Orbital speed is defined by sqrt(G*M/r). If this 'following' the ISS and at a lower altitude, it will slowly travel away from it because by definition its orbital speed is slower. Let's assume it's the Cygnus as pointed out by another comment, and explain out a possible scenario.<p>If the two are roughly in line vertically with one another, then a viewer on the ISS will be looking down at it and will see the clouds and Earth below it. However, as the object travels away from the ISS due to differing orbital speeds, it will appear to move 'up' relative to the Earth. Tracing a ray path between the two objects, it will go from being a line from the ISS, through the object and into the earth, to a line that at its extreme will be from the ISS, through the object, and then over the horizon of the atmosphere. Draw this system on some paper and you'll see what I mean.<p>From a fixed vantage point on the ISS, that will make the object look like it 'travels up' when in reality it is just traveling away from the ISS due to a slower orbital speed. If the camera remains facing downwards, it will naturally track out of the top of the camera frame. Project that onto the uniform blackness of space and you'll have no visual reference point to see it travel back down as it disappears away from view.<p>The green burst could also be explained by a retro-firing of the capsule to slow it down to re-enter orbit (or shift its orbit closer to earth, as is what happens if you slow down). This would appear as if it is firing 'down' in the camera view, when in reality it's firing tangentially to its orbital position, which as a vector would pass underneath the ISS. Alternatively, it could just be visual artifacting from either compression, light reflection or any other number of explanations.