Space Station Alpha is having mechanical problems so the inhabitants(humans, robots, man-eating plants) have to be moved to another station…

Space Station Alpha is having mechanical problems so the inhabitants(humans, robots, man-eating plants) have to be moved to another station with a two person shuttle. Each plant is large enough to require a seat of its own on the shuttle, but a plant and a human cannot travel together for obvious reasons. At no point, at either station, can the man-eating plants outnumber the combination of humans and robot. If there are three plants, three humans, and two robots on Space Station Alpha, what is the fewest trips it would take to empty the station?