This sort of stupidity is on a par with calling it an “insurance policy.” Dana has it right:

Last year’s request for this “back-up system” was more than 300% of the appropriated level of the primary system. By acting on this type of faulty logic, we have created a national debt as large as our GDP and still our nation refuses to take its foot off the deficit spending accelerator. SLS is unaffordable, and with relatively modest expenditures on specific technology development, we do not need a heavy lift vehicle of that class to explore the Moon, Mars, or near-Earth asteroids.”

Of course, it has nothing to do with “exploring” any of those places. It’s pork and workforce preservation.