Regular flashing light moving through the sky over the UK like a normal satellite, but clearly flashing on and off 30 times.We were outside to watch the meteor shower on 12th August. All through the evening we had watched satellites passing in orbit through the sky. One of these satellites however appeared to "flash" on and off several times, as if the reflection from the sun was being blocked. This was not a normal flicker, but a repeated regular pattern, with the light source clearly switching on and off. The light itself was white as with all satellites. The flashing repeated probably 30 times (about half a second on and half a second off) as the object moved across the entire sky, without fading in strength as satellites normally do. We watched the object until it moved below the treeline. There was no sound during this time, and the object was definitely not a plane - too high, the light too small, and moving too fast. The object's path seemed constant and straight as it moved.