Answer: talking innovation
The exact details of the June 8 meeting between Tesla/SpaceX Founder Elon Musk and Secretary of Defense Ash Carter are unknown, but a Department of Defense spokesperson hinted at what the federal government is up to.
Carter "has been reaching out to a number of members of the technology community to get their ideas, their feedback, find out what's going on in the world of innovation," spokesperson Peter Cook said.
In response to an article questioning the reason for his visit, Musk referenced the Iron Man superhero in a joke tweet.
Something about a flying metal suit...https://t.co/6Z1D9iZ1fV— Elon Musk (@elonmusk) June 9, 2016
Founder of the Silicon Valley- and Boston-based Defense Innovation Unit Experimental, Carter shared in March that the new body’s facilities will allow the Pentagon "to better tap into the region's innovation ecosystem and build relationships with local companies."