On Pentagon's Wish List: Building a 'Mothership' So far, it's just at the drawing stage By Matt Cantor, Newser User Posted Nov 24, 2014 11:17 AM CST 38 comments Comments In this March 27, 2008, file photo, the Pentagon is seen in this aerial view in Washington. (AP Photo/Charles Dharapak, File) (Newser) – In the latest effort to make reality out of what is currently science fiction, US officials are looking into the possibility of building a mothership: a large aircraft from which smaller ones take off. "This is the float-the-idea stage of the concept. It's not the build-me-a-prototype stage," says an expert. But this month, the Pentagon asked companies to envision designs for a drone-carrying cargo plane, AFP reports. The request seeks a design that could be demonstrated within four years, CNN reports. The effort has focused on converting aircraft the Pentagon already has. "One promising idea is enabling existing large aircraft, with minimal modification, to become 'aircraft carriers in the sky,'" says an official with the Defense Advanced Research Projects Agency. Versions of the idea have been around since the 1920s; in the 1930s, airships carrying Sparrowhawk biplanes crashed and the US dropped the effort for the time being. An underwater version of such a system could come sooner than a flying version, AFP notes: The US has already managed to launch a drone from a submarine's missile tube.