Strange super fast moving orb.

Very clear summer night with great visability of the night sky. Could see all stars overhead. Object was really high up, well above the altitude of comercial passenger jets or military aircraft. Object travelled from west to east, was not the ISS(as checked ISS tracker) and was not as bright as the ISS. Viewed the ISS many, many times from my location and can normally have very bright visual contact for around three to four minutes. There were no flashing lights to indicate an aircraft of any sort. No sound or sonic boom(which I would expect from something moving many times faster than the speed of sound.) It disappeared before entering the Earth's shadow. It was directly overhead. There was no trail to indicate a merteorite burning up. It seemed impossible for something to travel so fast given the altitude. If an aircraft passes near our location we can normally hear it after it has passed. It was my 19yr old Son and I that witnessed the object. Also, last summer, the two of us(my Son and I) witnessed another object travelling really, really fast fly overhead and made a very sharp 90 degree angular turn which defied everything I know about physics and the capabilities of aircraft travelling many times faster than the speed of sound. Did not have time to take any pictures as was sat in a hot tub at the time of both sighting and always lay, looking straight up as we have a great view of the night sky. Hot tub was not warm enough to cloud our vision with steam as it was kept quite cool as it had been a very warm day and we needed to cool off a little.