The one problem I see is that it will take several light years for the moves to be transmitted.
Ack! A "light year" is a unit of distance. You can convert to miles or kilometers or parsecs or furlongs or .... Your sentence, therefore, could be rewritten, "The one problem I see is that it will take several trillion miles for the moves to be transmitted."
What?
The time unit you are looking for is just "years."
Most important question: how can I get better at chess?