Graviton catapult
A graviton catapult was a unique form of technology, designed by an alien named Tash, that was created to propel a spacecraft across interstellar space.

Design

The power core of the catapult generated a massive graviton surge that locked onto a ship through an array of projectors. The surge sent the ship hurtling into null space for some hours. Upon emerging back to normal space, the vessel had jumped many hundreds or even thousands of light years. The distance was determined by the graviton field strength. ()

History 
In 2376,  discovered a stranded alien starship, commanded by Tash. Their crew had built such a device as a means of getting home in a shorter period of time than by warp drive. The first test had destabilized the tetryon reactions of the tetryon reactor used as the power core, causing it to leak bursts of epsilon radiation. Voyager used graviton pulses fired from the deflector dish to stabilize the reactions.

Having helped Tash's starship to successfully use the catapult to get home, Tash sent recommendations for deflector shield adjustments to the Voyager so they would not experience similar system overloads during mid-flight. Following the enhancements to the shield variance, the crew of the Voyager used this device to travel across thirty sectors in less than an hour, taking three years off their journey home. 

A confused Seven of Nine theorized that the catapult technology may have been derived from the displacement wave technology used by the  to bring ships to the Delta Quadrant. Both the catapult and the Caretaker's array were powered by tetryon reactors, the only two ever encountered as of 2376.  

According to Seven of Nine, the catapult constructed by Tash's crew could also be used to bring ships from Alpha Quadrant to the Delta Quadrant. ()

Appendices

Background information 
The script described this structure, which it offhandedly called a "space catapult", as "[a] strange piece of technology. A vast portal-like structure that looks cobbled together with sections of different design and alloys of different colors –­ as though the pieces came from several alien sources." It was identified as a "graviton catapult" in an okudagram, but otherwise was unidentified as such in dialog or the script.

Tash's catapult was designed by Rick Sternbach, and the studio model was built by Digital Muse. Digital Muse produced six widely different effect "ingredients" for the catapult-effect, which Ronald B. Moore then combined in the editing bay. ()

The design of the catapult station was later used as a Cardassian shipyard in the video game Star Trek: Armada II.

External link

de:Katapult (Antrieb)
ja:亜空間カタパルト
Propulsion technology
Space stations
Transwarp