AKA: H2B. Status: Active. First Launch: 2009-09-10. Last Launch: 2018-09-22. Number: 7 .
Basic diameter is 5.2m in diameter versus 4.0 m for the H-IIA. The first stage contains 70% more propellant than that of the H-IIA.
First launch of the H-IIB booster and the HTV International Space Station resupply spacecraft. HTV-1 rendezvoused with the ISS on 17 September, stationkeeping 10 m away. It was grappled by the station's Canadarm and berthed to the Harmony port of the station and then unloaded. HTV-1 was unberthed from the ISS at 15:02 GMT on 30 October 2009 and deorbited on 2 November.
Second Japanese H-II Transfer Vehicle, delivering equipment and supplies to the International Space Station. Detached from the station by the station's robot arm and released into space on 28 March at 15:46 GMT. Following retrofire burned up over the Pacific Ocean on 30 March at 03:09 GMT on 30 March.
Arrived at the ISS on 27 July. Grappled by the station's Canadarm and berthed to the ISS Harmony module at 14:34 GMT. Unberthed by the SSRMS arm of the ISS at about 12:02 GMT on 12 September and released into space at 1550 GMT. After one of HTV-3's onboard computers failed, a planned small separation burn was replaced by a much larger abort burn which safely and rapidly separated HTV-3 from the vicinity of the ISS. HTV-3 was successfully deorbited over the Pacific on 14 September.
Fourth Japanese H-II Transfer Vehicle mission to the ISS. Carried on its external pallet the Space Test Program H4 package to be installed on ELC1 (around 400 kg), a spare Main Bus Switching Unit for ELC2 (100 kg), and a spare SARJ Utility Transfer Assembly for ELC4 (around 300 kg). The pressurized cargo was packaged in 8 HTV Resupply Racks and included the FROST freezer, the Kirobo robot, NASA's RRM Task Board 3 robotics experiment, and two J-SSOD cubesat launchers. The J-SSODs were later taken outside via the Kibo science airlock ejected five cubesats. HTV 4 reached the ISS on 9 Auguest, holding 10 metres off the Station until the Canadarm-2 robot arm captured it at 11:22 GMT. The arm berthed the module on the Harmony node at 15:28 GMT. The hatch to the pressurized cabin of the HTV was opened at 11:11 GMT on 10 August. On 11 August at 21:07 GMT the Canadarm removed the Exposed Pallet (EP) from the HTV, and at 03:59 GMT 12 August the EP was installed on the end of the Kibo Exposed Facility pallet. The equipment on the EP will be relocated to the ELC pallets on the truss using the Japanese and Canadian robot arms. After completing operations, it was unberthed from Harmony at 12:07 GMT on 4 September and released by the Canadarm at 16:20 GMT. After several maneuvers, final retrofire was over Japan at 06:11 GMT on 7 September, with burnup over the South Pacific at around 41 deg S at 06:37 GMT.
HTV-5 arrived at the ISS on 24 August and was berthed at the Harmony nadir port at 14:02 GMT. HTV-5's External Platform carries the CALET electron/cosmic-ray detector which was installed on the Kibo Exposed Facility. The pressurized compartment carried nine racks: the US Galley Rack, to be installed in the Unity node; the JAXA Multipurpose Small Payload Rack 2 (MSPR-2), installed in Kibo at JPM1F2; and seven HTV Resupply Racks. One of these used the new HRR-D storage system to increase the HTV capacity. Contained in the HRRs were a SAFER EVA backpack, a Mouse Habitat Unit (but no mice for it), 18 cubesats, the Nanoracks External Platform (NREP) and JAXA ExHAM-2 expsoure unit. The latter two were used for mounting external experiments. The cubesats were: PlanetLabs Flock 2b-1 to 2b-14, for Earth imaging; GOMSpace GOMX-3, for tests of ADS-B aircraft data relay; Aalborg University AAUSAT-5, a 1U sat for tests of AIS ship tracking receivers; Brazilian Space Agency/University of Brasilia SERPENS with technology communications payloads; Chiba Inst. Of Technology S-CUBE with UV and visible imagers to observe meteors from above. All the cubesats are 3U form factor except for AAUSAT-5. CALET had a mass of 650 kg; the 7 HRR racks carried 6057 kg of cargo. HTV-5 carried 2306 kg of propellant. The Galley and MSPR racks probably had a mass around 500 kg each; the dry HTV without payloads was about 6100 kg. On 25 August the SSRMS robot arm extracted the HTV Exposed Pallet and handed it to the JEM RMS, which berthed the EP on the Exposed Facility at location EFU10. The JEM RMS then grappled the CALET experiment and moved it to EFU9. The SSRMS arm unberthed the HTV-5 from the Harmony module at 11:12 GMT on 28 September. Release was delayed one orbit due to a robotics problem and occurred at 16:53 GMT. The next day HTV-5 lowered its orbit with two burns and then made a final deorbit burn at 20:08 GMT, with atmosphere entry around 20:33 GMT for destruction over the South Pacific.
16-tonne Japanese HTV-6 (Kounotori-6) cargo ship. The pressurized module contains 600 kg of water and 2152 kg of dry cargo. This included two JAXA J-SSOD and one Nanoracks NRCSD-10 cubesat deployers; these were to be transferred to the Kibo module. The HTV also has an Exposed Pallet, which on this mission (using the enhanced capacity EP6B+) carried a set of replacement batteries for the ISS truss, with a total cargo mass of 1367 kg. The S4, S6, P4 and P6 truss segments each contain an Integrated Electronics Assembly (IEA), with 12 Ni-H2 batteries apiece in separate ORUs (Orbital Replacement Units). On this mission the S4 batteries are to be replaced. Six new 197 kg Li-ion battery ORUs were to be installed and six of the 166 kg Ni-H2 battery ORUs were to be transferred to the HTV EP for disposal on reentry. The remaining six Ni-H2 ORUs remained on S4, but they were taken off line and new 29 kg Adapter Plate ORUs were to be installed between them and the truss. On Dec 14 the Exposed Pallet was grappled by the Canadarm-2, pulled out of HTV-6 and attached to the Mobile Base System on the ISS truss. On Dec 15-16 the J-SSOD #5 was moved to the Kibo module's airlock. On Dec 19 the Japanese RMS arm took the MPEP platform, with J-SSOD attached, out of the airlock and the STARS-C cubesat was ejected from it at 0855 UTC. On Dec 27 J-SSOD #6 was installed in the airlock with its sats to be deployed in January. Japan's HTV 6 cargo ship separated from ISS on Jan 27 at 1546 UTC. However, its KITE tether experiment failed to deploy when commanded to do so on Jan 28. HTV 6 was deorbited on Feb 5 at 1442 UTC and entered the atmosphere over the South Pacific at 1506 UTC.