A NASA-Langley film showing some early testing of the parawing (Rogallo wing) concept. This was originally intended as a stowable wing that could be deployed from space capsules, stricken aircraft or ejected pilots. Testing was done with landing-gear-equipped Gemini capsule mockups (see HERE), and on a whole range of models, including the B-70 and the Saturn I first stage. But while NASA and the USAF never really did anything with it, it gained a whole lot of popularity at the first truly practical hang glider wing.
The video is 20 minutes long. My favorite few minutes, however, are the first few, showing some introductory flights.
[youtube LlwZ1R_wHZg]
Imagine an alternate history where nothing like the parawing has been invented, never mind demonstrated. Imagine further that you work at NASA and dreamed this idea up. Now… try to imagine that your idea of demonstrating the concept *today* involves something other than CGI, costing spreadsheets and Powerpoint presentations.