People pay attention when people are sent to space. Also, it manufactures "heroes", which is something every society needs. Just look at the Apollo astronauts,

People pay attention when people are sent to space. Also, it manufactures "heroes", which is something every society needs. Just look at the Apollo astronauts, they have been revered for ages and have done a great public service in inspiring future generations. Sending R2D2 to mars doesn't do that.