Wanxingyuan / Stellaria (ST-01)

Wanxingyuan (designation ST-01), also referred to as Stellaria, is the lead ship of the Stellaria-class interplanetary exploration mothership. The vessel has a unique dual-origin construction history: it was originally laid down as a Xihe-class base mothership in September 2050, built in parallel with Xihe (XH-01); after 871 days of construction it was halted in February 2053, transferred to the Stellaria Program, and reconfigured as the Stellaria-class lead ship, with reconfiguration completed in April 2054. As of March 2060, Wanxingyuan is executing Outer Solar System Exploration Mission 1, en route to Neptune.

Wanxingyuan is the first crewed deep-space mothership in human history equipped with a lightspeed engine, and the first mothership to execute missions to Mercury, Venus, Saturn, and Neptune. Over five years of service it has completed a string of pioneering missions: inner solar system exploration (Mercury + Venus), Mars base construction, Europa Outpost construction, and Saturn exploration. A comprehensive upgrade in low Earth orbit from late 2059 to early 2060 brought it to full Stellaria-class specifications, including dual artificial-gravity habitation rings, a central extension section, cryo-sleep chambers, and enhanced radiation protection.

Design overview

Wanxingyuan is the lead ship of the Stellaria class, adopting a long axial-spine multi-module cylindrical configuration that extends the proven axial modular layout of the Xihe class across several key dimensions. Following the 2059-2060 Star Port comprehensive upgrade, the vessel measures approximately 125 m in overall length and features dual artificial-gravity habitation rings (each 30 m in diameter), a central extension section, a greenhouse module, cryo-sleep chambers, and enhanced radiation protection. Propulsion is centered on the lightspeed engine powered by an Ark cold-fusion reactor, with a retained Perseverance mass-driver propulsion system serving as backup.

Wanxingyuan is not capable of atmospheric re-entry or planetary landing; surface access and short-range transport are handled by two carried Echo-class shuttles (or compatible ferry craft). The ship accommodates a long-duration crew of 25 (up to 50 short-duration), with the dual artificial-gravity rings operating at different rotation rates to provide adjustable artificial gravity between approximately 0.4 g and 0.6 g. The greenhouse module features multi-zone rotational hydroponic cultivation, providing stable food supplementation and atmospheric regeneration for long-duration missions. Cryo-sleep chambers support reduced metabolic consumption during ultra-long transits such as outer-planet missions. For a complete description of design details, see the main Stellaria-class interplanetary exploration mothership article.

As the Stellaria-class lead ship, Wanxingyuan uniquely combines the "genetic" heritage of the Xihe-class base frame with the core capability of Stellaria-class lightspeed propulsion. This hybrid origin meant that during its early missions (2055-2058) the ship operated a lightspeed engine with otherwise Xihe-standard systems, gained a second artificial-gravity ring and greenhouse upgrade in the 2058 maintenance, and finally achieved full Stellaria-class specifications in the 2059-2060 Star Port upgrade. This progressive evolutionary pathway provided irreplaceable operational data for the design of subsequent Stellaria-class sister ships.

Construction

Initial construction: Xihe-class base mothership (2050-2053)

Wanxingyuan's predecessor was one of two "base motherships" laid down in parallel with Xihe (the other later became ST-02 Kristen). On 2050-09-15, the first module was delivered to low Earth orbit by an uncrewed Vulture Shuttle (Block 1), initiating 871 days of initial construction.

Construction employed the same "orbiter relay" method used for Xihe: the first launch delivered the initial module via an uncrewed orbiter that remained on orbit as the assembly platform; each subsequent launch brought a new module and assembly crew aboard a crewed orbiter, with the crew using the orbiter left behind from the previous mission as their operations base. Wanxingyuan's initial construction (then without an ST designation) overlapped heavily with Xihe's construction timeline, with the Vulture fleet sustaining parallel construction of two motherships simultaneously during 2050-2053 -- the fleet's highest operational tempo in its history.

The following table records the key launches of the initial construction phase:

By 2053-02-02, initial construction had accumulated 871 days. At this point the hull had completed primary structural mating and most cross-module connections, but the main propulsion system (the Xihe-class Perseverance mass-driver) had not yet been delivered. Just as the propulsion module was about to arrive, a strategic decision altered the ship's destiny: the emerging Stellaria Program offered the revolutionary lightspeed engine propulsion technology. Completing it as a standard Xihe-class mothership would have missed the window to leverage the new technology.

Construction was formally halted on 2053-02-02. Three months later (2053-05-11), the hull was officially transferred to the Stellaria Program and entered the reconfiguration phase. The other base mothership (future ST-02) was also halted on 2053-02-10 and subsequently transferred as well.

Reconfiguration: Stellaria-class lead ship (2053-2054)

Reconfiguration work commenced on 2053-05-11 at Star Port Station, lasting 352 days and completing on 2054-04-28. During this period, the ship's original Xihe-class propulsion module mounting base was replaced with a lightspeed-engine-compatible interface, and lightspeed engine core components were delivered in batches to Star Port by Qingtian cargo ships (LEO upmass capacity approximately 150 t) for orbital installation and static testing.

It is crucial to emphasize that this reconfiguration's core change was the replacement of the Xihe-class Perseverance mass-driver propulsion system with the lightspeed engine -- all other systems (including command center, habitation modules, greenhouse, docking interfaces, and life-support systems) remained at Xihe-class standards. In other words, upon completion of reconfiguration in 2054, Wanxingyuan was essentially a hybrid platform: "Xihe-class hull + Stellaria-class propulsion core." This identity defined its early operations from 2055 to 2058, until the 2059-2060 Star Port upgrade brought it to full Stellaria-class specifications.

Testing and commissioning

Following reconfiguration, Wanxingyuan entered testing and commissioning preparation across three phases:

Trial Run (2054-05-12 to 2054-08-22, 102 days): Conducted in lunar orbit. This was the first time the lightspeed engine received systematic validation in an actual space environment. Testing covered low-power lightspeed engine ignition, propulsion-to-Xihe-standard power bus compatibility verification, command center adaptation to the new propulsion control interface, and artificial-gravity habitation ring dynamic balance testing under lightspeed engine vibration. The lunar orbit round-trip provided gravity environment and communications delay conditions closer to actual deep-space missions than LEO could.

Deep Space Test (2054-09-07 to 2054-11-28, 82 days): Wanxingyuan proceeded uncrewed to the Sun-Earth L2 Lagrange point, executing the first deep-space autonomous flight validation of the lightspeed engine. The mission verified thermal control stability under sustained high-power lightspeed engine output, integration of lightspeed engine thrust models into the long-duration autonomous navigation system, and ship-wide structural response at lightspeed-class velocity increments. This was the first time in human history that a lightspeed engine performed maneuvers at Sun-Earth L2 distance.

Pre-commissioning Maintenance (2054-12-01 to 2055-02-28, 89 days): After the deep space test, Wanxingyuan returned to LEO and docked in low Earth orbit, where the engineering team applied system optimizations based on trial run and deep space test data. Key items included lightspeed engine thrust vector calibration fine-tuning, propulsion control redundancy loop upgrades, command center navigation computer software updates, and life-support flow-rate rebalancing to accommodate the lightspeed engine's higher power fluctuation levels.

In March 2055, Wanxingyuan formally entered service, becoming the first operational lightspeed-engine crewed deep-space mothership in human history.

Operational history

Since entering service in March 2055, Wanxingyuan has executed six major missions (including one in progress), progressively advancing from the inner Solar System to outer Solar System deep space. The following details each mission phase in chronological order.

Inner Solar System Exploration Mission 1 (2055-03-20 to 2056-04-12)

On 2055-03-20, Wanxingyuan departed Earth in a crewed configuration for its first operational mission -- Inner Solar System Exploration Mission 1. The mission's objective was to validate lightspeed engine performance in the high-energy inner Solar System environment and conduct scientific surveys of Mercury and Venus.

Mission Phase 1: Wanxingyuan departed Earth with a 180 km/s injection (FAST TRANSFER trajectory), completing the heliocentric transfer to Venus in approximately 35 days and arriving at Venus orbit on 2055-04-24. Approximately 60 days of atmospheric sounding and orbital remote sensing were conducted at Venus (2055-04-24 to 2055-06-23). Wanxingyuan then executed a Venus-to-Mercury transfer using the lightspeed engine, arriving at Mercury orbit on 2055-07-10. Approximately 45 days of surface remote sensing and solar-wind environment measurements were conducted at Mercury (2055-07-10 to 2055-08-24).

Following Mercury operations, Wanxingyuan departed Mercury orbit on 2055-08-24 for the return to Earth. Due to Mercury's proximity to the Sun, Wanxingyuan leveraged the lightspeed engine's high efficiency to execute multiple deep-space maneuvers in the strong solar gravity field, completing the approximately 230-day return voyage and arriving at Earth on 2056-04-12. This mission irrefutably proved that the lightspeed engine could operate reliably in the extreme thermal and strong gravity conditions of the inner Solar System, and that a Stellaria-class mothership could efficiently visit multiple inner-planet targets in a single mission.

Mars One Construction Mission 2 (2056-06-02 to 2056-11-03)

On 2056-06-02, Wanxingyuan departed Earth for Mars with a 135 km/s injection (STANDARD TRANSFER trajectory), arriving at Mars orbit on 2056-07-07 after approximately 35 days. The mission delivered construction materials and rotation crew to Mars One Base.

Mars surface operations ran from 2056-07-07 to 2056-09-25, totaling 80 days. During this period, Wanxingyuan's crew met the crew of Xihe (XH-01) -- then simultaneously operating at Mars -- on the Martian surface on 2056-09-17, completing humanity's first interplanetary crew handover in history. This historic moment marked the dawn of coordinated multi-mothership operations. With two motherships simultaneously present in the Mars system, the vessels completed the first inter-mothership cargo transfer and joint communications relay test.

For the return leg, Wanxingyuan departed Mars on 2056-09-25 with a 140 km/s injection, completing the approximately 39-day return voyage and arriving at Earth on 2056-11-03. The success of Mars One Construction Mission 2 further validated the Stellaria class's reliable delivery capability at Mars distance and the feasibility of multi-mothership coordinated operations.

Europa Outpost Construction Mission 1 (2056-12-15 to 2057-12-20)

On 2056-12-15, Wanxingyuan departed Earth with a 195 km/s injection (FAST TRANSFER trajectory) bound for the Jovian system. This was the first Stellaria-class mission beyond Mars orbit into the outer Solar System, and the first operational test of the lightspeed engine on a long-distance interplanetary voyage. After approximately 55 days of cruise, Wanxingyuan arrived at the Jovian system on 2057-02-08.

Wanxingyuan spent approximately 285 days in the Jovian system (2057-02-08 to 2057-11-20), executing the initial construction phase of Europa Research Outpost:

• Outpost core module delivery: Wanxingyuan used its forward main docking interface to tow large modules to Europa orbit, with carried Echo shuttles completing terminal landing and mating.
• Subsurface ocean sounding: Deployed penetrating radar and seismic sensor networks, obtaining data on Europa's ice shell thickness and subsurface ocean structure.
• Radiation environment assessment: Measured radiation levels at multiple candidate surface sites on Europa, providing design inputs for outpost radiation shielding.
• Life-support system pre-installation: Power bus routing and fluid plumbing integration for the outpost's initial life-support modules.

On 2057-11-20, Wanxingyuan departed the Jovian system for the return voyage with a 190 km/s injection. Thanks to favorable planetary alignment, the return transit took approximately 30 days, arriving at Earth on 2057-12-20. This mission irrefutably proved that the Stellaria-class mothership was capable of executing long-duration infrastructure construction missions in the outer Solar System, and that the lightspeed engine maintained stable operation in Jupiter's intense radiation environment. The year-long expedition duration provided invaluable physiological and psychological data on crew endurance during extended deep-space habitation.

Maintenance and Upgrades (2058-01-05 to 2058-05-15)

Following completion of the Europa Outpost construction mission, Wanxingyuan began a 130-day maintenance and upgrade cycle in low Earth orbit on 2058-01-05. This was the ship's first major upgrade since entering service, with core projects including:

• Addition of a second artificial-gravity habitation ring: A second 30 m diameter rotating habitation ring was installed amidships, forming a dual-ring configuration with the original ring. The two rings operate at different rotation rates, providing approximately 0.4 g and 0.6 g respectively, offering the crew a gradient gravity adaptation environment.
• Greenhouse module comprehensive upgrade: Hydroponic system upgraded from single-zone to multi-zone rotational cultivation, with automated environmental control and disease monitoring added; nutrient-loop efficiency improved by approximately 40%. The upgraded greenhouse supports longer-duration missions with reduced reliance on resupply.
• Life-support system upgrade: Closed-loop water recovery rate raised above 97%; atmospheric regeneration catalytic units replaced with next-generation high-efficiency components; redundant oxygen generation units added.
• Lightspeed engine routine servicing: Thrust vector calibration, magnetic confinement field coil inspection, and cooling loop comprehensive flushing.

This maintenance cycle significantly enhanced Wanxingyuan's mission endurance, thoroughly preparing the ship for the upcoming Saturn expedition. The dual artificial-gravity ring configuration made Wanxingyuan the only active mothership at that time with multi-gradient artificial gravity capability.

Saturn Exploration Mission 1 (2058-06-01 to 2059-11-24)

On 2058-06-01, the upgraded Wanxingyuan departed Earth with a 210 km/s injection (FAST TRANSFER trajectory, leveraging lightspeed engine high efficiency) bound for the Saturn system. This was humanity's first crewed Saturn mission. After approximately 70 days of interplanetary cruise, Wanxingyuan arrived at the Saturn system on 2058-08-10.

Wanxingyuan spent approximately 415 days in the Saturn system (2058-08-10 to 2059-09-29), executing multi-target exploration with a focus on Titan:

• Titan surface operations (2058-08-10 to 2059-05-01): Wanxingyuan remained in high Titan orbit while carried Echo shuttles executed multiple surface descents and sampling runs. Key research focused on Titan's methane seas, atmospheric chemistry, and surface geology. The crew deployed automated weather stations and seismic monitoring networks on Titan's surface.
• Saturn ring transit sounding (May 2059): Wanxingyuan traversed the outer edge of Saturn's rings at low relative velocity, using its onboard sensor array to conduct close-range in-situ measurements of ring particle composition, density distribution, and dynamical characteristics. This was the first crewed transit of a planetary ring structure by a human spacecraft.
• Enceladus plume sampling (June-July 2059): Carried probes flew through Enceladus's southern polar plumes, collecting ejecta samples for analysis of subsurface ocean chemistry and potential biomarkers.

On 2059-09-29, Wanxingyuan departed the Saturn system for return. This return voyage was the first validation of lightspeed engine cold-restart performance after extremely long-duration cruise. With a 205 km/s injection, the return transit took approximately 56 days (benefiting from the lightspeed engine's high specific impulse and favorable planetary alignment), arriving at Earth and docking in low Earth orbit on 2059-11-24. The success of Saturn Exploration Mission 1 extended the frontier of crewed deep-space exploration from the Jovian system further outward to the Saturn system, and accumulated critical outer Solar System long-duration operational experience for the subsequent Neptune mission.

Star Port Full Upgrade (2059-11-25 to 2060-02-10)

On 2059-11-25, immediately upon completing the Saturn mission, Wanxingyuan entered a comprehensive upgrade phase in low Earth orbit. This 77-day upgrade was the largest and most thorough transformation in the ship's service history -- its objective was to upgrade the "Xihe-class hull + Stellaria-class propulsion core" hybrid platform into a complete Stellaria-class specification mothership.

Core upgrade projects included:

• Central extension section installation: A Stellaria-standard central extension section was inserted between the command center and habitation modules, providing additional laboratory space, cryo-sleep chambers, and redundant life-support units.
• Radiation protection comprehensive reinforcement: Dual-layer composite shielding was installed in all crew-occupied zones, bringing radiation protection to Stellaria-class deep-space standards.
• Cryo-sleep chamber deployment: Twelve cryo-sleep chambers were installed in the central extension section and habitation modules to support crew rotation hibernation during ultra-long-duration missions.
• Command center comprehensive refit: Navigation computers, communications equipment, and mission planning systems were replaced with the latest Stellaria-class standards, integrating deep autonomous navigation with lightspeed engine thrust models.
• Docking system standardization: All forward and lateral docking interfaces were upgraded to Stellaria-class standard quick-release interfaces, compatible with next-generation Stellaria-class carried vehicles.
• Structural integrity inspection: A full-range non-destructive inspection of the hull structure assessed the fatigue state of the original Xihe-class frame after 9 years of service.

On 2060-02-10, the upgrade was completed. At this point, Wanxingyuan had achieved a thorough transformation from "lightspeed engine verification platform" to "complete Stellaria-class deep-space mothership." The upgraded vessel measures approximately 125 m in overall length, features dual artificial-gravity rings, a central extension section, cryo-sleep chambers, and complete Stellaria-class life-support and mission systems -- fully meeting Stellaria-class specifications.

Outer Solar System Exploration Mission 1 (2060-02-11 -- ongoing)

On 2060-02-11 -- the day after upgrade completion -- Wanxingyuan departed Earth in full Stellaria-class specification, executing Outer Solar System Exploration Mission 1 with Neptune as its destination. This is humanity's first crewed Neptune mission and the farthest crewed deep-space flight ever undertaken at that time.

Wanxingyuan injected into heliocentric transfer orbit with a 240 km/s burn (FAST TRANSFER trajectory). Benefiting from the full Stellaria-class lightspeed engine's exceptional performance and the dual-ring artificial gravity's support for long-duration crew health, the transit is estimated at approximately 200 days, with arrival at the Neptune system expected around late August 2060. The mission plan encompasses:

• Neptune atmospheric remote sensing and magnetic field mapping
• Triton surface exploration -- one of the coldest bodies in the Solar System, whose retrograde orbit and possible subsurface ocean hold exceptional scientific value
• Neptune ring system close-range observation
• Autonomous mission operations validation under extreme deep-space communications delay conditions

As of March 2060, Wanxingyuan is on its heliocentric transfer trajectory to Neptune, with all systems operating nominally and the entire crew in good condition. Data from this mission will provide irreplaceable operational experience and technical validation for humanity's exploration of farther outer Solar System bodies and ultimately the Kuiper Belt.

Specifications

See also

• Stellaria-class interplanetary exploration mothership
• Kristen (ST-02)
• Xihe-class interplanetary exploration mothership
• Xihe (XH-01)
• Echo Shuttle
• Vulture Shuttle
• Star Port Station
• Qingtian cargo ship
• Mars One Base
• Europa Research Outpost