Metalic object blinking light slow moving

While at work watching planes landing at San Jose international airport noticed what looked like a metalic balloon reflecting the sun . As me and three others watched the object appeared to be blinking and traveling in a deliberate path. Its altitude from first sight was low with in minutes it accended to a very hight altitude and then traveled southwest at what seemed to far above normal airplane traffic. There was a white light that seemed to be blinking until it reached a certain altitude then stopped the light remained steady. It also appeared to have a grayish cloud around it until it lifted in to the sky moving deliberately with the light still visable.