McGregor also checked his watch before nodding. Prebreathing 100 percent oxygen was required prior to a space walk to remove nitrogen from his bloodstream. Inside the airlock, they breathed a mixture of oxygen and nitrogen at a pressure of 14.7 pounds per square inch, the same as sea level. But once inside a space suit, McGregor would breathe pure oxygen at a reduced pressure of only four PSI—the pressure required by the Extravehicular Mobility Unit suit for ease of limb movement during EVA without excessive physical effort. The rapid drop in pressure around his body would cause bubbles of nitrogen to form and expand in his bloodstream, causing severe nausea, cramps, paralysis, and even death—the same problem faced by scuba divers when surfacing too quickly following a deep underwater session.
Diane headed for the changeout station to the right of the airlock, and, extending the privacy curtain, she changed out of her crash suit and into the blue coveralls standard for shuttle missions.
She floated back up to the flight deck. She wanted to run some tests on the RMS arms. Its proper functionality was paramount to the mission.
Five
The Flight Control Room was located on the third floor of the Mission Control Center at Johnson Space Center in Houston, Texas. Capsule Communicator (CapCom) Jake Cohen sat back on his swivel chair in the rear of the large room, where almost thirty flight controllers for this mission worked behind console computer displays arranged in rows of six or seven across the entire length of the room. A few projection screens on the front wall displayed different mission-related information, including a world chart that plotted Endeavour’s location in orbit and actual television pictures of activities inside and outside the shuttle, like the view of Earth on the screen to the right of the world chart, and a view of the payload bay on the screen to the left. Other displays showed critical data such as elapsed time after launch, or the time remaining before the next maneuver, which in Endeavour’s case was the time to rendezvous with the Titan target.
Jake removed his glasses, rubbed his eyes, and loosened his tie. So far, so good. Being CapCom was an important but quite stressful responsibility, particularly since he had to pretty much live inside Mission Control for the duration of the flight. But like his predecessors, going all the way back to the Mercury Program of the early sixties, Jake understood the significance of him being here. He was the primary voice that the crew aboard Endeavour heard after launch. He was their primary contact while the astronauts traveled in space at over twenty-four times the speed of sound. In his hands, and in the hands of the Flight Director (called Flight) sitting to Jake’s immediate right, rested the responsibility of making sound split-second decisions and passing them on to the crew in space in an emergency. CapComs and Flights have been doing basically the same thing for over forty years: assisting countless crews on countless spacecraft accomplish their missions and return home safely.
Since it opened for business on a 1,620-acre site twenty-five miles southeast of Houston in February of 1964, the responsibilities of the Johnson Space Center have included the design, development, and testing of spacecraft, the selection and training of astronauts, the planning and conducting of manned missions, and many other activities related to help man understand life in outer space. And it all started with the Mercury Program.
The Mercury Program. Jake couldn’t help a tiny smile. The term Capsule Communicator was a holdover from those early manned flights, when Mercury was called a capsule rather than a spacecraft. Those had been simpler times, when compared to current events, yet … look at what we have done with our accomplishments.
Jake felt disappointed that despite all the technical advancements and all the scientific breakthroughs, man was still man. And at that moment one madman was at the controls of the world’s most advanced—and most expensive—technological wonder, and the U.S. had sent an equally technological wonder to stop him before he wiped out the downtown area of every major capital in the world—according to a communiqué broadcast just hours ago from Grozny, Chechnya. Unless the United Nations—Russia in particular—agreed to a twenty-point list of demands from the Chechen president, including the acquisition of nuclear missiles to protect itself again future Russian threats, the terrorist would start releasing the GPATS deadly cargo one at a time according to a priority list of targets.
Jake could only pray that Colonel Ward’s team was indeed as good as he claimed, and that nothing went wrong with the orbiter. Clearly, there was no other way to regain control of the ISS than by force.
Six
From the aft mission station of the flight deck, Diane Williams guided one of two Remote Manipulator System arms from its stowed position on the main longeron of the starboard payload-bay upper wall to the large segmented mirror hovering thirty feet above the orbiter.
She looked through one of the two rear-facing windows at the fifty-foot-long mechanical arm, which had six joints designed to mimic the human arm. The RMS had shoulder yaw and pitch joints, an elbow pitch joint, and wrist pitch, yaw, and roll joints—all controlled by a joystick-type hand controller.
Slaved to Diane’s hand motions, the RMS slowly extended toward one side of the rectangular mirror, nearly as long as Endeavour and just as wide as the orbiter’s wingspan. Anchored to the end of the robot arm was Gary McGregor in his Extravehicular Mobility Unit (EMU), an untethered pressurized suit that provided McGregor with a one hundred percent oxygen environment pressurized to three pounds per square inch (PSI), the equivalent atmospheric pressure of 14,000 feet in altitude.
They already almost had to scrub the mission because of the difficulties in retrieving the large segmented mirror from a malfunctioning Titan shroud. The procedure, which NASA had scheduled to take only four hours, had actually taken three times as long, requiring two separate space walks because the oxygen supply inside the EMU backpack only lasted eight hours. Using a battery-operated circular saw, McGregor had cut the faulty latching mechanism halfway through his second EVA, allowing the spring-loaded shroud to separate along its longitudinal axes, exposing the mirror, which then had to be unfolded before attempting to secure it to the ends of the two RMS arms.
This flight was the first time that NASA had loaded two RMS arms aboard a shuttle. Normally, only one robot arm was needed to accomplish most operations involving satellite deployment and retrievals, but this situation was quite different. Two arms were required in order to achieve a strong grip on the mirror, particularly during orbit transfer maneuvers, when Endeavour would use the Orbital Maneuvering System engines to change orbits and chase the space station. But loading a second RMS arm aboard the shuttle had come at the price of sacrificing the Ku-band antenna, normally used for communication and data transmissions at a much faster rate than the orbiter’s S-band antennas. This was a reasonable compromise to increasing the odds of keeping that mirror snuggled tight against the shuttle.
McGregor disengaged himself from the end of the RMS arm and grabbed a handle at the edge of the mirror.
“Tether yourself to the RMS, Gary,” she said when noticing that McGregor had not secured his EMU suit to the manipulator arm after disengaging from the RMS. If something went wrong at that moment, McGregor could be sent floating out of control away from the orbiter with nothing to hold him back.
“Okay,” he responded as he attached one end of a woven cable to the RMS while clipping the other to a metal ring on the side of his pressure suit. “All right, now bring the end up … nice and gently.”
The arm’s standard end was only about three feet from the edge of the mirror. Using the two-position slide switch on top of the rotational hand controller, Diane changed the sensitivity of the arm from coarse to vernier. The RMS motors moved now at a fraction of the speed they did before. Operating in this fine-adjusting mode, Diane positioned the end of the RMS within inches of a special fitting welded onto the aluminum-and-graphite frame supporting the segmented mirror.
“All right. How’s that?”
“Almost there. Bring it up just a dash.
> Slowly, following McGregor’s hand signals, Diane brought the end of the arm in direct contact with the latching pin on the mirror, until the latch snapped in place.
Locking the arm, Diane Williams switched control of the Rotational Hand Controller to the second RMS, set the vernier/coarse switch back to coarse, and mimicked the position of the first RMS. This time she did it without the help of McGregor, who was still strapped to the first RMS and was currently engaged in clamping a high-resolution TV camera to the edge of the mirror to be able to see objects on the other side of the mirror.
One of the complications of having two manipulator arms on board was that Diane could only control one arm at a time. Although the wiring for a second hand controller existed, NASA had never installed it because it had never been needed, until now. But such installation would had taken weeks to complete—time the world did not have.
“All right, Gary. I think you can come in now.”
“On my way.”
McGregor returned to the payload bay by crawling back along the first RMS. When he reached the airlock he said, “I’m inside.”
“All right. Good job,” Diane responded as she commanded the second RMS to pull the mirror closer to Endeavour, leaving just a foot between the orbiter’s upper fuselage and the honeycomb frame supporting the mirror.
“How much clearance does that gives us?” said Colonel Frank Ward, who had been standing behind Diane for the past minute. The Lockheed boarding vehicle stored in the payload bay needed at least ten feet of clearance between the edge of the cargo bay wall and the mirror.
Without looking at the large black soldier, Diane said, “Not enough for your boarding vehicle. You tell me when you’re ready, and I will lift one side to let you out. Otherwise, I’m keeping that mirror as close as possible to the orbiter.”
“That’s fine,” Ward responded.
Diane felt bad enough that the vertical fin, the OMS pods, and a portion of the nose were not covered by the mirror. She didn’t want sections of the wings also exposed by moving the mirror around. The OMS pods and the nose had to be exposed since that was where Endeavour’ s attitude vernier rockets were located. Those rockets were critical for orbital maneuvering, and their exhaust paths could not be obstructed. But anything else was safely hidden behind the segmented mirror.
NASA had estimated the chances of the laser hitting the unprotected sections of the orbiter at less than three percent. And given the fact that she would just be dropping her load and then quickly getting out of the laser’s range, she would be exposed to that three percent for just over twenty minutes. To make matters even safer for the crew of Endeavour, the mission plan called for approaching the station during nighttime, when the gigantic solar panels of the station would be essentially off, and the only power available for the laser would have to come from the GPATS module’s vast array of storage batteries. According to the laser manufacturer, the batteries would only support somewhere around fifteen laser shots, depending on the energy level used and the duration of each event. After that, the Russian terrorist would be unable to fire the weapon until the station came back around into the daylight portion of the ninety-minute orbit. That gave Diane roughly forty-five minutes to make her approach, take the laser hits, drop the UNSCF soldiers and their gear, and get out of Dodge.
“How much time will we have to clear Endeavour once we’re in position?” asked Ward.
“About ten minutes.”
Ward nodded before turning around and propelling himself down one of the interdeck hatches.
Diane thought of Ward’s secret cargo stored in the lockers below, hoping it wasn’t anything flammable. An explosion inside the crew module would be bad news for everyone aboard. But she didn’t realistically expect NASA to approve the storage of any dangerous substance inside the crew’s living quarters.
Diane reached for the intercom. “Colonel?”
“Yes, Commander?”
“Please secure your gear in the crew compartment. We have a twenty-five-minute window to start our approach to the ISS. OMS burn in fifteen minutes.”
“No problem.”
“Gary? You’re through?” Diane asked.
“I’m getting rid of the EMU.” McGregor responded from inside the airlock.
“Get up here now.”
McGregor floated into the flight deck a few minutes later.
“Diane … I think we have a little problem down there,” he whispered, pointing to one of the hatches leading to the crew compartment below.
“Yes?”
Swallowing hard, McGregor said, “I got a chance to take a good look at what Ward’s been guarding so carefully.”
“And?”
“While I was changing inside the airlock, I saw them through the hatch’s window.”
“What is it, Gary?”
“HEP.”
“Wh—what?”
“And from the looks of it, those guys down there were inserting fuses into the plastic. I guess they were waiting until after we reached orbit to arm the explosives to avoid the strong vibrations during ascent.”
Putting a hand to her forehead, Diane Williams struggled to calm down. She couldn’t believe that someone would be insane enough to bring high-explosive plastic onboard a shuttle. And armed?
She rushed past McGregor and dived through one of the interdeck openings.
“Colonel!” she screamed, reaching the crew compartment and startling the four UNSC soldiers, who were setting up the seats in preparation for the orbital maneuvers to chase the station. Each soldier had an oxygen mask over his face. A plastic tube ran from each clear mask to a pint-size tank strapped to the belt of each uniform. The soldiers were prebreathing pure oxygen in preparation for their space walk.
Ward pulled down the mask. “I’m right here, Commander. There’s no reason to scream.”
“Who gave you permission to bring explosives aboard this orbiter?”
Ward gave her an odd little glance. “I thought we had an understanding here about our respective roles.”
“Not when it involves bringing HEP inside my shuttle.”
Ward exhaled slowly, obviously not happy that she had found out about the HEP, but still trying to see if he could reason with her. He put his arms in front of him, palms facing Diane while the other soldiers looked on with curiosity. “Look, nothing’s going to happen. We are profession—”
“I want to jettison the explosives immediately,” she said.
The UNSC colonel simply crossed his arms. “Can’t do that, Commander. The HEP’s a critical element of our mission. If we can’t regain control of the station before the terrorist regains access to the launching software, then my orders are to blow up the module. Besides, HEP doesn’t just blow on accident because of vibrations or anything else. It need to be detonated.”
“It wasn’t a request, Colonel. It was an order.”
“Sorry, Commander. That’s an unreasonable request. Besides, I only take orders from the Secretary General of the United Nations. This is the way the UNSC has approved to carry out the mission, and the White House has bought into it.”
“Do you realize what can happen if any of those charges go off inside the crew module?”
“Won’t happen.” Ward was beginning to show an edge. “The only time we were at risk was during ascent, and during that time I had the detonators removed from the charges. Now I need to get the charges ready for my mission. You’ve just told me I would only have ten minutes to get ready after reaching the ISS. That’s barely enough time to—”
“We’re not going anywhere until you lose those,” Diane said, pointing a thumb toward the lockers. “And that’s final.”
“You’re compromising my mission, Commander. I have permission from the UNSC to neutralize anyone who jeopardizes my team’s ability to achieve our objective.” Ward placed a hand on the stun gun strapped to his belt.
Diane tightened her fists and said, “And who’s going to fly this shuttle?”
&n
bsp; “Your Mission Pilot.”
“He’s not going to do it.”
“Let’s ask him.”
Diane didn’t like the way this was headed. She was losing control. “I’m calling Houston.”
“Be my guest. But do it quickly, or we’re going to miss our window.”
Fuming, Diane headed back up to the flight deck, where a stone-faced McGregor stood by one of the interdeck openings.
“Jesus Christ, Diane. Let’s just do it. Let’s drop them off by the ISS and get the hell away from there until it’s safe to return.”
Reaching her seat, Diane put on her headgear and contacted Houston using the S-band frequency.
“Houston, Endeavour.”
“Endeavour, Houston. Go ahead,” came the voice of Jake Cohen.
“Houston, I’m afraid we have a problem. Colonel Ward has stored HEP inside the crew compartment. I want to jettison it. We can’t afford to have an explosion in here.”
“Ah … that’s a negative, Endeavour. The explosives are secured, and are a vital component of this mission. HEP is very safe unless purposefully detonated.”
“Houston, we’re talking about high-explosive plastic that could kill us all and destroy the orbiter. This goes totally against NASA policy. Remember Apollo 7? We can’t allow anything that volatile on board.”
“Sorry, Endeavour. The soldiers must keep the HEP. We don’t have a choice on this one. Their orders are to blast the GPATS module if they can’t get inside the station. Besides, the Apollo 7 incident happened because the capsule had a 100 oxygen environment. You don’t.”
“But they already have the fuses in and connected to the detonators. All it takes is one electric charge, and they’ll blow!”
“This one comes straight from the top. The HEP stays. And you better get everything secured or you’ll miss the window to reach the ISS in time.”
Combat Page 49
