Rose Tyler: Earth Defence was the title given to a proposed, but ultimately aborted Doctor Who spin-off set some time after Rose's final parting from the Tenth Doctor at the conclusion of Doomsday.
Based on dialogue in that final story, the series most likely was intended to feature Rose's life on the alternate Earth the Doctor had dubbed "Pete's World", working with that reality's version of the Torchwood Institute.
The series had been commissioned by BBC One but abruptly cancelled by Russell T Davies, who decided that it would have lessened the impact of Doomsday. The spin-off was cancelled before Billie Piper had been formally approached. Reportedly the original plan was to produce a one-off special (likely for broadcast around a holiday, possibly Easter), followed by more specials if demand warranted, in lieu of a weekly series. The name 'Rose Tyler: Earth Defence' was inspired by the Doctor's meeting with Rose in Doomsday. Rose says that she plans to join the Torchwood Institute of Pete's World. The Tenth Doctor smiles and replies Rose Tyler, Defender of Earth.
Recipe : Rose Tyler head on Gwen Cooper body.