Digital Trends' Watch a NASA astronaut jettison part of the ISS into space which was linked in says:
Writing in Air & Space last year about the process of jettisoning objects, veteran NASA engineer Mike Engle explained how launching decommissioned parts from the space station can be a risky process, a fact that prompted him to help create an official ISS Jettison Policy to ensure that such activities are carried out safely.
“Jettisoning trash from a spacecraft is no mere stroll to a dumpster,” Engle wrote. “First and foremost, you have to make sure that whatever you throw away doesn’t come back and hit you — a frightening possibility in the weird realm of orbital mechanics.”
The engineer added, “Simple trigonometry led to the conclusion that pushing an object away at two inches per second within a 30-degree cone centered on a line directly opposite the direction that the ISS was traveling as it orbited the Earth would be enough” to send the part safely on its way.
The same speed is mentioned in the Air and Space link it cites. From Tossing Out Trash From the Space Station Takes More Planning Than You’d Think:
Our idea was to have EVA astronauts manually push jettisoned items away in the direction opposite the station’s orbit. Analysis showed that a surprisingly small retrograde change in velocity was required: only about 1 to 1.5 inches per second would ensure no recontact. The drag of the jettisoned object would be greater than that of the ISS, further ensuring that the jettisoned object would keep moving behind and below the ISS until it eventually burned up in the atmosphere. In the case of the EAS, however, we scheduled a thruster burn to raise the ISS orbit after jettison just to make sure. Safety engineers insisted that we define a jettison “cone” to account for any directional errors, so that even if an object were at the edge of the cone, it would still fly away safely. Simple trigonometry led to the conclusion that pushing an object away at two inches per second (a rate easily achievable by an EVA astronaut) within a 30-degree cone centered on a line directly opposite the direction that the ISS was traveling as it orbited the Earth would be enough.
This seems to be a lot faster than that
In the video in this International Space Station tweet it looks more like two feet per second than two inches, an order of magnitude difference. I estimate that the antenna cover moves more than it's own length in one second.
.@AstroVicGlover jettisons a science antenna cover into space since it is no longer needed. It will eventually enter Earth's atmosphere and burn up safely.
Question: What's the root cause of the disparity between what the article says and what's shown in the video?