NASA has developed a long-range plan to send a human crew to Mars, following up on robotic missions. But Weinberg says robots can do a lot more than humans on Mars.
For the $1 trillion cost of sending human beings to Mars, perhaps to just one location on Mars, we could have unmanned rovers wandering all over the planet
The Director of the Hayden Planetarium in New York, Neil deGrasse Tyson, agrees with Weinberg on the cost-effectiveness of robots for pure science, but he says having humans in space fulfills another need.