Interstellar Travel

Interstellar travel is the act of moving between two different star systems. Prior to the development of the hyper drive, this could only be done at sublight speeds, taking dozens to hundreds of years. The discovery of faster-than-light travel at the beginning of the 23rd century CE instead allowed for those systems to be reached in a matter of days or weeks, permitting the creation of interstellar societies. Space, however, is still a very big place. Even as subspace relay networks across tens of thousands of light years and hyperspace allows ships to traverse fractions of those distances nearly instantly, moving at sublight speed is still painfully slow. A typical civilian starship can traverse the Sol System entirely in approximately two weeks, but the Deneb System can take up to two months.

Ship Design

The most important part of any starship is the airtight hull - without it, the interior would be exposed to hard vacuum, cosmic radiation, fast-moving debris, and other health hazards. Modern starship hulls are typically made from materials such as plasteel and durasteel, while older ships are made from ceramo-metal alloys, nanocomposites, or even titanium. Hulls are buttressed with a structural integrity field, or SIF, that maintains the hull shape even under high stresses or damage. As a further layer of defence, energy screens, also called 'shields', are projected from a field emitter to deflect incoming objects or energy sources. Some types of shield, such as those found in most hangars, are designed to maintain an atmosphere but permit objects to move in and out. Most ships are designed with a bulkhead design, separating different sections in the event of a catastrophic hull breach. If one section is breached, others can be safely sealed off to minimise exposure to vacuum.

Inside a ship, artificial gravity keeps the crew oriented and dampens the effects of high-g maneuvers. Life support systems, such as oxygen generation (or other gases, depending on species), stored provisions (food and drink), heat management, and waste disposal, keep a crew alive and functioning throughout the long journey an interstellar spacecraft takes. For prolonged flights, a crew might employ the use of cryopods to pass the time faster. This is common on long-haul cargo ships, while colony ships and transport ships place their huge number of passengers in cryo pods to massively reduce inflight resource requirements. Some ships are completely autonomous, flown by artificial intelligence, allowing a crew to sleep for an entire journey and only be awakened in an emergency.

There are four different elements to a ship's propulsion: takeoff, maneuvering, thrust, and FTL travel. For most small to medium size ships, they use repulsors to take off, land, and hover inside of gravity wells. Larger ships, due to the square-cube law, become too heavy for repulsorlifts to efficiently handle, or landing gear to take the strain of. Water landings are an option for some large ships, but others are entirely restricted to operating in space. In-space maneuvering is accomplished through repulsors or small thrusters on the ship, while the main engines provide the primary thrust for any sort of travel. Hyper drives are expensive pieces of hardware that allow a ship to breach hyperspace entry points, allowing them to transit to other systems through the hyperlane network. Ships that do not plan on leaving a given system are built without hyper drives, in order to save cost.

Takeoff

Before taking off, ships undergo a preflight checklist. This involves actions such as running systems diangostics, loading fuel, reaction mass, and provisions, acquiring a flight plan from local authorities, updating ship computers with the latest traffic and weather information, securing passengers and cargo, inspecting the ship exterior for issues (such as hull fractures or damaged components), and sealing the ship for exoatmospheric flight. Once the fuel (uranium, deuterium, or antimatter) is onboard, the ship's reactor can be started. This process can take some time, usually up to an hour or two depending on the reactor, so it is begun early in the startup procedure.

Once a ship is verified for takeoff, it engages its repulsors to lift itself off the ground. Once clear of any obstacles, it uses its main engines to boost itself into space. This can take anywhere from five to ten minutes, and the passengers are subjected to mild g-forces as the onboard artificial gravity compensates for both the planet's gravity and the ship's acceleration. If a ship is launched from a space station, mothership, or other non-planetary facility, it performs similar pre-flight checks, but skips the atmospheric ascent phase.

Intrasystem Flight

Once free of an atmosphere, a ship will continue based on its flight plan. If it intends on stopping at an orbital station (or even planetary landing location) around the same gravitational body, it follows the procedures for landing at the station. If the destination is elsewhere in the system or galaxy, the ship first enters an orbit in a holding pattern. After being given departure clearance from the local traffic authority, the ship proceeds on a direct route to its destination.

While space is extremely vast, most ships travel along well-established routes between common destinations. In an established colony system, the route between hyperlane entry points and planets will be heavily populated by civilian shipping, for example. This is especially common around popular destinations, such as planetary orbits, starbases, and habitat orbitals. Systems with extensive habitat complexes, such as the Sol System, will be criss-crossed with dozens or even hundreds of shipping lanes. Due to this, ships are expected to stay along their specified route and follow any further instructions given by local traffic authorities.

Most of a ship's actual flight is handled by the onboard computer. In ideal conditions, the computer is capable of flying a ship from takeoff to landing completely on its own. In systems classified as least-risky, automated transport barges are commonly used to save on crew costs. However, ships that experience anything more than minimal risk effectively require intelligent crew onboard, be they organic or synthetic. A ship's crew is responsible for piloting it through hazards like storms, subspace disturbances, and asteroid fields, conducting inflight repairs, emergency management, and other minor tasks that an onboard computer cannot handle.

FTL Travel

As hyperlanes effectively act as "tethers" between gravity wells, they do not necessarily orbit a star. Instead, they can be imagined as a taught link joining the systems together - where the entry point is depends on the relative positions of the star systems to each other in the galaxy. Due to this, ships approaching a hyperlane entry point are required to slow their velocity to remain within the approximately gas giant-sized region of space where hyperspace is thinnest. Once there, a ship diverts its power to the hyper drive and begins charging it.

The process for charging a hyper drive can take up to sixteen hours, depending on the size of the ship and the type of drive installed. Modern hyper drives have advanced sensor and computer systems that identify optimal breach points, reducing the energy requirements and charge time by up to a quarter. At the same time, the ship's computer calibrates the drive for travel, in order to prevent any issues during the jump. Failure to properly calibrate a hyper drive can result in the drive failing mid-jump, causing the ship to exit hyperspace in the void between stars.

When fully charged and calibrated, the ship's hyper drive opens a portal in front of the ship, leading directly to the dimension of hyperspace. The ship proceeds under its own power into the portal, which closes when the ship has fully entered. Other ships can enter a hyperspace portal with the ship, but this has a high chance of destabilising the jump and causing a catastrophic failure. Once inside a hyperlane, the ship flies under its own power through the dimension, while the hyper drive keeps the ship from being ejected back into realspace. Although the realspace distances covered by hyperlanes are incredibly vast, the time taken inside a lane is considerably shorter: typically only a few hours to just under a day, depending on how long the strand is. Exiting a ship mid-hyperspace is technically possible but extremely dangerous, as leaving the hyperparticulate field surrounding the ship will cause the individual to be shunted into realspace.

When a ship has reached the end of the hyperlane, the hyper drive opens a second portal that leads back to realspace. While a ship can simply shut off the hyper drive and be ejected, this can cause severe damage to a ship's hull or hyper drive and is ill-advised. In addition to hyperlanes, ships can use other forms of FTL travel, such as wormholes, hyper relays, subspace navigation, and reactivated gateways.

Dangers

Space is incredibly hostile to organic and synthetic life. Space itself is a vacuum with no atmosphere, which can kill an exposed organic in mere seconds. Cosmic radiation is extremely harmful to both organics and synthetics alike, causing tumours and hardware failures. However, these two dangers are relatively simple to solve with modern hulls. However, space has far more dangers than its mere existence.

Some of the most common natural hazards spacers encounter are solar flares and rogue asteroids or space debris. System traffic control authorities keep track of loose objects in a system, and monitor stars for any hazardous solar phenomena. Less common natural hazards include gravitational anomalies, subspace disturbances, and extrasolar radiation emissions from nearby stars. All of these hazards are included in system navigational databases, which ships update whenever they land or take off from a spaceport. In an emergency, local authorities use subspace alerts to send messages to all ships in a system of potential hazards.

Not all dangers are stellar phenomena, however. Spaceborne fauna has shown a remarkable tendency to attack starships, including Space Amoebae, Crystalline Entities, and Void Clouds. The most common type of space fauna, Tiyanki, are harmless and do not attack ships. Depending on the space in question, military patrols may clear spaceborne fauna from major spacelanes. Some governments, such as the United Nations of Earth, enforce regulations on starships in their space regarding signals and radiation emissions. These protocols have been shown to effectively pacify Crystalline Entities and Space Amoebae respectively, though Void Clouds are perpetually hostile. Luckily, they rarely venture outside of systems with black holes.

In unpatrolled space, particularly space that has rich trade lanes, some individuals may find illicit methods to earn a living. The earliest space pirates were armed with little more than cargo ships and asteroid defence lasers, but modern piracy is far more advanced - especially when funded by foreign adversaries. Pirates are typically connected to organised crime gangs on inhabited worlds, but others operate purely out of their hidden bases (usually converted asteroids). The standard advice when facing pirates is to determine whether the ship one is piloting can reach either a hyperlane entry point or military outpost before the pirates can get within weapons range, and if so, immediately make for that location. Otherwise, unarmed civilian ships are usually advised to comply with pirates and dump cargo (in order to avoid being destroyed).

Cosmic storms are subspace-based meteorological events that can create significant impacts on space travel in systems. Electic storms can interfere with shields, gravity storms can create hazardous anomalies, stardust storms can obscure sensors, and particle storms can severely damage ship hulls. In all cases, ships are advised to heed local safety bulletins for best practices regarding storms. However, in the event of a nexus storm or shroud, ships are always advised to refrain from space travel. Ships already in space when one of these storms hits are advised to leave the system, or if that is out of the question, land at the nearest docking facility.

With the number of dangers in space, ships have a multitude of defensive options at their disposal. Armour plating and shield generators can provide some protection against radiation and weapons fire. Escape pods can preserve a crew's lives in the event of a catastrophic hull or reactor failure. Some civilian ships are armed with point-defence weapons for intercepting missiles and asteroids, and in some parts of the galaxy, civilians are permitted to own armed, militarised vessels. In addition, if facing overwhelming odds, a ship's crew may elect to engage the emergency FTL feature on its hyper drive. This immediately creates a portal around the ship that sends it into subspace, where it can follow subspace beacons to reach safe systems. However, this action creates immense strain on the hull and systems. If a ship is already damaged, using its emergency FTL may destroy it entirely. As such, it is only used as a last resort.

Arrival

Arriving at a destination is something of the inverse to departure, though with similar steps. The crew files their flight plan with the local traffic authority via subspace communication, requesting landing clearance at their destination. If the destination is a habitat or space station, it is a simple matter to dock and disembark. However, ships entering a planet's atmosphere require more preparation. After entering a holding orbit around the destination planet or moon, the crew runs systems diagnostics and checks the ship for any hull breaches. Once ready, the ship descends into the atmosphere. It should be noted that particularly large ships cannot enter gravity wells, as their repulsors are not strong enough to land safely.

Ships enter the atmosphere at high speeds, using their repulsors to gradually slow them down. Shields are typically disabled during atmospheric re-entry, as they overload due to the massive and continuous levels of heat and pressure. Powerful military shields can sometimes withstand the heat of re-entry, but the hull and armour plating of any ship is sufficient to withstand the heat. As the ship's repulsors slow it down, it uses its main thrusters to fly through the atmosphere at (relatively) slow speeds, at or below the speed of sound.

Ships switch to entirely repulsors on final approach, ideally landing gently in their assigned berth. From there, the ship's reactor and systems are powered down, as it plugs into the planet's electrical grid. Due to the destructive potential of nuclear and antimatter reactors, most docks require starships to disengage their reactors as a safety precaution. During this process, the crew files any necessary paperwork for disembarkation, then undergoes a decontamination process either onboard the ship or in the spaceport. Passengers and cargo also disembark, and the ship is inspected for any wear and tear. When the ship and crew are ready, they start the launch procedure all over again.