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 himself 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
