As you can imagine, they've been very helpful, because being in space is all about math, science and engineering.

It's a good day in space. I like it.

There is only one nature - the division into science and engineering is a human imposition, not a natural one. Indeed, the division is a human failure; it reflects our limited capacity to comprehend the whole.

We tend to hear much more about the splendors returned than the ships that brought them or the shipwrights. It has always been that way. Even those history books enamored of the voyages of Christopher Columbus do not tell much about the builders of the Nina the Pinta and the Santa Maria or about the principle of the caravel. These spacecraft their designers builders navigators and controllers are examples of what science and engineering set free for well-defined peaceful purposes can accomplish. Those scientists and engineers should be role models for an America seeking excellence and international competitiveness. They should be on our stamps.

What we did in that review article is look at what is known and what science and engineering can deliver.

Progress depends on the unreasonable man.