Cargo spacecraft "HTV-X1"

Launch, orbit & landing data: Designation  66174 / 25241A Launch date - time  26 October 2025 - 00:00:15 UTC Launch site  Tanegashima, LA-Y2 Launch vehicle  H3-24W Flight 7 Spacecraft type  HTV-X Manufacturer  Mitsubishi Heavy Industries Launch mass (kg)  ~14,500 Dimensions  8.0 x 4.4 m Earth orbit on :    - Perigee / Apogee  Low Earth orbit    - Eccentricity      - Inclination   51.6°    - Period   min

RMS capture - time  29 October 2025 - 15:58 UTC Berthing date - time  30 October 2025 - 11:10 UTC Berthing port  ISS/Harmony nadir Docking orbit:    - Perigee / Apogee   km    - Inclination  °    - Period   min Unberthed date - time  January 2026 (planned) UTC RMS release date - time  January 2026 (planned) UTC Time berthed (dd:hh:min)  109 days (in progress)

Description:

• HTV-X1 is the first flight of the HTV-X series, serving as a technical demonstration mission of the new uncrewed expendable cargo spacecraft. It launched on 26 October 2025.

Mission details:

• As the maiden flight, HTV-X1 is flown as a technical demonstration and was thus not loaded to maximum capacity, with a deficit of approximately 1,500 kilograms (3,300 lb) deducted mainly from unpressurised cargo. Attaining the full design capacity of the HTV-X, 4,069 kg (8,971 lb) pressurised and 1,750 kg (3,860 lb) unpressurised, requires use of the H3 rocket's optional Autonomous Flight Safety System, which enables the flight to be aborted autonomously if anomalies are detected while the rocket is out of range of ground control centers. This system was first tested, but not fully operational during HTV-X1's launch on H3 Flight 7.
• HTV-X1 is scheduled to remain berthed to the ISS for up to six months, during which cargo will be transferred to the ISS and waste loaded onto the HTV-X.

The new HTV-X1 in the grips of the Canadarm2

• Development: The HTV-X project was formally initiated in 2017, originally intending to launch the first flight in JFY2021, though eventually it was delayed to 2025 due to the delay of H3 launch vehicle development. Manufacturing of a proto-flight model began in 2018. The Pressurized Module (PM) for HTV-X1 was assembled by Mitsubishi Heavy Industries in Aichi Prefecture and shipped to the Tanegashima Space Center (TNSC) in August 2022. The Service Module (SM) was assembled by Mitsubishi Electric in Kanagawa Prefecture and delivered to TNSC in January 2025.
• At TNSC, the PM and SM were integrated, and a full system checkout was completed in May 2025. The modules were then separated for cargo and propellant loading beginning in August 2025. The PM and SM were reintegrated and encapsulated within the payload fairing on 9 October, and mated to the H3 launch vehicle on 14 October. Late-access cargo, including perishable food, was loaded on 19 October
• Launch: HTV-X1 was initially scheduled for launch on 21 October 2025.[12] The launch was postponed due to unfavorable weather conditions.
  HTV-X1 was successfully launched on 26 October 2025 at 00:00:15 UTC (09:00:15 JST) aboard Flight 7 of the H3 launch vehicle from Launch Area 2 of the Yoshinobu Launch Complex at TNSC. This mission marked the first H3 flight to use four solid rocket boosters and the first with a wide payload fairing.
• On 29 October 2025, JAXA astronaut Kimiya Yui, assisted by Zena Cardman, captured the spacecraft using the robotic Canadarm2 at 15:58 UTC. Akihiko Hoshide served as CAPCOM from NASA’s Mission Control Center at the Johnson Space Center in Houston, Texas. Ground teams at NASA and JAXA's Tsukuba Space Center completed berthing to the nadir (Earth-facing) port of the Harmony module at 19:43 UTC. Power transfer from the ISS to HTV-X1 was confirmed at 11:10 UTC on 30 October. During the approach, the spacecraft conducted a commanded retreat maneuver as part of a proximity operations demonstration.
• The hatch of the Pressurized Module was opened at approximately 12:37 UTC on 30 October.
• On 4 November, the Canadarm2 removed the i-SEEP3B payload from the unpressurized cargo deck and transferred it to the robotic JEMRMS arm for installation inside the Kibo module’s airlock.
• Following its departure from the ISS, HTV-X1 is scheduled to conduct a series of technology demonstration missions lasting approximately three months.

External links:

• Wikipedia:

  HTV-X1 overvieuw