215: Chapter 215 Next time, he'll send a signal into space.

The [ EARTH - MOON RELAY / NO LINK ] at the very bottom of the main screen was still lit up, and Jiang Lin had already dragged the access route into a blank mission page.

The page required him to first fill in the current epoch of the target orbit.

The old archives preserved a family of three-dimensional periodic orbits located on the far side of the moon and near the Earth-Moon L2, which could not be directly copied into the navigation coordinates of the current epoch.

The reference epoch, orbit-insertion phase, antenna-pointing window, and correction amounts required to maintain the orbit all corresponded to the Earth-Moon state of that year before the cataclysm.

The moon was still there, but the old coordinates had long since lost their navigation significance.

Jiang Lin returned the pre-cataclysm orbital state to the reference column, and behind the current epoch item, he connected the Seventh Canopy Station, the surviving equipment of the ground observatory, and the Outpost's long-term timing system.

"The house numbers are all left quite complete, but the time to open the door still has to be recalculated."

He wrote a new name at the very top of the mission page.

[LF-03 Earth-Moon Access Link Restoration]

The mission objective was only to restore a bidirectional link capable of completing authentication, without assuming that the facilities on the far side of the moon were still operating.

As long as the challenge returned by the far side of the moon could pass verification by the old root directory public key, the link would enter the next stage; if no response was received, the conclusion could only stop at no return, and it could not write a death certificate for the far side of the moon.

That night, the ground-extended search in the observation indexing area was all transferred to low priority, and the twenty-four read heads only completed the queued media protection tasks.

Jiang Lin retrieved the emergency access volume from the low-dependency civilization core, and along the LF-03 access route, he reverse-checked the spacecraft, TT&C stations, launch sites, and manufacturing dependencies required by the ground end.

This query ran for six days.

Some of the dependencies pointed to specialized factories that had already vanished, some fell in old industrial zones with surviving structural records on the surface, and three launch sites retained the last engineering surveys and mapping before the cataclysm.

The closest to the Outpost was LC-04, located more than three hundred kilometers away in the southeast direction.

Its launch service tower had already exited the status table, and the propellant depot and power supply center had no feedback whatsoever, yet the underground assembly room, flame trench, and two transport channels still retained structural indexes.

Jiang Lin handed over the first batch of long-distance surveying and mapping tasks to twelve engineering platforms, and pulled two relay vehicles and one mobile maintenance unit from the underground trunk line.

After the motorcade walked out of the Outpost's existing communication coverage, it left passive road signs every fixed distance, and upon encountering bridges and subgrades with unknown load-bearing conditions, light inspection platforms would cross first.

The three hundred-plus kilometers were not compressed into a straight line on the mission map.

The motorcade spent over four months and finally reached the periphery of LC-04; the spare parts points, charging spots, and relay stations newly built along the way took up nearly another year.

In the autumn of the 36th year of the current cycle, Jiang Lin stood in the center of the old launch pad for the first time.

The ground could still outline the contour of the circular service area, and the original service tower only had its lower half leaning westward left, with several platforms squeezing against each other as the wind passed through the rusted-through grates.

The flame trench below the launch pad accumulated half a trench of gravel, with large areas of the refractory lining peeling off, yet the main concrete at the deepest part did not show through-cracks.

Both underground transport channels could be found; the eastern one was blocked by collapsed debris for more than seventy meters, while the western channel led all the way to the outer wall of the assembly room.

Jiang Lin walked a full circle along the launch pad's reference point, measurement rods moving in and out of the old hole positions, and the structural diagram on the folding terminal gradually brightened from gray bit by bit.

The original service tower was not on the reuse list, and the old propellant tanks, flight computers, high-pressure valves, igniters, and all pressure-bearing components exceeding their service life were also crossed out in batches.

The reuse list ultimately retained only the retested foundations, the main body of the flame trench, the pipe galleries buried in the rock strata, and the clearance space originally cleared for launch vehicles on this site.

When the old liquid oxygen tank underwent its first hydraulic pressure re-verification under isolation conditions, a circle of strain gauges quickly developed unacceptable branching.

The automatic pressure relief valve immediately opened, the test water returned to the settling basin along the discharge pipe, and the machine responsible for operation stopped outside the safety boundary to wait for the next task.

Jiang Lin deregistered the old tank from the equipment tree.

"The pit can still be kept, but let's replace the tank with a new one."

The old launch site saved him a few years of civil engineering, but it did not save him a flying industrial chain.

Starting from the 37th year, the missions between the Outpost and LC-04 were no longer strictly divided into two places.

New profiles and electromechanical modules manufactured by the underground industrial zone were sent to the launch site along the surface transportation line, and qualified heat-resistant materials and structural samples dismantled from LC-04 were sent back to the material center for analysis; return vehicles were rarely empty.

The Seventh Canopy Station continued to work on another line.

Jiang Lin restored its high-precision angular datum, and deployed optical measuring equipment at two old observation points far enough apart, re-fitting the state of the current Earth-Moon system with years of continuous observations.

The orbital families left before the cataclysm were still usable, but every launch window, correction pulse, and antenna-pointing table had to be switched to the current epoch and regenerated.

The vicinity of the Earth-Moon L2 was also not an empty space where satellites could be parked and left unattended.

For the repeater to enter a suitable periodic orbit, it needed to continuously see the Earth while keeping the far side of the moon target within the communication field of view, and subsequently reserve margins for orbit maintenance and attitude control.

Jiang Lin took the reference orbit in the old flight volume as the initial value, re-integrated using the Earth-Moon state obtained from current observations, and then allowed different navigation errors, thrust deviations, and delayed orbit-insertion conditions to enter Monte Carlo verification item by item.

This part of the calculation could be completed in a fixed workstation, but the manufacturing end had to make up for missed lessons starting from materials.

The civilization core preserved several sets of mature launch vehicles capable of undertaking Earth-Moon relay missions. The set with the highest performance depended on three specialized factories that no longer existed, while the lowest-dependency version used liquid oxygen and methane, and its flight technology and ground equipment could correspond to LC-04's old interfaces.

Its carrying capacity left sufficient margin: the launch vehicle was responsible for delivering the repeater into the Earth-Moon transfer orbit, and the repeater then used its own propulsion system to complete mid-course correction, target orbit capture, and subsequent maintenance.

Jiang Lin chose this set.

The flight plan continued to maintain the verified old configuration, while the Wasteland processing line started from material test samples to re-obtain every manufacturing qualification.

The liquid oxygen line was rebuilt from air purification, compression, separation, and cryogenic storage, while the methane line was connected after water electrolysis for hydrogen production and stable carbon source processing, with the products undergoing dehydration, purification, and batch analysis.

After the new storage tanks completed weld inspection, pressure resistance, and vacuum interlayer re-verification, they were first filled with liquid nitrogen for a cooling cycle. Valves, pipelines, and fueling arms had completed multiple rounds of contraction and re-warming before actually contacting the flight propellants.

The first batch of liquid oxygen and methane meeting purity requirements entered the ground acceptance loop to complete batch sampling, heat exchange loads, and cold joint debugging.

What the assembly room lacked was not just an engine.

The combustion chamber liner, turbine hot end, cryogenic valve seat, tank plates, seals, and non-destructive testing equipment each dragged out a string of material and process dependencies; until any item finished its test samples and destructive appraisal, the material designation on the old blueprints could not be changed to a flight part.

The Outpost's processing area expanded eastward twice, and vacuum smelting, precision casting, clean assembly, and high-pressure testing were divided into mutually unconnected areas.

Some of the single-purpose machines originally manufactured in batches for underground engineering also changed their jobs.

Transport platforms began moving cryogenic pipe sections, inspection platforms ran automatic scans along welds, and maintenance platforms were responsible for replacing consumable modules on the test stand. What truly required Jiang Lin's signature was still material release, design status, and flight configuration.

By the 39th year of the current cycle, LC-04 already had a new, low service tower.

It did not pursue restoring the shape of the old tower. Parts of the umbilical interfaces, personnel evacuation, and high-altitude maintenance that originally belonged to multi-person crews were rearranged to ensure machines could complete most operations from the ground.

The flame trench under the launch pad was cleared down to the original base plane, all damaged linings were replaced with new ones, and the water system and discharge area each ran through their independent loads.

Jiang Lin newly built an engine test stand on the north side of the site.

Before the first full-scale qualification engine entered the test stand, the injector, ignition system, turbopump, and thrust chamber had respectively undergone cryogenic flow, overspeed, pressure cycle, and hot-component tests.

In the autumn of the 40th year of the current cycle, it finally obtained the qualification for full-mission-duration ignition.

Jiang Lin sat in the underground control room 180 meters away, with four screens in front of him respectively displaying the propellant status, engine boundaries, test stand structural response, and physical feedback from the evacuation zone.

The last patrol machine retreated past the red line, and all ground tasks for LC-04 were locked down.

After the pre-cooling sequence was completed, the automated program opened the valves in turn, and the turbopump rotation speed entered the ignition window.

The first ball of flame spread from beneath the nozzle into the flame trench.

The desk in the control room soon began to vibrate continuously, and Jiang Lin steadied the metal clip holding the paper test sheets to keep it from slowly creeping down the edge of the desk.

Through the external camera, the exhaust plume brushed against the newly laid heat-resistant lining as it rushed toward the discharge area, while white water vapor swept past the low service tower and was carried by the wind toward the cleared barren land.

This was the loudest sound Jiang Lin had ever heard in this world since coming to the Wasteland.

He continued to watch the screen in the original order.

The combustion chamber pressure, mixture ratio, turbopump vibration, thrust chamber wall temperature, and test stand load all remained within the acceptance envelope, and the program shut down as planned after the full mission duration ended.

The exhaust plume vanished, the water in the deflector trough continued to boil, and the ground platform only began to move once the temperature and gas monitoring returned to the acceptable range.

The task page had already scheduled the assembly window for the next engine, and the test stand peripherals could be activated in as little as three hours.

Jiang Lin dragged the start time to the next morning.

"Let's call it a day here and let the deflector trough dissipate all this heat."

Only after saying this did he release his hand holding down the metal clip.

At the bottom of the test sheet, the status of the qualification engine had changed from pending verification to passed.

Even after the engine was able to ignite, that road to the far side of the moon had still only traversed half of the ground leg.

The key fragment stored at the Seventh Canopy Station was read from the passive mirror, while the other part of the observation index area remained in Sector 16, and a long-term online complete key chain was not established between the two locations.

Jiang Lin only combined the authentication materials in the temporary execution area of the isolated terminal, and after generating the task signature, he immediately cleared the working status, and then used two Physics records to separately prove that this combination used the correct version.

The repeater itself did not carry the complete key capable of unlocking LF-03.

It only saved public routing, capture sequences, and restricted forwarding rules, while the actual challenge-response was still completed jointly by the two separate ground authentication terminals.

This way, even if the repeater lost control or was incorrectly hijacked along the way, the main archives on the far side of the moon would not surrender their access rights along with it.

The first repeater engineering prototype was fixed to the attitude table in the LC-04 assembly room.

On the ground, Jiang Lin fed it a round-trip delay of over two seconds, orbit-dependent Doppler shifts, segmented packet loss, and long periods of no return, while at the other end, the offline simulator in the LF-03 root directory initiated a challenge according to the old protocol.

Antenna capture, code switching, cache protection, and authentication forwarding each ran through their worst-case combinations, and any response that could not prove its origin would be left in the isolation zone and would not be automatically sent to the main ground archives.

The engineering prototype subsequently entered thermal vacuum and long-cycle attitude tests, radiation qualification of critical electronic components was completed separately in the materials testing area, and the flight hardware was manufactured by another assembly line that did not share equipment batches.

In the forty-second year of this cycle, the flight repeater completed acceptance, and the unfueled two-stage launch vehicles entered their dry storage positions respectively.

The launch site already possessed the equipment to send them into the sky, but Jiang Lin left the ignition permit for the next cycle.

The true Earth-Moon mission began with transfer, final assembly, fueling, and launch, followed by days of flight, orbital correction, lunar backside capture, link searching, and potentially long periods of unresponsive waiting.

He had lived in this Wasteland for forty-two years of this cycle, the close-up lenses inside his protective mask had been replaced for the third time, and after walking down the service tower's maintenance ladder, his knees needed a moment to recover on the platform.

Returning to reality would restore his body to eighteen years of age, while the Wasteland would not tick away an extra second between two transmissions.

Leaving the longest leg of the mission to a younger body was much more meaningful than proving to oneself in front of the launch pad that one could endure for a few more years.

On the second day after the flight hardware was sealed, Jiang Lin connected the underground Outpost, the observation index area, the Seventh Canopy Station, the surface transportation line, and LC-04 into the same long-term unmanned maintenance test.

All non-essential manual operation entrances were sealed, and the remote links only retained the highest-level alarms that would trigger a safe shutdown.

He himself moved into the old control area of LC-04 to live, and the underground system over three hundred kilometers away maintained contact with him only through status summaries.

The earliest batch of engineering platforms had been in service for nearly forty years, and expansion no longer pursued numbers on the asset tree.

Whenever an old machine was retired, its tasks were first taken over by a backup machine in the same zone, the disassembled modules were graded according to remaining lifespan, and anomalies that could not be locally closed would have their sections frozen until Jiang Lin's next arrival.

During this time, the Outpost independently replaced three sets of pumps, two sets of fans, and a batch of track power modules; the observation index area completed the return of media to storage; and the timing reference of the Seventh Canopy Station was not interrupted.

Eleven tasks requiring postponement had appeared in the task tree, but not a single one crossed the safety boundaries pre-drawn by Jiang Lin to push forward recklessly.

A month in reality would not make the Wasteland's pumps turn one extra circle.

What Jiang Lin wanted to verify was the period following the next launch.

He might stay at LC-04 for several consecutive months, or even need to focus all his attention on the Earth-Moon link, at which point the pump stations, civilization core, and media warehouses dozens of kilometers underground could not wait for him to sign a maintenance ticket every day.

In the forty-third year of this cycle, the long-term unmanned maintenance test reached a full four hundred days.

When Jiang Lin returned to the Outpost, the railcar drove all the way from the north entrance to the observation index area, and every section of the underground trunk line already in use along the way had independent power supply and low-power lighting.

The busbar of the old power station was maintained within the approved range, the drainage stations started and stopped sequentially according to the water level, and the machines on the distant construction branch road were still processing the next batch of spare parts for LC-04.

The lights along more than forty kilometers did not always reach the same brightness simultaneously, the maintenance sections would dim, and as the transport platform passed, a row of position lights would move forward along with it.

The entire trunk line was already able to continue operating in the absence of the only living person.

Jiang Lin completed the final round of task sealing in Assembly Room No. 1.

The current Earth-Moon ephemeris, launch window, launch vehicle flight software, ground telemetry and control sequence, and LF-03 authentication package were written into three sets of storage media brought from reality, while the Wasteland side retained engineering copies that did not share power sources with each other.

The flight hardware of LC-04 was in dry storage, the propellant production line was maintained in no-load preservation, and any fueling valves required him to reacquire Physics authorization after arriving in the next cycle.

Several statuses at the very top of the task page had changed.

[ LC-04 Ground Facilities: Acceptance Passed ]

[ Earth-Moon Repeater: Acceptance Passed ]

[ LF-03 Ground Authentication Chain: Valid ]

[ Far Side Lunar Facilities Current Status: Unknown ]

That forty-one-year calendar book by the door had long since been leafed through to the end.

Jiang Lin bound another two years of handwritten pages behind it, and on the final page, aside from the LC-04 sealing date, was also recorded the seed batch to be changed for the next batch of wheat in the Outpost's greenhouse.

He packed the calendar book, the three sets of storage media, and the paper task cards into two narrow boxes brought from reality with this cycle, and T-01 transported them along the internal track to the outside of the fixed receiving yard.

The shell and wheel-edge modules of this transport platform had been replaced many times, but the shallow dent bumped during the ramp test still remained on the earliest chassis.

Jiang Lin untied the fastening straps between the box body and the chassis, but T-01's task page was still waiting for an unloading confirmation.

He signed it on its behalf and casually jotted down the wheel-edge components needed for the next maintenance onto the reality checklist.

"Next cycle, replace the wheel-edges first before I assign you long-distance work."

T-01 retreated along the track beyond the red line, its yellow position light paused in the assembly room for a few seconds, and then turned toward the internal standby position.

In the center of the fixed receiving yard, only Jiang Lin and the two narrow boxes remained once again.

At the very top of the two narrow boxes lay the flight task card for the next cycle.

[ Primary Task of Cycle 15: Deliver a communications satellite to the designated Earth-Moon relay orbit ]

[ LF-03 Response: Verify after link establishment ]

Jiang Lin buckled the handles of the two narrow boxes into the attachment straps on his body, and finally confirmed that no Wasteland materials had entered the judgment range within the receiving zone.

He thought of the cup of soy milk on the reality warehouse workbench with its straw not yet inserted, and recalled the public briefing where the site seats were already filled by nine o'clock.

The lights of the assembly room vanished from his field of vision.

November 29th, 06:01:00.

The red electronic clock of the independent warehouse had just ticked past one minute.

That cup of soy milk still carried warmth, and the water vapor on the cup wall had not yet dissipated.

Jiang Lin raised his right hand, the loose skin on the back of his hand had recovered, and his knuckles had returned to how they looked forty-three years ago.

He bent down to untie the attachment straps, and his lower back felt none of the soreness that followed the LC-04 maintenance ladder.

The two narrow boxes landed inside the yellow boundary line, the cover of the forty-one-year calendar book had worn white, with two additional years of handwritten pages trailing behind it.

On his mobile phone schedule, there were still two hours and fifty-nine minutes left until the nine o'clock public briefing.