Re:ROI (Score 1)

Absolutely correct. The ratio according to one study of lunar flight is 300:1 of human efficiency to robot efficiency. What a human can do in a one hour takes a robot 300 hours.

Robots are lighter at first. The current Mars program starts hitting a wall of mass-to-science after the Mars Science Lab rover in 2009. After that it's sample return, because we can do more science in person. But sample return is 1 kg poorly selected versus 250 kg of whatever could not be analyzed by humans in 500 days on the surface, so we are back to ratios for humans again very quickly.

Let's consider the ratio again. Both humans and robots are "offline" at night, because the night side of Mars is away from earth. Yes, the current missions do spectroscopy at night, but so can humans with hand-deployed units or rocks in the habitat lab. So that being equal, the nominal 500 day human stay on Mars would take robots 410 years to match. So how slowly do you want to learn useful things? Will you live that long?

OK, what about cost? The current missions have went from $300 million to $850 million for two rovers and the next could easily top $1.5 billion for a single car-sized rover. Zubrin's human missions can be done for $30 billion start up and $2 billion per year after that, or less than the shuttle budget. We are in an embryonic phase of exploration where robots make sense to a point, but for Mars that point is rapidly approaching and we must be ready to meet it. For the moon that point is past. For the outer solar system, it may easily take our lifetimes and then some. That said, no one is proposing Callisto in a decade, but Mars in 22-30 years. That sounds about right, scientifically and economically.

Deep space missions have led to arms agreements and clean air standards via learning of global cooling similar to nuclear winter on Mars and global warming in the case of Venus. We call it discovery for a reason - we don't know what we will learn out there. We have an excellent case log dating back to the amphibians of new environments leading to progress. There is no reason to assume that will suddenly stop at the atmosphere.

One more bit to the article author. You should remember that when scientists clamored for the cancellation of the Superconducting Super Collider because they weren't working on it, the money they expected to flood in their direction evaporated instantly. A science funding tide lifts all boats, especially in the non-specific sciences such as physics.