Siege of Lightning

CHAPTER SEVEN THE LAWS OF PHYSICS

“T minus four minutes and counting. Preparations for main engine ignition. The main fuel valve heaters have been turned on. T minus three minutes, fifty-seven seconds; final fuel purge on Lightning’s main engines has been started.”

The NASA public affairs commentator was broadcasting over numerous loudspeakers and through the orbiter’s communications system.

Kessler closed his eyes and desperately fought against the excitement that slowly consumed him.

“Heart rate is up to one hundred twenty beats a minute. Relax, Michael,” Kessler heard Neal Hunter’s reassuring words through his helmet’s built-in headset. Hunter was Mission Control’s capsule communicator, or CapCom, for STS-72, the number of their mission.

“Trying… I’m trying.” Kessler inhaled deeply and looked over to his right. Jones sat rock still, apparently frightened. That helped Kessler relax. He had never seen Jones scared before.

“Say, CJ,” Kessler commented. “I thought you boys from Texas weren’t scared of anything.”

“Eighty-two beats a minute, Jones. You’re doing just fine.”

Kessler frowned. The bastard was indeed ice cold.

“Just think of something pleasant,” Jones said to Kessler. “Happy thoughts.”

Kessler gave him the bird.

“T minus three minutes, thirty-five seconds.”

Kessler watched Lightning’s General Purpose Computer responding to commands from the Launch Processing System — the KSC’s ground computer network at the launch site — by moving the elevons, speed brake, and rudder to ensure that they would be ready for use in flight. The control stick barely moved in all directions. LPS had taken control of the launch sequence at T minus twenty minutes, and it would remain in direct control of the GPCs until thirty-one seconds before launch.

“T minus three minutes, twenty seconds. Lightningis now on internal power, however, fuel cells will continue to receive fuel from the ground-support system for one additional minute.”

He looked through the heat-resistant glass panels. Nothing but blue skies; another beautiful day in central Florida.

Kessler decided that the wait prior to the launch had to be the worst part of the flight.

“T minus two minutes mark. It’s gonna be smooth sailing, baby.”

Easy for you to say, Kessler thought. The NASA announcer was not the one sitting over several million pounds of volatile chemicals. Kessler decided to follow Jones’s advice, and closed his eyes and thought about the sea, about the clippers, about the courageous Captain Forbes and Lightning. For a moment he felt ashamed. Ashamed of being scared. He had to force his mind not to be afraid of something for which he knew he was more than adequately trained. He was ready, he was prepared. But what if something goes wrong and… damnit, Michael! Stop it! If something goes wrong you will have to deal with it. You are in charge here. You make the calls. Just like Columbus on the Santa Maria or Henry Hudson on Discovery. You are the captain of your vessel. Start acting like one!

He inhaled deeply and opened his eyes. The sky was so blue. So peaceful. He admired it through the 1.3-inch-thick transparent center pane. Although the sun was in his field of view, it didn’t bother him. The outer surface of the pane was coated with an infrared reflector that transmitted only the visible spectrum. Kessler closed his eyes once more and relaxed.

“Heartbeat’s down to one hundred three, Michael.”

Kessler’s lips curved upward. He was in control. He was the mission commander.

“T minus one minute mark and counting. Sound-suppression water system is being armed… it has been armed. T minus forty-five seconds.”

Kessler could not help himself. He felt his heartbeat increasing once more. But this time he was not afraid; he was still in control of his own thoughts and movements. His senses sharpened to an all-time high.

“T minus thirty-five seconds.”

The Launch Processing System switched off. Its last command enabled the automatic launch-sequence software of Lightning’s five General Purpose Computers.

“Switching to redundant sequence start. T minus twenty seconds, T minus ten… nine… eight… seven… six… we’ve gone for main engine start… we have main engine start!”

The rumble. The powerful, mind-numbing rumble of Lightning’s three main engines pounded through the orbiter as they unleashed a combined 1.2 million pounds of thrust against the jet-blast deflectors of the launchpad. The turbine blades of the SSME’s turbopumps accelerated to 37,000 RPM, pressurizing the volatile chemicals to three thousand pounds per square inch. Liquid hydrogen and liquid oxygen savagely clashed in the nozzle section and exploded in a ferocious outburst of highly pressurized steam. At the same moment, the sound-suppression water system poured water onto the bottom section of the launchpad at a peak rate of 900,000 gallons per minute, protecting the orbiter and its payload from the damaging violence of the acoustical energy reflected off the Mobile Launcher Platform.

The SSME boost was titanic, but not strong enough to launch Lightning into its maiden flight. It needed additional power, additional force. It came a millisecond after the General Purpose Computers verified that all three engines had reached the required ninety-percent thrust level after three seconds of operation. Kessler felt the vibrations reach his soul the moment the two Solid Rocket Boosters kicked into life with a brutal roar, shaking not only Lightning, but the ground itself for several miles around. Kessler clenched his teeth as the pounding shock waves of six and a half million pound of thrust thundered across Cape Canaveral in a howling, ear-piercing crescendo. Suddenly the blue skies disappeared. Lightning had been engulfed by the wake of its own engines.

The GPCs verified that both Solid Rocket Boosters had ignited properly before initiating the eight twenty-eight-inch-long explosive bolts anchoring the shuttle to the platform. The GPC started the on-board master timing unit and mission-event timers. Lightning’s main engines throttled up to one hundred percent.

“Lift-off! We have achieved lift-off of America’s Lightning!”

Kessler noticed upward movement, felt a light pressure pushing him down against his seat. Out of my hands, he thought. No human could ever provide the precise thruster controls to achieve a smooth lift-off. The thousands of microscopic adjustments issued by Lightning’s powerful computers every second kept the orbiter on track.

“The shuttle has cleared the tower!”

In the cockpit, Kessler and Jones monitored equipment and instruments as Lightning rose higher and higher into the blue sky. A billowing trail of exhaust marked its path.

“Twenty seconds, all systems go,” commented Kessler in a controlled monotone. He noticed something happening to him. The fear was gone. “Roll maneuver starting.” The shuttle began to roll clockwise 180 degrees. “Twenty-five seconds. Roll maneuver completed.”

NASA’s ground-tracking stations received Kessler’s S-band radio transmission before relaying it to Houston. During the liftoff and ascent phase, Lightning’s S-band system transmitted and received both communications and systems-status information through Merrit Island, Ponce de Leon, and Bermuda ground-tracking stations.

“Zero-point-six Mach and rising,” Jones remarked. “The ride is very smooth, Houston.”

“Forty-five seconds. Approaching Mach one. Throttling engines down for Max Q,” Kessler reported as the computers reduced thrust for a moment to relieve the tremendous strain on the structure as Lightning approached the speed of sound. The entire cabin glowed from the light of the engines far below.

Suddenly ice, accumulated over the upper section of the external fuel tank, began to break off as the orbiter cruised through Mach one. Pieces exploded against the flight deck’s forward windows, but the sound of their impact was lost in the low, hard roar of Lightning’s engines ninety feet behind.

“Mark one minute, Houston,” Jones reported. “Five nautical miles in altitude, twenty-three nautical miles downrange, velocity twenty-three hundred feet per second.”

“Roger, Lightning. You’ve passed through Max Q. Looking good to throttle engines back to one hundred percent.”

“Roger, throttling up,” responded Kessler.

“One minute and forty-five seconds, Lightning.”

“Roger,” acknowledged Kessler.

“Looking good, Lightning. Mark one minute, fifty-five seconds. Twenty-one miles high, five thousand feet per second. Initiate Solid Rocket Booster separation.”

“Roger, Houston. Starting SRB sep.”

Kessler watched the pyrotechnic display as both SRBs simultaneously separated from the sides of the external tank.

“Confirm separation, Lightning.”

“Smooth as glass, Houston, smooth as glass.”

“Good, Lightning. Two minutes, fifteen seconds. Press for MECO.”

“Roger, Houston. Press for MECO,” acknowledged Kessler as Lightning’s on-board guidance system converged, steering Lightning for its precise window in space for Main Engine Cut-Off. Lightning was now thirty-five nautical miles high.

“Okay, Houston, the engines are coming down and looking good,” reported Jones as he monitored the main engines’ status on the control panel to his left.

Lightning rose higher and higher as its speed blasted past six thousand feet per second. The communications link between the orbiter and Houston switched from NASA’s ground-tracking stations to one of three satellites from the Tracking and Data Relay Satellite System in geosynchronous orbit 22,000 miles above the Earth. Lightning’s data, acquired by the five-thousand-pound satellite, was transmitted to the EDRSS ground station at White Sands, New Mexico, where it was relayed to Johnson Space Center.

“Lightning, Houston. You’re looking good at three minutes.”

“Roger, copy looking good at three.”

The sky began to darken. The colorful blue of just a minute earlier had turned into one of a less vivid hue, as the orbiter scurried through the Earth’s stratosphere at nearly ten times the speed of sound. Kessler had only been exposed to a maximum of three Gs during Max Q. Quite a contrast from his days as a naval aviator when pulling seven or eight Gs in a twisting, turning F-14D Tomcat was an everyday occurrence.

“Mark three minutes, fifty-five seconds, Lightning. Mark negative return. Repeat, negative return. You’re a go for space!”

“Roger, Houston.” Kessler eyed the instruments. Fifty-eight miles high at eight thousand feet per second. He looked over at Jones, who smiled and gave him a thumbs-up. He stared at Jones for one more second before he felt a strange vibration. Something he had never felt before. Lightning began to tremble.

“Houston, Lightning here. I think we’ve got a—”

His words were cut short by a powerful blast. It shook the entire vessel. Images of Challenger’s explosion flickered in front of his eyes as what was once a clear view of the cosmos was suddenly engulfed in a ball of flames. Kessler felt momentarily disoriented. He wasn’t sure what had gone wrong.

“SSME failure! SSME failure!” screamed Jones.

“Shut it down, Lightning!Shut down number-one SSME now, NOW!”

Kessler reached with his right hand for one of three covered switches located in the middle of the wide center console. He lifted the cover and shut off number-one Space Shuttle Main Engine as they left the wrathful flames behind and free space was in plain view once more. “Number-one SSME off.”

“Lightning, you are to press to ATO! Repeat, press to ATO!”

Kessler frowned. There were four abort modes for the space shuttle. The first was to simply return to the launch site, but at this altitude and speed, that option was no longer available. The second abort mode was called TAL, for Transoceanic Abort Landing to a landing strip at either Zaragoza or Moron Air Bases in Spain, but a powerful storm had all but closed those bases. The third abort mode was called AOA, or Abort Once Around, meaning the shuttle was unable to reach a stable enough orbit but had enough speed to circle the Earth once and then land. The fourth, and preferred option was to Abort to Orbit, or ATO, and it was used when the shuttle could not achieve its desired orbit but could reach a lower stable orbit. Given Lightning’s current speed and altitude, and the fact that two of its SSME engines continued to provide plenty of thrust, NASA was opting for ATO, which was actually the preferred of the abort options.

“Roger, press to ATO,” he finally responded.

Kessler rotated the abort mode switch to the ATO position and depressed the abort push button, initiating the computerized programs that would manage the abort. He then throttled up the two remaining main engines to 109 percent. He felt the light kick and nodded approvingly.

“Houston, Lightning,” Kessler said. “Sixty miles altitude, five hundred miles downrange, velocity twenty thousand feet per second. What the hell happened?”

“Can’t tell for sure, Lightning. Computers are running diagnostics on number-one SSME.”

“Press to MECO in one minute, thirty seconds. Systems remain nominal,” he reported, referring to Main Engine Cut Off, the moment he would shut off the two remaining engines, which he was keeping burning for a little longer to reach a reasonable orbit.

“Roger, we copy, Lightning.”

Everything appeared normal once more, but Kessler knew that could be deceiving. The explosion could have loosened some of the heat-resistant tiles that protected the orbiter from the extreme temperatures during re-entry. He was not that concerned about losing tiles on the upper fuselage, but it would be critical if tiles underneath were missing, where temperatures would reach over two thousand degrees during Earth re-entry.

“Houston, MECO in fifteen seconds.”

“Roger, Lightning.”

“MECO in five… four… three… two… one… MECO! Seventy miles at twenty-seven thousand feet per second,” Kessler called out as both operational main engines shut down. He then proceeded to prepare Lightning for External Tank separation.

“Five seconds for ET sep. Four… three… two… one… we have ET sep.” Kessler performed an evasive maneuver by moving below and beyond, and translating to the north of the External Tank. He watched it moving away from the side window. He relaxed. They would reach orbit. A low orbit, but nevertheless an orbit. With their current speed he estimated Lightning would achieve an egg-shaped orbit of 140 by 110 miles, the balance point between the Earth’s gravitational pull force and Lightning’s centrifugal force.

“Lightning, Houston here. We just double-checked all computer outputs before launch. All systems showed nominal.”

“So what do we do now?”

“You’re in low Earth orbit. OMS burn in fifty-three minutes, ten seconds.”

The two Orbital Maneuvering System engines would be used to reach a more stable orbit. Each OMS was powered by highly pressurized helium reaching a titanium-layered tank filled with 4500 pounds of hydrazine, and another tank packed with an oxidizer. The helium gas — performing the same role as an SSME turbopump — would force both propellant and oxidizer through an array of pipes and valves leading to the combustion chamber. The chemicals would then ignite on contact in a hypergolic reaction, generating a combined thrust of twelve thousand pounds.

“Roger, Houston,” Kessler replied before unstrapping himself and removing his flight helmet. But he held onto it. They were in zero G. Jones did the same. Both were about to go aft simultaneously.

“You first, Mike.”

Kessler used a single arm motion to lift himself toward the aft flight deck station. He threw the payload bay doors’ switch on Panel R13L, and noticed the talk-back indicator light underneath the switch changing from CL to OP, showing that Lightning’s General Purpose Computers had received his directive. The starboard door slowly opened first, gradually giving Kessler a partial view of the orbiter’s vertical fin. The port door followed sixty seconds later, and he noticed a few white tiles missing over the OMS pods.

“Damn,” Jones said. “I hope the tiles underneath are intact.”

“No shit.” Kessler nodded as he briefly enjoyed the spectacular view of northern Africa overhead before flipping the two radiator-control-release switches on the same control panel to deploy the thirty-foot-long environmental-control-and-life-support-system radiators, incorporated over the forward inside sections of both doors. Talk-back lights showed proper deployment and nominal circulation of Freon-21 coolant looping from both sides of the radiator panels for heat rejection by Lightning’s systems, including the heat that had built up on the orbiter’s skin during the ascent phase. Without radiators, the life-support system could not maintain a suitable temperature inside the crew compartment.

“Let’s go below and get rid of these flight suits.”

“In a minute. I want to see something.” Kessler turned on the payload bay’s floodlights and visually inspected the sixty-foot-long compartment.

“Looks in pretty good shape,” commented Jones.

“Yep. Looks that way. I guess we won’t know for sure until we get a chance to go out there and take a closer look.”

“But first things first. Let’s get into more comfortable clothing. These flight suits are too bulky. See you down there,” Jones said as he pulled himself through one of the two interdeck access hatches on the flight deck’s floor. Below was the mid-deck crew compartment, where most everyday living activities took place, from eating to sleeping. “Boy! This weightlessness beats the heck out of the simulated stuff on those parabolic KC-135 flights.”

Kessler shook his head. The Air Force captain was in space for the first time in his life and seemed determined to enjoy it as much as possible, even if the mission wasn’t going as planned.

Kessler watched Jones disappear through the hatch. He shrugged and dove after him.