Attachment Hardpoints

Every spacecraft has a set of hardware attachment points, which come into play when the ship docked, either to allow the attachment of a walkway to an airlock, or for the transfer of cryogenics.

Hardpoint attachment types:

• Airlock walkway attachment frame:

These often take the form of a series of recessed grooves around the airlock hatch, the attachment gantry will mate with these grooves, and servo mechanisms either on the gantry or hatch extend a flexible seal between the parts to make airtight.

• Cryogenic Loading Ports

These kinds of ports are designed to support pressure loads, as there is likely to be a reasonable amount of pressure generated from the evaporation of the cryo-liquid on the craft. The hatch points themselves are recessed into the hull a fraction, and are complex in structure, the first part is a cap which folds out, which reveals the mating collar which supports and locks the supply hose, after this mechanical attachment are a sequence of valves that ensure that safe pressure equalization of the hose outlet, and the return feed pipe. The valves on the cryo supply lines are multiply degenerate, to prevent loss of cryo-storage in the event of hull damage. Also a pump complex near the storage tank can act to reverse the usual flow and provide ships a way of emptying tanks prior to system overhaul.

• Antimatter Transfer Hardpoints

Though these ports share a lot of gross design similarity with the cryogenic attachment points, these supply hoses contain a much more dangerous supply, and any trace that escapes at the end of loading and hose release is a major safety risk. The antimatter is instead streamed in an ultra fine stream as a plasma held in magnetic containment. Magnetic pumping and flow reversal act to clear the ducts of all antimatter prior to hose release, in addition a series of sturdy physical valves on hose and internal tank supply line prevent loss of containment.

• Data Transfer Ports

There are as many different types of these as there are spacecraft, most craft have many different types in a combined data port complex on the hull, most craft can accept a full range of standard fiber optic cable arrays, some more sophisticated craft have larger data trunks for interfacing, or to allow them to access sensor platform data. All of these types have a (sprung or magneto) hinged cap which protects the underlying material, most fiber trunks have only one correct orientation into the port, and are held in place by a series of mechanical catches.

• High Energy Plasma Transfer Ports

These support attachments allow high-energy transfer to a spacecraft in dock, while internal power plants are offline. The transfer is of high energy, high speed, but low pressure (less than 2 bar) plasma, and the supply hoses match up with a universal adaptor in the ship’s hull, though behind this adaptor is a regulator complex that limits plasma flow (hence low pressure feed), this stops a small shuttle from receiving the full flow that a starship would require. Larger vehicles have several feed lines as their demand is higher, and also they can use return flow on lines to clear out their plasma conduits.

• Matter stream feedlines

Are practically identical to the plasma transfer ports, though much small diameter as they are carrying only cool matter plasma, and therefore do not require the same amount of armour. These lines nearly always directly interface with an onboard matter processing facility that will separate out the stream, and allocate for onboard storage. On mining vehicles, which have larger onboard matter stores, the ports are often somewhat different, generally much larger to handle the greater load, and generally shielded for transmitting larger quantities of radionuclides (this is mainly just a precaution).

Common port structures;

Most acceptor units are seated in a sliding frame which allows for small movements in the craft when the cables are attached, in addition cables self detach when larger loads are placed on them, this mechanism prevents hose breakage and possibly risk of loss of containment on the contents (in the case of antimatter this can be very bad). Hose release is usually mechanically mediated at the ship end, though if these mechanisms fail the attachment nozzles can safely detach by commanding through the hose datalines.

Rather than manually loading each line, the feedlines are generally attached to the docking frame, or on robotic attachment arms, and the process in essentially autonomous, though the loading procedures should be overseen by at least one operator (in case of loading routine failure)