# Stellaria Interplanetary Exploration Mothership

## Overview
The Stellaria class is a series of interplanetary exploration motherships designed for long-duration missions within our solar system. These vessels are equipped with advanced life support systems, scientific laboratories, and modular habitat units to support a crew of up to 30 astronauts for missions lasting up to 15 years. The Stellaria class is intended to facilitate deep space exploration, planetary research, and potential colonization efforts on other celestial bodies.

## Key Features:
- **Propulsion System**: Stellaria utilizes an ultra advanced mass driver propulsion system called Light Speed Engine, allowing for efficient travel over vast distances in space. Propellant are accelerated to up to 0.1c before exiting the engine nozzle, allowing for ultra-high delta-v maneuvers. However, due to the incredible exhaust velocity, the engine cannot operate in this mode near planetary bodies, and must switch to High Thrust Mode which has a much lower specific impulse.
- **Life Support**: The mothership is equipped with closed-loop life support systems that recycle air, water, and waste, ensuring sustainability for missions lasting several years. The on-board greenhouse can support a crew of up to 30 members for 35 years.
- **Artificial Gravity**: Stellaira uses the same rotating habitat module design as Xihe class motherships to provide artificial gravity for crew health during long-term missions. It has 2 habitat rings, instead of the single ring design on Xihe, each capable of generating up to 0.41g of artificial gravity.
- **Towing Capability**: Stellaria is designed to tow smaller spacecraft, such as landers and shuttles. It has multiple docking ports and a robust structural framework to accommodate the stresses of towing during interplanetary travel.
- **Scientific Research**: The mothership is equipped with state-of-the-art laboratories and observation decks, allowing for in-depth scientific research and data collection during missions. It also has facilities for remote operation of planetary exploration vehicles.

## Design:
Stellaria's design is a direct evolution of the Xihe class, incorporating lessons learned from previous missions and advancements in space technology. 
The overall shape of Stellaria is also an elongated, muti-segmented cylinder or spine, with major modules stacked together along a central axis. But the middle section features an expansion to allow for more modules. This allows for better structural integrity during main engine thrust and towing operations, while minimizing the ship's cross-sectional area to reduce collision risks with micrometeoroids and space debris.

### Front Docking Port
At the front of the mothership is a single 5m large docking port for supporting larger exploration vehicles, primarily used by Qingtian Cargo Vehicle to transport supplies and equipment to planetary bases. the docking port is structurally reinforced to handle the stresses of towing heavy payloads during interplanetary travel. To put into perspective, the front docking port can support a Qingtian fully loaded with an entire O-2 base module, which has a mass of over 200 tons.

### Command Center
Directly behind the front docking hub is the command center, which is identical to Xihe's command center. It houses the ship's navigation, communication, and control systems. The command center is equipped with advanced sensors and computer systems to ensure safe and efficient operation during interplanetary travel. The command center also packs with two airlocks for crew and cargo EVA operations. With a diameter of 5 meters, the command center is spacious enough to accommodate the ship's crew and essential systems.

### Artificial Gravity Habitat Module
Located behind the command center is the artificial gravity habitat module. Stellaria uses the same rotating ring design, but has one more ring compare to Xihe. The habitat module is designed to provide a comfortable living and working environment for the crew, with sleeping quarters, recreational areas, dining facilities, and science labs. The habitat module has a diameter of 25 meters and rotates at a speed of 4 revolutions per minute to generate 0.41g of artificial gravity.

### Greenhouse Module
Next in line is the greenhouse module, which is essential for long-duration missions. The greenhouse module is designed to grow food and recycle air and water for the crew. It features hydroponic systems, LED grow lights, and climate control to ensure optimal growing conditions for a variety of crops. The greenhouse module has a diameter of 5 meters and is capable of supporting the dietary needs of up to 30 crew members for 35 years. Greenhouse operations are fully automated, requiring minimal crew intervention, allowing the crew to focus on other mission tasks. 

Greenhouse produce fresh fruits, vegetables and staple crops, supplementing the crew's diet and improving their overall health and well-being during extended missions. Artificial meat production systems, such as lab-grown meat bioreactors, are also integrated into the greenhouse module to provide a sustainable source of protein for the crew.

The greenhouse module also plays a crucial role in maintaining the ship's life support systems by recycling carbon dioxide into oxygen through photosynthesis.

The greenhouse double the volume of Xihe's greenhouse module to support the larger crew size and longer mission duration, and packs more fertilizer storage to support the extended operations.

### Central Expansion Segment
Following the greenhouse is the central expansion segment. This section consists of 5 cylindrical modules, one 5m diameter module at the center like Xihe, and four additional 5m diameter modules symmetrically attached around it. These additional modules provide extra space for scientific laboratories, storage, and crew quarters. The central expansion segment is designed to be modular, allowing for easy reconfiguration and upgrades as needed.

The center module consists of 2 hubs at the top and bottom for connecting the side modules. Between the hubs are the main storage areas packed with supplies, spare parts, and scientific equipment. More than 460days (for a crew of 30) of consumables are stored here to support the crew in the event of greenhouse failure.

The 4 side modules are largely identical, each housing a combination of crew quarters, scientific labs, 2 docking hubs with a total of 3 docking ports for towing smaller exploration vehicles, and a cryopod bay for long-term stasis of additional crew members or passengers. A total of 40 cryopods are distributed evenly among the 4 side modules. 2 copula modules are installed on 2 of the side modules to provide additional observation decks for crew recreation and scientific observation, with another 2 side modules having RA-100 long-range communication arrays installed on top. 

Each side module also has its own airlock for EVA operations, and has 3 docking ports. 1 1.875m docking port at the side at the front hub, 1 1.25m docking port at the bottom of the rear hub. 2 of the side modules have 1.25m docking ports at the side of the rear hub, and another 2 side modules have 2.5m docking ports at the side of the rear hub. These docking ports allow for flexible towing and docking configurations for smaller exploration vehicles. It is worth noting that due to the proximity of the side modules to the center module, the 4 1.25m docking ports at the rear hubs of the side modules can only accommodate small vehicles with a maximum diameter of 4m to avoid collision with the center module. This prohibits the use of standard Amalthea MPVs, which have a diameter of 5m. But Amalthea Explorer variants with a diameter of 3.75m can be used instead, And the standard version can use the side 1.875m docking ports at the front hubs.

Each side module is connected to the central module via pressurized passageways, allowing crew members to move freely between modules while maintaining a controlled environment.

### Truss Structure
Following the Central Expansion Segment is the truss structure. It is very similar to the Truss Structure on Xihe, only longer and with better shielding to reduce the radiation from the much more radioactive Light Speed Engine. The truss structure is designed to withstand the stresses of interplanetary travel and towing operations. There are also 2 docking ports at the top and bottom of the truss structure for additional docking options, both supporting towing operations. 

An additional small Arc-reactor and as well as a secondary storage module are located at the bottom of the truss structure. The small Arc-reactor provides power to the ship in the event of a main reactor failure. It is nowhere near as powerful as the main reactor, but it is sufficient to power essential systems and maintain life support for the crew. The secondary storage module is used to store EVA equipment, spare parts, and other essential supplies needed for maintenance and repairs during the mission.

### Propulsion Module
At the rear of the ship is the propulsion module, which houses the main engines, fuel storage tanks, fusion reactor, additional comms, radiators, attitude control thrusters, and other essential systems needed for interplanetary travel. The propulsion module is designed to provide the necessary thrust and maneuverability for the mothership during its missions. 

The main engine is an ultra advanced mass driver propulsion system called Light Speed Engine, allowing for efficient travel over vast distances in space. Propellant are accelerated to up to 0.1c before exiting the engine nozzle, allowing for ultra-high delta-v maneuvers. The fusion reactor provides the necessary power to operate the engines and other systems on the ship. The engine is capable of operating at 2 different mode: Standard Mode and High-Thrust Mode. In Standard Mode, the engine provides can produce 4800KN of thrust at an ISP of 3,000,000s, allowing for efficient travel over long distances. In High-Thrust Mode, the engine can provide a higher thrust output at the cost of reduced specific impulse, allowing for quicker maneuvers and acceleration when needed. In High-Thrust Mode, the engine can produce up to 7200KN of thrust at an ISP of 1,500,000s. Due to the nature of mass driver propulsion, the engine can be throttled smoothly in both of 2 modes, allowing for precise control over thrust and fuel consumption. Due to the incredible exhaust velocity, the engine cannot operate in Standard Mode near planetary bodies, and must switch to High Thrust Mode which has a much lower specific impulse. And neither mode can be used within atmospheres or near crewed spacecraft, as the high-velocity exhaust would cause catastrophic damage. Firing of the main engine is only allowed in deep space, and trajectory planning must be very careful to ensure no spacecraft or celestial bodies are in the exhaust path.

The main engine requires a significant amount of power to operate, which is provided by the fusion reactor. The main reactor is a large cold fusion Arc-reactor capable of producing up to 80TW of power, most of which is used to power the engines and other critical systems. In the event of a main reactor failure, the small Arc-reactor located at the bottom of the truss structure can provide backup power to essential systems. But it is too weak to power the main engines, but it can power the ship's attitude control thrusters and life support systems, allowing the crew to maintain control of the ship and ensure their safety until repairs can be made or rescue arrives.

A total of 118 tons of reaction mass is stored in the propulsion module, allowing for a total delta-v of 3500km/s when carrying a 500-ton payload. It is worth noting that the first and second Stellaria motherships, ST-01 and ST-02, due to its transitional design, have not changed the fuel tank design, resulting more reaction mass(196t, same with Xihe), and has less payload capacity(300t max payload) compared to later Stellaria motherships. This limits their payload delivery capability, but allows them to achieve a higher delta-v of 4500km/s, making them more suitable for deep space exploration missions rather than planetary base construction missions.

The propulsion module also includes large radiators to dissipate heat generated by the reactor and engines, ensuring the ship remains within safe operating temperatures.

## Construction
### Transition to Stellaria Class
The first two Stellaria motherships, ST-01 and ST-02, represent a transitional design from the Xihe class to the full Stellaria class. They were initially constructed as Xihe class motherships, but were modified during construction to incorporate key features of the Stellaria design. But to speed up construction, only the spine and propulsion modules were modified, while the rest of the ship retained the Xihe class design. This resulted in a mothership that closely resembles the Xihe class in appearance and layout, but with the enhanced capabilities of the Stellaria class. 

ST-01 and ST-02 were also constructed by multiple Vulture Shuttle launches, each carrying several major modules into orbit for assembly. This approach was later abandoned in favor of constructing the motherships at Star Port Station using Qingtian Cargo Vehicles, which allowed for larger modules to be transported and assembled more efficiently.

### Construction at Star Port Station
After Star Port Station became operational, all subsequent Stellaria motherships were constructed there. Each Stellaria mothership requires 5 Qingtian Cargo Vehicles to transport the major modules and components to the station for assembly. 

- Qingtian-1: Central Expansion Segment with all 4 side modules and part of the center module.
- Qingtian-2: Central Expansion Segment and Truss Structure.
- Qingtian-3: Propulsion module, including fuel tanks, radiators and comms.
- Qingtian-4: Command Center, Greenhouses and Artificial Gravity Habitat Ring #1.
- Qingtian-5: Artificial Gravity Habitat Ring #2 and front docking port.

The construction process begins with the assembly of the central expansion segment, which will serve as the core structure of the mothership. Once the central expansion segment is complete, the truss structure and propulsion module are attached to the rear of the segment. The command center, greenhouse, and habitat modules are then added to the front of the central expansion segment. Finally, the front docking port is attached to complete the assembly of the mothership.

After the major modules are assembled, the ship's Artificial Gravity Habitat Rings are spun up to their operational speed to ensure proper functioning. One or two Qingtian Cargo Vehicles are then used to deliver smaller components, fuel, equipment, and supplies to the mothership for final outfitting. This includes scientific instruments, life support systems, crew quarters furnishings, and other essential items needed for the mothership's missions.

After the modules are assembled at Star Port Station, the mothership undergoes a series of tests and inspections to ensure all systems are functioning properly. Once the mothership passes all tests, it is cleared for its maiden voyage.

### Testing and Commissioning
Before being commissioned for active service, each Stellaria mothership undergoes a rigorous testing and commissioning process. This includes system checks, propulsion tests, life support system validation, and crew training exercises. The mothership is also subjected to simulated mission scenarios to ensure the crew is prepared for various situations they may encounter during their missions.

Before launch and commissioning, each Stellaria mothership is required to complete a shakedown cruise, which involves a series of test maneuvers and system checks. Testing typically consists of several trips to Geostationary orbit and back, to verify the performance of the propulsion system, life support systems, and other critical components. Trips to the Moon and back are also conducted to simulate deep space operations.

After successfully completing the shakedown cruise and all tests, the mothership will be brought back to Star Port Station for final preparations before being commissioned for active service. Commissioning ceremonies are held to officially induct the mothership into the fleet.

## History
During the construction of the second Xihe class motherships(XH-02), the decision was made to redesignate it as ST-01(Stellaria) after significant design changes were made to incorporate the new Lightspeed Engine and other enhancements.  Similarly, XH-03 was also redesignated as ST-02(Kristen) for the same reasons.

ST-01 was launched in 2055 to support the Mars One base construction and resupply missions. It has since completed several successful missions, delivering supplies and equipment to the Mars One base and conducting scientific research in deep space.

ST-02 was launched in 2057 to support the Europa Research Outpost rotation and Venus exploration missions. It has also completed several successful missions, delivering supplies and rotating crew members for the Europa Research Outpost.

ST-01 was brought back to Star Port Station in November 2059 after returning from a Saturn Exploration Mission for a major upgrade. The command center and habitat module were replaced with new Stellaria class modules, and the central expansion segment was added to increase capacity and capabilities. The Propulsion module is not expected to be replaced, as it is already equipped with the Lightspeed Engine, and the fuel tanks are actually larger than the standard Stellaria class design, allowing for greater delta-v performance. The upgrade is expected to be completed by mid-2060, after which ST-01 will be re-designated as a full Stellaria class mothership.

ST-02 is also scheduled for a similar upgrade in early 2061 when it returns from the Europa Research Outpost rotation mission.  Once the upgrade is complete, ST-02 will also be re-designated as a full Stellaria class mothership.

The decision to launch ST-01 and ST-02 as transitional designs was driven by the need to quickly deploy motherships capable of supporting ongoing planetary base construction and exploration missions. And with XH-01 also planned for an upgrade after a few missions, the shortage of motherships was alleviated while the Stellaria class design was still being finalized.

## Naming confusion
The second and third Xihe motherships were originally intended to be XH-02 and XH-03 respectively. However, during the construction of XH-02, the decision was made to redesignate it as ST-01(Stellaria) after significant design changes were made to incorporate the new Lightspeed Engine and other enhancements.  Similarly, XH-03 was also redesignated as ST-02(Kristen) for the same reasons.

Stellaria and Kristen serve as transitional designs between the Xihe class and the more advanced Stellaria class motherships. They are essentially Xihe class motherships with the new Lightspeed Engine. Both of which are already enter into service to support Mars One and Europa Research Outpost. Upgrades are planned to bring them closer to the full Stellaria class specifications. 

## Specifications
### Performance
- Propulsion: Light Speed Engine (Mass Driver Propulsion System)
- Main Engine Thrust: 4800KN (Standard Mode), 7200KN (High-Thrust Mode)
- Specific Impulse: 3,000,000s (Standard Mode), 1,500,000s (High-Thrust Mode)
- Delta-V: 3500 km/s (with 500-ton payload)
### Weight and Dimensions
- Length: 107.5 meters
- Diameter: 25 meters (at habitat ring)
- Fuel: 196.3t(ST-01 and ST-02), 117.8t(later Stellaria motherships)
- Wet Mass(without payload): 537 tons
- Max Mass(with 500-ton payload): 1037 tons
### Payload Capacity
- Maximum Payload: 500 tons (including planetary surface exploration vehicles)
- Towing Capacity: Up to 300 tons at the front docking port, 100 tons at each side docking port
### Crew
- Crew Capacity: 30 (sustainable for up to 35 years), 60 (short-term missions)
- Life Support supplies: 460days for 30 crew members without greenhouse support

## Missions
Stellaria motherships are primarily used for crewed exploration missions to outer planets and celestial bodies within the solar system. They are also suitable for planetary base construction missions as their excellent payload capacity allows them to transport large amounts of equipment and supplies. These missions typically involve a combination of scientific research, celestial body surface exploration, and technology demonstration. The mothership serves as a mobile station of operations, allowing the crew to conduct extended missions in deep space.

The first Stellaria mothership, Stellaria(ST-01), is launched in 2057 to support the Mars One base construction and resupply missions. After returning from Mars, it is sent on a Saturn Exploration Mission. Stellaria visited most of the larger Saturnian moons, sending crews to do surface exploration and research. After completing its mission, Stellaria was brought back to Star Port Station for a major upgrade to full Stellaria class specifications.

The second Stellaria mothership, Kristen(ST-02), is launched in 2058 to support the Europa Research Outpost rotation and Venus exploration missions. It is currently on its first Europa rotation mission, transporting crew and supplies to the outpost. After completing its mission, Kristen is also scheduled for a major upgrade to full Stellaria class specifications.

## Fleet
| Name        | Designation    | Status        | Description                                      |
| ----------- | -------------- | ------------- | ------------------------------------------------ |
| Stellaria   | ST-01          | Active        | Transitional design to Stellaria class, equipped with Lightspeed Engine.  |
| Kristen | ST-02       | Active        | Transitional design to Stellaria class, equipped with Lightspeed Engine.  |
| Muelsyse | ST-03       | Under Construction        | First full Stellaria class mothership, intended to support Jupiter moon exploration and asteroid belt research.  |

# Naming
Stellaria is named after Arc-01 Stellaria, symbolizing humanity's ambition to explore the cosmos. Designed by Dr Kristen Wright, Arc-01 was Terra's first spacecraft ever passing the Fake Sky Barrier and enter into space and marked the beginning of Terra's Space Age. Dr Wright was on board Arc-01 and had to went into cryo sleep due to the lack of power. Dr Wright is still not found to this day, but her legacy lives on through the Stellaria motherships that bear her name.

The second Stellaria mothership, Kristen, is named directly after Dr Kristen Wright herself, honoring her contributions to space exploration and her pioneering spirit.

The third Stellaria mothership, Muelsyse, is named after Dr Muelsyse, director of the Ecological Section at Rhine Lab. Dr Muelsyse made significant contributions to the development of closed-loop life support systems and sustainable space habitats on board Arc-01 Stellaria, which laid the foundation for long-duration space missions.

There's also a series of rocket family -- Kristen -- named after Dr Wright. In fact, Kristen-90 was used to launch the Artificial Gravity Habitat Module on Xihe(XH-01), Stellaria(ST-01) and Kristen(ST-02).

## Related Vehicles
Echo Shuttle: /home/Space_Shuttles/Echo_Shuttle
Amalthea: /home/Vehicles/Amalthea
Star Port Station: /home/Stations/Star_Port_Station
Lightspeed Engine: /home/Engines/Lightspeed_Engine
Qingtian: /home/Cargo_Ships/Qingtian
Stellaria: /home/Exploration_Motherships/Stellaria
Xihe: /home/Exploration_Motherships/Xihe
XH-01: /home/Exploration_Motherships/Xihe/XH-01
ST-01: /home/Exploration_Motherships/Stellaria/ST-01
ST-02: /home/Exploration_Motherships/Stellaria/ST-02
Mars One: /home/Bases/Mars_One
Europa Research Outpost: /home/Bases/Europa_Research_Outpost
Kristen Rocket: /home/Rockets/Kristen_Rocket
Kristen-160: /home/Rockets/Kristen_Rocket/Kristen-160

## Note
Xihe - 羲和
Taibai - 太白
Changxi - 常羲
Stellaria - 万星园
Qingtian - 擎天
Echo Shuttle - 回声航天飞机
Amalthea - 阿玛尔塞亚
Kristen - 克丽斯腾


