4 days ago the Japanese Aerospace Exploration Agency (JAXA) launched the first flight ready version of their HII Transfer Vehicle (HTV) line. Whilst on the surface that might not sound like much it marks a significant step forward in Japan’s space capability, as up until now their involvement with the Internation Space Station only involved the Kibo laboratory, all of which was hoisted up by their American counter-parts. It’s quite an interesting craft due to the omission of certain things and the reason it was built. Before I get into that however here’s a bit of eye candy showing it’s rendezous with the International Space Station:http://www.youtube.com/watch?v=115pSsW9aXU
Apart from the amazing view of earth that this video shows it also demonstrates one of the oddities of the craft. Now the HTV isn’t the first of this kind of spacecraft to visit the ISS. The most frequent visitor is the Russian Progress craft, which has been responsible for delivering the majority of supplies to the space station. It’s basically a Soyuz craft minus all the gear to support a crew replaced with cargo storage, as it was impractical for the Soyuz craft to be used for both crew and cargo (it is quite small after all). The other is the European Space Agency’s Automated Transfer Vehicle (ATV) which made its madon voyage to the ISS in March last year. What separates these from the HTV is that they both have an automated docking capability allowing them to hook up to the space station with no involvement from the ISS crew. That’s why you see the CANADARM2 stretching out to grab it. You’re probably wondering then, why the heck do we need another cargo ship to supply the ISS and beyond?
The HTV is something of a special purpose craft. Whilst its payload capacity is less than that of the ATV it does sport a much larger docking portal. That by itself doesn’t sound like much but the ATV can’t carry the Interational Standard Payload Racks because of this limitation. The only other way of getting these things inside the ISS is through Multi-Purpose Logistic Modules which fly with the space shuttle, something which is scheduled to stop happening in the near future. In essence the craft is a cheaper alternative to getting standard cargo payloads up to the station once the shuttle is retired, which is a good niche for JAXA to fill.
It might not be the most sexy or exciting craft around but the more countries that develop a capability like this means a lot to humanity at large. We’re starting to see a critical mass developing in both the public and private sector space industries and for a space nut like myself it provides many an hour of slack jawed reading and gazing. Japan’s fresh view on how to get cargo into space is an idea that not many have considered in the past and I hope they continue their involvement past this endeavour.
Big thumbs up to you guys 🙂