London, England (CNN) -- The British nuclear submarine that got stuck on the Scottish coast is heading back to port under its own power, escorted by tugs and a minesweeper, the Ministry of Defence said.
The HMS Astute -- which the United Kingdom calls its most powerful attack submarine -- ran aground off the Isle of Skye last week.
Its nuclear propulsion system was not damaged and its reactor is "completely safe," the ministry said, adding: "There was no environmental impact".
The sub was pulled free as the tide came in Friday afternoon.
It's heading back to Faslane, Scotland, the port it sailed from on October 5, where a "full service inquiry" will follow, the ministry said.
HMS Astute was commissioned in August.
The craft is a "highly complex feat of naval engineering" that is "at the very cutting edge of technology, with a suite of sensors and weapons required to pack a powerful punch," the ministry said.
The submarine was undertaking sea trials when it ran aground. People were transported out of the craft.
The ministry said the sub can carry a mix of up to 38 Spearfish heavyweight torpedoes and Tomahawk land-attack cruise missiles.
CNN
