Feared by Goa'uld across the galaxy, the Asgard mothership is the main arsenal of defense for the Asgard fleet. Incorporating the general shape of Thor's Hammer at its bow, the Asgard mothership is a relatively flat vessel with two vertical hyperdrive engines at the stern, giving the ship a sleek, streamlined look.
Within the vessel are many labyrinth-like, curved corridors in exotic, violet tones. The ship is equipped with a deceleration drive to facilitate the return to normal velocities after exiting hyperspace. The ship is also equipped with advanced weapons, and multiple transporter arrays.
The most well-known of all Asgard motherships is the Asgard ship Beliskner, commanded by Supreme Commander Thor and nicknamed "Thor's Chariot." It was the flagship of the fleet before being destroyed in Earth's atmosphere.
Thor's Chariot - After SG-1 successfully communicates with the Asgard through the Hall of Thor's Might on the planet Cimmeria, Thor himself travels to the planet in his mothership to remove Heru'ur's presence from Cimmeria.
Fair Game - Thor arrives in Earth's orbit in his mothership to facilitate a peace treaty between the Tau'ri and Goa'uld System Lords.
Shades of Grey - Covertly informed of their location, an Asgard mothership descends over Colonel Maybourne's off-world operation to retrieve their collection of stolen technology.
Nemesis - The Replicators infest Beliskner and bring the ship to Earth, where Thor enlists SG-1's help in destroying the ship to stop them. The Beliskner is incinerated in Earth's atmosphere.
Small Victories - Carter and Thor attempt to stop the Replicators from reaching Thor's homeworld in a fleet of infested Asgard ships by launching a new, O'Neill-class ship.
Revelations - Thor's mothership is no match for Osiris' Ha'tak, now operating with Anubis's advanced shielding and weaponry. But three more Asgard ships arrive under the command of Freyr, and the Goa'uld retreat.
Prometheus - Thor, commanding the latest Asgard mothership, once again seeks help from SG-1 aboard the Prometheus.
Unnatural Selection - Thor's mothership tows the Prometheus into the Asgard's galaxy in hopes of stopping the Replicators for good.
New Order, Part 1 - Asgard ships engage the Replicators in battle at their new homeworld, Orilla, destroying the enemy craft.
Camelot - An Asgard mothership under the command of Kvasir joins the Milky Way coalition fleet in attempting to fight off Ori warships invading through the Supergate.