Kounotori 4

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Kounotori 4
ISS-36 HTV-4 berthing 2.jpg
HTV-4 being grappled by the SSRMS on 9 August 2013
Mission typeISS resupply
COSPAR ID2013-040A
SATCAT no.39221
Mission duration35 days
Spacecraft properties
Spacecraft typeHTV
Start of mission
Launch date3 August 2013, 19:48:46 (2013-08-03UTC19:48:46Z) UTC
Launch siteTanegashima Y2
End of mission
Decay date7 September 2013, 06:37 (2013-09-07UTC06:38Z) UTC
Orbital parameters
Reference systemGeocentric
RegimeLow Earth
Perigee281 kilometres (175 mi)
Apogee302 kilometres (188 mi)
Inclination51.6 degrees
Period90.34 minutes
Epoch5 August 2013[1]
Berthing at ISS
Berthing portHarmony nadir
RMS capture9 August 2013, 11:22 UTC
Berthing date9 August 2013, 15:28 UTC
Unberthing date4 September 2013, 12:07 UTC
RMS release4 September 2013, 16:20 UTC
Time berthed25 days, 20 hours, 29 minutes
Mass5,400 kilograms (11,900 lb)
Pressurised3,900 kilograms (8,600 lb)
Unpressurised1,500 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.[2] Kounotori 4 undocked on September 4, 2013 and was destroyed by reentry on 7 September 2013.[3][4]


Major changes of Kounotori 4 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.[5]
  • 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 (PicoDragon, ArduSat-1, ArduSat-X, TechEdSat-3p), 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[edit]

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.

The H-IIB rocket carrying Kounotori 4 lifts off from the Tanegashima space center early on 4 August 2013 local time.

After 5.5 days of orbital manoeuvres, it arrived to Approach Initiation Point (5 km behind ISS) at 05:31, 9 August 2013 UTC,[6] and started the final approach sequence at 08:05.[7] 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.[8]

Operation while berthed to ISS[edit]

The ISS crew opened the hatch and entered to Pressurized Logistics Carrier at 11:11, August 10, 2013[9]

Departure from ISS and reentry to earth atmosphere[edit]

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.[3]

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.[4]


  1. ^ McDowell, Jonathan. "Satellite Catalog". Jonathan's Space Page. Retrieved 9 November 2013.
  2. ^ NASA - Japanese Cargo Craft Captured, Berthed to Station (2013)
  3. ^ a b NASA (September 4, 2013). "Station Releases a White Stork and Awaits a Swan". Retrieved September 4, 2013.
  4. ^ a b JAXA (7 September 2013). "Successful re-entry of H-II Transfer Vehicle "KOUNOTORI4" (HTV4)". Retrieved 1 December 2013.
  5. ^ "Features of HTV4". Retrieved 29 July 2013.
  6. ^ "KOUNOTORI4 Reaches 5km behind the ISS". JAXA. August 9, 2013. Retrieved August 15, 2013.
  7. ^ "KOUNOTORI4 Resumes Approach to the ISS". JAXA. Retrieved August 15, 2013.
  8. ^ "ISS Crew Completed KOUNOTORI4 Berthing Operation". JAXA. August 10, 2013. Retrieved August 15, 2013.
  9. ^ JAXA (August 12, 2013). "ISS Crew Entered KOUNOTORI4 Pressurized Logistics Carrier (PLC). Transfer of the Exposed Pallet (EP) was Completed". Retrieved August 15, 2013.


External links[edit]