It includes: Aquatic Habitat (AQH),[5] JEM Small-Satellite Orbital Deployer (J-SSOD), five CubeSats: (RAIKO, FITSAT-1, WE WISH, F-1, TechEdSat), i-Ball [ja] and REBR reentry data recorders, ISS SERVIR Environmental Research and Visualization System (ISERV).

[6] Additionally, loaded onto Kounotori 3's Resupply Racks was NASA's Water Pump Assembly (WPA) catalytic reactor to replace the former unit that broke in March 2012 in orbit and a cooling water circulation pump to replace the old unit in the Japanese Experiment Module (Kibō) that also broke at the end of March 2012.

"As a result, aquatic breeding over three generations, from fish parents to grandkids, previously impossible in space shuttle experiments, has become a reality", NASA said in a press kit.

Two experiments, originally designed by the winners of the international YouTube Space Lab competition, would examine how Bacillus subtilis and the Jumping spider would react to microgravity.

Unpressurized cargo consists of Multi-mission Consolidated Equipment (MCE) and Space Communications and Navigation Program (SCaN Testbed).

Kounotori 3 was placed into free-drift and NASA astronaut Joseph M. Acaba, operating the station's robot arm, captured the HTV's grapple fixture at 12:23 UTC.

Then robotic operators on the ground in Mission control in Houston (ROBO team) completed the manoeuvre of the HTV to the pre-berthing position at the nadir port (Earth-facing) of the space station's Harmony module.

The JAXA astronaut and flight engineer of Expedition 32/33 Akihiko Hoshide then resumed berthing operations, moving the spacecraft into the interface for installation.

The EP was then handed off to the JEM Robotic arm, being operated by Akihiko Hoshide, and installed to the Kibō's Exposed Facility on 6 August 2012 6.

In preparation for unberthing, the Re-Entry Data Recorder (REBR) and the i-Ball were installed and activated, and the hatch was closed on 11 September 2012.

SpaceFlightNow reported that it was triggered by a failure of In/out Computer 2, citing daily space station On-Orbit Status posted on a NASA website.

[23] Later, Aviation Week & Space Technology reported that it was caused by the friction between Kounotori's grapple fixture and the station's robotic arm.