One bright cloudless summer's day I climbed over our back fence to visit my friend Billy. The day was beautiful: I looked up into the blue clear sky and saw...what? To this day I don't know but I know what it looked like: A solid metallic body with two elongated pods at it's extremes, slowly and silently rotating in a plane about it's longitudinal center parallel to the ground and moving slowly across the sky. No rotors, no blades, no extensions on the pods, no sound, no lights.
It appeared to be very high, above the height of a commercial jetliner. I ran in to get Billy (who did see it), then to to get a camera but he could not locate one before the craft passed over the forest's horizon.
One of my greatest regrets in life is not getting a picture of this: the optical conditions were absolutely perfect.
I have searched all my life and never found a picture of a craft like the one I saw. I believed it had to be a spacecraft of some sort in an orbit but this was in circa 1957 and at that time only small probes were being launched according to the history books.
Anyway, build a craft like that: it's within our technology and it could create an artificial gravitational field that would suffice. And it's a tested design!8-))