Exo: A Novel (Jumper) (15 page)

Theoretically we had more than three hours endurance left in the pack and oxygen bottles after yesterday’s tests, but we weren’t going to use it at altitude with anything less than maximum capacity—not this first time. Cory started to hand me the list but I said, “No,” and handed it back. I pointed at my chest. “I’ll do it.”

Yes, he had a checklist for emptying the backpack, too.

“Release latches.”

I unsnapped all three. “Check.”

“Remove hatch.”

I pulled and twisted on the end plug until the two O-rings slid past the seal surface and it released with a slight popping sound. “Check.”

“Remove filter packs.”

I turned the frame ninety degrees so the open end of the tube faced down and the mesh packages with soda lime, silica gel, and activated charcoal slid out, forming a stack on the bench. “Check.”

“Dump contents.”

We had a disposal can set up for these, but the mesh cylinders were tricky to open without destroying them so it was the longest part of the operation. “Check, check, and finally check.”

I filled them in reverse order: activated charcoal, silica gel, then soda lime, using an electronic postal scale to standardize each load. As soon as I filled each one, they were sealed in ziplock bags. “Check.”

“Dump batteries.”

I pulled the alkaline batteries from their holders at both ends of the cylinder, bagged, and dumped them. “Check.”

“Install fresh batteries.” We’d bought retail packs of six AAs so that the new ones always came from sealed packages. I popped them one by one into their holders, paying careful attention to polarity. “Check.”

“Test outflow fan.”

I clicked on the switch for the bottom fan and it whirred to life. I put my fingers in the helmet to feel the airflow up the back of the helmet. “Check.”

“Turn outflow fan off.”

“Check.”

“Test return fan.”

I turned on the fan in the cylinder’s lid. It whirred to life and the breeze moved across my fingers. “Check.”

“Turn return fan off.”

“Check.”

“Load activated-charcoal filter.”

I took it from its bag and slid it all the way down into the chamber. “Check.”

“Load moisture absorbent.”

I loaded the silica gel pack and slid it in until it touched the charcoal mesh. “Check.”

“Load CO
2
absorbent.”

I slid the last mesh cylinder in. “Check.”

“Apply lubricant to the seal surface.”

I took the tube of silicone grease and put a thin film all the way around the O-ring seal surface of the rebreather cylinder. “Check.”

“Insert hatch.”

I eased the plug back into the end. “Check.”

“Secure latches.”

I snapped all three shut. “Check.”

“Document maintenance.”

I wrote on the cylinder itself with an indelible marker:
Batt & filters repl
followed by the date and time.

“Check.”

The procedure for replacing oxygen was similar, though both used tanks would go back to the medical-supply house for refilling. When I’d made sure the new ones were secure in their clamps, I screwed on their regulators. I opened the valves briefly to read the gauges, confirming their fully charged state, then shut them back down again. I wrote their psi reading, and the time and date right on the tanks themselves.

“Next, Cory?”

He handed me a sealed packet with an optical wipe, the kind used for cleaning glasses. “Antifog treatment.”

I nodded and carefully wiped down the entire interior of the polycarbonate fishbowl. “Check.”

He took a deep breath. “We’re going to do the donning checklist there, right?”

“Right, but I should put the suit on here. Don’t want to get sand in the mesh.”

He nodded his head. “Right, we don’t want that.”

I was wearing my wool coat over my underwear, base layers, socks, and a pair of Merrill Moab Mid Ventilator ankle-high lightweight hiking boots one size too big for my feet. I kicked these off and hung the coat while Cory relaxed the suit.

I took off the oxygen briefly and held my breath, for the transition.

I was in the suit immediately, and even though I had to put the oxygen back on and Cory took his time tightening the suit back over my body, I was disconnected from the power supply in under two minutes. I put the hiking boots back on over the suit feet, and laced them up, stepping forward and back, then bouncing in place. Good fit over the thickened suit.

“Ready, Cory?” I said, strapping the aviation GPS onto my left wrist.

He sighed. “I guess.”

I checked the clock. Local time was five minutes until seven. Five minutes until nine at my destination.

*   *   *

First I took a tarp.

Mom and Dad were there, sitting on folding lawn chairs, a cooler between them.

I pointed at the cooler and raised my eyebrows.

There were staring and I realized I must look pretty odd between the oxygen face mask and the suit. Absently Dad said, “Water. What’s with the mask?”

“I know,” said Mom. “She’s prebreathing oxygen to outgas nitrogen from her bloodstream.”

Dad nodded. “Right. Bends. Got it.” He shook his head. “Knew that. Forgot about it. Glad you guys are on top of it.”

Mom said, “Cent was doing that from the beginning.” She touched the suit fabric. “That doesn’t seem like very much protection.”

I rolled my eyes.

Dad helped me spread the tarp on the ground and anchor it with rocks against the slight breeze.

“Back in a sec,” I said through the mask.

I ferried extra oxygen, the helmet, and attached backpack to the tarp, and then finally, Cory and his clipboard of checklists.

Cory staggered, but recovered quicker than he had his last jump. He looked from Mom and Dad to me and then back again, focusing finally on Mom.

“These are your parents.”

Ah, well, the resemblance is there, of course.

They stood and shook Cory’s hand. “I’m David. This is Millie. Pleased to meet you, Dr. Matoska.”

“Call me Cory,” he said, automatically. “You understand what Cent is trying to do?”

“Return to the mother ship?” said Dad.

If he weren’t out of reach I would have kicked him.

Mom said, “Behave!”

Dad smiled. “She wants to conduct activities in low Earth orbit. More importantly, she wants to
survive
activities in low Earth orbit. Is that pretty much what she’s told you?”

Cory nodded. “Amounts to the same thing. She said she was building her own space program.”

Mom looked at me over her sunglasses. “Indeed.”

I blushed and turned to Cory, pointing at the checklist.

He lifted the clipboard and looked at it, almost as if he was surprised it was there. “Ah. Checklist. Yes.” He looked back at me. “Hydration.”

I took a bottle of water out of the ice chest and, temporarily lifting the mask, chugged it. Before breathing in again, I purged the mask. “Right. Next?”

He looked at his watch. “When did you start prebreathing?”

“Six fifteen, Pacific.”

He scribbled on his clipboard. “We’ll do another twenty minutes and do the last bit of flushing in the suit.”

Dad took a bag from beneath his chair.

“Here,” he said. “I talked to someone.”

He took out a clear-plastic box about two inches by three, and an inch thick. Inside I could see a nine-volt battery and a double stack of circuit boards. The top board had a surface mount, multiline LED display. The bottom of the box had four thumbscrews clamping it shut on a black rubber gasket and the same lockdown posts passed through brass grommets on a Velcroed wrist strap.

It was already turned on and I compared its readings to the aviation GPS on my wrist.

The longitude and latitude differed by less than a tenth of a second, but the altitude was completely different. “Ah, metric?” I compared them. “And in
kilometers
. Great!”

Dad had been listening carefully, his head tilted, and he understood me. “And it won’t stop working above eighteen kilometers or at speeds faster than half a kilometers per second.”

“How’d they get around the ITAR regulations?”

“The manufacturers limit it in the firmware. This one uses open-source hardware and software so, even though they also have the limits, you can overwrite them. The GPS module has an integrated antennae. It handles data logging and display using an Arduino processor.”

It didn’t do map displays but it had the information I needed: altitude, bearing, horizontal and vertical speed, longitude and latitude, and time.

“Thanks, Dad.”

He smiled. “How do you guys communicate while you’re up there?”

“We don’t.”

“What if you need help?”

“Well, I’ll come back and get some. It’s not as if anyone can come to my aid.”

Mom’s eyes narrowed and Dad’s jaw did that thing where it juts forward, and he tapped himself on the chest.

“Only one suit,” I said. “Maybe later. Don’t worry. Something happens, I’m back on the ground like
that
.” I tried to snap my finger but it didn’t work with the suit fabric on my hands.

Dad looked unhappy but he didn’t say anything. Good thing, because I was doing this, with or without his permission.

Cory had been watching the back and forth intently, wondering, I think, if my parents were going to halt the proceedings. But when neither Mom or Dad said anything, he checked his watch again.

“Fans.” He read out the procedures while I did them—unlatching, removing the hatch from the rebreather chamber, switching on both ventilation fans, and sealing it back up.

“Check,” I said.

“Don life-support harness.”

He handed Dad the clipboard for this next part. While I slung the backpack on and fastened buckles and snugged up straps, Cory held the helmet up, keeping the armored hoses out of the way. I moved my shoulders around and twisted my waist back and forth. Secure
and
comfortable. “Check.”

“Remove prebreathe mask.”

I held my breath again. While it took two hours to get rid of the nitrogen, a few full breaths of regular air would put dangerous amounts back into my bloodstream.

“Don helmet and latch.”

He lowered the helmet over my head, and I took it, guiding it into the flange fifteen degrees off center to engage the threads. I then rotated it to the locked position, and latched the safety clamp. I held up my fingers and thumb in the okay sign and he checked off the next line.

“Turn on main oxygen.”

I reached back with my right arm and felt for the main oxygen valve. I eased it on and the feed valve hissed, pressurizing the helmet, and my ears popped. The hissing stopped as pressure reached the valve’s set point. “Check” I said, and my voice bounced oddly in the helmet.

“Test purge valve,” he said. His voice sounded distant through the helmet, but still easy to understand.

I bumped the purge button and it hissed, oxygen jetting into the weave of the suit over my fingers. Immediately the hissing switched to the feed valve, then stopped again when the pressure was back up. I took deep breaths and held up my forefinger and thumb.

“Turn off main oxygen.”

I reached back and twisted the valve in the other direction. “Check.”

“Turn on backup oxygen.”

“Check.”

“Test backup feed valve by purging helmet.”

I bumped the purge valve and the backup oxygen-feed valve repressurized the helmet immediately. “Check.”

“Turn off backup O
2
.”

“Check.”

“Turn on main O
2
.”

“Check.”

He nodded. “Right. Let’s say you end up someplace else, where I’m not there to read the checklist. What’s the shutdown procedure?”

“I turn off all oxygen, then I slowly vent the helmet with the purge valve, and then I can breach the helmet seal.” I saw him start to open his mouth and said, “Yes, I know.
Exactly
in that order so I don’t pull off the pressurized helmet and blow an eardrum.”

“
If
I’m here, though,
wait
for the checklist.”

I held my thumb up.

He turned a page on his clipboard and then said, “Okay. You want to swap the GPS out?”

I looked at the two units. “Let’s do the first test with both.” I strapped the one Dad gave me onto my left forearm, next to the off-the-shelf unit.

“Altitude above sea level?”

“At three thousand seven hundred fifty-three feet and—” I tapped the new unit. “—approximately one point forty-four kilometers.”

“Okay. Starting life support log at nine-thirteen.” More formally Cory said, “You are cleared to forty-five thousand feet.”

I could’ve jumped directly there, but I guess I wanted to wow them. I left the ground at about two hundred miles an hour, more speed than I’d normally add in the atmosphere, but I wanted to make some noise that they could hear. When the altimeter passed two kilometers above sea level, I jumped another five kilometers up, exhaling sharply. My ears popped and the purge valve dropped the helmet pressure, but my breathing was still effortless. The old GPS read twenty-three thousand feet. And it still worked when I jumped to thirty-five thousand feet, then forty-five thousand.

The sky above was black but it was blue at the horizon.

It was cold.

I checked the new GPS: 13.7 kilometers up.

The problem was that there was still enough mass in the air at this altitude for thermal transfer, so the thin but very cold air was leaching away my body’s heat. I didn’t want any
more
frostbite.

I turned face down and fell, feeling the air shrieking past, then jumped all the way back to the tarp on the ground, my jaw working and my mouth open.

My ears adjusted without a problem.

“Why are you sitting like that?”

Cory was off the edge of the tarp, sprawled in the sand.

Mom said, “He was surprised, when you took off like that. I think we all were. He fell down. I just expected you to jump straight to altitude.”

I couldn’t help grinning. “First time and all that.”

Dad rolled his eyes. “You wanted an audience.”