Silver cylinder craft flying silently, lower than normal air craft, rotating as it flew, with writing on the side (could not read it)

The craft was flying lower than normal airplanes in the area, which is what grabbed my attention to it.  I looked up and saw a short, cylinder shaped craft flying horizontally through the air, and rotating while it flew.  There was no sound, nor any trail.  It glided through the sky seamlessly.  It was grey/silver/white in color and had writing on the side.  
It flew from east to west at the same speed an airplane would pass.  It was like seeing a satellite that floats out in our orbit here under the clouds.  My age at the time was 8 years and I was very interested in space exploration, so I assumed it was a NASA craft and didn't even mention it to anyone, not even my teachers.  
It was only later when I was an adult that I realized I had never heard of that type of technology existing and what I saw was odd.  Never seen anything else like it since.  The craft was not flashy, no special lights, no aura, no glowing, nothing.  It looked like normal, current technology to an 8 year old in 1986.