Transporting cargoes to the International Space Station (ISS) is the most important mission taken over from KOUNOTORI. The HTV-X will transfer essential cargo such as large-sized devices for the ISS and life support goods for astronauts. The costs for the HTV-X will be cut down through compact designing and efficient operations. Moreover, the HTV-X will be designed to become more useful for owners of experiment devices on earth.
Stronger transportation capabilities
For exposed cargoes such as extravehicular devices for the ISS, the HTV-X has been designed so that they can be mounted on the top plate called "exposed cargo mount support system".
This will allow use of space in the rocket fairing to be maximized. For pressurized cargoes, the HTV-X has been designed to have rack structures so that the space in the spacecraft can be used effectively. As a result, the HTV-X will be capable of transporting more pressurized cargoes than KOUNOTORI.
Moreover, the streamlining of the HTV-X's fuselage in weight will enable it to transport heavier cargoes.
Improvement of cargo services
Supporting cargo that require power
The HTV-X will be capable of transporting refrigerators and some experiment devices that require power supply during transportation. KOUNOTORI did not have this capability.
For example, like the low-temperature home delivery services on earth, the HTV-X will be capable of transporting experiment samples that must be kept at low temperatures during transportation.
Cargoes can be mounted on the HTV-X 24 hours before launch
Previously, cargoes had to be mounted on KOUNOTORI at least 80 hours before launch. With the HTV-X, the minimum required time for mounting cargoes has been minimized to 24 hours before launch. Thus, the HTV-X will be capable of transporting a wider range of fresh foods and experiment samples that require freshness.
Longer cargo-acceptance period
The period of cargo assembling at the Tanegashima Space Center (TNSC) has been shortened for the HTV-X compared to KOUNOTORI. With this change, cargoes can be accepted in the HTV-X for a longer duration until shortly before launch. Requests from cargo owners can be implemented more flexibly.