Valkians have special FTL that is by no means actually "moving," but rather closer to teleporting. If they use traditional FTL drives, then a Valkian will, quite simply, 'see' everything on the way to the destination, so even in space, that'd literally make their brains give up and die from the inability to process so much information at once. So, they always go into cryosleep right before jumping, and then the entire ship is demolecularized and reformed wherever they need it to be. Because of this, ships are much more likely to remain strong and sturdy as long as they teleport from the edge of a system to another, since there is far less outside a system than in. The more dust and such that's around, the less likely the metals will stay as strong. Molecular deterioration, as they say.