ISS and a Mystery Satellite

No other satellite was found that fits the time frame or the trajectory of this unknown satellite. There is also another faint satellite to the left of these two satellites. In the first frame or photo, the ISS looks orange because I caught it as it was exiting the earths shadow but the trailing object did not look orange in that area and it could be because it was at a different altitude. I also noticed that the magnitude of the unknown sat is changing and this is typical of a tumbling satellite and rocket bodies. The Blimp-like object seen here is an aerial radar station that is used to monitor activity in the Caribbean Sea. These photos were taken with a Canon T3 modified for full spectrum photography using a 50mm lens at F/1.8 for 8 seconds at ISO 1600. I was trying to capture an early Perseid meteor near the aerostat but instead I got this.