|Mission type||ISS resupply|
|Mission duration||35 days|
|Start of mission|
|Launch date||3 August 2013, 19:48:46UTC|
|Launch site||Tanegashima Y2|
|End of mission|
|Decay date||7 September 2013, 06:37UTC|
|Perigee||281 kilometres (175 mi)|
|Apogee||302 kilometres (188 mi)|
|Epoch||5 August 2013|
|Berthing at ISS|
|Berthing port||Harmony nadir|
|RMS capture||9 August 2013, 11:22 UTC|
|Berthing date||9 August 2013, 15:28 UTC|
|Unberthing date||4 September 2013, 12:07 UTC|
|RMS release||4 September 2013, 16:20 UTC|
|Time berthed||25 days, 20 hours, 29 minutes|
|Mass||5,400 kilograms (11,900 lb)|
|Pressurised||3,900 kilograms (8,600 lb)|
|Unpressurised||1,500 kilograms (3,300 lb)|
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 destroyed by reentry at 06:37, 7 September 2013 UTC.
Kounotori 4 specifications
Major changes from previous HTV are:
- Although the previous Kounotori 3 used RCS thrusters by IHI Aerospace, Kounotori 4 uses the RCS manufactured by Aerojet, similar to HTV-1 and 2. This will be the last Kounotori to use Aerojet parts, and future Kounotori are to use IHI's.
- One of the solar panels was replaced with a sensor module to measure the surface electrical potential when berthing to ISS.
- Continued improvement of ground operation to allow more late access cargo.
- First time for Kounotori to reenter atmosphere with unpressurized waste cargo (a NASA engineering experiment module STP-H3).
- The orbital trajectory after departure from ISS is adjusted so that the reentry is to coincide with ISS passing over, to allow the reentry to be observed from ISS.
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 (Pico Dragon, 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
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 operation 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.
- McDowell, Jonathan. "Satellite Catalog". Jonathan's Space Page. Retrieved 9 November 2013.
- NASA - Japanese Cargo Craft Captured, Berthed to Station (2013)
- NASA (September 4, 2013). "Station Releases a White Stork and Awaits a Swan". Retrieved September 4, 2013.
- JAXA (7 September 2013). "Successful re-entry of H-II Transfer Vehicle "KOUNOTORI4" (HTV4)". Retrieved 1 December 2013.
- "Features of HTV4". Retrieved 29 July 2013.
- "KOUNOTORI4 Reaches 5km behind the ISS". JAXA. August 9, 2013. Retrieved August 15, 2013.
- "KOUNOTORI4 Resumes Approach to the ISS". JAXA. Retrieved August 15, 2013.
- "ISS Crew Completed KOUNOTORI4 Berthing Operation". JAXA. August 10, 2013. Retrieved August 15, 2013.
- JAXA (August 12, 2013). "ISS Crew Entered KOUNOTORI4 Pressurized Logistics Carrier (PLC). Transfer of the Exposed Pallet (EP) was Completed.". Retrieved August 15, 2013.
- "宇宙ステーション補給機「こうのとり」４号機（HTV4）ミッションプレスキット" (in Japanese). JAXA. July 23, 2013. Retrieved July 29, 2013.
- HTV4 (Kounotori 4) Official page, JAXA
- 「こうのとり」4号機打ち上げ（ダイジェスト映像） on YouTube Official JAXA channel
- "KOUNOTORI 4" (HTV4) MISSION DIGEST on YouTube Official JAXA channel
- HTV-4 Mission Updates, Spaceflight101.com