White Crane — The Shirotsuru Program (Under revision)

[Daitō]

(OOC Note: The events of this series of posts are under revision, do not consider them strictly canon until after the date on them has passed)
White Crane: Part One — Origins

Ever since the cancellation of the UYS program in 1997, there have been efforts to repurpose hardware intended for it. Perhaps none have seen as much contention as the Shirotsuru Orbiter, which was the program's first—and only—orbiter. While it was useful as a base for its replacement, the UHS, it alone was deemed unfit to fly into orbit thanks to its less advanced systems and overall weight. After all, it was, thanks to its 3.6 thousand kilogram higher mass compared to later spacecraft, ill suited for docking with a space station and also for carrying heavier payloads. Not only that, thanks to significant cost overruns, the program was believed unsustainable in the wake of a financial recession in the late 90s, and so, it was put to rest for the time being. Over a decade later, as it sat in a hangar at MFS Artsiv, the world went by, and slowly the program faded from the public eye.

Then, in late 2001, everything changed. The Kyūden IV space station, planned originally as a stopgap for the space program until a larger station could be built, once again caught the public's imagination. At first, it wasn't much, just two KYE-type core modules docked together, but it was enough. The arrival of Expedition II in July of 2002 aboard their Ryū YK spacecraft would see this spotlight brighten further, especially following the release of Uchū Kichi (宇宙基地, Space Station), a documentary detailing Expedition II's mission aboard the station including the arrival of the Kasei Module, in 2003.

Pictured: Kasei Module as seen in Uchū Kichi

In part a result of this new-found interest in itself, the DNSA would start to see its funding slowly but surely increase. By 2006, it had completed the Kyūden IV space station and would begin to look into other projects. It was then that the UYS Program was reexamined. This led, in part, to a series of programs to recycle unused UYS equipment and to fine tune it. One such project that came from this was the UHS spaceplane set to launch in October 2021. It would, at least in the early years, make use of the older Shirotsuru Orbiter for aerodynamic flight tests until the Tenryū Orbiter was ready to take over that role. Another program that came from this was the so-called "UYS Applications Program", which examined how the DNSA could make use of other hardware. It was thanks to that program that the Tenjin CK-22 through 43s would get their current solid rocket motors, while another would begin work to modify the purpose-built LC-17A and B facilities for the UHS program. However, this is not the story of those projects. Rather, it is a story of a space station derived from the UYS launch system's components.

The UYS Station Team had almost immediately come to the conclusion about at least part of the station: It should, in some fashion, incorporate the External Fuel Tank (EFT) into the design, whether it meant disassembling it on orbit and making habitats out of the pieces of it or creating a wet workshop out of it. And so, a design competition began to find the most optimal design for such a station. Some of the following designs were pitched, and the modern program would indeed take elements from many of them.

The Zayasu "Space Facility"

The "Space Facility" concept proposed by the Zayasu Aerospace Company was one of the earliest brought forwards, calling for two launches of a modified UYS/UHS Fuel tank to LMO which would be rendezvoused and berthed to one another. The bottom of each fuel tank would have a built-in habitation module or science lab, with the second launch also carrying solar arrays. It was rejected as a result of fears that it would affect the flight profile of the spacecraft launching it, presumed at the time to be crewed, thus causing further unnecessary risk to it on two separate occasions. It would also require a specially designed system by which the fuel tanks would rendezvous, which was a capability that the UHS Orbiter was likely to lack, not to mention it would only be capable of having a single spacecraft docked at any given time, further limiting its usability.

The Adler "Spacelab"

The Spacelab proposal by Adler is seen by many as one of three early "ancestors" of the Shirotsuru Space Station, using a hull similar to the UYS and UHS orbiters as a base for space station, which would see two additional modules attached to a docking port in what would've been its hull. It would also see the attachment of two truss segments near the engine block as well as a telescope and solar arrays at the top of the fuel tank. The Hydrogen and Oxygen tanks would've been converted into both habitats and laboratories for the crew. It would have two docking ports, one for a UHS Orbiter and one for any other visiting vessel to dock with. However, the means by which supplies carried aboard the UHS would enter the station, that being a design often referred to as the "Scissor Lift" by members of the project thanks to its shape, proved to be its downfall. This would require extensive modifications to the UHS orbiter in order to lift a Multipurpose Logistics Module to its docking port, modifications the UHS team was unwilling to make as it would seriously limit the given orbiter's normal capabilities.

The Kitagawa Orbiter-derived Space Station, Proposal I

The Orbiter-derived Space Station was one of the most seriously considered designs for the station by the DNSA, even though it lacked the incorporation of the External Fuel Tank into the design as mandated by the competition. However, it would see extensive modifications to the UYS orbiter Shirotsuru upon the completion of its atmospheric flight tests in the UHS program and the addition of Five large modules to the station, with the first launching on the orbiter. Due to its failure, however, to make use of the EFT in the design, Kitagawa Technologies would be asked to revise the design, leading to the next design.

Kitagawa Orbiter-derived Space Station, Proposal II

Proposal II/III Intertank Crew Tubes

Proposal III

Space Station Shirotsuru (Note: Proposed Zayasu-manufactured Emergency Crew Return Vehicles docked)

Eventually, the UYS Station Team would settle on a modification of the Kitagawa Technologies design, one which would include elements of the Adler Spacelab proposal. It is this design that is scheduled for launch in 2022 and will see multiple flights starting in the weeks immediately after its launch in order to outfit it for permanent habitation. If it is successful, it will prove the viability of similar designs, opening up an entirely new way to live in space. Space Station Shirotsuru will, in the coming years, serve as a base camp for expeditions beyond low Mundus orbit to the moon and beyond.

[Daitō]

White Crane: Part Two — Construction

Despite a design for the station being picked, the sheer scope of the issues encountered by Artsiv and other facilities around the nation as they began to allocate tasks and start the challenges of converting a Shuttle stack could hardly be overstated. Even in the early days, as project teams were still being formed, many argued that the effort of converting a shuttle into a station would be better invested into a clean-sheet station similar to previous studies of shuttle-built designs. The DNSA had, after all, spent decades imagining how to assemble a station launched by a shuttle, whereas the shuttle-converted station was still rather... immature, to say the very least. This would, of course, result in people asking whether such a design was truly worth it, if it was faster or more capable than a shuttle-assembled station, and of course lingering debates on its value and scheduling would haunt the project over the next few years as costs and scope spiraled and budget requests had to be altered as a result. Were it not for the rapid progress and completion of the Rokkenjiman station Adora, it was quite possible that the Space Station Shirotsuru program would've been abandoned and alternate projects might have replaced it--were it for better or for worse, depending on who you might've asked. When the Akari was announced, many in the nation were able to convince themselves that its existence and rumors of its ability to launch very heavy monoblock payloads on its launch vehicle had to mean that Adora was only the beginning, another stepping stone to a massive presence in space. Despite the fact that, at least at the time, there was no word on such plans, the Imperial Government continued to evaluate Space Station Shirotsuru as a priority through the most critical years of the project as hardware began to be constructed.

Of course, the program wasn't all troublesome. For every challenge as daunting as the orbiter and structural revisions, there was one that was found to be rather straightforward. In 2015, as Artsiv and Awara contemplated the first cuts into Shirotsuru's structure, the production of a permanently-orbital shuttle-mounted lab was well-underway in Tsukishima. While Yuzawa was struggling with the inflatable intertank corridors and the challenges of foam which was too well-sealed yet also too poorly attached for long-term use, other teams were issuing final contracts to begin the production of the station's 50 kW Shirotsuru Power Module (SPM) and pair of robotic arms. The Autumn and Winter of 2015 would come to be seen as the nadir of the project, when Shirotsuru managers dodged questions about its justifications and tradeoffs from various agencies and the Imperial Diet as well as internal dissent from other DNSA station planners who had seen their concepts discarded for a makeshift alternative.

Despite this, time would prove fears of cancellation unfounded. While yes, it had started to become more expensive than initially anticipated, the immense pressures placed on the DNSA's schedule and budget also served as a lure which drew teams in to solve the challenges of the project. One by one, systems and subsystems passed from preliminary design reviews to prototyping, then fabrication. As days turned to weeks, men and women would go to work on the project and parts began to take shape. In Goris, the external tank began fabrication, being designated ET-001. This unique, one-time tank proceeded in a lightning-fast pace, at least for new hardware, and would in time gain many nicknames among engineers. At the same time, the Yuzawa team began its modifications to the orbiter's primary structures. Progress, when it came, was certainly noticeable to a trained eye as engineers tore apart the spacecraft's aft boat tail to begin the installation of new engines and propellant lines.

When this task was completed, the most notable change to the orbiter were made. In 2018, the White Crane's wings were clipped; she would never land again. As with other systems removed (i.e. landing gear actuators and doors), this process would prove not as simple as merely cutting them away with torches and saws. The orbiter's wings and tail were, after all, some of the most critical lead structures on the spacecraft, though the addition of an extra set to the stockpile would likely assist in the construction of future UHS shuttles. Many systems vital for flight would require conversion, such as the radiators, tanks for cryogenic fluids, OMS and RCS, radars, and star trackers had not yet been installed when the UYS program was cancelled. Another system which, thanks to the UYS program's cancellation, had gone uninstalled was the shuttle's internal airlock, yet unlike others, this would not be installed. Rather, it would be replaced instead by an external airlock fitted to the aft of the station's integrated laboratory module and eventually be phased out in favor of a dedicated airlock module. This airlock would be just forwards of the station's mounts for deploying her power module from the bay.

As time went on, every kilogram saved in removed heat shield tiles and wings, as well as other hardware, would be returned as the station's systems swallowed the project's weight margins at a most terrifying rate. 2721 kg of landing gear would become the mass margin for the new pressure tunnel linking the intertank to the orbiter and its ascent fairing. Nine thousand kilograms of tiles would be melted into an entry on a weight and balance sheet before emerging as the margin for the intertank tunnels themselves. 907 kg of fuel cells and hydrogen tanks for said fuel cells were replaced in favor of the new power system mounted in the bay and another nine thousand kilograms of wing and tail structures and actuators were replaced with modifications to the systems deemed critical to support the orbiter's flight in her new home, and so on and so forth. In total, more than twenty metric tons of additional payload were added through removal of unnecessary systems. Some would need to be unbolted, cut, or otherwise removed like the shuttle's wings and tail. Much of the weight removed would ultimately come back in the form of various systems to enable long-term operation of a spacecraft that was originally designed for mere weeks in orbit. The 114.3-centimeter diameter fuel cell hydrogen supplies were replaced with new tanks of a similar volume to augment the station's oxygen supply. Additional water tanks were also incorporated into the cabin. By 2017, the station's design was largely stabilized, with its total launch weight reaching nearly 150,000 kilograms— more than the performance of the Tytorian moon rocket and with almost twice the mass of some of the largest space stations considered for a rocket of such size. Major hardware such as the orbiter itself was already undergoing conversion by their respective subcontractors, and the external tank's tubes were beginning to be built. The slips in the schedule began to shrink and the launch date began to stabilize. In spite of the odds, it seemed possible the station would launch by 2022 after all.

[Daitō]

White Crane: Part Three — The Flight of the Dragon

With the successful completion of the final flight tests of OV-201 (a process that would, in order to ensure the safety of the vehicle, be repeated for all shuttles to follow), now named Tenryū, the first launch was swiftly approaching. This flight would be a test of critical systems necessary for the construction and operation of Shirotsuru in the early days. Specifically, the mission, UHS-01, would see the vessel rendezvous and dock with the Kyūden IV Space Station before undocking the Setsugō module then, with the assistance of its SRMS, repositioning it to Port 1 on the Myōjō module's Multiple Docking Node (MDN) then redocking. This will mimic the transpositioning of Node 1 to the bottom docking port of the station when launched, though it would naturally lack the use of a second robotic arm to aid in this task. Once this job was done, the plan called for a stay aboard the station lasting a week and a half, during which time preparations would be made for its decommissioning at the start of 2022.

It was an odd sight, seeing the vehicle fully stacked on the pad on the night of the 23rd, its orange cryogenic tanks starkly contrasted against the brightly illuminated pad and white orbiter. After all, for the majority of the manned program's history, crews had launched aboard a Tenjin variant. But in the coming hours, everything would change, and a new era of Daitōjin spaceflight would begin.

As the sun rose over the eastern coast of Tsukishima, the launch grew ever closer. The countdown had begun a while ago as the crew—Uchūnauts Hiroji Ryoma, Jin Shirokawa, Kinuko Arakawa, and Erich Weber—boarded the spacecraft and prepared for launch. Hours would pass as the launch window approached. At T-7:30, the orbiter access arm would retract, leaving the crew alone, and only a minute and thirty seconds later, the Auxiliary power unit would start. Just a few more minutes remained until liftoff, and likewise, only ten steps were left until then. Both inside the cabin and in launch control, there was a sense of trepidation, after all, the basic design may have been relatively old, but this was an entirely new vehicle at the end of the day. After a few more minutes, over the comms loop, a voice came over, counting down. It was go-time.

"T-15 seconds and counting...

12...
11...
10...
9...
8...
7...
6...
Main engine start..."

The shuttle's main engines roared to life like a loud, continuous thunder which echoed for miles around.

2...
1...
Secondary engine ignition and liftoff!"

"Go Tenryū!"

The vessel leapt off the pad with a ferocity seldom felt by crews until the beginning of the lunar program. After two minutes, the shuttle's Liquid Boosters would separate, falling back to Mundus where teams were already waiting to recover them. The orbiter and it's external fuel tank, on the other hand, would continue onwards and upwards, performing MECO at eight minutes twenty-four seconds before achieving orbit forty-five minutes after liftoff. Now, all that was left was to rendezvous with the station and perform the tasks necessary for the mission. It would take a little over a day from here, however, to do so.

The crew awoke on Day Two to the 1961 classic "Ue o Muite Arukou", which had become something of a tradition in the DNSA for the first day of any mission in a new spacecraft or station, starting with the ill-fated Kyūden I while also paying homage to the program's "lost love", that being the station they were preparing to rendezvous with. Over the next few hours, the crew would see the station draw closer and closer through the binoculars carried aboard. Eventually, the fair ship would come to dock at port 5 on the Setsugō module. The crew would then, after getting the go-ahead, briefly board the station before preparing the module for its undocking. At approximately 17:31, the vessel, alongside the Setsugō module, would undock once more.

Repositioning the module would a minor challenge, after all, while there had been simulators, nothing was ever quite the same as the real experience. First, the crew would need to close both the external and internal hatches of the station's MDN and Setsugō. Once Uchūnaut Jin Shirokawa accomplished that and subsequently returned to the orbiter, the hatches allowing for the crew to enter Setsugō from the orbiter would be sealed and the shuttle and module wound undock from the station. Then, Tenryū would over the course of the next few hours reposition itself so that it would be pointed 90 degrees relative to port 1 on the station's MDN before Mission Specialist Kinuko Arakawa grabbed the module with the vessel's SRMS and undocked it from the shuttle. The next phase of the mission would see the module berthed to port 1, after which the orbiter would dock once more. However, they would not reenter the station for today, saving that for the day after.

The next few weeks would see the crew perform various operations relating to the operation of the station, starting with reconnecting electrical cables between Setsugō and the rest of the station. That would largely be a simple task, one that would be accomplished in just a "few" hours, at least as far as spaceflight went. The rest of the time aboard would be spent performing experiments and preparing the station for its decommissioning.

Tenryū as seen from the Rikai module, 26 October

On the 27th, thanks to advancements in technology, the crew of Kyūden IV would be able to cast their ballots in the election. Later that day, Hiroji Ryoma and Jin Shirokawa would go on EVA to inspect the exterior of the station as well as perform a sort of "practice run" for spacewalks aboard Shirotsuru. While Jin Shirokawa would remain attached to the orbiter via the Robotic Arm, Hiroji would find himself test-flying a new Manned Maneuvering Unit that would aim to assist in future missions bot to the station and to various satellites.

Erich Weber monitoring the spacewalk from the Kasei module
Photo taken by Hiroji Ryoma

Eventually, the time would come for the crew to depart, and so they would on the 1st of November. They were the last crew of Kyūden IV, and soon, the last spacecraft to visit, a modified Kōnotori II, would launch in order to deorbit the station. However, that would be another story for another time. For the crew of Tenryū, however, this mission was done, and at 5:57 AM on the 2nd of November, the orbiter would land at MFS Artsiv.

Tenryū lands at Artsiv

It was the end of an era, but also a symbolic passing of the torch which would truly open the gateway to the stars for years to come. Now, all attention turned to the coming launch of Space Station Shirotsuru.OOC Note: For those who did not read the section in the title on this post, this takes place from October 23rd to the 2nd of November.

[Daitō]

White Crane: Part Four — The Beginning of an Era

Early in the morning of January 6th, 2022, the relative calm of the southern Alucard was broken by a loud sonic boom. The Kyūden IV Space Station, whose program was officially concluded by the DNSA with the successful return of UHS-01 in early November, had been docked to by Kōnotori II-17, a modified Kōnotori II Orbital Resupply Vehicle in mid-November. At roughly 11:34 AM AST, the first burn was performed, lasting approximately 21.5 minutes. The second was then performed at 01:34 AST and lasted for twenty-four minutes. The final burn commenced at 17:07 AST and would be performed until depletion with the vehicle's main thrusters. And as the sun arose over the southern sea, observers from all around (though safely outside of the area where it was targeted to impact) would capture images such as the following:

The Palace among the Stars, scattered across the sky

With the successful deorbit of the station, eyes quickly turned once more to Shirotsuru, now scheduled to launch on the 11th of March. As the weeks wound down, many across the country watched eagerly to see what would come of the old station's replacement. Would it even work? And if it didn't, then what would come of the program?
Eventually, the final week before launch approached, and there was naturally an air of excitement and fear among the members of the UYS Applications Program. After all, they were about to see the culmination of close to two decades of work or thirty, if you counted the original UYS Program. As Tenryū was prepared in the VAB's High Bay 1, so too would Shirotsuru in Bay 2, as it had been for the better part of the last five months. Tenryū would serve as a "launch on need" mission for the time being, even as her sister, Shirotaka, underwent her own flight tests in preparation for a launch later in the year. Should anything go awry during the launch that would require repair as soon as possible, the crew of UHS-02 would launch a week early in order to save the station. Of course, everyone on the ground was hoping and praying that this wouldn't be necessary.

Thanks to the removal of the vessel's internal airlock module, the forward cargo-bay pressure bulkhead was able to be modified to allow for a direct, axial passage into the ILM (Integrated Laboratory Module), now dubbed "Koshiba" in honor of one of the founders of neutrino astronomy, thus allowing for it to save meters of valuable space. Like similar laboratories planned for future shuttle flights, its first segment would effectively be the "core" of the module, featuring equipment necessary to sustain the module as well as a window on the overhead to allow for the observation of external experiments. The second segment, located to the aft of the first, was the experiment segment, built with several drawers designed for mounting temporary experiments aboard the station. The overhead circular plug of this segment was fitted with the experiment airlock, a small airlock intended for the exposure of experimental samples. The third segment, not standard among other such planned modules, added additional experiment spaces, such as a furnace and a freezer, but also additional ECLSS. Most importantly, however, was in it's overhead plug, which mounted a Common Berthing Mechanism which would permit further expansion to the station as well as docking for the Block I variant of the Karasu ECRV.

Located at the back of the Koshiba laboratory, a duplicated forward cone led into an airlock derived from planned ILM modules. Its placement would mean that it could be used without interfering with passage between Koshiba and the orbiter's crew spaces, which would now be used as the station's initial habitat and its control deck. To the rear of that, the Shirotsuru Power Module (SPM) located on the ILM's external pallet was in place, designed to be folded out from the bay and deploy four massive 36.6 meter-long solar arrays that would provide the station with 50 kW of electrical power. An important part of the design was that it be modular, allowing for the relatively easy replacement of parts in the event of damage. There were formerly plans for the entire module to be able to be replaced, however, the system devised for it proved too expensive for consideration. This module would provide the batteries located beneath the cargo bay's floor to provide an average of 25 kW of power per orbit. Every remaining volume of the bay was filled with additional systems, for example, OMS refueling arrangements, the forwards and aft RCS interconnects, systems for refilling the station's consumable tanks from inside the pressure volume, and other systems that would have to be painstakingly arranged around the permanently-fixed Koshiba lab and airlock as well as the deployment systems for the SPM.

And then, a few days before the 11th of March, as Tenryū waited on LC-17B, Shirotsuru rolled out to LC-17A for the first and last time. Unlike the shuttle which was bound to service her, she would be launched aboard a UYS-derived launch stack, a requirement of the program though one which, even until the last days, was pressured to be dropped in favor of similar LRBs to those used by the UHS. As she stood there in the morning sun, the light bouncing off her white exterior (the external fuel tank had been covered in a white anti-popcorning sealant), the day had finally come. Tenryū, on the other hand, stood waiting to launch, being planned to launch later in the day just in case the station failed to deploy its panels in it's hold-over configuration after orbital insertion. So vital was it that it launched on the same day that, if the weather showed even a slight risk of deteriorating, the launch would be scrubbed and held on another day.

As the sun rose on the 11th, the go-ahead to launch had been given. First, Shirotsuru, given the designation UHS-02A, would launch, then launch control would switch over to managing the launch of UHS-02B, set to launch six hours later. However, before the launch occurred, a tragedy had befallen the station: It's holdover solar panel had failed to deploy fully, finding itself jammed and unable to rotate to meet the sun.

And so, as Tenryū lifted off from LC-17B and the clock kept ticking, it's mission had changed. No longer was it simply to bring the station online, although that was still a major component of it. No. The mission was simple now: Save Shirotsuru.

[Daitō]

White Crane: Part Five — Saving Shirotsuru

Though it was in orbit and capable of generating enough power to remain in operation, the DNSA saw Shirotsuru's predicament as one that would require immediate addressing, which led to the crew of UHS-02B being cleared for launch on the same day as the previous rocket. This was an exceptionally uncommon decision, with no station in the nation's history having been launched on the same day as its first crew and hopefully, it would also be the last. Given that they only had the one station, there was no room for the spacecraft's already precarious situation to deteriorate. And so, Tenryū's mission profile was updated to include a series of EVAs to repair the panel's rotary joint, thusly permitting it to fold out of its keep-alive position and function properly, even if it might ultimately require more frequent servicing in the future.

Flight Day One would primarily be spent launching and performing the rendezvous with the station, although morning would come early for the crew, commanded by Uchūnaut Daisuke Hanagata, as the spacecraft would soon be making its final approach to the station. Well over a week of hard work was ahead of them, but for now, the most important task was actually docking. Unlike the Hakken operated by the Rokkenjimans, the UHS orbiter lacked an extendable docking compartment, thusly necessitating that this first mission launch with a docking adapter in its cargo bay alongside supplies for the initial outfitting mission.

There was something particularly striking about the station as it glistened in the sunlight. For starters, it was massive, even compared to the venerable Kyūden IV, which in total was only about half as large. Then there was it's all-white appearance, save for the radiators and solar panel, the latter of which was locked in a 90-degree position relative to the "front" of the vessel, putting it at about a 15-degree angle away from the sun at the time that the crew began its approach. Otherwise, it seemed normal, even if its size intimidated even the most experienced pilot. As the two vessels drifted closer and closer to one another, the crew would reposition the docking module via the shuttle's RMS to its docking port before slowly but surely edging ever-closer. If they couldn't get a good docking, the mission was effectively over then and there, given that they would have no way to enter the station short of an extremely risky EVA, which the DNSA was never going to approve.

When the station was launched, a panel had been fitted to the intertank in order to cover the docking ports for the orbiter as well as, in the future, a pair of truss segments. Now that the station was in orbit, however, these had been jettisoned, allowing any visiting crew to dock. With Shirotsuru's keep-alive panels deployed, access to the docking port on the Chiheisen lab module was blocked, as the port was primarily planned for future expansion. Nonetheless, Hanagata and his crew would bring the orbiter underneath the massive structure, its docking adapter connected via its RMS to Tenryū's docking port. Compared to the orbiter's docking to Kyūden IV, this docking would seem "easy", not having to worry about damaging a module they couldn't, at least in theory, repair. Nonetheless, it was still an immensely complicated procedure, but one that would go entirely to plan, with the orbiter achieving a hard dock by the middle of Flight Day 2. Now, it was on to phase two of the mission.

While it was a priority, performing the repair on the keep-alive solar panel prior to the SPM would have to wait as the crew was, at present, incapable of accessing the former payload bay on Shirotsuru due to the nature of the station's intertank access tubes. And so, late on Flight Day 2, the crew would open the hatch on their side, although they were still separated from it via the station-side hatch. In this small space, the crew would begin hooking up the fittings designed to allow Tenryū to inflate and deploy these tubes. While it was expected that the first pressure introduced into the intertank passages would lead to them easily beginning their deployment against the vacuum of space filling the rest of the intertank. Despite this, the passages didn't seem to inflate at first. The crew tried again, but after reaching several psi on the station-side of the hatch, they were told to call it off for the day so that ground controllers could work on the problem. With disaster looming on their minds, the crew would resume their efforts early on Flight Day 3.

It was determined overnight that the friction between the fabric folds may have exceeded ground expectations, and the crew was ordered to simply supply air into the module at a slow but steady pace. The risk existed, of course, that a sudden "snap" to inflation would occur, potentially damaging the connections between the tubes and the rigid portions of the station. Thankfully, such an issue did not occur, and over the next few hours, the module would inflate, allowing the crew to finally reach the airlock and prepare for an EVA to perform repairs.

At approximately 5:15 PM AST, a pair of Uchūnauts would perform the first EVA from Shirotsuru in order to inspect and repair the keep-alive solar panel. Over the course of the next five hours, the two would work to repair a rotary joint which had become jammed due to a piece of debris that had been shaken loose during its launch. This was not necessarily surprising in light of the vehicle the station had ridden into orbit, nor was it particularly dangerous to the success of the mission, however, it would prove tedious in dislodging. Nonetheless, in time, the debris would be successfully dislodged and the panels would be deployed from their keep-alive to their operational position.

With the "rescue" part of their mission complete, the crew would spend Flight Day 4 bringing various systems online and monitoring the solar panels in the event of any further work being needed; this would allow them the chance to prepare for what would be the most arduous tasks of the mission as well: Securing the LOX and LH2 tanks starting on Flight Day 5.

With the dawn of Flight Day 5, the crew had now spent three days making Shirotsuru fit for human occupation, including the two days spent wrestling with the tubes in the intertank. Now, the majority of the crew would find itself confined to Tenryū again as these tubes were used as an impromptu airlock by the two-person team of Uchūnauts Daisuke Hanagata and Goro Hagihara, with Masako Kimura suited up in Tenryū's' airlock as a contingency. After the hatches to Tenryū and Shirotsuru proper were closed, the pair opened the inspection manhole into the LOX tank, their lights catching on the stringers and baffles of the tank. The pair would spend roughly half an hour around the base of the tank, sealing the main propellant fill/drain line in the process. This task was complicated by the baffling designed to prevent sloshing during ascent or geysering during tank fill procedures. Once this task was completed, Hanagata would perform a somewhat risky procedure where he would leap to the top of the tank, trailed by a tether in case something went wrong. Once at the top, he would jam a sealing plug into the nose LOX vent, where the vent hood had made its pre-launch contact to capture boiling LOX and the smaller port, where oxygen recirculated from the Main Engines provided tank pressurization. These sealant plugs would serve to provide a backup against the valve actuators in order to ensure the valves would never pass the crew's air supply the way they had once passed oxygen.

Upon completing their IVA into the LOX tank, the pair would close the hatch into it before repeating the job in the much larger Hydrogen tank. First, the crew would plug the hydrogen vent valve and pressurization lines near the top of the tank before making a 25-meter leap to the bottom of the tank. Once there, they would work to plug the main fill and drain lines. After close to six hours, they finished their work in the hydrogen tank and closed it as they had the oxygen tank before it. They would then test their work by bleeding a small amount of air into each tank once the intertank was repressurized, meant to be monitored over the coming days and weeks. Of course, the final results wouldn't come until increases in the station's onboard consumables could allow more air to be wasted in filling unpressurized volumes. Nearly eight-hundred kilograms of air would be needed to fully fill the LOX tank to the necessary psi for habitation, while two-thousand kilograms would be needed for the hydrogen tank. Even sparing 280kg to reach 10% final pressure required the consumables brought by Tenryū in order to charge the station's tanks. Nonetheless, while the IVA team worked in the tanks and Kimura stood by in order to assist, the rest of the crew had worked on the shuttle to prepare for consumables transfer in the remaining days.

On March 16th, for Flight Day 6, the DNSA gave the crew of UHS-02B a day of relative rest, allowing them free-reign of Tenryū, her cargo module, the ET-001 crew tubes, the passage between the intertank and orbiter, mid-deck and orbital operations center of Shirotsuru, Chiheisen Laboratory Module, and Airlock in OV-101's former cargo bay. The day would be spent in organizational tasks and cargo transfer, with the crew forming a sort of "bucket brigade" to pass cargo bags and air cannisters around the tight corners of the intertank access tubes. With major work to activate the station now complete, the time constraints on UHS-02B fell away. Over the remaining days of the mission, the crew would gradually complete the process of unloading their cargo, stocking the station's larders, and setting the station into a standby mode to wait out the time until the next crew. And as the crew pulled away on their final day, the crew was granted a view most grand of their accomplishments in the last week. The majestic White Crane of Daitō soared across the sky, its massive solar wings outstretched and ready for the next crew to arrive. What had once been deemed a risk for the agency was now turning into a source of pride.

The next mission to the station, set for launch in a month, would be performed by new orbiter: Inari. This mission would be given the task of supplying the LOX tank with the air required for habitation as well as to outfit it for said habitation.

[Daitō]

White Crane: Part Six — New Technologies, Old Ideas

UHS-03 was, in comparison to the dramatic UHS-02B, a seemingly less important mission than its predecessor, at least on paper. However, owing to its so-far unique flight plan, it would actually find itself watched by far more people across the planet. The first flight of OV-202, designated Inari by the DNSA, it carried a crew of five led by Katsuya Hisagae to Shirotsuru. The mission was three-fold: First, the crew would perform a consumables transfer into the station's soon-to-be habitation module—approximately eight hundred kilograms of air— in order to fully pressurize the module and make it safe to work in without a suit, install handrails and grappling points along the outside of the station's hull for ease of movement and to allow the station's SSRMS to move along the hull, and to perform the first docking test of a Karasu ACRV in preparation for EO-1 in June.

Perhaps the most notable part of the mission was not its arrival at Shirotsuru, but rather its launch, owing to it being the first operational flight test of a reusable flyback booster, that being BV-101 Nissaka. The idea of a flyback booster was not a new one, the UHS program had ultimately necessitated its use if it wanted to reach the flight regime the agency wanted. The technology had long been around, albeit on a much smaller scale, with the DNSA testing a liquid booster capable of gliding to a soft landing at sea in 2012, but if it succeeded here, then super-heavy lift launch capabilities could be achieved for a fraction of the cost. Even if it failed, the DNSA planned to keep testing it until it did work, but thankfully, minus a small hiccup with vehicle's forward landing gear, it would ultimately prove successful.

On Flight Day 2, Inari arrived at the station, moving to a position just above Shirotsuru's payload bay. From there, two members of the crew would board the ACRV in the payload bay, which would be plucked out of the bay by the shuttle's RMS before being released. The crew aboard would then test the vehicle's maneuverability before beginning its docking sequence with the station at the top of the Chiheisen, which had, for the time being, an adapter on its Common Berthing Adapter to convert it to the IDS standard docking port. When it would come time for the station's second node to be attached, this adapter would be removed by a cargo vehicle, likely a Konōtori II, before burning up in the atmosphere.

As the ACVR flew, it kept in communication with both the crew of Inari and with mission control. It would perform a brief fly around of the orbiter, using the opportunity to inspect for any damage to the vehicle's heat shield—a formality, really, but one that was felt necessary with the new vehicle— before returning to a position near the vehicle's docking port, after which it would move on to the station, docking at approximately 3:20 PM AST. Following this, Inari would move to the station's nadir docking port. From there, the crew would begin preparing for the station's consumables transfer, a process which was expected to take at least four days with proper supervision.

Over the next few days, the Shirotsuru-Inari complex would undergo its consumables transfer, slowly but surely pressurizing the LOX tank and transferring some of the smaller components for the module's outfitting over the course of EO-1, set to last six months as had been the case on Kyūden IV and her predecessor, Kyūden III. On flight day seven, with the LOX tank fully pressurized, the crew would enter for the first time, installing a rudimentary lighting system during its outfitting. According to the commander of the mission, Katsuya Hisagae, it was much like being aboard Kyūden IV once more, owing to its cavernous interior while also reporting an incident where a member of the crew had found themselves stuck in the middle of the module and required him to push off the hull in order to impart enough force to push his "stricken comrade" and himself to the other side of the module.

Flight Day Eight would see two members of the crew go on the first of four EVAs to install handrails and attachment ports along the outside of the hull. These handrails would be used to allow for future crews to have easier access for repairs and other tasks on the outside of the station. Each EVA would last approximately five hours, during which one crewman would be mounted on the station's RMS via a pylon carried into orbit when the station launched. The other crew member was attached to the pylon via a tether hooked onto a handrail, performing support to the uchūnaut on the arm. Over the next four days, the crew would attach the handrails and grappling points for the arm, and by flight day twelve, this task would be completed. The last day aboard the station, Flight Day Thirteen, would be used to perform small-scale experiments in the Chiheisen module and test the RMS's ability to walk along the hull, which proved successful.

Finally, on Flight Day Fourteen, the crew would return to home, having spent a fortnight in orbit readying the station for its first mission. The ACRV would be left in orbit rather than reentering the atmosphere, with that particular test not being deemed necessary (the vehicle had undergone said testing in January) for this mission. The next flight to the station would mark the beginning of Expedition One and the first expansion of the station.

[Daitō]

White Crane: Part Seven — Expedition One

UHS-04, the third flight of Tenryū, launched on the 16th of June, 2022 from Launch Complex 17-C, carrying a crew of eight, with half of the crew remaining aboard the station. This crew, made up entirely of Daitōjin uchūnauts, was set to inhabit the station for around 145 days, during which time outfitting of the station's habitation module would be performed and the first three additional components of the station, those being Node 1, the Tansa module, alongside truss segments S0 and P0, as well as a number of resupply missions to bring up further equipment and supplies. The first crew would be made up of uchūnauts Eiji Hasegawa, Goro Saionji, Hinako Yagishita, and Toshinari Yamanishi, with two of the crew, Eiji Hasegawa and Hinako Yagishita, having flown aboard Kyūden IV in 2013 and 2017, respectively. In spite of the Karasu ACRV having the capacity for the full crew (due to its purpose solely for returning crew, comfort was deemed less important than safety and ensuring an entire crew could land) and the orbiter having autonomous flight capabilities, the first expedition was limited due to the station's present crew capacity, both in space and supplies. The launch went without a hitch, with booster BV-101 Nissaka gliding safely back to the runway, marking the first time the system had been reused.

Flight Day 02 for the crew of UHS-04 would see the crew rendezvous and dock with Shirotsuru, where the crew would begin work to outfit the station's LOX tank. In the meantime, however, the crew of EO-1 would reside in the station's core module, as would be seen aboard a standard shuttle mid-flight. Outfitting the LOX tank had been considered a priority for the crew, to be performed upon its pressurization, as it would open up a space with a volume of 559 square meters, itself larger than the core module of any of the Kyūden series of stations. However, outfitting it was a problem which had to be wrestled with prior to the station's launch, with several "floor plans" being drawn up.

As early as 2014, considerations were made for two "floor plans" were drawn up, each of which featured two separate designs. The first of these, the transverse option, would feature a layout similar to that of the Kyūden core modules, albeit on a larger scale. The transverse model had two options, featuring a set of three to four floors. The first of these options, the three-floor option, would see the module's top and bottom levels not be considered "full floors", but with the others, going from top to bottom, featuring ones with 56.7m² floors and the bottom having one with an area of 50.2m². The four-floor option was similar, albeit with the top and bottom levels considered full floors and having more equipment. This design, while tempting due to the DNSA's experience with similar layouts in the past, was decided against due to the sheer size of said floors being deemed of limited utility for the module. Thusly, the second option, the longitudinal design, would be picked, with the three-floors design being selected for it.

Starting on Flight Day 3, the crew would begin unloading the remaining supplies for outfitting and begin working on the process. Outfitting would take up most of the crew's time, with much of the work done while the UHS orbiter was docked making any efforts afterwards seem almost laughably slow. This was in part, however, due to the crews being able to split their time more efficiently between outfitting and running experiments. Once Tenryū had undocked two weeks later, however, the crew of four settled into a slow but steady pace with regards to construction, with the floors themselves largely coming together within a month of undocking. With that done, while most of the work was completed, it was rather bare-bones, unfurnished as the resupply ship that was to bring in much of said furnishings could not be launched until after Node 1.

Sōsei shortly after departure of Tenryū, 2 July, 2022

In late July, UHS-05 launched from MFS Artsiv, carrying aboard the station's first node, Tansa (Exploration). This launch also featured the addition of a second pressurized mating adapter, similar in function to the one mounted to the station to allow the UHS to dock, albeit of a different, smaller design. While the mission itself was shorter than previous ones, it was perhaps among the most significant, as it opened the door to proper resupply by a Konōtori II CRV (Cargo Resupply Vehicle) such as the one set to launch in August with the remaining supplies for the LOX tank's outfitting. Upon arrival at the station, the module would be plucked from the orbiter's cargo bay before being docked to the station via the nadir docking port. When this was completed, the station's RMS would undock the module and docking adapter from itself before, in a manner somewhat reminiscent of a complex Towers of Mueang[1] puzzle and returning it to the station, with the module now directly docked to the station with the docking adapter facing outwards. Once this was completed, the orbiter, Inari, would dock with Shirotsuru and the PMA would be attached to the module's Port 3.

Over the course of a week, the crew of Inari would take part in various scientific and operational activities aboard the station, including taking part in an EVA to inspect the station's attachment points on its former EFT in preparation for the arrival of the P0 and S0 truss segments in two months aboard a Tenjin IC-launched orbital tug. The crew of UHS-05 would return to Mundus on the 5th of August, having spent eleven days in orbit.

On the 21st of August, the first Kōnotori II CRV docked with the station, making use of Tansa's Port 2, a common berthing adapter set to eventually host the Kagaku laboratory module in 2023. This spacecraft carried both provisions and the final pieces necessary to outfit the Sōsei module. And so, over the course of September, culminating in the 26th, the crew would once more turn their attention to outfitting the module. The results spoke themselves, not to mention they didn't have to sleep in the crowded lower deck of the core module... or worse. At long last, Shirotsuru was open for business. In September, Space Shuttle Albion docked with Shirotsuru, spending eleven days docked to the station. This marked the first time that a foreign spacecraft docked with a Daitōjin-built space station, although not the first time a foreign spacefarer was aboard such a vessel. Similar plans were made for Kyūden IV prior to the Challenger disaster, with the mission plan largely being unchanged from that proposed mission. It would not be the last time such missions occurred, as the DNSA made room for similar joint Cross Straits missions to be hosted aboard the station in the coming years.

In October, the S0 and P0 truss segments arrived aboard a Konōtori II-derived orbital tug, being attached over the course of several hours to the station via its remote manipulator system. Following this, it would be mostly smooth sailing until the launch of UHS-06 and the beginning of Expedition 2, the first to have a crew of eight and a personal record for the agency, which had never had more than eight crew in orbit up until that point.

1.	IRL Towers of Hanoi puzzle. Name was based on one of the cities in Lan Na as a placeholder.