Kounotori 4

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.

Specifications

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.
 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.

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-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).

Operation

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.

Notes

References

External links

 HTV4 (Kounotori 4) Official page, JAXA
  Official JAXA channel
  Official JAXA channel
  Official JAXA channel
 HTV-4 Mission Updates, Spaceflight101.com

Category:Spacecraft launched in 2013
Category:H-II Transfer Vehicles
Category:2013 in Japan
Category:Spacecraft which reentered in 2013
Category:Supply vehicles for the International Space Station
Category:Spacecraft launched by H-II rockets