Reborn in 2011, I am the chief designer of aerospace.

Read Chapter 109, "The Out-of-Control Model Machine (Part 2)," now to start your exciting day.

"Alright, now all the data is perfect."

"Things aren't that simple, Mira." Song Xingye began to talk at length about optimal polynomials and complex curves, along with a bunch of technical terms that even Mira found confusing.

She simply ignored him.

She watched the track beneath her feet slowly slide backward. Her gliding was incredibly smooth; the PGNS worked flawlessly, and she barely needed to touch the controls. A surge of accomplishment welled up inside her. "Mom, see? I've done another one! Another step on my climb up the ladder to Mars!"

She's about to complete her first real landing. She's made her stance clear: she doesn't want things to get too tense with Sheng Tianhong, but perhaps she can persuade him to refuel MLTV and let her fly again. Next time, she plans to try different landing sites.

The huge "three" hung there like a reflection as she looked up, slightly obscured by the dust kicked up by the rockets and jet engines, but it grew closer and clearer.

The MLTV tilted back to slow its forward movement. She quickly checked the data; the clear image on the CRT monitor was perfectly superimposed on the real scene outside the glass windshield.

The roar of the auxiliary thrusters gradually subsided, and MLTV began to descend.

Perhaps the drop was a bit too sharp.

Song Xingye was still rambling on in her earphones, but she was too lazy to listen. Instead, she calmed down and observed, staring intently at her descent trajectory, trying to predict the path ahead in her mind.

Something was clearly wrong; she was falling too fast.

She waited a few more seconds to confirm her judgment. Indeed, her flight path had become a steep downward curve, and at this rate, she would eventually land more than a hundred meters away from "Point Three".

So what? Maybe PGNS miscalculated; maybe the scope needs recalibration. If she lands smoothly but just lands in the wrong spot, then she can easily blame it on equipment malfunction...

But she couldn't land smoothly at all. The rocket suddenly bounced in the opposite direction, and she felt herself crashing heavily to the ground.

Song Xingye and Sheng Tianhong were both yelling at her at the same time.

She could only watch helplessly as the ground magnified, and in the golden morning light, the particles of soil, the floating dust, and the joints of concrete were all revealed to her.

Mira pressed the button, shutting off the automatic control system.

Instead of struggling to adjust the MLTV's attitude, she slammed on the accelerator, sending the turbofan jet carrying her straight off the ground. She felt a violent acceleration, a powerful G-force, strong enough to tear her from the Earth's unpleasant gravitational pull.

She pulled the plane up to a height of about 100 meters, then shut down the turbofan engines and landed smoothly.

Song Xingye immediately rushed towards the MLTV that was on the verge of crashing.

Technicians in white protective suits had surrounded the trainer, and Mira had already climbed out of the pod. Her flight helmet flattened her hair, and when the visor was pushed open, her round face glistened with sweat. Judging from the amount of peroxide she had previously ingested, her eyes were bright red.

"You bastard, Mira," Sheng Tianhong began, "I warned you long ago, if you dare to destroy that training device..." Sheng Tianhong looked down at Mira, his hands clenched into iron fists. He began to curse at Mira.

Song Xingye understood that Mira's anger was justified to some extent. If Mira had relied on her reckless drive, she would have either killed herself or damaged critical equipment like the MLTV, and the entire project would probably have collapsed long ago. Song Xingye felt that Mira deserved a good scolding, so he let her rant for a few minutes.

But he immediately stepped forward and stood between the two. "Actually," he said, "it's not entirely Mira's fault."

Sheng Tianhong turned to face him, her anger undiminished.

"There's a problem with the landing program. Mira, I think there's a bug in it; it almost killed you." He turned to Sheng Tianhong. "We can verify this by repeatedly running Mira's flight path in the simulator."

Sheng Tianhong smiled helplessly: "How much programming knowledge do you really have?"

He sighed. "Not particularly many. But I'm the quick-witted guy, remember? Even though it's not my area of ​​expertise, my math skills are enough for me to understand how routine operations like PGNS work."

"Look," he gestured to the famous MLTV that was falling, "PGNS always finds the smoothest curve between your position, speed, and target, but it's not magic, it's just math, and it has its limitations."

This program uses polynomial curves. While the curves appear smooth, they actually have a wavy pattern; the higher the order of the polynomial, the greater the fluctuation of the curve. Furthermore, the choice of curve is not infinite. It's like trying to select one from a fixed set of templates to fit the current task requirements. Also, the more complex the data input to the program, the greater the fluctuation required for the polynomial to fit these data points. Do you understand?

"So what's wrong with that?" Mira asked, feigning innocence. "Why do I need to know this?"

He suppressed his temper, trying not to lose patience. "Because this program has no idea the ground exists. It's completely different from human pilots, Mira, it's ridiculously stupid. All PGNS does is fit a curve between two spatial locations. It doesn't care how violently the curve swings in the middle, or if one of those swings happens to make you crash to the ground and then bounce back up,"

Sheng Tianhong whistled, "That's why Mira was flying so low and fast back then."

The solutions for polynomials, which are the so-called "optimal solutions" that PGNS can think of, are often high-order polynomials and are full of twists and turns.

"Experience with helicopters," Mira murmured to herself.

Song Xingye was confused by this illogical statement. "Hmm?"

"Helicopter piloting experience. This type of aircraft has excellent performance and is relatively simple to operate. But in stark contrast, it completely contradicts the instinctive reactions a pilot develops when flying a fixed-wing aircraft." He clearly wasn't listening to her explanation. Perhaps he was just trying to grasp the core points she was conveying; after all, he felt it was necessary to have this information, and then immediately moved on to the next thought process, continuing to advance his established plan for Mars exploration. "If the joint mission team proceeds according to this plan, anyone with extensive helicopter operating experience will have an advantage, that's obvious."

"I guess you've already..."

"No, but I'll have it soon."

She tucked her helmet under her arm and strode briskly toward MLTV along the track, her steps short and firm, radiating an indomitable spirit.

Sheng Tianhong scratched the back of his buzz cut head. "What a tiring day. What a jerk."

Maybe so, Song Xingye thought. But in my eyes, she's a complete jerk on her way to Mars.

……

A new round of training has begun.

Although it wasn't even 10 a.m., the scorching sun had already made Sheng Tianhong's head and back feel burning hot. He could feel beads of sweat constantly seeping out from under his collar and the lightweight Snoopy helmet, seeping into his vest and then into the heavy backpack he was carrying.

To him, the ground was all black rock, and the scorching heat emanating from the cloudless sky overhead pressed down on him. Within a radius of several kilometers, there was nothing to see but jagged cliffs, low bushes, and scattered pebbles.

A bag of aerial photographs of the area, along with several outline maps drawn by the Geological Survey, hung in a plastic clip on Sheng Tianhong's belt. He unpacked the bag and looked around, trying to compare the terrain features he saw with the photographs and maps in his hand. These photographs had all been artificially blurred, so he couldn't see any finer details than the Martian surface photographs sent back by Mariner.

The landscape here is breathtaking, with rolling hills and deep valleys. Some landforms jut straight into the rock strata, a spectacle he had never seen before.

"I really don't know where we are," he admitted. "It's incredibly difficult. From the ground, everything looks different."

Mira, who had been hiking alongside him, also carrying a helmet, backpack, and Mars boots, stopped. She was pulling a two-wheeled cart called a MET (Modular Equipment Transporter), leaning forward with her hands on her knees, her blonde hair seemingly burning in the sunlight. "I think I know where we are," Mira said wearily.

"Um?"

"I just heard a whistle about one kilometer east of the railway."

Song Xingye's voice came through Sheng Tianhong's earpiece, sounding intermittent. "Please say it again, I can't hear you." Song Xingye was sitting in the tent, enjoying the relatively comfortable environment, playing the role of a liaison.

Mira straightened up, met Sheng Tianhong's gaze, and then uttered a curse.

Sheng Tianhong said, "Received, Song Xingye. We're all a bit tired on the surface of Mars; it seems we're using up consumables at an absurd rate."

"Then let's have a drink, you idiots."

Mira cursed a few more times, but Sheng Tianhong waved her off. "He's right, damn it, hurry up!" She reached up and touched the back of her head, finding two short plastic tubes hanging on her backpack. She pulled one over and sucked on it, a warm liquid sliding down her tongue.

Mira took a sip of water from her plastic tap, swirled it in her mouth, and spat it onto the black rock at her feet. The water hissed on the rock, then flowed away and dried quickly.

"Let's try Down syndrome," Sheng Tianhong said.

"Yes, but you also need to replenish the potassium lost through sweating, which is good for the heart..."

"Are the two heroes ready to continue their mission?"

"Oh, good luck, Song Xingye," Sheng Tianhong said.

They straightened their backs and continued on their way.

They arrived at a wide expanse of gravel and clay, the bedrock jutting out from the surface like charred bones. "We've found this looks like loess, Song Xingye," Sheng Tianhong said. "It's valley sediment." He found himself breathing heavily and noticed that Mira, struggling against the heavy MET, was drenched in sweat, her thin T-shirt soaked through. "I think we should go set up the SEP device now."

"Received, EV1."

"Fuck you, got it." Staying put and playing the scientist for a while is much easier than running back and forth in this damn volcanic battlefield. After all, this is worse than the real thing, and his Mars suit even has air conditioning.

"Mira, go scout ahead. Go that way, over that layer of loess."

"Okay." Mira put down the MET lever, slung her backpack over her shoulder, and set off along the loess slope, her blue Martian boots covered in mud.

Sheng Tianhong took out a pair of gloves from the metal cabin. These gloves were reinforced with thickened metal wire, simulating the pressure gloves he would have to wear on Mars. After putting on the gloves, he took out the SEP (a set of scientific instruments) from the vehicle. This set of equipment was folded into a heavy dumbbell shape, and its counterweight design simulated the feel of operating it under the gravity of real Mars.

Mira walked down the loess slope for about a hundred meters. "This way," she called out, "this place is flat and comfortable."

Sheng Tianhong started walking towards her. "Okay, Song Xingye, I'm deploying SEP now."

"receive."

With great effort, he managed to grip the dumbbell-shaped barbell with his stiff gloves while simultaneously moving the package aside. After walking about thirty meters, he stopped and put the SEP down.

Mira laughed. "It's just plywood, Sheng Tianhong."

"Damn it!" Sheng Tianhong yelled at her, "Did you really have to come this far?"

"You know I really have to do this."

Of course, Mira is right. On Mars, they would have to carry SEPs (Surface Electron Probes) far enough away from their MEM (Magnetoelectric Module) or rover to ensure they found a pristine surface undisturbed by dust kicked up by the vehicles.

He took off his gloves and tossed them aside without even glancing at where they went.

Mira whistled. "Captain, should you do that?"

"Report me."

He carried the SEP model to where Mira was and placed it in place, after which the two began to deploy the relevant equipment.

Assembling a SEP is like building a home barbecue grill. First, remove the bolts and take the contents out of the styrofoam box. Then, compact the soil and level the ground—this is no easy task, as the yellow soil is mixed with gravel and is quite hard to work with. Next, level the instruments. Make sure each instrument is aligned correctly and maintains proper spacing from the others, being careful not to let them get covered in dirt.

When assembled, this SEP presents a peculiar multi-point star-shaped structure, with the radioisotope power unit located at the very center, while the ground instruments are surrounded by thin orange cables.

The seismograph is the silver-painted metal casing. A weather observation pole stands tall; the SEP will serve as a weather station for astronauts during their stay on Mars. The slender, gold-leaf-sculpted object is the magnetometer. Two tall, delicate stereoscopic color cameras are mounted at the front of the device, and a sophisticated S-band antenna sits atop the entire structure, pointing directly at the imaginary Earth.