Kasq is SAM's homeworld, where her Makers live and where time moves so quickly that seventeen years pass in two Earth weeks.
Kasq is the homeworld of SAM, the first Kasqian to attend Starfleet Academy, and of the Makers who created her. In The Life of the Stars, SAM's glitching threatens her life, and the Doctor and Chancellor Ake take her there hoping the Makers can save her.
The Makers cannot repair her, and Ake and the Doctor realize she was overloaded because she was created without a childhood. SAM is rebuilt and the Doctor spends seventeen years on Kasq raising her as his daughter, which equals two weeks on Earth.