Linear Induction Projectile Transport

Linear Induction Projectile Transports (LIPTs) are vehicles which hold between 1 and about 20 people, and are launched in suborbital trajectories via linear induction. They are a common mode of transportation in places with little other transportation infrastructure.

## Technology Overview

The term "LIPT" colloquially refers only to the pod in which people and supplies are transported, but the system itself includes:

* a pod, a small vehicle carrying people or cargo
* a launch tube, in which the pod travels during the acceleration phase of the journey
* a receiving tube, in which the pod is collected and decelerated at the end of the journey
* a station, used for handling the logistics of loading and unloading people and cargo from the pods
* an energy source, used to charge the launch tube to a sufficient energy to launch the pod

Conductive fins protrude outward from the pod, and are used as the source of propulsion in the launch tube. The fins are exposed to a strong magnetic field, which creates the acceleration force needed to launch the pod out of the launch tube, and send it on it's journey towards the receiving tube.

## Advantages

* speed: LIPTs provide the fastest travel time between any two points on a celestial body
* ease of setup: unlike most other forms of transportation, a LIPT can be implemented with relative ease, especially on a body for which there is no existing transportation infrastructure.
* not affected by surface terrain: since a LIPT travels above the surface of the celestial body, rough terrain can be easily traveled across. A LIPT system would not encounter the same difficulties as a railway or over-the-surface mode of transportation would.

## Disadvantages

* weight/range limit: for heavier loads and longer travel distances, the amount of energy needed to operate the LIPT becomes impractical.
* energy inefficient: a LIPT uses more energy per kilometer of travel than other transportation modes such as rail and over-the-surface travel.
* relatively unsafe: compared to other forms of travel, a LIPT can fail in a more catastrophic manner. For instance, if the pod fails to correctly connect with the receiving tube (although this is a rare occurrence), then the pod is usually destroyed, depending on the speed at which it is moving.

## Surface to orbit LIPT

Though most LIPTs travel in suborbital trajectories, a special kind of LIPT can be used to enter the orbit of a celestial body, provided that the body is small enough. The moon is a good example of where such a system is used. A surface to orbit LIPT is used at both Equatorial Launch Sites on the moon.

A surface to orbit LIPT requires a special pod with built in impulse thrusters. These thrusters are usually small rocket engines (though other propulsion systems have been proposed), and are used to inject the pod into orbit at the apoapsis of the suborbital path of the pod.

## Notable Uses

### Shackleton <> Novia

Perhaps the most notable use in the solar system, the two settlements of Shackleton and Novia can only be traveled between via LIPT. This is ideal for the residents of Novia, who would prefer to have as little contact with the outside world as possible. As such, the construction of a railway or road between the two communities has never been considered. The Shackleton <> Novia LIPT provides food and supplies to Novia.

This is also one of the shortest LIPTs in use in the solar system. Since Shackleton and Novia are relatively close together, the travel time between them using the LIPT is only a few minutes.

### Kasei Colony <> Mars Equator

Due to the high latitude of Kasei Colony, it is sometimes not possible for a spacecraft in martian orbit to land directly at the colony's spaceport. In this situation, a craft can land at a small landing site at the equator, and the supplies and people from the craft can then travel to the colony via LIPT.

## Use on Earth

A LIPT works best on a celestial body with little to no atmosphere. As such, the use of a LIPT system on Earth is usually too inefficient to be practical. Tests over longer distances have been performed, and show greater promise due to the smaller percentage of flight time spent in the atmosphere. However, these types of journeys present their own problems, such as the need for a pod with ablative heat shields, used during reentry into earth's atmosphere. This also reduces the re-usability of the pod. Suborbital rockets are much more common on Earth, and on other bodies with denser atmospheres, such as Venus.