Since manned spaceflight is a lot harder, rising to the challenges it sets and finding solutions arguably (or is that ideally?) leads to greater advances. It's also a lot more inspiring and exciting, meaning that it's more attractive to young scientists, engineers etc. to get into it.

You can only do so much with robots, and their limitations become more apparent the further away they are. So on Mars, where signals have about a 40-minute round trip, new instructions to the robot take up valuable time. Granted, you can just plan for longer missions but imagine a human just making that decision to go and pick up that specific rock right there spontaneously. The human, as trained geologist, can also recogise  which rocks are useful and more importantly be able to place them in their geological context. The best example is the moon Genesis Rock, would any robot have found that? Probably not.

It's the fable of the tortoise and hare.

Sure, once you're on the surface, man craps all over robot.

But given the MUCH longer development time for manned over robots, Team Robot has already a 20 year head start.

And if each team had the same amount of money, then Team Robot can deploy 20,30,50 (some say 100) robots for every manned mission.

Name any budget - big or small. You'll get more science data from robots, not man. Manned missions waste too much budget on life support systems, redundancy, PR, and having to return to Earth. And the gap between capabilities is hopefully closing, despite the glacial pace of AI research. Robots can work 24/7 in extreme radiation environments with detectors that operate outside normal senses.

Yes, manned missions have political benefits. Sure, they're inspirational. And you can't put a value on that. But if you care purely about the science, then robot beats man when factoring in project time, safety and budget.

How much for one manned mission to Mars? $500B? Probably more. After all, look how much the ISS cost. For the SAME money, you have 10 x Curiosity 2.0 rovers on Mars PLUS major Cassini-class orbiters around ALL the planets and major moons, the Terrestrial Planet Finder, balloons in Titan's atmosphere & Venus' atmosphere, floating probes on Titan's lakes, ice-core driller on Europa and Enceladus, etc.

What'll it be? You can have one Chinese man plant a flag on Mars or you can flood the solar system with probes?

Obviously in an ideal world, it'd be nice to have both manned & unmanned, but given finite budgetary constraints, I'll take robots every time as you can have more of them deployed in more difficult, exotic and interesting areas.

Anyway, that's my little rant. And I'm a big AI skeptic.

All I want, really, out of a future space program, is for someone to come up with a way to get to Europa's ocean. Forget space stations, forget Mars landings, forget everything else. Let's see if there's fish down there.