The Destiny of Man
Gate are large ring like structures that link two points in space via an artificial worm hole. The gate generates large amounts of energy and focuses it to create this hole. Most links have a gate on both ends which reduces the amount of energy required to keep the gate open. Links can be made from one end, but require exponentially greater amounts of energy to maintain. Because of this one sided links are only used to send teams to build the gate through.
Because these gates only connect two points most gates connect one end to a “Gate Hub”. These hubs are areas in open space that have many gate connections. This allows for controlled and more efficient space traffic.
Gates were developed as a method of travel between far away systems and was an alternate method due to failed faster-than-light travel experiments. Many scientists saw the problems plaguing FTL as impossible to overcome adn began attempts to control worm holes. Once successful conlonization of other planets began quickly. Further experiments refined the process such as a two gate link. Gate building grew rapidly and upon meeting other alien species trade agreements were formed to allow use of the gates to alien species.
In the recent future there have been a number of setback with the gate program. A couple disasters saw the creation of Team 3, a military unit to secure gate building sites. Political pressure on the Humans has caused them to slow building for various reasons.