HTV-X1

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Wikipedia

HTV-X1
Mission typeISS resupply
OperatorJAXA
Mission duration~30 days (planned)[1]
Spacecraft properties
Spacecraft typeHTV-X
ManufacturerMitsubishi Heavy Industries
Launch mass16,000 kg (35,000 lb)[2]
Dimensions8.0 m × 4.4 m (26.2 ft × 14.4 ft)
Start of mission
Launch date21 October 2025, ~01:58 UTC (planned)[3]
RocketH3-24W[2]
Launch siteTanegashima, LA-Y2
ContractorMitsubishi Heavy Industries
Orbital parameters
Reference systemGeocentric
RegimeLow Earth orbit
Inclination51.6°
Berthing at the International Space Station
Berthing portHarmony or Unity nadir
Cargo
Mass5,819 kg (12,829 lb)[1]
Pressurised4,069 kg (8,971 lb)[1]
Unpressurised1,750 kg (3,860 lb)[1]

HTV-X1 is the first flight and the technical demonstration mission of HTV-X, an uncrewed expendable cargo spacecraft. It is planned to be launched on 21 October 2025.[4][5]

Cargo

In the pressurised compartment, HTV-X1 carries the following cargo:[6]

  • Crew supplies
  • DRCS (Demonstration of Removing Carbon-dioxide System)
  • NORS (Nitrogen/Oxigen Recharge System) tank
  • RST (Water Resupply Tank)

As unpressurised cargo, HTV-X1 carries following cargo:

  • i-SEEP, an exposed experiment platform

In addition to the primary mission of carrying the resupply cargo to the ISS, HTV-X1 carries the following payloads:[2]

  • DELIGHT, a technology demonstration of lightweight expandable flat antenna
  • Mt.FUJI, a technology demonstration for satellite laser ranging
  • H-SSOD, to deploy a CubeSat (Ten-Koh 2) after departure from ISS

References

  1. 1 2 3 4 G. D. Krebs. "HTV-X1, 2, 3 (Kotonotori 1, 2, 3)". Gunter's Space Page. Retrieved 25 August 2025.
  2. 1 2 3 新型宇宙ステーション補給機（HTV‐X）の開発状況について [Development status of the new space station resupply vehicle (HTV-X)] (PDF) (in Japanese). MEXT. 9 February 2021. Retrieved 4 March 2021.
  3. ↑ "HTV-X1". Next Spaceflight. Retrieved 26 October 2024.
  4. ↑ "Launch Schedule of New unmanned cargo transfer spacecraft（HTV-X1）aboard the 7th H3 Launch Vehicle (H3 F7)". JAXA. 22 August 2025. Retrieved 23 August 2025.
  5. ↑ "Japan to launch new ISS resupply vehicle in October". The Japan Times. 23 August 2025. Retrieved 25 August 2025.
  6. ↑ 新型宇宙ステーション補給機（HTV-X）1号機の開発状況 [Development status of the first HTV-X (HTV-X) space station resupply vehicle] (PDF) (in Japanese). JAXA. 2 June 2025. Retrieved 3 June 2025.