There was another one, a smaller one, & there might have been others. I saw them in the air more than once in So. Cal., transporting rocket bodies to parts unknown back in the 1970's & 1980's. I have several other photos of them. When I first saw them, I thought that they were not air worthy, but they do fly. I used to work on the Van Nuys Airport as a draftsman, for the company that did the conversion on these, & other, aircraft. I went inside this particular airplane, & it looked like a basketball court in there. Those were the days.