Now, I am not asking whether we should explore the universe. I also dream of the day that we become galactic citizens. The question is whether the initial exploration of space should be done by humans or by robots. I would argue that, for the moment, robotic exploration should have the upper hand.
Proponents of the astronaut-preferred camp point, quite rightfully, at the versatility and independence of humans. Fans of human spaceflight are certainly correct when they remind us that humans are highly versatile. People observe the conditions around them and can react to circumstances as needed.
However, people are also fragile. They need food, water, and air. They can exist in only a narrow range of temperatures and find inhospitable both vacuums and a radioactive environment. While some adventurers might prefer to remain in space forever, many of them expect to land gently back on Earth. All of these considerations are extremely challenging and not important for robotic missions.
Possible manned missions to Mars are imagined to cost about $1 trillion, with the outcome being limited exploration of the Red Planet by about 2030 (with some estimates saying 2050). And a mission with that price tag would hamstring the rest of the space program.