[zizee]

The SLS is widely understood to be less about research and development, and more about pork barreling, and jobs program. I don't buy that humanity should avoid investing in space travel because US Congress and surrounding governmental beaurcracy is not running projects effectively. That argument would stop just about any human activity.

It's pretty difficult to predict what spinoffs would come from attempting to put a colony on Mars. I would imagine to succeed we would need to solve a lot of challenges with human biology, genetic engineering, automation, and many novel engineering solutions.

But economics is not the only reason to do things, and I bet you don't expect everything humans do to have a purely economic rational.