Faster-Than-Light engine

"Faster-than-light, yet not through hyperspace"

- Nicholas Rush

The Faster-Than-Light engine, or FTL engine, is a technology used on the Ancient ship Destiny and the seed ships sent ahead of it. It is capable of faster-than-light travel without entering hyperspace. FTL has also become a Tau'ri expression for an engine capable of travel at speeds greater than that of light, whether it is through use of hyperspace or not.

Overview
The technology behind the Faster-Than-Light engine has not been explained in detail, but does not function in the same manner as a hyperdrive. When engaged, the ship is quickly accelerated beyond the speed of light, in contrast to hyperdrive which opens a window into hyperspace. The drive's top speed has also not been made clear, though it has been shown to traverse an intergalactic void in a seemingly short amount of time - making it faster than many of the hyperdrives used by races such as the Goa'uld and the Wraith. While the inter-galaxy FTL speed seems comparable to that of an Asgard hyperdrive (a few weeks to cross a void in either case), the FTL's intra-galaxy speed is also shown as much slower (taking several months to cross a galaxy, instead of about a day).

The ship's ability to survive FTL travel is directly dependent on its shield. Without the shield's protection, anything nearby will be instantly vaporized by the sudden energy burst. Destiny itself would also be destroyed if its shield failed mid-flight. Safeguards prevent the ship from jumping to FTL if its shield is too weak to do so; once the problem is corrected, FTL capability is restored. The shield will expand to cover objects that are latched securely onto the hull.

In addition to being able to bring any ships latched to the hull into FTL, a seed ship has shown the ability to bring both itself and Destiny into FTL while the latter is docked to it. The reverse is likely possible, as well. The process carries the risk of destroying both ships should the structural integrity fail en route. The ship responsible for the jump also has full control of the ship's course. In addition; there appears to be no way for the ship being towed to judge the current course.

FTL is apparently much more sensitive to phenomena in normal space than hyperdrive is. Destiny's ability to maintain FTL seems to be dependent on a foreknowledge of the space along its course. It was brought out of FTL by the gravity well of an uncharted star and could not re-establish FTL flight until it passed beyond the star's range.

According to Dr. Rush, the FTL drives, once engaged, must remain active for a minimum of four hours, and remain inactive for a minimum of three hours to prevent damage to the drives. According to Eli shields below 10% the ship has a high possiblity of getting destroyed if weak spots are unable to hold the pressure of FTL.

An incoming wormhole to Destiny's Stargate will trigger the drive to temporarily shut down, enabling the gate to connect, but this only applies to a nine-chevron address - its rapidly changing position will quickly invalidate any seven or eight chevron address while it is in FTL. This suggests that subspace communication is possible while the drive is in use. The activation and deactivation of this device creates a disruption that momentarily interrupts communication between the Tau'ri version of the Ancient long-range communication devices. (Traditional hyperdrive travel does not seem to interfere with the communication stones.)

The blueberry aliens appear to possess a similar technology, which is used in their motherships; however, the actual technology used is not made clear and so it may be an entirely different form of propulsion technology.