpanes, and instead of seeing the black supporting frame of the mirror, she saw stars.

  “Where is it?” she asked.

  “The starboard RMS has broken loose from the payload bay. The mirror’s off to the side! I still got ahold of it with the port RMS, but it’s no longer shielding us!”

  “Jesus Christ,” she mumbled as the nose verniers ran out of fuel.

  Black-and-white tiles, the Earth, and the stars flashing across her field of view, Diane glanced at the array of warning lights between CRT#1 and #2, and noticed the PAYLOAD CAUTION and the HYDROGEN PRESSURE warning lights on the red. At least the OMS engines and the aft RCS thrusters are still healthy, Diane thought as her left hand reached down for the Rotational Hand Controller. Now that she did not have to fight the damaged nose verniers, she had a chance to stabilize the orbiter before using the OMS engines. She could not attempt an orbital burn until the shuttle had achieved the proper attitude; otherwise, the burn would simply send Endeavour into even more uncontrollable gyrations.

  “Get that mirror under control, Gary!”

  “Working on it!”

  Her hand applied forward right pressure to the RHC. This time the orbiter responded, but sluggishly because it was operating on only a partial set of rotational vernier engines.

  “Houston, Houston, this is Endeavour. I’m bringing the orbiter under control. OMS burn in ten seconds. Eight … seven … five … three … now.” She threw the switch, expecting to feel the slight acceleration from the OMS engines.

  Instead, a powerful explosion thrust Diane into her restraining harness. A side view of McGregor’s body flying past her and crashing against the front windowpanes brought images of dummies inside automobiles during crash tests. The explosion shook the entire vessel as the CRTs on the center control panel burst in a radial cloud of glass that reached Diane’s face before her own hands.

  She screamed as razor-sharp glass rushed past her and crashed against the aft crew station of the flight deck.

  Bouncing back on her flight seat as the orbiter went into another set of uncontrolled rotations, Diane forced herself to breathe between her teeth to avoid inhaling any glass particles or the floating beads of blood lifting off the multiple cuts on her face and neck. McGregor was out of sight, probably floating somewhere behind her.

  Alarms blaring, Diane turned her head, only to see Gary McGregor choking on his own blood from a shard of glass embedded in his throat.

  “No, no!” she screamed as their eyes met while she unstrapped her safety harness.

  Diane reached him near the center of the flight de
ck, feeling utterly helpless as McGregor made guttural noises while small clouds of foam and blood left his slashed neck and were inhaled by his opened nostrils. He was drowning in front of her.

  Slowly, she reached for the piece of glass and pulled it out, but the stream of spherical blood globules that spewed out of the wound nearly drowned her, forcing her to pull away with her hands on her face.

  Holding her breath while waving away the floating blood, Diane refocused on McGregor’s eyes, but saw no life in them. She reached with her right hand to close them, but another flash, followed by a horrifying explosion, shoved her against the front windowpanes.

  “Oh, God!” she mumbled as her head and right shoulder burned from the impact. Bouncing against the panes, Diane floated right past McGregor and toward the aft crew station, where she hit legs first before bouncing back to the front of the flight deck.

  Disoriented from the multiple blows, Diane wildly tried to reach for anything to slow down her momentum and prevent another collision, which came a second later, against the back of her own flight seat.

  The disciplined Marine inside her taking command, Diane wrapped both arms around the back of the flight seat and tried to take a peek at the control panel.

  Warning lights filled control panel F7, where three rectangular holes showed the place where the CRTs had been a minute before. A look outside the windowpanes revealed nothing but a cloud of broken tiles and other debris she couldn’t make out. All she could figure was that the OMS engines had been damaged by the laser and blew up when she had tried to use them.

  Finding it hard to breathe, Diane quickly reached for the lightweight headset floating over McGregor’s head. She disconnected it from McGregor’s portable leg unit, and plugged it in her own unit. Once more she hugged the back of the flight seat.

  “Houston, Houston. Endeavour, here. Do you copy?”

  Nothing.

  “Houston, this is Endeavour. Do you—”

  Another flash, followed by three explosions as the laser cut deeper into the orbiter, destroying its core. The blasts pressed her against the seat with a force so great that for a moment Diane felt she was pulling Gs in an F-18. She felt the sudden urge to vomit, and bending over, she did, coughing a large cloud of blood from a number of burst capillaries in her mouth and throat. Her eyes filled as she turned her face away from the floating blood moving toward the rear of the flight deck, where it mixed with the smoke still rising from the crew compartment below.