by Douglas Messier
On May 21, a Japanese H-IIB rocket roared off the launch pad with the ninth and final H-II Transfer Vehicle (HTV) (Kounotori) resupply ship to the International Space Station (ISS).
But, the launch was not the end of the line for Japanese cargo delivery. The Japan Aerospace Exploration Agency (JAXA) is developing an improved variant known as HTV-X to supply the space station and possibly the lunar Gateway.(more…)