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

Song Xingye recorded all the key construction milestones and transmitted the videos back to the ground control center. In the event of any malfunctions in the future, analyzing these videos may provide crucial clues for solving the problems.

The main body of the "Xihe" spacecraft still retains three parallel compartments side by side, 100 meters apart. The two outermost compartments are each 100 meters long and are still used as living quarters for the crew, named No. 1 and No. 2 living quarters respectively. The central compartment is used to store supplies and serves as the docking hub for the spacecraft.

This central axis beam does not end at the intersection with the rear elevator passage, but continues to extend for a full 270 meters. In the middle section of this extended axis beam, the entire structure is still in a state of zero gravity, where the nuclear power plant's engineering area and two reactors are located.

100 meters behind the reactor, the variable ratio impingement magneto-plasma engine for propulsion is still under construction. Between the reactor and the engineering system, there is a cluster of huge spherical water tanks that will be filled with thousands of tons of water to be used as the working fluid for the engine.

Minan kept her promise to solve the waste heat problem. In the nine weeks since the launch of the spacecraft from Country A, she worked desperately to catch up on the schedule and miraculously persuaded a large number of stubborn engineers.

From Song Xingye's perspective, between the engineering module and the reactor module, two 400-meter-long trusses extend straight outward from the central axis, one pointing upward and the other downward.

Although Song Xingye, who has extensive experience, is used to calling them "masts," the structure at the end of each truss resembles the crossbeam at the top of a capital letter "T."

The other two supports, which are the same length as the "T"-shaped crossbeams, extend horizontally for hundreds of meters along the central axis to both sides. Special extrusion nozzles are fixed on these crossbeams to spray molten heat dissipation alloy to cool the reactor. This was a design personally overseen by Mi Nan.

Once the high-temperature alloy cools and solidifies in space, turning into a thin metal foil layer, the "T"-shaped crossbeam at the end collects it again and circulates it back to the reactor.

Dozens of extremely thin cables, almost invisible to the naked eye, extend from each boom and "mast" and are firmly anchored to the central axis.

These cables are made of high-strength graphene composite material, which firmly locks all the disparate components into a rigid whole. They are not only stronger than traditional metal supports, but also much lighter.

This scene reminded Song Xingye of a giant, unfinished box kite, with only a bare wooden frame and taut cables remaining, and at this moment, the frame was completely empty.

Soon, sails will be hoisted here.

The engineers and design team ultimately approved Minan's plan to cope with the extremely large power demand, not because the plan itself was so perfect, but because they racked their brains and really couldn't think of any other way to make the spaceship defeat Country A while flying in Mars orbit.

After much thought, they developed a ceramic core reactor that emits a faint yellow light when in operation, heating the main coolant, pressurized liquid sodium, to over 1900 degrees Celsius.

Superheated liquid sodium flows through a heat exchanger and vaporizes into sodium vapor. This vapor then drives the main ceramic composite turbine, enabling it to operate at full speed under extreme conditions of 200 atmospheres and 1900 degrees Celsius.

Sodium vapor condenses downstream of the turbine and then enters the secondary heat exchanger, where it is reheated to a supercritical state of 880 degrees Celsius, thereby driving the next set of turbines. Although the whole process is complicated, from the perspective of physical mechanism, it cannot be called "wishful thinking".

But the final cooling process is a completely different story.

Downstream of the second-stage turbine, steam cooled to 650 degrees Celsius enters the heat exchanger of the spacecraft's cooling system. The high temperature of the steam melts the heat-dissipating alloy, a eutectic alloy composed of aluminum, magnesium, and beryllium with a melting point of 600 degrees Celsius.

Each kilogram of molten material can absorb nearly 200 watt-hours of heat. Minan's system only needs to dissipate the heat from these molten alloys, which is why it is called a "heat pump".

The heat exchanger extrudes the alloy into a liquid metal strip one meter wide and only one-tenth of a millimeter thick. At the extrusion nozzle, the cold rolling rolls coat the strip surface with a solidified rough surface layer a few micrometers thick.

This rough surface not only improves heat dissipation performance, but also prevents the long and wide liquid metal strip from breaking into splashing droplets during high-speed movement. When they are shot at extremely high speeds toward the support frame 400 meters away, the metal strip will cool and solidify rapidly, radiating a huge amount of heat energy into the vast space.

Although this solution is simple and crude, it can remove a huge amount of waste heat extremely efficiently, but it is quite tricky to implement in practice.

These semi-molten metal strips need to be precisely guided by electromagnetic force to be ejected from both sides of the extruder and extended all the way to the support rod more than 400 meters away. The rollers on the support rod catch the solidified metal strips and transport them back to the melting tank along the central mast.

Manipulating a single metal strip is already a huge technical challenge, but if Minan's system is to support the spacecraft to reach Mars, it must simultaneously extrude and precisely control hundreds of such metal strips.

Therefore, they look like sails, or to put it more poetically, the entire spaceship looks like a moth with giant wings but an extremely small body.

Each "sail" consists of nearly a hundred metal strips that extend from the crossbar to the mast and then back to the heat exchanger's storage tank. The alloy circulates continuously within this system, with hundreds of semi-molten metal strips flowing together to safely dissipate the waste heat generated by the reactor.

When the spacecraft is operating at full capacity, its dark silver metallic surface, covering an area of ​​150,000 square meters—equivalent to the size of 28 rugby fields—will radiate up to 9 gigawatts of heat into space. Of course, this is just a theoretical vision.

As for the actual results, the first comprehensive test will reveal the truth.

Nuclear physicists must start the reactor to generate enough heat and electricity to test the turbines and boilers, while simultaneously melting the alloys in the heat exchanger reservoir.

However, they must not rush things, because the spacecraft's relatively weak auxiliary cooling system must bear the entire heat load before the main heat exchanger is fully activated.

This is an extremely difficult problem. The special design of this reactor means that it is simply impossible for it to operate stably at less than 1% of its rated power. Once the system becomes unbalanced, it is very easy to cause the core to melt down. At that time, not only will the mission be in vain, but the space station itself may also face catastrophic destruction.

According to Song Xingye, the accompanying cameraman, the first few days of testing were incredibly boring. Once you captured an engineer staring at the status display screen with a worried expression, you had basically filmed all the highlights.

But a week later, things finally took a turn for the better. The reactor entered its optimal operating state, the heat exchanger storage tank stabilized at an operating temperature of over 600 degrees Celsius, and all guidance sensors were functioning normally.

Minan took a deep breath and ordered one of the extrusion nozzles to be opened at the lowest operating pressure.

A metal strip, one-tenth the thickness of a millimeter and one meter wide, slowly emerged from the nozzle, extending like a giant python toward a support rod. The metal strip swayed slightly in the air for a moment before the guide sensor and control magnet locked it firmly in place.

A dedicated supercomputer quickly analyzed its slightly hesitant trajectory, issued commands to the guide magnet, precisely induced electromagnetic eddy currents, and then the electromagnetic force exerted itself, forcibly pulling the metal strip back to a straight track, shooting it straight towards the waiting support rod.

Two minutes later, the front end of the metal ribbon successfully reached the recovery crossbar, was steadily caught by the rollers, and was then transported back along the crossbar and mast.

The engineers erupted in cheers, and Song Xingye was overjoyed. The visual effect was incredibly dramatic; the silver metal strip crawled slowly through the 400-meter-long field of view, creating a breathtaking sense of tension.

Song Xingye secretly resolved to cram every second of this scene into the final edit, wanting future viewers to be completely captivated by this sense of suspense, just like the engineers were now.

Next, the engineers activated the second nozzle, extruding another one-meter-wide strip. Its performance was exactly the same as the first one, practically perfect. There were still 350 more metal strips waiting to be deployed.

Including the downtime spent on various status checks along the way, the engineering team needed to work continuously for eighteen hours to fully deploy all four "metal sails". Song Xingye fixed the camera to the pod that maintained the attitude and let it automatically record this long and repetitive deployment process, while he withdrew from the scene.

The next morning, when Song Xingye returned to the observation cabin, the scene before him greatly shocked him.

The four sides resemble giant rectangular "sails" made of tin-plated lead plates, each hundreds of meters long, already formed, stretching from the central mast all the way to the supporting crossbars.

Their arrangement is so precise that from a distance, they look like a single, seamless piece of metal canvas, with no indication that they are made up of hundreds of parallel heat-dissipating alloy strips.

He retrieved the automatic cameras, readjusted their positions and parameters, and replaced the memory modules. These cameras not only have their own local storage but can also perform remote synchronous recording, directly transmitting the images to the observatory's dedicated storage core.

Many people think that since the equipment is so powerful, there is no need to go through the trouble of physical backups. But Song Xingye has never thought that way. He insists on double backups of all materials, which is his bottom line.

He didn't stay on site when the work started that morning, because Minan and the other engineers were preparing for the next major step: testing whether their "baby," to which they had poured so much effort, could really take its first steps and run.

The reactor control team plans to ramp up the power to 25% of the rated output. This will be the first time the reactor has been field-tested under near-normal operating conditions. At this stage, they intend to bypass the turbine generator and inject all the power directly into the heat exchanger to test its ability to operate at more than 50% full load.

The concept of improving the operating efficiency of a heat exchange system is quite straightforward. The core is to increase the speed of the extruder. The faster the liquid metal flows through the cavity, the higher the efficiency of dissipating waste heat.

Currently, the extruder's jetting speed is only a conservative three meters per second, but under full load, this number will soar to an astonishing 160 meters per second. Today's test goal is to increase the strip speed to 90 meters per second.

Once the goal is achieved, the system will pause operation and allow engineers to carefully verify the massive amount of real-time data collected by dozens of recorders.

However, even at a relatively "slow" speed of 90 meters per second, all the precision components must maintain near-perfect coordination. The heat exchanger needs to continuously draw enough heat from the reactor to maintain the molten state inside the alloy storage tank.

If the extruder operates at a rate exceeding the reactor's heating rate, the heat exchanger will lose too much heat into space, causing the temperature of the storage tank to drop sharply. When the temperature falls below the melting point of 600 degrees Celsius, the alloy will solidify and freeze inside the storage tank, forcing engineers to shut down the machine immediately.

In short, it's a delicate balancing act: the reactor relies on the heat exchanger to prevent itself from melting down, while the heat exchanger depends on the reactor to avoid freezing.

While waiting for the test to begin, Song Xingye used various imaging techniques to meticulously photograph different perspectives of the space station for Sasha, switching back and forth between conventional true-color images and thermal imaging modes.

In thermal imaging, the hot metal sail appears a dazzling bright white, standing out against the dark gray mast, boom, and other space station components, while the background is a dull gray Earth.

After shooting enough of this set of shots, he switched to the pseudo-color mapping mode, using rainbow-like hues to show the temperature distribution in different areas of the sail. These materials will become an excellent source material library for post-production editing. He doesn't want to miss any visual elements that can add interest to the final image.

The test officially began, and at first, everything seemed calm and uneventful, with no visible changes on the surface.

Song Xingye paced slowly inside the observation cabin, whispering his recording notes into the throat microphone. The camera faithfully recorded his every muttering and simultaneously captured the various audio signals from the engineering communication channel.

In just fifteen minutes, he had accumulated so much video footage that he could never use it all in his lifetime. So he simply chose an excellent observation point a kilometer away from the main axis, set up two cameras with different focal lengths, took out his tablet computer, and continued reading the novel he hadn't finished.

An hour later, the reactor output power increased to 5%, continuously pouring nearly a billion watts of terrifying heat into the heat exchanger and cooling system. The cooling strips, like a silver waterfall, gushed out continuously at a speed of 20 meters per second.

The reactor control team members smiled, and the heat exchanger engineers also seemed quite satisfied.

Even Mi Nan, who always had a tense expression, relaxed her brows slightly, and Song Xingye turned his gaze back to the novel in his hands.

This is a hard science fiction novel about humanity's first mission to explore Jupiter. Although the plot is simple and straightforward, it is also very interesting. The novel is set ten years in the future.

He couldn't help but feel a bit absurd; the real mission they were currently undertaking was so extraordinary that it would dwarf the Jupiter exploration program in that novel.