SWNOVELS Chapter Chapter Six - The Limits of Aerodynamics
“We’ll be ready to align and set course in just a few minutes,” Sally spoke up. “Unless you’d like to navigate this one yourself, Ian. I’d understand.”
“Oh, by no means!” Ian assured her. “You earned your wings back in that mining drone, no bones about it! We’re on a program now and these things practically fly themselves. I’ll wait for your signal that we’ve completed safe distancing.”
“Five seconds, four . . . three . . . two . . . one . . . Mark!”
The ship jolted as the maneuvering jets barked and hissed, more loudly this time. The navigational target display now showed a graphic sphere indicating the planet below. The ship’s progress towards atmospheric entry was marked by an arc and a target point. A diamond-shaped icon displayed their current orientation. As the thrusters fired, the ship gradually lined up with the target through a multitude of tiny eruptions. The display glowed green when alignment was complete. The system confirmed it with a joyful beep.
“T’riffic,” Ian said. “We’re under budget on that maneuver.”
“Good,” Sally agreed. “Every drop counts.”
“I’ve got good news on that score,” he added. “Before we left, I ran our experimental flight plan through the simulator. I don’t think the computer thought I was serious and I had to dodge a lot of procedure warnings, but it didn’t tell me it wouldn’t work. Coming from this system, that’s practically a standing ovation!”
“And the air currents?”
“I couldn’t simulate that, but they seem to be in our favor. You’ll also notice we’ll be following the night-line. The sun is setting, but there’s still enough light for visible navigation. By the time we actually land, however, it should be just about dark.”
“I didn’t realize that was possible,” Sally said in amazement.
“That’s a variation on an RAF training exercise,” Ian said with a hint of pride. “In a hostile situation you want to maximize what you can see while keeping your enemy from seeing you. In the old days planes would hide from other planes by getting between them and the sun. The same thing applies to shadows. When we do land, we’ll be in the darkest part of the sky.”
“What about reentry?”
“We might look like a shooting star, but nothing more than that. Also, I doubt that would give anybody on the ground much of an idea where we’re actually coming down.”
“And, without using the main engine, we’ll be even harder to see,” Sally marveled.
“Absolutely!”
“And you’re saying the chutes can bring us down right on target?”
“They should do, but I may have to do some other tricks, too, like deploying the backup chutes at the same time or letting one go if we’re drifting off course.”
“Is the system really designed to do that?”
“Well, yes and no. You see, any good parachute does basically the same thing as any other. They’re designed to inflate and create drag. Now, individual parachutes can vary in size and shape. Aerialists and competitive skydivers often use rectangular chutes that are thin and flexible. These are very easy to steer and can be piloted with amazing accuracy. On the other hand, the sort of chutes used to drop heavy equipment, or in our case a ship, are generally round and very deep. These don’t really steer very well, but this ship uses four of them. When they’re all fully deployed, together they can have a similar effect as the skydiver’s chute. I don’t pretend it’ll be easy, but the theory is sound and I’ve worked enough with gliders that I think I can handle it. Mostly it’s a matter of feeling it out. Of course it would be easier to land in full daylight, but I figured you’d want us to keep a low profile.”
“I’d like to be completely invisible,” Sally agreed. “Hopefully this’ll be good enough.”
“Well, if they have sophisticated tracking equipment or even simple radar, it won’t much matter, but assuming they’re just looking up from time to time, we should be about as anonymous as a flock of birds or a big cloud. Since we haven’t seen any air traffic to date, I’d say it’s a fair toss. Even when we fire the main engine, from a distance that won’t look much brighter than a bonfire and we’ll darken up almost immediately. Even if they do see or hear something, it’ll be hard to pinpoint exactly where.”
“Wow!” was all Sally could say. “That’s quite brilliant.”
Ian turned to her and smiled. “Well, fortunately, there’s more to the RAF than just air shows. I’ve been on my share of maneuvers and, though I wasn’t top of my class by any means, some of my strategic formations were reasonably well received. Of course, under normal circumstances, a stunt like this would get me a week peeling potatoes,” he added with a chuckle.
“I see what you mean about the struts,” Sally commented, looking at one of the diagrams on the flight plan window. “We’ll probably bow them a bit.”
“A calculated risk. As long as they protect the main motor, we can do without them. We’ll be jettisoning the landing ring on the way up anyway, so I can’t see as it’ll matter. I don’t plan to be landing here again, that’s for sure.”
“Good point.”
A buzzer sounded.
“Ten minutes to atmospheric burn,” Ian announced. “Brace yourself, this one could be nasty.”
“Ian, there’s something you have to know,” Sally said. “I should probably tell you now because we’ll have a lot on our minds down there. I wasn’t entirely honest with Vlad about locking the navigation. I told him it was keyed to my voice alone.”
He chuckled. “Now, that I truly enjoyed!”
“I told him that because I don’t trust him, but I wouldn’t want to kill him either.”
“I’m sure the space commissioner could override the system if need be. Even he should know that.”
“Well, even so, that would only work under remote guidance and it wouldn’t be possible to set up until well after the early window.”
“And it’d make him look pretty impotent to his Russian friends,” Ian added with a grin.
“But, anyway, you should know that your voiceprint will unlock navigation as well, and I put a copy of my command key in the safe in my quarters. I’ve programmed it to open with your biometrics. If Scott’s dead and we get separated, go back to the ship yourself. Take either pod. If I’m alive I’ll make for the other one. It’s a last resort, obviously, but I won’t leave Angela without a husband.”
Ian paused, unsure how to react at first. “Thank you,” he said. “But I have no intention of getting separated.” He smiled with as much confidence as he could muster. “And let’s hope it won’t come to all that.”
The atmospheric entry burn was more of a roar than a bark and it forced them forward against the straps. As they slowed they could feel some of their weight returning, causing them to settle lightly into their couches. The stars became hazy as the gasses grew thicker. The silence outside was gradually replaced by the first whispers of the storm that was to follow. Sally had experienced atmospheric entry in a variety of ships during her training, but had never gotten over her primal fear. Space vehicle design had come a long way since the American Apollo missions, but Sally knew any unseen structural weakness in the pod’s heat shield could fry both of them before they could do anything about it. But, added to this fear was something new. During every one of her previous flights into atmosphere she had been heading home. This was her first flight in which the term “re-entry” was not accurate. They were not going home this time, but farther away. And, when they did land, instead of the welcome of friends, their best hope would be isolation. The Kelthy was the closest to home they could get now, and they had seen their last glimpse of it for a long time. In its absence, they had only the small capsule they were in as a lifeline, and they were about to seriously test its limits.
The ship began to shimmy as the layers of atmosphere mounted. This was normal for entry, but it felt different this time. The gravity was greater than Earth’s and the air itself was thicker. What was worse, this time there wasn’t even the reassuring presence of a clear view below. They were plummeting into darkening clouds, and alien clouds at that. Moments later, the sound of the air outside grew from a whisper into a howling rumble.
“Moving into decent position!” Ian shouted over the din.
The ship wheeled about, positioning them on their backs looking upward into the thickening black sky that held only a hint of dark blue. By now they could feel the air coursing around them like a shower of sand. Waves of heat radiated from the walls, carrying the subtle smell of cooking plastic and hot electronic parts. Sally envied Ian for having somewhere to put his concentration. And then, with an explosive burst, the chutes opened, blocking their view of the night. The force of the new drag caused Ian’s hands to fall hard against the armrests. Sally felt her skull sink deep into the couch. Her eyeballs grew heavy in their sockets and the weight of her chest forced the air from her lungs. She struggled to keep her eyes on the instruments. Then a new concern fell on her. As her bones sunk into the padding and her muscles strained, she realized that part of this heavy feeling was not caused by the opening of the chutes but by the return of gravity itself, which would not go away when they landed. After six months without it, she now questioned how well she could perform even in normal Earth gravity. But the gravity on the planet would actually be higher. She took a moment to do the math, calculating her weight by adding ten percent to her Earth weight. The results were not encouraging. Her neck felt tired from straining and she had to let her head fall back again. She fought the urge to close her eyes. The next sensation she felt was that of rocking. The ship was sailing downward, dangling below the chutes like a rodent caught in the clutches of a great eagle. The temperature inside the cabin was still high, but the howling had subsided. It was becoming quiet, almost peaceful.
Once the chutes opened, Ian’s work had really begun. Human paratroopers could control the direction of their descent through manipulating the shape of a single pocket of air. Letting some air out on either side would alter the aerodynamics to favor movement in that direction. The technology was easy to understand and possible to master. But the shuttlepod had four chutes scooping the air at once, and none of them had been designed for that kind of control. Add to this the fact that the ship weighed several tons and the gravity was greater, and Ian had his work cut out for him. The landing site was small. It had been selected to be secluded and yet relatively close to the other pod. It was a bald area on a wooded ridge. From orbit they could tell very little about it except that it was not a body of water and it appeared to be surprisingly flat. Were it not so small, it would have made an ideal landing site for the first ship. The problem was that, if they deviated even a few hundred yards from their expected course, they could fall into the trees on either side or tumble helplessly down the ridge into certain destruction. It had looked much easier in the simulations. He had even allowed himself to look forward to it. But sitting in the couch, feeling his arms grow heavier by the second, and recognizing the complexity of his task, what they were attempting was absurd! It was like throwing a dart into a hurricane with the intent of hitting a perfect bull’s-eye two miles down wind!
“Looks like you were right so far,” Sally spoke up. “If the wind follows this pattern we’ll touch down right where we need to be.”
But Ian didn’t respond this time. He stared at the map. The tiny rectangle they were aiming at had grown, but, though they were still being carried in that direction, he could already see some deviation. He gently manipulated the controls for the servomotors attached to the great cables that held the chutes, watching for the slightest response in their course. To his surprise, the deviation decreased as the adjusted drag on the chute he was controlling pulled the ship ever so slightly faster on that side. But then he had to be concerned about overcompensating. He angled back before the course had completely optimized, letting the current gradually nullify the ship’s new momentum. He kept his sweating fingers within pressing distance of the other servo controls with the diligent posture of a young boy enthralled with a video game. But this was no game.
“I’ve extended the struts,” he said. “We’ll be down in ten minutes.”
Sally held her nose and blew hard to relieve the pressure in her ears.
Suddenly the ship pitched hard to the left.
“Hold on!” Ian warned. Then, moving with the efficiency of a master chef, he threw several switches that were already uncaged. With an explosive popping sound, the ship rocked back.
“We lost a chute!” Ian announced. “I just deployed the backup!” He stared at the map, working hard with the remaining three original chutes to get them back on course. His fingers stroked the buttons, first making gross adjustments and then gentler ones.
“Stabilizing,” he said. “We’re not too far off.”
“Are you sure?”
“Yeah, just don’t tell the Safety Commission!” he said, trying to lighten his own mood as well as hers.
“Don’t worry,” Sally said in the same spirit. “I know they don’t really like us using our backups.”
Now came the part Ian dreaded the most. The light was all but gone now and the patch of bare ground had progressed from a microscopic dent far away to a growing piece of real estate they were approaching very quickly. The computer highlighted the region as the display shifted to night mode. Ian now had to work on instinct as well as instrumentation. At a critical moment, when the ship was almost directly over the small patch of land, he would have to release all the chutes at once, causing them to fall the remaining distance much faster and at a far steeper angle. He had to take into account what momentum they would still have in a lateral direction and calculate the optimum time for the drop with a very small margin for error. The landing thrusters would have to be engaged immediately to break most of their fall. Again, it sounded great when he was convincing the computer to simulate it, but if the thrusters misfired or Ian’s reaction time was too slow, the ship would break open like a raw egg dropped onto a sidewalk. He felt his shoulders tense further. He then reached forward and rested his fingers on a large pull-out lever, which was made up of several levers chained together. It was made intentionally hard to reach from a comfortable position.
“I’m going to release the chutes in a moment,” he said with a slight edge in his voice. “When they’re off, I’m going to fire the main engines very close to the ground, so it’ll probably feel like something’s wrong. Trust me, we’re saving fuel.”
“Got it.”
His eyes were dry from not blinking. The rectangle of land now looked much larger, almost spacious. They were not approaching it as fast now, as the gentler air currents closer to the ground were not acting on them with as much force as those in the upper atmosphere had been and the ship was losing momentum to the downward pull of gravity. For a brief instant, Ian actually thought the ship might land right on target without releasing the chutes, but he quickly saw it would not. His hand, still resting on the release lever, tugged at it experimentally, sampling the resistance. And then, when the landing site settled directly below them, he pulled hard. At first it did not release, sending him into a panic, as if he had fallen down a well and was grasping madly for a rope! He pulled with both hands, and would have lifted himself out of his couch had it not been for the straps.
The chute assembly released with a hollow twang, sending the large parachutes drifting aimlessly into the night. A jolt rang through the pod, heralding the terrible feeling of falling. Ian leaped to the waiting thruster controls, almost closing his eyes as the loud roar of the engines pushed them back into their seats with an invisible slap.
The impact with the ground was frighteningly hard and came with the screeching sound of the metal struts bending in protest. The ship bounced upward briefly as the massive springs fought back and resettled. The screeching continued while the ship twisted into its final resting place. And then all was silent.
Ian paged feverishly through the screens, checking for damage to the systems. He finally drew a great sigh of relief and settled back into the couch. “Well, thank God for that!” he exclaimed, pulling his metal cardkey from the console. The engines hissed to silence and the hydraulics controlling the valves hummed, bringing everything to its respective closed position. Finally, the displays dimmed.
“Good job,” Sally whispered. “Any damage?”
“The struts took the worst of it, but they were designed to do just that. I wouldn’t want to try to land on them again, of course, but I don’t see a problem with us taking off.”
“Good,” Sally said, relieved. “I don’t expect to be returning here once we leave.” She tried to sit up, but settled back down again with a grown.
“Don’t bother,” Ian said. “We won’t be going anywhere till dawn anyway. Let’s work into it slowly.”
“Of course,” Sally agreed.