Launch and rendezvous with ISS

Approach to the ISS

HTV-1 before capture

HTV-1 was successfully launched at 17:01:46 UTC on 10 September 2009, to the initial orbit of 199.8 kilometres (124.1 mi) of perigee, an apogee of 299.9 kilometres (186.3 mi), an inclination of 51.69° (planned 200 kilometres (120 mi) ± 10 kilometres (6.2 mi) / 300 kilometres (190 mi) ± 2 kilometres (1.2 mi) / 51.67° ± 0.15°).^[21][22] The launch took place from the (Yoshinobu Launch Complex (Yoshinobu-2) at the Tanegashima Space Center, and was the first to use the second pad of the complex.^[11]

Flight operations are chronicled using Flight Day (FD), the ISS crew timeline.^[6] Arrival of HTV-1 occurred during Expedition 20, (Gennady Padalka, Commander, Michael Barratt, Nicole Stott, Frank De Winne, Roman Romanenko, and Robert Thirsk). Expedition 21 supervised the departure of HTV-1, (Frank De Winne, Commander, Roman Romanenko, Robert Thirsk, Maksim Surayev, Jeffrey Williams, and Nicole Stott). The station was visited by Space flight participant Guy Laliberté. No Japanese astronaut was present during the attached phase of the HTV-1 to the ISS. The launch day is FD1 (10 September 2009). On FD3 (12 September 2009), HTV-1 performed the demonstration tests of ISS proximity operation such as collision avoidance manoeuvre. It went successfully and on FD6 (15 September 2009), ISS Mission Management Team approved the final approach.^[23]

On 17 September 2009, HTV-1 rendezvoused with the International Space Station.^[24] It arrived at the Approach Initiation Point, 5 kilometres (3.1 mi) behind the space station at 13:59 UTC, and began its final approach sequence at 15:31.^[25] It approached to within 10 metres (33 ft) of the station, from where it was grappled using the Canadarm2 robotic arm of the space station, operated by Nicole Stott. Initial capture occurred at 19:47 UTC, with the procedure being completed at 19:51.^[26] Robert Thirsk then used Canadarm2 to move it to a "ready-to-latch" position over the nadir CBM port of the Harmony module. It arrived at this position at 22:08 UTC, and by 22:12 four latches had engaged to hold it in place. Sixteen bolts were subsequently driven in to achieve a hard mate.^[27] The spacecraft's rendezvous systems are based on those tested on the ETS-VII satellite.^[28] It remained berthed at the station until 30 October 2009.^[29]

Departure from the ISS and re-entry

Expedition 21 crew members, Nicole Stott, Robert Thirsk, and Frank De Winne completed the final steps of preparing for HTV's release from the ISS. These steps included disconnecting the final remaining power jumper line, closing the Harmony module (Node-2) nadir hatch, depressurizing the vestibule and performing leak checks, removing Common Berthing Mechanism bolts and deploying latches and unberthing the HTV-1 with the Space Station Remote Manipulator System.^[30]

While passing above the Pacific Ocean, the robotic arm of the space station released the HTV-1 positioned at 12 kilometres (7.5 mi) below the station on 30 October 2009. The departure was delayed for one ISS orbit to avoid debris (Kosmos 2421).^[31][32] HTV-1 was loaded with 199 items of discarded equipment and waste of 727.7 kilograms (1,604 lb), as well as 896 kilograms (1,975 lb) empty racks, totaling 1,624 kilograms (3,580 lb).^[32] At 17:32 (UTC), HTV-1 was released from SSRMS and began its planned maneuvers to leave the station proximity. HTV-1 gradually departed from the ISS orbit by performing several thruster burns and entered to its solo-flight mode.

The HTV flight control team sent commands for three engine burns at 14:55, at 16:25, and at 20:53, on 1 November 2009 (UTC) to prepare the vehicle's destruction in the atmosphere of Earth. The first de-orbit engine burn lasted for approximately 8 minutes and was completed at 15:03, on 1 November 2009. The second de-orbit engine burn lasted for approximately 9 minutes and was completed at 16:34. Following the second de-orbit maneuver, the HTV-1 was inserted into an elliptic orbit with an altitude of a perigee of 143 kilometres (89 mi) and an apogee of 335 kilometres (208 mi).

HTV-1 began the third and final de-orbit maneuver at 20:53 on 1 November 2009 as planned, while the spacecraft was passing over Central Asia. The maneuver that lasted for about 8 minutes was successfully wrapped up at 21:01 as the spacecraft flew near the southern half of Japan. According to the Japan Aerospace Exploration Agency (JAXA), HTV-1's atmospheric re-entry occurred at 21:25 UTC at 120 km above and over the Pacific Ocean just off the coast of New Zealand. The fiery re-entry and disintegration in the atmosphere of Earth marked the successful completion of the HTV-1's 52-day mission.

It is believed that some of the surviving debris from the HTV would have likely fallen in a rectangular area stretching across the Pacific Ocean between New Zealand and South America, according to the Japan Aerospace Exploration Agency.^[33]