As subject says, spawn a drone.
I have been running around in Part 2 alpha mode for a little bit now and my suggestion would be something like;
When lvl 19 on your plasma symbiote has been reached... (*) 1 its dps type is less effective than that of a graviton beam. 2 hence u sell remove or replace it at the moment.
* the option of spawning this symbiote to space instead appears, making it effectively a drone at your side.
Not sure about the details tho, should the drone grow as u do? or should its energy use function as your bioship does? Should u grow your drone manually, or even be able to refit it to a full fleghed ship? Maybe lvl it is spawned (19minimum) is the lvl it shoud stay at?.... not sure about the details, plenty choice i suppose.
Anyway, this would be my 2 cents for the moment.