XH-01 Xihe side view image placeholder (Xihe-class lead ship, assembled in LEO)
Xihe is the lead ship of the Xihe-class interplanetary exploration mothership, assembled segment-by-segment in low Earth orbit by Vulture Shuttles between 2050 and 2052.
Current status: Active (Europa Expedition 3, Jovian system)
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Construction method: Vulture Shuttle LEO assembly
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Primary missions: Mars base construction, Jovian system exploration
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Home port: Star Port Station
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Xihe (designation XH-01) is the lead ship of the Xihe-class interplanetary exploration mothership and the first large crewed interplanetary mothership to enter service in human history. Named after Xihe, the solar deity in Chinese mythology, the vessel was assembled segment-by-segment in low Earth orbit by Vulture Shuttles between 2050 and 2052, formally entering service in December 2052. As of March 2060, Xihe is in the Jovian system executing Europa Expedition 3, having completed two Mars base construction missions, one Mars expedition, two Europa expeditions, and one deep-space test mission over eight years of service, with a total operational range spanning Earth orbit, the Mars system, and the Jovian system.
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The construction and operation of Xihe pioneered an entirely new paradigm for deep-space motherships. It demonstrated that assembling a large crewed deep-space platform in low Earth orbit and using it to execute interplanetary missions was both technically and operationally viable. Its operational experience directly led to the construction of subsequent Xihe-class sister ships (XH-02 Taibai, XH-03 Changxi) and provided critical data for the design of the second-generation Stellaria-class mothership. As the class leader, Xihe achieved a string of historic firsts — the first crewed Mars construction mission, the first interplanetary crew handover, and the first outer Solar System expedition — each a milestone in the history of crewed deep-space exploration.
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Design overview
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As the lead ship of the Xihe class, Xihe adopts the class's signature long axial-spine multi-module cylindrical configuration. The vessel measures 83.4 m in overall length with a maximum diameter of 25 m at the artificial-gravity habitation ring, and is composed of nine major modules arranged sequentially along the central axis: forward docking hub, command center, artificial-gravity habitation ring, static habitation module, central docking hub, greenhouse module, main storage module, truss section, and propulsion module. Standardized mechanical, electrical, fluid, and data interfaces between modules enable in-orbit maintenance and localized replacement.
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Propulsion is provided by the Perseverance mass-driver propulsion system, powered by an Ark cold-fusion reactor with approximately 8 TW output class, delivering a full-load delta-v of about 1700 km/s (with a 300 t payload). Standard mode produces 2400 kN of thrust at 500,000 s specific impulse; high-thrust mode reaches 3800 kN at 250,000 s specific impulse. Xihe is not capable of atmospheric re-entry or planetary landing — surface access is handled by two carried Echo shuttles (or compatible ferry craft). The ship accommodates a long-duration crew of 15 (up to 30 short-duration) with an artificial-gravity habitation ring producing approximately 0.41 g at roughly 4 RPM and a greenhouse module providing food supplementation and atmospheric regeneration via closed hydroponics. For a complete description of design details, see the main Xihe-class interplanetary exploration mothership article.
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Construction
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Xihe LEO assembly process image placeholder
Xihe underwent a 693-day assembly campaign in low Earth orbit, with the Vulture Shuttle Block 1 fleet handling all heavy module transport.
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The construction of Xihe marked the first time in human spaceflight history that a hundred-tonne-class crewed deep-space platform was assembled in low Earth orbit. Construction officially began on 2050-03-15, when a Vulture Shuttle delivered the first module — the forward docking hub — to LEO and released it at the designated assembly position. This was among the largest segment-transport missions executed by Vulture Shuttles at the time and signaled the dawn of the orbital mothership construction era.
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Over the following 693 days, Xihe's assembly proceeded at a near-continuous tempo. The Vulture Shuttle Block 1 fleet handled all heavy-module transport, with 2050-2051 representing the fleet's peak operational year. Nine major modules were delivered and mated in the following sequence: forward docking hub (2050-03-15), command center (May 2050), static habitation module (July 2050), central docking hub (September 2050), main storage module (December 2050), greenhouse module (March 2051), truss section (July 2051), propulsion module (November 2051), and artificial-gravity habitation ring (December 2051). The habitation ring, with its 25 m diameter exceeding Vulture Shuttle cargo-bay capacity, was launched separately by a super-heavy launch vehicle and positioned by orbital tugs.
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Primary assembly was completed on 2052-02-06, followed by the outfitting phase (2052-02-07 to 2052-05-31, 114 days). Outfitting encompassed ship-wide power bus redundant connections, cross-module life-support plumbing integration, rotating ring dynamic balance fine-tuning, docking-interface hydraulic pressure testing, greenhouse hydroponic system pre-installation, and reactor low-power startup commissioning. A substantial portion of verification work that could not be performed on Earth was transferred to orbit, including pressurized compartment isolation tests, towing-interface limit-load trials, and long-duration attitude-control hold verification. From first module arrival to completion of outfitting, total construction spanned nearly two years.
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Phase
Period
Duration
Activity
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Orbital assembly
2050-03-15 to 2052-02-06
693 days
Sequential delivery, docking, and integration of 9 major modules
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Outfitting
2052-02-07 to 2052-05-31
114 days
Ship-wide system connections, plumbing integration, equipment installation and commissioning
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Total
2050-03-15 to 2052-05-31
808 days
From first module arrival to outfitting completion
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Testing and commissioning
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Xihe's commissioning phase ran from 2052-06-01 to 2052-11-30, a total of 182 days, conducted in three progressively demanding stages.
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Phase 1 (June-July 2052): Earth orbit systems check. A comprehensive item-by-item verification of all ship systems in LEO, including the Ark reactor full-power run, Perseverance propulsion static fire, artificial-gravity habitation ring continuous 72-hour rotation test, closed-loop life-support system full-crew simulated operation, communications antenna omnidirectional scan calibration, and thermal-control radiator deployment and retraction testing. All critical systems met acceptance criteria.
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Phase 2 (August-September 2052): GEO transfer and station-keeping. Xihe fired its main propulsion system for the first time, transferring from LEO to geostationary orbit (GEO). Four weeks of station-keeping tests at GEO validated propulsion response precision under continuous fine-adjustment mode, deep-space communications link stability at GEO distance, and the reliability of the onboard computer in long-distance autonomous navigation.
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Phase 3 (October-November 2052): Lunar orbit round-trip. Xihe departed GEO, executed an Earth-Moon transfer, and entered lunar orbit. After three weeks of orbit-keeping and sensor calibration in lunar orbit, the vessel returned to Earth. This was the first time a Xihe-class mothership performed an orbital maneuver beyond the Earth-Moon system boundary and the first validation of navigation and attitude-control adaptability in the lunar gravitational environment.
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Following commissioning, Xihe returned to LEO, where the engineering team applied targeted optimizations to propulsion redundancy loops, communications antenna pointing mechanisms, and life-support recirculation circuits based on commissioning data. The successful completion of commissioning certified all of Xihe's systems to deep-space-grade standards and its crew as qualified for deep-space operations. Xihe then entered a pre-maiden-mission maintenance window (2052-12-01 to 2053-01-05) for final preparations ahead of the Deep Space Test Mission.
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Service and operational history
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Since formally entering service in December 2052, Xihe has executed eight major missions, evolving from a near-Earth test platform into a front-line outer Solar System expedition vessel. The following details each mission phase in chronological order.
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Deep Space Test Mission (2053-01-12 to 2053-12-18)
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On 2053-01-12, Xihe departed LEO in an uncrewed configuration bound for the Sun-Earth L2 Lagrange point, executing a 340-day deep-space test mission. This was the first Xihe-class mothership operation beyond the Earth-Moon system and the longest uncrewed autonomous deep-space flight in the Chinese space program at that time.
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During the mission, Xihe validated several systems critical to subsequent crewed operations: long-duration autonomous navigation and station-keeping reliability without real-time ground intervention, deep-space communications stability at the Sun-Earth L2 distance (approximately 1.5 million km), radiation shielding effectiveness in the actual deep-space environment, and extended uncrewed operation of the closed-loop life-support system. The flight computer independently executed all orbital maneuvers and system scheduling across the full 340 days without a single anomaly requiring ground intervention.
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On 2053-12-18, Xihe completed the mission and returned to LEO. Based on telemetry analysis, the engineering team applied targeted upgrades to propulsion redundancy, communications antenna pointing mechanisms, and life-support recirculation loops. The success of the Deep Space Test Mission formally transitioned Xihe from an orbital test platform to a mission-capable deep-space asset, clearing the final critical hurdle for crewed Mars missions.
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Mars Mission Demonstration (2054-07-10 to 2055-02-28)
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On 2054-07-10, Xihe departed LEO uncrewed for its first Mars demonstration mission, injecting at 102 km/s. After 42 days of interplanetary cruise, it arrived at Mars orbit on 2054-08-21. The mission's core objective was to validate the mothership's deep-space delivery capability and Mars orbital operations in the actual Martian orbital environment.
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Upon arrival, Xihe successfully delivered the first Mars One Base equipment package, containing habitation module components, solar array support structures, and initial life-support hardware. The mission also validated Xihe-class Mars orbit insertion precision and long-duration orbital station-keeping for the first time. The surface operations phase ran from 2054-08-21 to 2055-01-10 — 142 days — with the mothership remaining in high Mars orbit, monitoring equipment deployment and self-check status via telemetry relay.
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On 2055-01-10, Xihe departed Mars orbit with a 97 km/s injection, reaching Earth on 2055-02-28. This mission definitively proved that the Xihe class could operate reliably at Mars distance and deliver heavy payloads to the Martian surface, clearing the final critical hurdle for crewed Mars missions.
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Mars One Base Construction Mission 1 (2055-06-15 to 2056-03-18)
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Xihe Mars mission artist's impression placeholder
Xihe was the first mothership-class platform to carry crew to Mars, remaining on standby in high Mars orbit while Echo shuttles handled crew and cargo surface transfer.
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On 2055-06-15, Xihe departed LEO carrying the first Mars construction crew, arriving at Mars on 2055-07-30. This was the first crewed Mars mission of the Xihe class and the first time astronauts traveled to another planet aboard a mothership-class platform. The mission's historic significance lay in extending crewed deep-space flight from lunar distances to interplanetary distances for the first time.
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Surface operations extended from 2055-07-30 to 2056-02-07 — 192 days. During this period, the crew established the core infrastructure of Mars One Base: mating and pressurizing the primary habitation module, activating initial life-support systems, erecting communications antennas, and conducting the first scientific surveys of the Martian surface. Xihe itself remained on standby in high Mars orbit, with two Echo-class shuttles providing crew and cargo surface transfer — establishing the "mothership holds safe orbit, ferry vehicles execute terminal transport" model as the standard protocol for all subsequent mothership missions.
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For the return leg, Xihe employed the FAST RETURN trajectory for the first time, injecting from Mars orbit into the Earth-Mars transfer with a 207 km/s burn, substantially shortening the return transit. Departing 2056-02-07 and arriving at Earth on 2056-03-18, the return trip took only 39 days. After return, Xihe entered an 87-day maintenance cycle (2056-03-25 to 2056-06-20) for its first comprehensive post-mission inspection of propulsion, docking interfaces, and life-support equipment.
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Mars One Base Construction Mission 3 (2056-07-30 to 2057-03-25)
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On 2056-07-30, Xihe departed again for Mars at 95 km/s injection, arriving on 2056-09-15. The defining moment of this mission came on 2056-09-17, when Xihe's crew met the Stellaria-class ST-01 crew on the Martian surface, completing humanity's first interplanetary crew handover.
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This historic moment marked the dawn of coordinated multi-mothership operations. With XH-01 and ST-01 simultaneously present in the Mars system, the two vessels completed the first inter-mothership cargo transfer and joint communications relay test. This was humanity's first coordinated two-mothership operation, proving the feasibility of operating two large crewed spacecraft simultaneously around another planet.
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The surface stay ran from 2056-09-15 to 2057-02-12. During this period, Xihe's crew took over Mars One Base operations while simultaneously extending base infrastructure and conducting a second round of scientific surveys. Return transit began on 2057-02-12, arriving at Earth on 2057-03-25. The dual-mothership coordination experience gained during this mission directly informed planning for later multi-platform Jovian-system operations.
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Mars Expedition 2 (2057-05-05 to 2058-05-20)
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On 2057-05-05, Xihe departed for the now-established Mars One Base, arriving on 2057-06-22. Unlike previous construction-focused missions, this expedition emphasized scientific investigation and base operations while pioneering the inclusion of commercial space tourism.
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The surface stay lasted 300 days — the longest continuous human presence on the Martian surface recorded to that date. The crew conducted extensive scientific work including Martian geological sampling, atmospheric studies, subsurface ice detection, and long-duration physiological data collection. The expedition also completed a base expansion, adding a dedicated laboratory module and upgraded water-recovery facilities. The 300-day continuous surface habitation dataset provided irreplaceable life-support system validation for subsequent longer-duration Mars and Jovian missions.
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The mission's most groundbreaking achievement was carrying the first paying passengers to the Martian surface. These passengers participated in science-support work and surface exploration activities during their stay. This accomplishment not only demonstrated the technical and operational viability of deep-space tourism but also showcased the commercial potential of deep-space transportation to the world. The return leg began on 2058-04-18 with a 115 km/s injection departing Mars, arriving at Earth on 2058-05-20.
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Europa Expedition 1 (2058-07-10 to 2059-11-15)
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On 2058-07-10, Xihe departed LEO with a 160 km/s injection bound for the Jovian system — the first Xihe-class mission beyond Mars orbit and into the outer Solar System. After 77 days of interplanetary cruise, Xihe arrived at Jupiter on 2058-09-25, formally opening the era of crewed outer Solar System exploration.
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Xihe spent 288 days in the Jovian system, conducting scientific investigations across multiple target bodies:
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Europa surface operations (2058-09-25 to 2058-12-15): Focused on subsurface ocean sounding, surface composition analysis, and radiation environment measurement. Deployed probes conducted detailed mapping of Europa's ice fractures and suspected plume regions.
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Io volcanic plume sampling (2058-12-20 to 2059-01-20): Deployed probes through Io's volcanic eruption plumes, collecting precious ejecta samples. This was humanity's first in-situ volcanic sampling in Io orbit.
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Ganymede exploration (2059-07-05): Completed magnetic-field mapping and surface geological surveys of Ganymede, validating its geological and resource conditions as a potential future outer Solar System resupply waypoint.
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On 2059-07-10, Xihe departed the Jovian system for the 128-day return voyage, docking at Star Port Station on 2059-11-15. The irrefutable success of Europa Expedition 1 demonstrated that the Xihe class was capable of executing long-duration, complex scientific missions in the outer Solar System, opening the door to subsequent Jovian expeditions.
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Greenhouse Upgrade and Maintenance (2059-11-16 to 2060-02-19)
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On 2059-11-16, Xihe began a 95-day deep maintenance and upgrade cycle at Star Port Station. After missions spanning from Mars to Jupiter, the mothership required a comprehensive systems overhaul to meet the demands of more intensive, longer-distance deep-space operations.
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The upgrade's core projects included:
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Greenhouse module complete renovation: Hydroponic system upgraded from single-crop cultivation to multi-zone rotational planting, nutrient-loop efficiency improved by approximately 40%, and automated environmental control and disease monitoring systems added, all aimed at supporting longer-duration missions with reduced reliance on resupply.
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Radiation protection reinforcement: Additional composite shielding installed around the command center, habitation modules, and medical bay to handle the higher cumulative radiation doses of outer Solar System missions.
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Water-recycling system complete overhaul: All membrane filters replaced and purification units upgraded, raising the closed-loop recovery rate above 97%.
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Navigation and sensor upgrades: Next-generation deep-space star trackers and inertial measurement units installed; external sensor array and communications antennas underwent full calibration and partial replacement.
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Docking system maintenance: All docking-seal assemblies on the forward docking hub replaced; rotating habitation ring bearings replaced and dynamic balance re-calibrated.
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This maintenance cycle restored Xihe's systems to near-new condition, thoroughly preparing the ship for the upcoming Europa Expedition 3.
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Europa Expedition 3 (2060-02-20 - ongoing)
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On 2060-02-20, the upgraded Xihe departed once more for the Jovian system with a 163 km/s injection burn. This is the Xihe class's third Jovian expedition and the most ambitious outer Solar System crewed mission to date.
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Xihe is scheduled to arrive at the Jovian system on 2060-05-01. The Europa Expedition 3 mission plan encompasses consecutive exploration of multiple Jovian targets:
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First, an Io surface landing operation — the first crewed landing on Io's surface in human history.
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Transfer to Ganymede for surface reconnaissance.
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Arrival at Callisto around 2060-05-25 for scientific observations.
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Crew rotation at Europa Outpost to sustain continuous outpost operations.
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This multi-target continuous exploration plan takes full advantage of Jovian-system orbital alignment windows, demonstrating the Xihe class's mature scheduling capability for complex multi-body missions. As of March 2060, Xihe is in transit on its Jupiter transfer trajectory, with all systems operating nominally and crew in good condition. Data from this mission will provide critical input for the expansion of Europa Outpost and the planning of second-generation motherships' outer Solar System operations.
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Specifications
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Parameter
Value
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Ship name
Xihe (XH-01)
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Class
Xihe-class interplanetary exploration mothership
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Type
Crewed interplanetary exploration mothership
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Configuration
Axial-spine multi-module cylindrical layout
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Length
83.4 m
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Maximum diameter
25 m at the artificial-gravity habitation ring
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Propulsion
Perseverance mass-driver propulsion system
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Main reactor
Ark cold-fusion reactor, about 8 TW output class
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Thrust
2400 kN standard mode; 3800 kN high-thrust mode
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Specific impulse
500,000 s standard mode; 250,000 s high-thrust mode
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Full-load delta-v
About 1700 km/s with 300 t payload
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Maximum payload
300 t
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Long-duration crew
15
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Short-duration crew
30
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Artificial gravity
About 0.41 g from the rotating habitation ring at roughly 4 RPM
Current status: Active (post-maintenance, preparing for next assignment)
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Construction method: Qingtian cargo ships + Star Port Station assembly
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Namesake: Taibai (ancient Chinese name for Venus), symbolizing inner Solar System exploration
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Taibai (designation XH-02) is the second ship of the Xihe-class interplanetary exploration mothership and the first Xihe-class vessel assembled at Star Port Station. Named after the ancient Chinese name for the planet Venus—"Taibai"—the name reflects the ship's specialization in inner Solar System and asteroid belt missions. Construction began in December 2054, assembly was completed in October 2056, and the ship was commissioned in April 2057. As of March 2060, Taibai is undergoing post-mission maintenance and preparing for its next assignment.
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Taibai follows the nine-module axial spine configuration of the Xihe class, integrating the Perseverance mass-driver propulsion system, an Ark cold-fusion reactor, closed-loop life support, an artificial-gravity habitation ring, and reinforced docking hardware. Compared with the lead ship Xihe (XH-01), Taibai incorporated operational lessons from XH-01's early missions, including improvements to the habitation module and upgraded radiation shielding. The ship is not capable of atmospheric re-entry or planetary landing; surface access is provided by carried Echo shuttles.
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Taibai's mission record emphasizes inner Solar System operations, covering the Vesta orbital survey and asteroid belt exploration, Mars expedition support, and Mars One Base resupply—validating the Xihe class's multi-ship production and coordination capabilities.
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Design overview
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Taibai is the second Xihe-class ship, using an axial-spine multi-module cylindrical layout with an overall length of 83.4 m, a maximum diameter of 25 m at the artificial-gravity habitation ring, a full-load delta-v of about 1,700 km/s, and a maximum payload of 300 t. Functional zones are arranged along the central axis: forward docking hub, command center, artificial-gravity habitation ring, static habitation module, central docking hub, greenhouse module, main storage module, truss section, and propulsion module.
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As the second Xihe-class mothership, Taibai benefited from approximately two years of operational feedback from the lead ship Xihe (XH-01). The habitation module's ergonomic interfaces were refined, and radiation shielding received additional composite layers around the command center, living areas, and medical spaces. These improvements enhanced crew safety and comfort on long-duration missions while maintaining the same baseline configuration and delta-v specifications as the lead ship.
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Taibai's standard carried-vehicle configuration is two Echo shuttles, used for crew, sample, and light cargo transfer between the mothership and target body surfaces. The ship was the first Xihe-class vessel designated from the construction phase with an inner Solar System mission emphasis, focusing on Mars-system resupply, asteroid belt exploration, and rapid-response near-Earth operations.
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Construction
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Construction method and innovation
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Taibai was the first Xihe-class mothership assembled at Star Port Station, marking the class's transition from "Vulture Shuttle-based free-flying LEO assembly" to "orbital shipyard construction using Star Port Station and Qingtian cargo ships." This shift freed large-module transport and integration from shuttle cargo-bay size constraints, significantly improving construction efficiency and module integration precision.
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During construction, Qingtian cargo ships delivered the nine major modules, the artificial-gravity habitation ring, and other large structural components to Star Port Station in batches. The station's orbital shipyard facilities provided a stable assembly platform, environmental control, and maintenance support, allowing Taibai's construction timeline to improve on the lead ship Xihe's approximately 693-day build.
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Construction timeline
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Phase
Period
Main activity
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Construction start
December 2054
First structural module delivered to Star Port Station; orbital assembly initiated.
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Major assembly
January 2055 to August 2056
Nine modules, artificial-gravity ring, propulsion system, and docking hubs integrated sequentially.
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Full-ship integration
August to October 2056
Cross-module plumbing, power bus testing, life-support loop verification, and system-level checks.
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Assembly complete
October 2056
Major assembly took approximately 22 months; entered shakedown phase.
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Taibai's construction benefited significantly from XH-01's operational experience. Habitation module design improvements, radiation shielding upgrades, and docking hub assembly processes all directly applied data accumulated during Xihe's Deep Space Test Mission and Mars Mission Demonstration. Additionally, Star Port Station's shipyard environment allowed more comprehensive subsystem verification during the assembly phase, reducing the subsequent shakedown workload.
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Operational history
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Shakedown (November 2056 to March 2057)
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Taibai began a five-month orbital shakedown in November 2056, covering low Earth orbit, geostationary orbit maneuvers, and lunar orbit round trips. The shakedown phase validated structural integrity, propulsion response, artificial-gravity ring dynamic balance, long-duration life-support capability, and ship-wide thermal control stability. All systems passed validation, with thermal control, communications, and propulsion performance meeting or exceeding design targets.
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During shakedown, Taibai also completed its first docking test with Star Port Station, verifying the forward docking hub and central docking hub performance in structural locking, power, thermal control, and data transfer. These tests established the operational baseline for routine mothership servicing and maintenance at Star Port Station. Shakedown concluded in March 2057, and Taibai was formally commissioned in April 2057.
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Vesta Mission (May 2057 to January 2058)
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In May 2057, Taibai departed low Earth orbit on the Xihe class's first asteroid belt mission—Vesta orbital survey and surface sample collection. This was the first Xihe-class mission beyond Mars orbit into the asteroid belt, and humanity's first crewed orbital survey and surface sampling of Vesta.
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During the roughly eight-month round trip, Taibai completed detailed Vesta orbital mapping, surface sample collection, and asteroid-belt deep-space environment assessment. Two carried Echo shuttles handled surface team descent and return, while the mothership remained in a safe orbit for telemetry monitoring, sample reception, and preliminary analysis. The mission validated Xihe-class operations under asteroid-belt radiation conditions, micrometeoroid risk, and extended communication delays.
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In January 2058, Taibai returned to Earth with Vesta samples, which were transferred to near-Earth orbital laboratories for detailed analysis. The Vesta mission's success proved that Xihe-class motherships were capable of asteroid-belt deep-space operations, expanding the class's mission envelope from the Mars system to the wider inner Solar System.
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Mission parameter
Value
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Departure
May 2057
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Return
January 2058
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Mission duration
Approximately 8 months
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Primary objectives
Vesta orbital survey, surface sampling, asteroid-belt environment assessment
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Carried vehicles
Two Echo shuttles
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Mars Expedition 3 (April 2058 to December 2058)
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In April 2058, Taibai executed Mars Expedition 3, conducting crew rotation and resupply transport to Mars One Base. The mission's core objective was delivering a new rotation of construction crew, supplies, and expansion equipment to Mars One Base while returning the previous resident crew to Earth.
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Taibai carried two Echo shuttles for crew and cargo ferry between the mothership and the Martian surface. The mothership remained in high Mars orbit while Echo shuttles handled surface rotation, supply unloading, and sample loading. The mission lasted approximately nine months, concluding with a return to Earth in December 2058. Mars Expedition 3's success cemented Taibai's position as a trunk-line platform for Mars base expansion.
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Mars Expedition 4 (October 2059 to January 2060)
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In October 2059, Taibai returned to Mars for Mars Expedition 4, with the primary objective of supporting Mars One Base expansion. This mission coincided with the critical surface expansion phase of Mars One Campus Alpha; Taibai delivered structural trusses, greenhouse components, and support supplies that were essential for the base's phased construction.
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Taibai completed Mars Expedition 4 and returned to Earth in January 2060. The mission validated the continuous resupply coordination model between Xihe-class motherships and Martian surface bases, further demonstrating the feasibility of multi-mothership rotational support for Mars base construction.
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Current status (March 2060)
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As of March 2060, Taibai has completed post-Mars Expedition 4 maintenance and is undergoing system inspections and servicing in preparation for its next assignment. Maintenance work is being conducted at Star Port Station, covering propulsion system inspection, docking hub seal replacement, life-support loop servicing, thermal control system calibration, and carried-vehicle interface checks. Taibai remains in good active service condition and is one of the most steadily-operating platforms in the Xihe-class fleet.
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Mission
Period
Main activity
Status
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Shakedown
2056-11 to 2057-03
LEO, GEO, and lunar orbit tests; full system validation.
Complete
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Vesta Mission
2057-05 to 2058-01
Vesta orbital survey, surface sampling, asteroid-belt environment assessment.
Complete
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Mars Expedition 3
2058-04 to 2058-12
Mars One Base crew rotation and resupply transport.
Complete
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Mars Expedition 4
2059-10 to 2060-01
Mars One Base expansion support; structural truss and greenhouse component delivery.
Complete
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Post-mission maintenance
2060-01 to 2060-03
Comprehensive Star Port Station maintenance and system inspection.
500,000 s standard mode; 250,000 s high-thrust mode
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Full-load delta-v
About 1,700 km/s with 300 t payload
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Maximum payload
300 t including surface vehicles and supplies
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Long-duration crew
15
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Short-duration crew
30
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Artificial gravity
About 0.41 g from the rotating habitation ring
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Carried vehicles
Typically two Echo shuttles, or an Echo plus Amalthea-type compatible vehicle mix
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Construction method
Qingtian cargo ships + Star Port Station assembly
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Build duration
Approximately 22 months (Dec 2054 to Oct 2056)
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Fleet role
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Within the Xihe-class fleet, Taibai is positioned as the primary platform for inner Solar System and Mars-system missions. Unlike the lead ship Xihe (emphasizing technology validation and outer Solar System expeditions) and the third ship Changxi (emphasizing deep-space communications relay deployment), Taibai's mission record concentrates on Mars base resupply, asteroid belt exploration, and near-Earth rapid response, reflecting the Xihe class's flexible division of labor across multiple mission directions.
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Taibai was the first Xihe-class ship to extend the class's mission range into the asteroid belt (Vesta Mission, 2057-2058) and consecutively executed Mars Expeditions 3 and 4, establishing the ship as the core Mars base trunk-line resupply platform. Among the three active Xihe-class ships, Taibai has maintained the most consistent operational tempo and accumulated extensive Mars-system operations and asteroid-belt deep-space experience.
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As of March 2060, the Xihe-class fleet has three active ships (XH-01 Xihe, XH-02 Taibai, XH-03 Changxi) and one under construction (XH-04). Taibai is in post-mission maintenance and is expected to resume inner Solar System and Mars-system missions after servicing is complete.
Construction method: Qingtian cargo ships + Star Port Station assembly
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Namesake: Changxi (moon charioteer goddess in Chinese mythology), symbolizing the transition from cislunar space to deep space
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Changxi (designation XH-03) is the third ship of the Xihe-class interplanetary exploration mothership and the first Xihe-class vessel purpose-modified for deep-space communications relay missions. Named after Changxi, the moon charioteer goddess in Chinese mythology, the name reflects the ship's role bridging cislunar space and deep-space operations. Construction began in February 2056 and assembly was completed in December 2059, making Changxi the longest-build Xihe-class ship at approximately 46 months. As of March 2060, Changxi is in its shakedown phase and is expected to be formally commissioned in June 2060.
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Changxi follows the nine-module axial spine configuration of the Xihe class, integrating the Perseverance mass-driver propulsion system, an Ark cold-fusion reactor, closed-loop life support, an artificial-gravity habitation ring, and reinforced docking hardware. Compared with its sister ships, Changxi's most distinctive feature is an enhanced deep-space communications suite integrated during construction, making it the first Xihe-class platform purpose-built for Jupiter relay network deployment and deep-space communications infrastructure support.
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Changxi's construction overlapped with operations of XH-01 Xihe and XH-02 Taibai, and the resource allocation required for three concurrent ships significantly extended its build time. However, this extended period also allowed the construction team to fully incorporate operational feedback from the first two ships into Changxi's design, achieving the highest level of systems integration in the Xihe class, particularly in communications, life support, and data management. The ship is not capable of atmospheric re-entry or planetary landing; surface access is provided by carried Echo shuttles.
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Design overview
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Changxi is the third Xihe-class ship, using an axial-spine multi-module cylindrical layout with an overall length of 83.4 m, a maximum diameter of 25 m at the artificial-gravity habitation ring, a full-load delta-v of about 1,700 km/s, and a maximum payload of 300 t. Functional zones are arranged along the central axis: forward docking hub, command center, artificial-gravity habitation ring, static habitation module, central docking hub, greenhouse module, main storage module, truss section, and propulsion module.
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Changxi's most prominent design feature is its enhanced deep-space communications suite, integrated during construction rather than added as a post-build modification. The suite includes a high-gain deep-space communications antenna array, multi-band relay transceivers, laser communications terminals, and dedicated data processing units, providing stable communications relay capability at Jupiter distances and beyond. Unlike standard Xihe-class ships that would require mission-specific communications equipment to be added later, Changxi's suite was pre-installed in the truss section and central docking hub, fully integrated with the ship's power, thermal control, and data buses.
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Beyond the communications enhancement, Changxi comprehensively benefits from XH-01 and XH-02 operational experience: the habitation module uses the same improved configuration as Taibai, radiation shielding is further thickened in critical areas, and the water-recycling system achieves a closed-loop recovery rate above 97%. These improvements give Changxi greater autonomy and survivability for Jupiter-system high-radiation environments and long-duration communications relay missions.
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Construction
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Background and challenges
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Changxi began construction at Star Port Station in February 2056, the second Xihe-class ship assembled at the station (after Taibai). The construction period coincided with the peak of XH-01's Mars expeditions and Jovian-system missions, as well as XH-02's Vesta mission and Mars expeditions. Running three ships concurrently placed significant strain on personnel, materiel, and Star Port Station's shipyard resources.
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This resource dispersion is directly reflected in the build time: from February 2056 to December 2059, approximately 46 months—the longest Xihe-class construction to date. However, the extended construction period was not without value—it gave the build team ample time to incorporate the latest operational data from XH-01 and XH-02 into Changxi's design. Integrating the communications suite during construction rather than as a retrofit avoided the structural interference and system conflicts that a post-build modification might have caused.
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Changxi's construction relied on Qingtian cargo ships for large-module transport and Star Port Station for assembly platform and integration environment. The Jupiter relay communications equipment—including the high-gain antenna array, relay transceivers, and laser communications terminals—was integrated during the truss-section assembly phase, with waveguides, power feeds, and data links pre-routed along the ship's axis, forming an organic whole with the ship's systems.
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Construction timeline
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Phase
Period
Main activity
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Construction start
February 2056
First structural module delivered to Star Port Station; construction initiated.
Cross-module verification, full system inspection, end-to-end communications link testing.
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Assembly complete
December 2059
Major assembly took approximately 46 months; entered shakedown phase.
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Operational history
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Shakedown (January 8, 2060 to April 12, 2060, planned)
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Changxi began its shakedown phase at Star Port Station on January 8, 2060, with a planned duration of approximately three months (to April 12, 2060). The shakedown is divided into three stages designed to comprehensively validate all ship systems and the real-world performance of the enhanced deep-space communications suite.
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Earth orbit and GEO tests (January to February 2060)
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The first shakedown stage focused on low Earth orbit and geostationary orbit maneuver tests. Changxi completed full-thrust-profile propulsion validation, artificial-gravity ring rotation tests, long-duration life-support system evaluation, and ship-wide thermal control response testing. During this stage, the deep-space communications suite completed end-to-end link calibration with Star Port Station and ground control centers, along with validation of multiple communications mode switching.
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Lunar orbit round trip (February to March 2060)
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The second stage targeted lunar orbit, validating Changxi's Earth-Moon transfer capability and long-range navigation performance. Changxi departed from low Earth orbit, completed Earth-Moon transfer, lunar orbit insertion, and return maneuvers. This stage also tested the communications antenna array's pointing accuracy and relay forwarding capability at Earth-Moon distances, accumulating baseline data for subsequent Jupiter-distance communications missions.
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Deep-space communications relay tests (March to April 2060)
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The third stage is a dedicated deep-space communications relay test, which began in March 2060. Test items include multi-band relay forwarding, laser communications terminal long-distance lock stability, communications link interference resistance, and autonomous protocol switching under simulated Jupiter-distance communications delays. This stage is the core validation element of Changxi's shakedown, directly determining the technical readiness for the subsequent Jupiter relay network deployment mission.
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As of March 2060, Changxi's shakedown is progressing on schedule. All test objectives for the first two stages have been met, and the deep-space communications relay tests are in progress. After shakedown concludes, Changxi is expected to be formally commissioned in June 2060.
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Shakedown stage
Period
Content
Status
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Earth orbit and GEO tests
2060-01 to 2060-02
Propulsion validation, life-support evaluation, communications link calibration.
After commissioning, Changxi will undertake two primary mission directions: Jupiter relay communications network deployment and Europa Outpost support.
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Jupiter relay communications network deployment
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Changxi's core mission is deploying a relay communications satellite network in the Jovian system. This network will cover communications links between Jupiter's major moons (Europa, Io, Ganymede, and Callisto) and Earth, providing stable, lower-latency communications infrastructure for subsequent long-duration Jovian-system scientific expeditions, Europa Outpost operations, and crewed missions. Changxi's enhanced deep-space communications suite allows it to simultaneously serve as network coordination node and communications test platform during relay satellite deployment.
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Network deployment is expected to proceed in phases: first, backbone node satellites will be placed in high Jupiter orbit; next, local relay stations will be positioned around the major moons; finally, network interconnection and end-to-end validation will be completed. Throughout the deployment process, Changxi will serve as a mobile command and control center, handling satellite release, orbital calibration, link establishment, and network integration.
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Europa Outpost support
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Changxi's second mission direction is providing communications and logistics support for Europa Research Outpost. As the first Xihe-class ship purpose-optimized for deep-space communications relay, Changxi can provide high-bandwidth relay links between the outpost and Earth while using its mothership-class platform for cargo transfer, crew rotation, and emergency evacuation capability.
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Changxi is the first Xihe-class ship designated from the design phase with deep-space communications infrastructure as its primary mission direction. This role complements XH-01 (emphasizing technology validation and outer Solar System expeditions) and XH-02 (emphasizing inner Solar System and Mars-system missions), reflecting the Xihe-class fleet's diversified development in mission specialization.
500,000 s standard mode; 250,000 s high-thrust mode
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Full-load delta-v
About 1,700 km/s with 300 t payload
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Maximum payload
300 t including surface vehicles and supplies
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Long-duration crew
15
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Short-duration crew
30
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Artificial gravity
About 0.41 g from the rotating habitation ring
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Carried vehicles
Typically two Echo shuttles, or an Echo plus Amalthea-type compatible vehicle mix
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Communications system
Enhanced deep-space communications suite (high-gain antenna array, multi-band relay transceivers, laser communications terminals, dedicated data processing units)
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Construction method
Qingtian cargo ships + Star Port Station assembly
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Build duration
Approximately 46 months (Feb 2056 to Dec 2059)
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Fleet role
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Within the Xihe-class fleet, Changxi is positioned as the dedicated platform for deep-space communications infrastructure and Jupiter-system relay network deployment. Unlike the lead ship Xihe (multi-role comprehensive validation and outer Solar System expeditions) and the second ship Taibai (inner Solar System and Mars-system workhorse), Changxi's mission direction centers on communications relay, representing the Xihe class's evolution from general-purpose motherships toward mission-specialized platforms.
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Changxi's enhanced deep-space communications suite gives it unique mission advantages among the three Xihe-class ships: in distant mission scenarios such as the Jovian system, Changxi can not only perform mothership-class transport and support missions but also simultaneously serve as a mobile relay communications node, substantially enhancing communications capability and network redundancy in the mission area. This role is critically important for subsequent large-scale Jovian-system scientific expeditions and Europa Outpost expansion.
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As of March 2060, the Xihe-class fleet has three active ships (XH-01 Xihe is in the Jovian system on Europa Expedition 3; XH-02 Taibai is in post-mission maintenance; XH-03 Changxi is in shakedown) and one under construction (XH-04). Changxi will soon become the fourth Xihe-class mothership to enter operations, and its communications relay specialization will significantly enhance humanity's sustained presence capability in the Jovian system.
Main roles: Mars-system operations, Jovian-moon operations, and off-world base support
Main facilities: Artificial-gravity habitation ring, greenhouse module, central docking hub, main storage module
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Propulsion: Perseverance mass-driver propulsion system
Full-load delta-v: About 1700 km/s
Successor: Stellaria class
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Current status: XH-01 at Jupiter system, Europa Expedition 3 (ongoing)
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Current status: Xihe at Jupiter system, Europa Expedition 3 (ongoing)
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The Xihe-class interplanetary exploration mothership is a first-generation large crewed mothership designed for long-range operations inside the Solar System. Named after Xihe, the solar deity in Chinese mythology, the class supports scientific expeditions, off-world base construction, crew rotation, and deep-space technology validation around Mars, the Jovian moons, and other target bodies. As of March 2060, the lead ship Xihe (XH-01) is in the Jovian system on Europa Expedition 3, continuing deep-space exploration and base-support duties. As of March 2060, the Xihe class has three active ships (XH-01 Xihe, XH-02 Taibai, XH-03 Changxi) and one under construction (XH-04). The lead ship Xihe is currently executing Europa Expedition 3 in the Jovian system.
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The Xihe-class interplanetary exploration mothership is a first-generation large crewed mothership designed for long-range operations inside the Solar System. Named after Xihe, the solar deity in Chinese mythology, the class supports scientific expeditions, off-world base construction, crew rotation, and deep-space technology validation around Mars, the Jovian moons, and other target bodies. As of March 2060, the lead ship Xihe (XH-01) is in the Jovian system on Europa Expedition 3, continuing deep-space exploration and base-support duties. As of March 2060, the Xihe class has three active ships (Xihe, Taibai (XH-02), Changxi (XH-03)) and one under construction (XH-04). The lead ship Xihe is currently executing Europa Expedition 3 in the Jovian system.
The class uses an axial modular configuration with a mass-driver main propulsion system, an Ark cold-fusion reactor, closed-loop life support, an artificial-gravity habitation ring, scientific facilities, a greenhouse module, and reinforced docking hardware. It is not capable of atmospheric re-entry or planetary landing. Surface access and short-range target-system transport are handled by carried ferry shuttles and surface vehicles.
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Before the Stellaria class entered service, Xihe-class motherships served as the main platform for multiple interplanetary missions. XH-01 was assembled in low Earth orbit from 2050 to 2052 and subsequently supported Mars-orbit validation, Mars base construction, Europa outpost construction, and Jovian-system scientific operations. The class provided the operational foundation for later interplanetary exploration motherships.
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The Xihe class refers both to the class led by XH-01 and to the technical lineage used by later XH-numbered motherships. XH-02 Taibai and XH-03 Changxi continued the class in Mars-base supply, Star Port servicing, and deep-space infrastructure support.
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Before the Stellaria class entered service, Xihe-class motherships served as the main platform for multiple interplanetary missions. Xihe was assembled in low Earth orbit from 2050 to 2052 and subsequently supported Mars-orbit validation, Mars base construction, Europa outpost construction, and Jovian-system scientific operations. The class provided the operational foundation for later interplanetary exploration motherships.
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The Xihe class is a large crewed mothership class designed for Mars and Jovian system exploration. The lead ship, Xihe (XH-01), was completed and commissioned in 2052. Subsequent ships Taibai (XH-02) and Changxi (XH-03) continue the class design with distinct mission specializations.