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

Through the narrow porthole of the airlock, Song Xingye gazed at the twinkling stars in the deep night sky.

Jupiter hung high in the sky, nearly a third brighter than when observed from Earth, its dazzling light even casting shadows inside the cabin.

In the east, a tranquil morning star stands quietly, its elegant blue-white light standing out prominently in the purple glow of the Martian dawn.

That is Earth.

Humanity's home planet is orbiting in the same direction as the sun, and is now at its closest point to Mars. It appears as a crescent moon in the Martian sky, with its shadowed hemisphere facing Mars.

The constellations in the sky looked exactly the same as those in his childhood memories.

They make us acutely aware of just how incredibly far humanity has come.

Those distant stars merely depict this vast interstellar journey, a daring attempt to push the limits of human technology, an expedition so far that it could turn Earth itself into a mere speck of light in space, as a child's first unsteady step.

The MEM has been floating on the sea for three days. The crew has to use this precious time to adapt to the weightless environment.

As he expected, Song Xingye found himself a few inches taller and about 15 pounds lighter than when he left Earth. Initially, he struggled to walk in the cramped MEM (Memory Enhancement Module), constantly bumping into the walls and forgetting his descent direction. He also had the thinnest "support legs." The three of us were stranded on the Martian surface. But in any case, under one-third of Martian gravity, those support legs were the only support he needed.

However, after three days on the surface of Mars, he still felt dizzy, as if the view outside the window illuminated by Jupiter's light was just another plaster model.

But when he went outside, it all became a reality.

Sheng Tianhong met him at the hatch. Like Song Xingye, Sheng Tianhong wore thermal underwear covered by a cooling and ventilated suit. This suit was made of layers of corrugated water-cooled pipes. Song Xingye had a catheter inserted, while Sheng Tianhong wore his own urine collection device—a huge and oddly shaped condom. The two looked both strange and sexually unattractive, somewhat comical.

"The scenery is beautiful, isn't it?" Sheng Tianhong murmured. "You know what? Mira said she can see the moon with the naked eye."

"Perhaps she can do it. It's possible." The moon should appear as a crescent of silvery-gray light, slowly rotating close to its owner.

Sheng Tianhong brought Song Xingye's lower body assembly—the lower half of his EVA suit, plus pants and boots. "Come on, Song Xingye, stop staring."

He stared at the spacesuit, as if in a dream. "That was a long time ago, wasn't it?"

That time has passed.

He hooked the sleeve of his cooling suit around his thumb to prevent it from slipping off during subsequent movements. He stared at his hands—the familiar skin covered in plastic bandages, wrapping around the base of his thumbs. This was the first step in the complex ritual of donning the gear, and this simple action already made his heart race.

He stepped into the lower body assembly device. The device was uncomfortably heavy, its layers of material stiff and difficult to move. When Sheng Tianhong tried to pull it up, it seemed to twist away between his legs. He found himself utterly exhausted, his strength rapidly depleting.

He then attached a catheter connector to a tubing that would connect to a urine collection bag with a capacity to hold several pints of urine. There was no need to collect feces—he wore an absorbent undergarment (i.e., a diaper) that, according to the training manual, could absorb "any bowel movements that could not be delayed during emergency intravenous access (EVA)."

Song Xingye's plans have been postponed.

Next came the physical assault phase. His HUT, like the upper part of an armor, was suspended from the airlock wall, with a built-in life support backpack.

He crouched beneath the HUT, raising his arms. He twisted upwards, crawling into the HUT. The darkness of the shell was filled with the smells of plastic, metal, and velvet, along with a fresh scent.

He slipped his arms into the sleeves, his hands through; the cool garment's buckles gently hooked around the soft skin around his thumbs. His shoulders arched back in pain. The whole process was far from easy. However, these spacesuits were much simpler than the old lunar suits—the command module astronauts had to assemble them on the lunar surface and connect the tubing that supplied water and oxygen from their backpacks.

His head popped out from the helmet hoops. Sheng Tianhong grinned as he greeted him. "Welcome back." He pulled off his helmet, pressed it firmly against his shoulders, then aligned the two halves of the metal waist rings and snapped them together.

He then helped Sheng Tianhong put on the clothes.

Song Xingye and Sheng Tianhong had been inside the cramped airlock for two hours. The Challenger's internal environment was maintained at 70% of Earth's sea level, consisting of a mixture of nitrogen and oxygen. However, to maintain the flexibility of their spacesuits, the airlock was filled only with oxygen, resulting in a pressure only one-quarter that of sea level. Therefore, Song Xingye and Sheng Tianhong had to inhale pure oxygen beforehand to remove nitrogen from their blood.

This was an incredibly daunting and laborious process. Extravehicular activities (EVAs) on Mars could only last three or four hours at most. While Apollo-era spacesuits could support seven hours of ground operations, Mars' gravity was twice that of the Moon, necessitating a reduction in the weight of the spacesuits, thus limiting the duration of EVAs. Each EVA was followed by a lengthy cleanup: the spacesuits had to be vacuumed to remove Martian dust, and if this highly oxidizing dust had gotten into the Challenger spacecraft, it would have been a nightmare for the astronauts' lungs.

On Mars, most of the long and frustrating days are spent on brief extravehicular activities (EVA), including preparing and cleaning the surrounding environment and setting up anti-contamination swabs.

Song Xingye secured his Snoopy flying helmet, then lifted his hard helmet with a mask from above the rock and twisted it onto the sealing ring that was close to his neck.

The last few items left were his gloves, which fit snugly against his wrists and were secured with buckles.

Sheng Tianhong gently flipped the switch on the front panel, and heard the sound of the pump and fan in his backpack.

Oxygen blew gently over his mask. He tapped the top of his helmet, raised his gloved thumb in front of his transparent visor, nodded to him, and smiled.

He raised his hand to show the reflective mirror sewn into his cuff, which clearly displayed the real-time data on the chest panel:

Blood oxygen saturation, carbon dioxide partial pressure, airway pressure, and multiple fault alarms.

At this point, his blood oxygen pressure level had stabilized.

Sheng Tianhong tested the radio link. "Hello, Song Xingye..." His voice sounded soft and high-pitched, masked by the muffled sound coming through the thick glass of his mask.

He inspected the plastic tube protruding from the inside of his helmet, and took a few sips of water and orange juice. The orange juice was fine, but the water was too hot. That didn't matter. He briefly increased the internal pressure of his protective suit to maximum to check for leaks. He secured the spiral-bound EVA checklist to his cuff.

After trying on their spacesuits, they looked each other over. Sheng Tianhong's spacesuit was snow-white and shiny, paired with bright blue Mars over-the-knee boots, and a red flag was prominently embroidered on the sleeves.

Sheng Tianhong asked, "Are we finished?"

He lost contact with the Challenger and was locked in his tiny, enclosed capsule. Taking a deep breath of cool, blue oxygen, he said, "Okay, let's begin."

"Roger that." He turned to talk to Mira, who was going uphill. "Mira, we're waiting for the 'depressurization' command to be issued."

"Received, Sheng Tianhong, go and give it a try. You might get depressed." Mira will monitor this first extravehicular activity from inside the ascent cabin.

Sheng Tianhong pressed the switch on the wall; Song Xingye heard a sound seeping into the air, and the internal noise of his own breathing seemed to become louder and more intermittent, in order to counteract the external interference.

"Received," Sheng Tianhong said. "Everything is ready now. We just need to wait for the cabin pressure to drop enough to open the hatch."

Song Xingye discovered that the pressure gauge showed the pressure had dropped to 0.2 pounds.

Mira said, "I measured the static pressure in your locks and it's very low. Do you think it's safe to open the locks now?"

Sheng Tianhong said, "I will give it a try."

The hatch exit was a small opening near the floor, with a simple lever as the handle. Sheng Tianhong bent down, twisted the lever, and pulled hard. Song Xingye saw the thin metal plate of the hatch bend inward, but the hatch remained tightly closed.

"Damn it."

"Let me try." He crouched down and fiddled with a corner of the hatch—which bulged out from the bulkhead. He was wearing metal mesh and rubber gloves, and he was terribly clumsy; his hands were large and numb. But he managed to pry open a small section of the hatch cover.

Through the crack between the hatch and the frame, he saw ochre light.

"I believe I broke the seal."

Sheng Tianhong pulled the hatch handle, and this time the hatch opened easily.

As their last oxygen dissipated in the Martian atmosphere, Song Xingye witnessed a brief flurry of snowflakes falling.

The two had to step back, allowing the hatch to retract naturally.

Next, Song Xingye spotted the platform suspended atop Challenger's short, stout landing legs—Quartz was about to retreat from here. The platform's surface was covered with brown debris kicked up during landing. Through the platform, the Martian surface was clearly visible: the sandy surface was covered with radial streaks extending outward from Challenger, traces left by the residual force of the landing engines' final exhaust.

It was nothing more than a desolate landscape; so ordinary to Earth that he wouldn't even notice it. But now he was in the Mangala Valley—a mere few meters of thin Martian atmosphere separating him from the Martian surface he had spent his life studying as an adult.

"Song Xingye," Sheng Tianhong said.

He turned around, his spacesuit gleaming white in the dim kitchen light inside the hatch, a stark contrast to the brown of Mars.

“We missed a check,” Sheng Tianhong said. “It’s on the checklist. We didn’t handle these properly.” Sheng Tianhong pulled a red EV1 wristband from his spacesuit pocket. As the commander of the first extravehicular activity, he was in charge of the entire operation; Song Xingye was his official backup, while Sheng Tianhong would wear the red wristband on his limbs for identification by television cameras.

But he always kept those ribbons for him.

I do not understand.

He smiled again. "I think you understand. Put on those bracelets."

He reached out and placed the bracelet in his palm. Through the clunky gloves, he couldn't feel the weight of the bracelet.

"You must be joking."

He said impatiently, “Listen, I’m not asking you to do that damn MEM mission. You’ve all done that in emergency simulations. For this first EVA, you just need to walk around, grab a few rocks, and talk to your family.”

His astonishing proposal left him feeling neither joy nor pride, only utter frustration. This damned rollercoaster ride again. "This is absurd, Sheng Tianhong. You actually gave up the chance to be the first human to land on Mars, God! What kind of idiot are you?"

“This operation,” he said angrily, “is crucial, Song Xingye. We discussed it before launch. We must get this EVA right—especially the first one—for the future. The next few minutes may be the core of the entire mission. Even more important than the scientific value—though I don’t expect you to agree. Song Xingye, it will be a long time before anyone else accomplishes this feat. But we are rewriting history; even if we fail now, people can look up at Mars and say: Yes, it is possible, we can get there, we can live on it. Because we know that someone did it.”

Listen, I know I can't compare to Neil Armstrong. You're much better at expressing yourself. This is your territory, your valley, your planet, to hell with it. You know this place better than anyone else in the world. And, to be honest, you'd explain this better than I could. Besides…

什幺

He smiled slightly. "I have a feeling. Perhaps people will remember me for a longer time because I was the one who gave up the chance to be number one."

"Hopefully he's following orders," Mira said.

"It's on par with his previous performance."

They had planned this all along. I've been set up.

"Take this," Sheng Tianhong said.

He extended his hand, and Sheng Tianhong gently placed a coin-sized disc, less than 2 centimeters in diameter, into his palm. It was a diamond-marked piece. "I think you're better suited to put it away properly."

He stretched out his hands and clenched his fists tightly around the marker. He was staring into his eyes.

He placed the marker into the sample bag of his spacesuit. Then, numbly, he put the red straps around his limbs and let the gold mask hang down over his face.

Sheng Tianhong pushed open the hatch. Song Xingye awkwardly knelt down, backed up to the hatch, and began to crawl backward out of the hatch and onto the porch.

Let's begin. Your stance is quite good, Song Xingye. Move a little closer to me. Okay, down. Roll to the left. Left foot to the right—no, the opposite direction. You did well.

He could feel the friction between his skin and the hatch. The coolant hose had pierced his knee.

Blood roared in his ears.

"Okay, I'm on the porch." He reached out and grabbed the handrails on either side of the porch.

He looked up and saw that the white paint on the outer hull was covered with landing dust and had a yellowish tinge due to the increasing Martian morning light.