Trying to find a name of an animated fairy tale

Hey guys,

not sure on which website I should ask, if this is the right one, but this one seems to have a lot of animated/anime enthusiasists so I will try.

I´m trying to find the name of an animated fairy tale or a cartoon (something like simpsons, etc.) for kids, which has two children (one is a redhead girl with glasses i believe) and the other one a boy, who are on vacation at grandmothers house (i believe) and then they go in the attic where there is a spaceship toy which takes them into space.  A green spaceship. Where they have to fight a black robot controlled by a mouse inside it.

On the DVD cover there was space and a big green spaceship with the faces of the two kids, one a redhead girl with glasses, not sure tho.

I´ve tried googling this for hours but didnt find anything similar to it. 

Anyone knows the name of this animated fairy tale please? Would be much appreciated. Thanks