All right, we know that force fields DO exist in the Animorphs universe, they're shown multiple times guarding installations, etc, so here's my question, something I've had on my mind for quite some time: WHY DON'T THEY PLACE FORCE FIELDS ON THEIR SHIPS? It's shown that it could be done almost a billion years earlier, when the technology was probably much, much less advanced than it is nowadays, so why don't either Yeerks OR Andalites shield their spacecraft? Is it impossible to do it space or something? But again, it was possible in the Ellimist Chronicles when technology was inferior.
So... a... reason?