Apr 2

ISS – with HTV-7 Exposed Pallet and JEM robotic arm

Evening International Space Station flyby period over London with very bright and high elevation passes, so I wanted to make the best of it. Three days ago I miserably failed with focusing, have not had this kind of problem for a while.

So on 31st March I really wanted to nail it as good as possible.

Luckily it all went absolutely fine this time. When I quickly ran through the frames, I noticed something I have never seen before. On the japanese KIBO module there is a so called Exposed Facility which usually visible on photos. This time around there was something attached to it, also a robotic arm was visible too. So I started and investigation to find out what is going on. I was almost sure it has something to do with the ongoing battery replacement “operation”, a series of three spacewalks to replace the old nickel-hydrogen batteries to the new lithium-ion ones.

Flyby forecast

Imaging and results

I must say it went very well this time, sometimes I really struggle with manually tracking the ISS. Not this time, it went smoothly and I knew this should be nice.

When I saw those frames with the unidentified objects on Exposed Facility, I got very very excited. It always feels good to discover something I have not seen before and this is exactly that uncharted territory for me. So first I turned to Google but could not find any useful information about the container. But I found a website where I could find out what the robotic arm is –  it is called the Japanese Experiment Module Remote Manipulator.

Eventually a user on Reddit (called brickmack) confirmed my idea, the container is the HTV-7 Exposed Pallet. His words:

“Its the HTV-7 Exposed Pallet, with replacement batteries to be installed on the station exterior. The spacecraft departed back in November, and would normally take the pallet with it, but the fallout of the Soyuz MS-10 failure had impacts on the rest of the EVA schedule and meant they wouldn’t be able to install the replacement until much later than intended. Battery swaps have been ongoing, once those are done they’ll most likely just release it and let the pallet decay naturally (not a huge debris risk and it should reenter within a few months)”.

What is HTV, Japanese Experiment Module Remote Manipulator System (JEMRMS) and also Exposed Pallet?

The japanese HTV cargo spacecraft is something I have made a very good friendship with in the past. Successfully photographed HTV-7 flying solo and also docked to the International Space Station. But how does it connect to this story?

Japanese Experiment Module or KIBO is the japenese module attached to Harmony module.


The Exposed Pallet is a module mounted on the HTV to carry various types of exposed payloads, in this case the lithium-ion batteries. In this video below you will see the HTV-2 mission spacecraft from early 2011 as astronauts removing the Exposed Pallet from HTV-2 Unpressurized Logistics Carrier. Then they mount it exactly the same place where it is right now –  atop of Exposed Facility.


Skywatcher 250/1200 Flextube dobson telescope
Zwo ASI224MC camera

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