"Look, the city, as you know, is just a giant spaceship with a stardrive capable of faster-than-light travel..."
Rodney McKay[src]

The stardrive is a feature on city-ships that allows them to travel through space at FTL speeds, and consists of both a sublight engine and hyperdrive.


An Asuran stardrive.

During the Goa'uld attempt to destroy Atlantis, a program set by the Goa'uld operative started powering up the Atlantis stardrive while the ZPM's failsafes were disengaged. Without the failsafes, this would've been more than enough to destroy Atlantis had the failsafes not been reenabled just in time. (SGA: "Critical Mass")

In order to drain the remaining power from the Tower's ZPM, Lt. Colonel John Sheppard ordered Doctor Rodney McKay to charge the Tower's stardrive, stating that it would be the single greatest power drain they could find. Charging the stardrive resulted in a great deal of shaking in the Tower, but successfully depleted the ZPM. (SGA: "The Tower")

After taking control of Atlantis, the Asurans attempted to fly Atlantis back to their homeworld using the stardrive. However, a drone attack by Doctor Carson Beckett disabled the stardrive before takeoff. The Asurans were able to repair the damage before they were eventually destroyed. (SGA: "The Return, Part 2", "First Strike")

The stardrive allows a city-ship travel to distant galaxies in only a matter of hours when at full power, and the sublight function of a stardrive is so fast, even when powered by nothing more than one ZPM, that the dialing device of a city-ship's Stargate is incapable of establishing a point of origin when the city-ship is traveling through normal space. (SGA: "Adrift", "Enemy at the Gate")

The stardrive requires an enormous amount of power to be exerted at once for the sublight engines to lift the city off of a planet, and so usually it can only be activated if there are at least 2 ZPMs powering the city-ship. This power requirement can be subverted, however, when an external power source supplies enough of the needed power that a single ZPM can supply the rest (such as when McKay and Sheppard powered the stardrive of Atlantis using only one ZPM and the drilling platform to supply the extra power needed to get it into flight). (SGA: "The Tower", "First Strike")

The hyperdrive itself requires relatively little power (compared to what a ZPM can generate) to travel interstellar distances, and the greatest amount of power expenditure during the entire process of taking off, flying through hyperspace, and landing on another planet typically occurs when powering up the inertial dampeners and achieving the necessary escape velocity to lift the multi-tonne city off of a planet's surface. When at full speed a stardrive is capable of matching the Asgard hyperdrives on the Daedalus. The only faster drive is the (experimental) Wormhole drive, installed only on Atlantis. (SGA: "The Tower", "First Strike", "Enemy at the Gate")

While in use, the Stardrive requires a constant pilot in the Control Chair at all times. The Lanteans would have three pilots to switch between but the Atlantis expedition only has Lieutenant Colonel John Sheppard and Doctor Carson Beckett to act as pilots, requiring them to switch off on long journeys such as that between Earth and Lantea. (SGA: "Legacy: Homecoming")

When discussing repairing the hyperdrive portion of the Stardrive, Colonel Samantha Carter told Teyla and Sheppard that while they can't repair the wormhole drive, the hyperdrive uses comparable components to the Asgard hyperdrive, meaning Earth can repair it with enough work by customizing components rather than trying to replace ones they don't understand. Despite this, it took Zelenka, his repair team, "half the Air Force", Doctor Bill Lee and his team and the SGC's entire maintenance section to do the repairs in a timely fashion with Zelenka stating that it would've taken months to repair the drive otherwise. (SGA: "Legacy: Homecoming")

During the Battle of the Super-hive, the Stardrive's number four induction array was damaged and gave Zelenka and McKay trouble repairing. Five days into the journey, it experienced a slight power variance, detected by Doctor Beckett as a "wobble." The induction array eventually malfunctioned nearly seven days in and drew power from all systems to expand the hyperspace envelope exponentially. While dropping out of hyperspace stopped this, the malfunction drained the three ZPMs to 20% power. It also fried the command crystal for the induction array which the Atlantis expedition lacks the ability to replace and thus rendered the hyperdrive permanently inoperable. (SGA: "Legacy: Homecoming")

While looking through the Satedan military museum, Doctors Radek Zelenka and William Lynn were able to locate a new hyperdrive induction array command crystal. With that, the expedition is able to restore the stardrive to full working order though they still lack the power to use it. (SGA: "Allegiance")

Before the Second Battle of Atlantis the Expedition considered fleeing to hyperspace rather than fighting the Wraith since the hyperdrive was operable again and they had an overwhelming force coming. However, they decided to stay and were able to launch the city as a mobile weapons platform. During the battle, the East Pier maneuvering engine was damaged which made the city harder to fly, but not impossible. It was also still capable of landing without it. (SGA: "Inheritors")