An Astral Gate is a device used to travel through hyperspace, connecting planets and moons within the Solar System. They make interplanetary travel possible within a matter of hours, a feat not achievable before their inception. Astral Gates are located outside of Mars, Ganymede and Venus, to name a few locations, and are similar to the interstate highways of 20th century Earth. They are run by the Gate Public Corporation, which charges a toll on all incoming traffic.
The underlying technology of the Astral Gates is that of Spatial Alternation Dynamics, based on the theory that our universe phases in and out of existence every 1/48 second, blinking on and off like a strobe light. While our universe is "off," it is temporarily replaced by a more compact universe called Phase Difference Space, which is 1/240th the size of our universe. By timing the entry and exit just right, it is therefore possible to travel 240 times faster within Phase Difference Space, which creates the illusion of extremely high-speed travel in our universe. For example, a journey from Earth to Mars takes 13-24 hours using an Astral Gate, while the same journey could potentially take six months without one.
Risks and SecurityEdit
The first Gate was built in 2021. In what came to be known as the Astral Gate accident of 2022, Earth's Astral Gate malfunctioned and exploded, destroying the Moon and killing a significant fraction of Earth's inhabitants. As a result, planet Earth has been rendered uninhabitable, with ongoing rock showers from the falling debris. The majority of humans have since abandoned the Earth and settled on other planets and satellites in the Solar System. 
If the gates were ever to be closed while a ship is inside of them, the ship would forever be stuck in hyperspace, regardless of whether the gates were to be reopened. Those on the outside of the gate would see a transparent image of the ship coming out of the gate, relevant to when the ship would actually come out of the gate. This image can not collide with matter and presumably lasts forever, going in the same direction. 
Public gates Edit
Dark Gates are travel routes kept secret from the public, and used by organized criminals. A special device is required to navigate these hyperspace areas.