HTV-X1

HTV-X1
Mission type	ISS resupply
Operator	JAXA
Mission duration	~30 days (planned)
Spacecraft properties
Spacecraft type	HTV-X
Manufacturer	Mitsubishi Heavy Industries
Launch mass	16,000 kg (35,000 lb)
Dimensions	8.0 × 4.4 m (26.2 × 14.4 ft)
Start of mission
Launch date	NET 21 October 2025, 01:58 UTC (10:58 JST)
Rocket	H3-24W, Flight 7
Launch site	Tanegashima, LA-Y2
Contractor	Mitsubishi Heavy Industries
Orbital parameters
Reference system	Geocentric orbit
Regime	Low Earth orbit
Inclination	51.6°
Berthing at ISS
Berthing port	Harmony nadir
Cargo
Mass	5,819 kg (12,829 lb)
Pressurised	4,069 kg (8,971 lb)
Unpressurised	1,750 kg (3,860 lb)
	HTV (Kotonotori) ← Kounotori 9 HTV-X2 → HTV-X HTV-X2 →

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 is scheduled to launch on 21 October 2025.^[5]^[6]

Cargo

Pressurised cargo

HTV-X1 will deliver the following pressurised cargo to the International Space Station (ISS):^[7]

Crew supplies
DRCS (Demonstration of Removing Carbon Dioxide System)
NORS (Nitrogen/Oxygen Recharge System) tank
RST (Water Resupply Tank)

Unpressurised cargo

i-SEEP (IVA-replaceable Small Exposed Experiment Platform)

Additional payloads

In addition to its primary cargo mission, HTV-X1 carries several technology demonstration payloads:^[2]

DELIGHT, a demonstration of a lightweight expandable flat antenna
Mt.FUJI, a technology demonstration for satellite laser ranging
H-SSOD, a small satellite deployer that will release the CubeSat Ten-Koh 2 following departure from the ISS