Blackcamper

hallo alle. I have been tryning to get a power station to work in space I have a 3,75m aegletes 2 fission reactor to start on and i like to get a ohter 3,75 fusion reactor up there as well. but i can not get the fussion reactor to work it will not start, just says lqd deuterium deprived, what dos that do and how do i fix it. i can find no info about this. Help me plz. Ps sorry for the bad english