H-II Transfer Vehicle (HTV)
The unpiloted Japan Aerospace Exploration Agency H-II Transfer Vehicle approaches the International Space Station. Image Credit: NASA
The components of the HTV. › View
HTV ULC and Exposed Pallet. › View
HTV Pressurized Cargo Layout. › View The H-II Transfer Vehicle (HTV), designed and built in Japan, is JAXA’s unmanned cargo transfer spacecraft that delivers supplies to the International Space Station (ISS). The HTV delivers more than 12,000 pounds of cargo, both pressurized and unpressurized, to the ISS. HTV performs a rendezvous with the space station and holds position several meters away. The crew uses the station’s robotic arm to capture HTV and install it on the bottom side of the station’s Harmony node.
HTV has two main parts. The Pressurized Logistics Carrier (PLC) carries cargo for onboard use (experiment racks, food, and clothes). Internal air pressure of the PLC is maintained at one atmospheric pressure (1 atm). The temperature inside the HTV is controlled during its solo flight phase and berthing phase.
The second part, the Unpressurized Logistic Carrier (ULC), accommodates an Exposed Pallet (EP) while the HTV flies to the ISS. The EP is a pallet used to carry external experiments and spare parts to be used outside of the ISS.
While the HTV is berthed to the ISS, ISS crew can enter HTV’s pressurized logistics carrier to transfer onboard supplies to the ISS. The ISS crew will also unload the unpressurized cargo using the station’s robotic arm and Kibo’s robotic arm. After the supplies are unloaded, the HTV will then be loaded with trash and other discarded items. Once HTV undocks and departs the ISS, it is sent intro a destructive reentry into Earth’s atmosphere.
|First launch to ISS||2009|
|Launch site||Tanegashima Space Center, Japan|
|Launch vehicle||HIIB rocket|
|Length||9.2 m (30 ft)|
|Diameter||4.4 m (14.4 ft)|
|Launch mass||16,500 kg (36,375 lb)|
|Cargo mass||5,500 kg (12,125 lb)|
|Pressurized volume||14 m3 (495 ft3)|
|Unpressurized volume||16 m3 (565 ft3)|
|Length on orbit||6 months|
|Docking method/location||Captured by the station’s robot arm/U.S. segment|
|Return method||Destructive reentry|