Instantaneous right-hand turn. Object was well above thirty miles in altitude.

On or about July 20, 1982, I was camped in an open alpine area near Mount Rainier, Washington State, with a male friend. We were at about the seven thousand foot level.
The stars were very bright that night, and it was clear. I spotted a very bright light moving slowly and steadily in the sky, from east to west. I pointed it out to my friend and we watched it as it moved along. I would estimate the object's altitude at more than thirty miles.
We thought it was a satellite.
Without warning, the object made an instantaneous right-angle turn and continued in a northerly direction. We watched it until it disappeared over the horizon.  We had no idea what it was, but the instant turn was definitely not somthing that any manmade craft could do.
Witness indicates that the date of the incident is approximate.  PD