Nonsense! he thought, shaking it off.
“Okay Houston, I’m ready to go here,” Mullen said, sounding, if not feeling, confident.
“We copy, Mullen, stand by. Break, break. Houston for Columbia. Are you guys set?” the CapCom asked.
“We’ve been ready for twenty-five days, Houston. My pilot’s hanging out the hatch with his thumb up. We’re ready for Mullen, send him up,” Columbia’s commander joked.
“Roger that Columbia,” the CapCom said. “Okay Mullen, we’re ready when you are.”
“Here we go,” Mullen said.
Garrett broke in. “Remember to keep your head on straight, buddy.”
Mullen knew exactly what Garrett meant. They’d talked it over so many times before, how the visuals can make you sick in an instant. “I’m good, it’s gonna be a beautiful ride, but thanks for the heads up. We’ll be done with this in thirty minutes, tops.”
Mullen reached out and disconnected his retractable tether from the slide wire. “Alright, I’m going to do a few familiarization maneuvers before I head up to Columbia,” he said for the benefit of Houston.
He rattled off Shepard’s Prayer a few more times, figured it couldn’t hurt.
He nudged the hand controller upward to the mechanical stop, saw the bright-red LED thruster light on the HCM illuminate. He rose straight up out of Atlantis’s payload bay. When he let go of the controller handle, the thruster LED went off, and the handle sprang back to the neutral, off position. Before he’d flown 10 feet, he pushed the handle again, but this time in a forward direction, and began to move forward instead of up. Atlantis was now out of his peripheral vision. He looked back to the HCM and flipped the Mode toggle to “ROT.” Now when he moved the handle to the left, he rotated like a ballet dancer performing a pirouette in slow motion.
“Nice flying there,” Garrett said.
“Thanks,” Mullen said. “You get a real sense of speed as you fly along, especially when flying near the orbiter. But overall, it feels just like it did in the lab. Works beautifully, goes just where you tell it to.”
Mullen flew back toward Atlantis until he was over her payload bay, hovering above by about 15 feet. “Okay, I’m going to try a precision approach down to you now.” He rechecked the Mode toggle. “TRAN” was selected. He pushed the controller handle down, the thruster light came on, and he began moving down toward Garrett. He pulled up on the controller slightly several times along the way to gradually slow his closing rate. When his boots were a few feet above Garrett’s head, he quickly pulsed the controller again, and his rate fell to nearly zero.
“Not bad for a first-timer,” Garrett said.
“Feels pretty easy. I’m not sure how it will feel with another astronaut in tow. I guess as long as he can stay close and tight, like we talked about, we should be able to move as a single unit.”
“Alright Houston, I’m ready to go.”
“Copy that, Mullen. Make us proud.”
“Don’t go anywhere, Garrett,” Mullen said, adjusting his grip on the hand controller. “I’ll be right back with the pilot.”
Garrett watched Mullen jet straight up toward Columbia. Forty feet seemed like a long way to go without a tether. Garrett raced through his own SAFER checklist. He knew that if Mullen got into trouble, he’d have to slide his boots out from the restraints without help, activate his SAFER, and go get him. For now, though, he simply watched, amazed by the sight of Mullen whisking along, a brilliant white speck approaching a huge spacecraft.
On his first trip up, Mullen overshot his target, just as if he were on an elevator and had gone up one floor too many.
“Ah, you want the one that says Columbia on it,” Garrett said.
“Roger that. The name was upside down, so I had a little trouble reading it. But I’ve found it now, thanks.”
A few pulses in the downward direction, a few flashes from the red thruster light, and Mullen was even with Columbia’s sidehatch opening. Best he could tell, he was about 20 feet away. A careful push forward on the handle, and he was moving right toward the sidehatch. He could see Columbia’s pilot waiting in the opening.
Ten, nine, eight feet out now, another pull backward on the handle. Slowing steadily. Four feet. Three-and-a-half. Three feet.
What if he freaks out, leaps out, and grabs me like a drowning swimmer?
Mullen stopped himself right in front of Columbia’s sidehatch opening. If he reached out now, stretched a bit, he figured he could touch Columbia.
There wasn’t a single person at Mission Control, at NASA, aboard Columbia or Atlantis, who didn’t know Mullen’s biggest challenge was still ahead of him.
Senca’s tiger team had struggled with the best way to transfer the two Columbia astronauts while using SAFER. The bear hug was out, because Mullen needed to see where he was going and be able to manipulate the hand controller. Having the astronauts hold on to Mullen’s backpack also was ruled out for fear that the rescued would in one way or another interfere with the firing of the thrusters. Another concern was the whipping action that would occur if the astronaut were simply tethered to Mullen and carried along like an air-conditioner unit being lifted to a rooftop via helicopter. Without gravity to keep the tether line tight, the rescued astronaut would continue to move in the same direction and at the same speed, despite any changes in direction or speed Mullen might make. It would be nearly impossible for Mullen to transfer the astronauts this way. It just wouldn’t be safe or practical.
“I just want to interject here,” Stangley said, talking over the NASA audio feed. The producer brought him onto a split screen of live video shot from Atlantis’s payload bay. “Before astronaut Mullen begins his first transfer with his SAFER jetpack, I want to explain a little bit more about how the SAFER system works. It may seem like a simple system: The astronaut moves a joystick and some jets fire and he moves along.” A NASA-supplied graphic of the SAFER unit replaced Stangley on-screen. “Ultimately that is what happens, yes. But to do that, for the astronaut to be able to control his flight with relative ease, engineers had to design a very sophisticated system. The SAFER’s electronics, or avionics, sense how the astronaut is moving, and they update the SAFER’s computer continuously. Much the way your inner ear informs your brain of the position of your head while on Earth, SAFER’s sensors tell the onboard computer which way is up and which way the astronaut is moving.
“Let me give you an example. Let’s say you want to move forward with your SAFER jetpack. You’d push the control handle forward, those jets would fire and away you’d go. But let’s say as you pushed the handle forward, you introduced a slight left or right diagonal motion in addition to the forward motion. If you didn’t have SAFER’s sensors working, then in addition to moving forward, you’d also begin to rotate. The computer helps the astronaut go only where he intends to go by filtering out extraneous control-handle inputs.” Stangley was back on the split screen. “Let’s go back to the live video and listen to communications between Mission Control Center and the astronauts.”
Columbia’s pilot had been floating in a prone position, had watched Mullen rise up to get him.
“Hey guys, you ready to do this?” Mullen asked.
“Been ready,” the pilot replied.
Mullen reviewed the transfer procedure with Columbia’s commander and pilot. When they indicated that they understood the details, he closed with, “Whatever you do, do not get sick until you’re safely aboard Atlantis. After that, you can barf your brains out if you want.” Mullen paused for any questions or comments. “Alright then, let’s go.”
The pilot disconnected his tether and held the clip in his left hand and with his right held the grab bar. He reached out through the sidehatch opening with his left hand and placed his tether clip in the palm of Mullen’s glove.
“Got it,” Mullen said. “Alright, I’m backing out.”
Mullen pulled back on his hand controller and started moving away from Columbia. Columbia’s pilot stabilized hi
mself with the sidehatch grab bar as he felt the tug on his suit, and watched his tether reel slowly unwind about 10 feet of braided stainless steel cable before Mullen stopped.
“Okay, I’m attaching your tether to my suit,” Mullen said. “I’m ready for you to come out.”
The tiger team had concluded that the best way to keep the two Columbia astronauts from snagging their suits on the sidehatch opening would be for them to come out slowly under their own power, not pulled out by Mullen. This is why Mullen had been instructed to hold the tether clip in his hand as he backed out. If the pilot’s tether wheel caught or his suit snagged in Columbia’s doorway, Mullen would simply let go of the pilot’s tether clip. This decreased the possibility of damage to either EVA suit.
“Okay, I’m gonna crawl out now,” the pilot said. First, his helmet came into view. Then, using a hand-over-hand motion, he advanced slowly along the tether cable. The slack was automatically stowed at the reel.
As soon as the pilot cleared the opening, Mullen slowly jetted straight up in order to get the pilot to move beneath him in tow. As he did so, the pilot crawled the rest of the way up the tether until Mullen’s boots were near his shoulders.
“Okay, I’m going to guide your boots onto my shoulders now,” the pilot said.
“Roger that,” Mullen said.
As soon as Mullen had his boots in place, the pilot pulled on his tether some more, helping to create a single unit from the two astronauts.
“That’s a good bit of tension now, just right. I can feel the tension in my thigh muscles. Now you’re going to need to maintain that tension as we fly back to Atlantis so that SAFER’s autopilot can operate as if we’re one single unit, and compensate accordingly.”
“Copy. Call it when you’re ready.”
Mullen and the pilot were currently 25 feet above Columbia and facing away from Atlantis. The sky was black all around and above. There was no visual reference. Mullen had no idea where he was.
“Garrett, I’m going to need another set of eyes here.”
“Copy that, Mullen,” Garrett said. He’d kept him in his field of vision all along, leaning farther and farther back in his restraints. “Okay, if you turn one-eighty first, then I’ll be forward and below you.”
“Got it, thanks.” Mullen looked down at the HCM, flipped the toggle switch from “TRAN” to “ROT” and prepared to make his first turn home. “Alright,” he said, addressing Mission Control and Columbia’s pilot in tow. “Here we go.” He pushed the hand controller to the left and the two astronauts turned counterclockwise, perfectly in unison. “Garrett. Let me know when I get close to oneeighty.”
“Alright, you’re three-fourths there now, better back off.” Mullen had already slowed significantly. “Another foot and you’ll be there, buddy.” Garrett waited a second, “Now hold it. Good. Alright, now if you tilt down while still in rotation mode, you’ll be able to see us before you start down.”
With “ROT” mode still selected, Mullen pushed the control handle forward for an instant. The two astronauts began to rotate slowly, head first. “Okay, there you are,” Mullen said.
“I have a visual, too,” Columbia’s pilot said. “She’s a beautiful sight!”
Mullen looked back to his HCM and flipped the switch from “ROT” to “TRAN.” “Houston, we’re starting our descent.”
“This is Houston, we copy.”
Mullen pushed the control handle forward against the stop for a count of almost three. Atlantis grew steadily in their visors.
“How you doing down there?” Mullen said to Columbia’s pilot.
“I’m good. I just hope you’ve had your brakes serviced lately,” he said, commenting on Mullen’s near-light-speed descent rate.
“Be on the brakes in just a few seconds, hang tight,” Mullen assured him.
Garrett watched the approaching astronauts and could see that Mullen had already started to slow his closing rate with Atlantis. The plan to keep the two astronauts held tightly together via the tether cable seemed to be working well.
“I think I’ll fly this rotation out before we come down the rest of the way,” Mullen said.
“Okay, good.” Garrett said.
Mullen pulled back on the control handle a few times more until he had them stopped. Next, he switched modes to “ROT” and pulled back on the handle, now causing them to rotate to a vertical position relative to Atlantis. He switched back to “TRAN” mode and pushed down on the control handle. Slowly, they descended. Mullen’s plan was to deliver the pilot chest to chest with Garrett. When he’d dropped him down to what seemed like an even altitude, he pushed the controller forward to begin moving toward Garrett.
Garrett had his hands out to help secure the pilot. Mullen inched forward, 3 feet out now. One final, brief pull on the controller stopped the pilot at the mark.
“Excellent flying,” Garrett praised. “I got hold of him if you want to release his tether.”
Mullen reached below the SAFER HCM and disconnected the pilot’s tether clip from his suit. “Tether disconnect, he’s all yours.”
Still on his platform, Garrett connected the pilot’s suit tether clip to his own suit, then had the pilot maneuver over to Atlantis’s payload bay slide wire. When the pilot confirmed he had hold of the slide wire, Garrett released the pilot’s tether clip from his suit.
“Alright, now attach your tether to the slide wire,” Garrett said. “When the commander gets down here, we’ll help you both get in the airlock, depress once for the both of you.”
“Copy that,” the pilot said.
When Garrett looked up, he saw Mullen already halfway back to Columbia. He may just get this done in under a half-hour, he thought.
Mullen arrived at Columbia’s sidehatch a second time, having demonstrated to all those watching impressive efficiency of movement and greatly improved accuracy. He felt good, felt like his work today had seemed easier than on past missions, particularly in comparison to work he’d done on the International Space Station. He guessed it had something to do with the situation, how the uncertainty of the rescue had allowed for improvisation. EVAs were usually highly scripted events, with every tool and movement overanalyzed for efficiency and suitability for a given task. Today had been a wonderful break from all that. Mullen hoped that NASA had learned something today. Maybe NASA realized that astronauts were smart enough to figure some things out on the fly.
Ten minutes later, Mullen had the commander out of Columbia and in tow beneath him; they were ready for final descent to Atlantis.
“Okay, I’m inbound with the commander,” Mullen said.
“Got a good visual,” Garrett said. “Picked a good day to go flying. Almost have you guys home.”
“Amen to that,” the commander said.
Chapter 75
TO DETERMINE HOW EFFICIENT an astronaut would be while working in space, NASA created a work efficiency index. The index was derived from a simple equation expressed as total EVA time divided by total EVA overhead.
EVA overhead referred to the time required to complete activities vital to performing any EVA, activities such as the pre-breathe protocol, donning and doffing of the space suit, and airlock ingress and egress.
Even though Columbia’s commander and pilot were almost ready to close Atlantis’s airlock for repress, engineers at Mission Control were concerned with Garrett and Mullen’s growing EVA elapsed time. They knew that airlock ingress or egress took 15 minutes, airlock repress or depress took 15 minutes, and that it took another 25 to doff the EVA suit. If you started adding up all the time, Garrett and Mullen were, at the very least, still 45 minutes away from breathing cabin air aboard Atlantis.
“Atlantis, Houston,” the CapCom said.
“This is Avery, go ahead Houston.”
“When Columbia’s commander and pilot conclude their airlock depress, we want the crew to help them get the interior airlock door open and helmets off. Then we want the commander and pilot to egress the airlock before d
offing their suits. We know it’s going to make it a bit more crowded in there, but we need to get the airlock turned around for a depress ASAP. Garrett and Mullen are going to be running up against EVA duration limits soon, so we need to speed things up.”
“Copy, airlock egress before doffing,” Avery said.
“Garrett and Mullen, you copy?”
Garrett gave a thumbs-up.
“We copy, Houston,” Mullen said.
“Commander and pilot?”
“We copy.”
Having just been updated on the status of Columbia’s commander and pilot, Julie Pollard strolled through the Mission Control Center. Another disaster averted, she thought. She didn’t feel smug, but rather satisfied, needed, high. As she approached the flight director’s console and saw Allan Warner look up, she flashed him an energized smile.
“Nice plan, Julie, way to go.”
“You’re welcome, Allan. Just getting the work done through the people, you know,” she said with a wink.
“Yeah, I guess,” he said, clearly not getting her manager-to-manager joke. “Hey, you got a minute?”
“Sure. I was just on my way to find something to eat, I’m starved.”
“You can eat at a time like this?”
“A time like what, Allan?”
“I’m still very concerned about two things, Julie.”
“Oh really? What things?”
“Well, Atlantis’s tile damage for one. I’m worried that after all the heroics we’ve seen today…”
“You’re worried about reentry.”
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