Mission type ISS resupply COSPAR ID 2013-040A Mission duration 35 days Launch date 3 August 2013 Inclination 51.6° Manufacturer Aerojet | SATCAT no. 39221 Spacecraft type HTV Mass 5,400 kg | |
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Similar H‑II Transfer, Kounotori 5, Kounotori 6, HTV‑1, Kounotori 2 |
Kounotori 4, also known as HTV-4, was the fourth flight of the H-II Transfer Vehicle, an unmanned cargo spacecraft launched in August 2013 to resupply the International Space Station. It launched from Tanegashima Space Center aboard H-IIB rocket on August 3, 2013 and connected to ISS by August 9, 2013; it carried 5.4 tons of cargo. Kounotori 4 undocked on September 4, 2013 and was destroyed by reentry on 7 September 2013.
Contents
- Specifications
- Cargo
- Launch and rendezvous with ISS
- Operation while berthed to ISS
- Departure from ISS and reentry to earth atmosphere
- References

Specifications
Major changes of Kounotori 4 from previous HTV are:

Cargo

Kounotori 4 carries about 5.4 tonnes of cargo, consisting of 3.9 t in pressurized compartment and 1.5 t in unpressurized compartment.

Pressurized cargo include: CANA (Cabin network system for Kibo), Stirling-Cycle Refrigerator (FROST), ISS Cryogenic Experiment Storage Box (ICE Box), i-Ball reentry data recorder, four CubeSats (PicoDragon, ArduSat-1, ArduSat-X, TechEdSat-3), and Kirobo (robot companion for Koichi Wakata).

Unpressurized cargo are: MBSU (Main Bus Switching Units) and UTA (Utility Transfer Assembly) which are ISS system spare parts, and a NASA experiment module STP-H4 (Space Test Program - Houston 4).
Launch and rendezvous with ISS

Kounotori 4 was successfully launched atop a H-IIB carrier rocket flying from pad 2 of the Yoshinobu Launch Complex at Tanegashima at 19:48:46 UTC on 3 August 2013.
After 5.5 days of orbital manoeuvres, it arrived to Approach Initiation Point (5 km behind ISS) at 05:31, 9 August 2013 UTC, and started the final approach sequence at 08:05. The ISS's robotic arm SSRMS grappled Kounotori 4 at 11:22, and fastened to ISS's CBM on 16:32. All berthing operations were completed at 18:38.
Operation while berthed to ISS
The ISS crew opened the hatch and entered to Pressurized Logistics Carrier at 11:11, August 10, 2013
Departure from ISS and reentry to earth atmosphere
Kounotori 4 undocked from the ISS at 16:20, 4 September 2013 UTC, Karen Nyberg then used the stations Canadarm 2 to manoeuvre HTV-4 away from the station.
Trajectory after the release was controlled so that the reentry coincides with ISS passing over to observe it. Japanese flight controllers have deorbited HTV-4 on 06:11, 7 September 2013 UTC, and it reentered to atmosphere around 06:37, 7 September 2013 UTC.