20-30 bright lights, evenly spaced, flying in a row one behind the other, from NW to SE, no sound, no blinking lights

I was stargazing facing NW when I noticed an airplane moving to the SE.  This is not a normal flight path in this area. After a minute or so I noticed another one behind it,  and looking past that one I see another one coming behind it from over the horizon. I went inside to get my friends to witness this and they too saw the lights, but now there were at least 10 in a row, evenly spaced and more coming behind them. We watched as they crossed overhead and disappeared soon after passing us.  We tried to watch them as long as we could as they seemingly just faded out, and still yet more were coming in a row. I counted between 20-30 trying to watch them as long as I could before they faded. This lasted about 20 minutes.  There was no blinking light or color change, no sound and no deviation from flight path. They sky is completely clear and bright with stars as the moon has not risen yet.
I was a jet mechanic in the navy, so I am familiar with aircraft. I have a background  in Quality Control for Electrical/Mechanical/dimensional. My male friend is in supervision at a Power plant, and his wife works in the medical field.