The Allied Worlds Survey Ship Zheng He is wormhole-going long-range fusion ship. Together with sister ship Marco Polo, the Zheng He was designed to explore space beyond the Ten Stars.

History

The Zheng He is a refit of Buraq, the lead ship of a class high-performance patrol spacecraft used to respond (relatively) quickly to distant emergencies in Allied systems. Compared to the Buraq, the Zheng He has had its armor reduced and weapons eliminated in favor of additional supplies, fuel, and landing craft, and a second habitat ring (taken from a decommissioned Buraq-class ship) for mission facilities. (It should be noted that the Buraq class was not intended to fight purpose-built warships at technological parity, and as such would not be competitive with them in open combat. This goes double for the Zheng He and Marco Polo which do not even have anti-ship weapons.)

Propulsion

To accommodate their long-range rapid-response role, the Buraq-class patrol spacecraft use deuterium/helium-3 fusion. (Most fast ships use deuterium/deuterium fusion) Helium-3 is considered a strategic resource by the AW; the same resolution of tensions in the Dirac system that has enabled the reexploration of connected space beyond it also makes the AW's Helium-3 extraction and production capacity more available for civilian purposes.

The drive of the Zheng He is a highly advanced Z-pinch fusion reactor with a direct electrical conversion system to supply both its own confinement magnets and other electrical service needs. The versatile drive can trade off efficiency and thrust to accommodate a variety of missions. Using only the fusion plasma as propellant, it can attain exhaust velocities in excess of 8% of lightspeed (20 000+ km/s). Alternately, thrust up to 0.1g can be realized with the use of supplementary water propellant. The Zheng He is outfitted with equipment for in situ propellant extraction and refining; combined with its high energy-density fuel (D/He3 fusion), this gives it outstanding effective range and independence from fixed infrastructure.

Mission

The Zheng He is intended to establish peaceful contact with the wormhole-connected worlds beyond the Dirac system, hitherto impassable to the Allied Worlds and separating them from the rest of connected space. Of course, the mission is fantastically expensive, and the AW are counting on the Zheng He and Marco Polo not only to establish diplomatic relations and collect geographical information, but to encourage the development of economically viable trade, identifying high-value resources of interest to the newly contacted planets or to the AW. Where appropriate to local techno-industrial development, the construction of infrastructure facilities to support interstellar trade will be encouraged.

The cargo space of the ships is being loaded with high-value objects believed to likely be of interest. They can be traded or dispensed as gifts to secure the cooperation of the civilizations visited. The ships' computer networks are loaded with a great variety of scientific, technical and cultural publications, as well as manufacturing instructions and programs, to be exchanged for their counterparts from other technologically advanced cultures, or for correspondingly precious material goods.

The ships will also have a scientific mission, to investigate the effects and scope of cultural divergence that took place in the long centuries since the fall of the Solarian Empire. Much of the habitat space added in the refits of the survey ships has been to accommodate scientific facilities and personnel, and expectations are accordingly high. A particular focus has been placed on the onboard medical and quarantine facilities, in light of the risks of encountering unusual pathogens. The advanced medical facilities will allow artificial hibernation to be applied in non-emergency situations to personnel who would not normally be considered medically qualified for hibernation.

Layout

There are two habitat centrifuges contained within the huge main pressurized compartment, which contain most of the living and working space. Having the centrifuges within pressurized space simplifies their design greatly, and the large pressurized volume, realized as an inflatable structure, provides a good atmospheric buffer capacity in case of fire or leaks. A garden and freefall recreation area are contained in the rest of the pressurized compartment, with the exterior configuration of the slowly-rotating centrifuges designed to avoid the possibility of catastrophic trauma caused by colliding with them in freefall. Other pressurized sections run axially on the ship. At the forward end is an observatory copula. Aft of this is the hangar bay pressurized staging and airlock area, a central passageway, a command center and storm shelter, the pressurized engineering spaces (including damage control robot control rigs), and the engineering airlock opening into unpressurised machinery spaces.

The forward centrifuge contains mostly facilities related to the ship's exploratory mission.

The after centrifuge contains mostly facilities related to the operation of the ship, though it has been refitted from its original condition.

After Centrifuge

Outer deck: Command center and control areas, mess, recreation and exercise areas. Middle deck: Meeting room, staterooms, galley, sanitary facilities. Inner deck: Short-term storage, auxiliary machinery, berthing, hibernacula.

Forward Centrifuge

Outer deck: Medical facility, quarantine living quarters, laboratories. Middle deck: Meeting rooms, staterooms, library, offices, sanitary facilities. Inner deck: Berthing, hibernacula, auxiliary machinery, short-term storage.

Weapons

The Zheng He is unarmed except for a pair of relatively weak point-defence lasers sufficient to protect it from small space debris or primitive weapons. Its powerful fusion drive, though not optimized for the purpose, is necessarily quite deadly if pointed in the direction of a relatively nearby enemy structure, but this is a basically unavoidable property of any high-performance propulsion system.

The AW strongly wishes the expedition not to start any wars, most especially any wars with enemies that cannot be finished by pointing the engine in their direction. It is thought that the unarmed ship will seem less threatening to advanced civilizations that might be encountered, reducing the odds of a hostile reaction, but that the inherent capabilities of the ship even excluding purpose-built weapons should be sufficient to intimidate primitive civilizations should such an action be deemed essential to the safety of the ship.

Small arms are stored onboard for the defence of landing parties in primitive conditions (e.g. wild planets or those where the existing civilizations may not have a well-developed respect for the customs of diplomacy.)