Underspace

The Underspace is a network of subspace corridors extending through large reaches of the Delta Quadrant, allowing swift travel across vast distances. Its use is largely controlled by the Turei Alliance, who have granted Starfleet limited access.

In late-2401, apertures to the network opened across the galaxy, showing it stretched at least across the Milky Way. This access was brief, with the new apertures closed soon after they opened, and travel through Underspace is again limited to the Delta Quadrant.

The corridors of the Underspace are dangerous to traverse

History

The first known users of the Underspace were the Vaadwaur prior to the 15th century. With a reach as far as Talaxian territory, they used the Underspace for trade, exploration, raiding, and expansion, but kept no written records of the phenomenon. When the Vaadwaur were defeated by the Turei and their allies, this understanding and knowledge were lost.

Since then, the Underspace fell broadly into the hands of the Turei. Despite their limited knowledge, they guarded use of the phenomenon jealously, driving out interlopers. One such encounter was with the USS Voyager, who stumbled upon the Underspace by accident and was subsequently instructed to delete from their databanks all evidence of its existence. Despite this fraught first contact, the Starfleet crew ultimately assisted the Turei against a militant group of surviving Vaadwaur, who fled into the Underspace.

This tenuous agreement paved the way for future cooperation between Starfleet and the Turei. In 2399, the Federation formed an agreement that included not only joint operations in the Gradin Belt but limited use of the Underspace for Starfleet ships.

In 2401, Underspace apertures opened across the galaxy, facilitating travel across the Milky Way in the blink of an eye. When consulted, the Turei Alliance expressed no understanding of how or why this happened. This led to weeks of chaos as travellers became lost, expeditions were launched, and the great powers of the galaxy saw tremendous strategic and geopolitical upheaval. While Starfleet sought to harness this expansion of the network for exploration, the Cardassian Union deemed the change to the galactic status quo far too dangerous to tolerate. They formed a brief alliance with the Turei, who brought their extensive knowledge of Underspace to bear in assisting the Cardassians in closing the new Underspace apertures.

As of late 2401, Underspace remains a network of corridors used to traverse solely the Delta Quadrant. There is no known way to safely exit or access Underspace tunnels that may exist elsewhere. While relations between Starfleet and the Turei are frosty after this incident, the Turei continue to hold a monopoly on safe traversal of Underspace, and retain their agreements with the Federation.

Use of the Underspace

Understanding of the Underspace remains limited

The Turei are familiar with multiple access points to the Underspace in the Gradin Belt, though their knowledge of exits further afield is much more limited. Starfleet has loosely charted routes to the Swallow Nebula, the Nacene Reach, and the Nekrit Expanse, allowing ships to travel to the Delta Quadrant through the Barzan Wormhole and from there proceed across the quadrant.

However, understanding of the Underspace remains limited and much knowledge was lost with the fall of the Vaadwuar. Just as ships have fallen accidentally into the corridors, some have tumbled out before reaching their exits and been left stranded, unable to regain access. Underspace corridors are dotted with the debris of ships lost within, making travel even more dangerous. Travel through the Underspace is not undertaken lightly.

A further restriction comes from Starfleet’s agreement with the Turei. Keen to maintain control of the Underspace, and especially to keep it from the hands of the remaining Vaadwaur, the Turei have not granted the Federation unrestricted access. Starfleet missions through the Underspace must be planned and proposed, demonstrating their necessity before the Turei will provide their essential aid. While the Turei have shown little interest in using this power to influence Starfleet operations, their oversight has limited use of the Underspace to only the most valuable and necessary of missions.

In Play

• The Underspace allows Starfleet ships to travel swiftly to the furthest reaches of the Delta Quadrant. This is how, along with the Barzan Wormhole, stories can be told across almost all regions Voyager visited on its journey home.
• After the events of the Fleet Action 'Labyrinth,' Underspace travel is once again limited to the Delta Quadrant. There is no way to access or exit tunnels that may exist elsewhere.
• The Underspace is not a safe or reliable means of travel. Starfleet are wholly reliant on the expertise of the Turei to plan routes, and potentially catastrophic accidents that could strand ships in the depths of the Delta Quadrant remain possible. As such, Starfleet only sends ships through the Underspace on serious and committed exploration missions for months, perhaps years at a time.
• The Underspace is a writing tool to let ships access distant regions. But these restrictions mean those missions are long-term operations in isolated regions, committed missions of deep-space exploration with no easy backup and no quick return to Starfleet or the Federation. It undermines the point of the Underspace if it is used to zip back-and-forth across the Delta Quadrant casually.
• Travel time in Underspace is variable. Some corridors may be very direct, some may be more meandering, but are all still vastly quicker than warp. An Underspace journey epitomises 'travelling at the speed of plot.' If you want to travel sixty thousand light-years in a matter of hours, or even less, then your ship just found a very direct and efficient corridor.