JAXA Japan Aerospace Exploration Agency

	Opening the Door to Future Space Mission Japan has been developing its own launch vehicles based onvarious research and experiments. Among such launch vehicles, the H-IIA Launch Vehicle has been supporting satellite andexplorer launch missions as a mainstay large-scale launch vehicle with high reliability. The H-IIB Launch Vehicle is an powerful version of H-IIA to open the door to a new possibility for future missions including cargo transport to the International Space Station (ISS). The major purpose of H-IIB is to launch the H-II Transfer Vehicle "KOUNOTORII" (HTV), a cargo transporter, to the ISS. The KOUNOTORI carries necessary daily commodities for the crew astronauts, spare parts for the ISS, experimental devices and samples, and other research items. By operating two launch vehicles, H-IIA and H-IIB, we can respond to broader launch needs.

Opening the Door to Future Space Mission

Japan has been developing its own launch vehicles based onvarious research and experiments. Among such launch vehicles, the H-IIA Launch Vehicle has been supporting satellite andexplorer launch missions as a mainstay large-scale launch vehicle with high reliability.
The H-IIB Launch Vehicle is an powerful version of H-IIA to open the door to a new possibility for future missions including cargo transport to the International Space Station (ISS).
The major purpose of H-IIB is to launch the H-II Transfer Vehicle "KOUNOTORII" (HTV), a cargo transporter, to the ISS. The KOUNOTORI carries necessary daily commodities for the crew astronauts, spare parts for the ISS, experimental devices and samples, and other research items.
By operating two launch vehicles, H-IIA and H-IIB, we can respond to broader launch needs.

Project Topics

index

May 21, 2020 Updated

Successful Launch of the H-II Transfer Vehicle "KOUNOTORI9" aboard H-IIB Launch Vehicle No. 9

At exactly 31 minutes and 00 seconds past 2 o’clock on the morning of May 21, 2020, the H-II Transfer Vehicle known as "KOUNOTORI9" (HTV9), the cargo transporter to the International Space Station (ISS), was launched aboard H-IIB Launch Vehicle No. 9 (H-IIB F9) from the JAXA Tanegashima Space Center. H-IIB Vehicle light up in blue before its launch ©JAXA Messa...

More to read

Press Release

index

May 21, 2020 (04:10) [release]

Launch Results of the H-II Transfer Vehicle KOUNOTORI9 aboard H-IIB Vehicle No. 9
Mar. 24, 2020 (14:00) [release]

Launch Schedule of the H-II Transfer Vehicle KOUNOTORI9

Characteristics of H-IIB Launch Vehicle

1.Key Capacity Improvement: Clustering

The H-IIB launch vehicle is a two-stage rocket using liquid oxygen and liquid hydrogen as propellant and has four strap-on solid rocket boosters (SRB-A) powered by polibutadiene. The H-IIB has two liquid rocket engines (LE-7A) in the first-stage, instead of one for the H-IIA. It has four SRB-As attached to the body, while the standard version of H-IIA had two SRB-As. In addition, the H-IIB's first-stage body has expanded to 5.2m in diameter from 4m of H-IIA's one. It has also extended the total length of the first stage by 1m from that of H-IIA. At the result of such enhancement, the H-IIB needs propellant 1.7 times more than the former. Clustering several engines, whose performance is already fixed, has the advantage in shortening the period and reducing the cost for its development.

The H-IIB launch vehicle is a two-stage rocket using liquid oxygen and liquid hydrogen as propellant and has four strap-on solid rocket boosters (SRB-A) powered by polibutadiene.
The H-IIB has two liquid rocket engines (LE-7A) in the first-stage, instead of one for the H-IIA. It has four SRB-As attached to the body, while the standard version of H-IIA had two SRB-As. In addition, the H-IIB's first-stage body has expanded to 5.2m in diameter from 4m of H-IIA's one. It has also extended the total length of the first stage by 1m from that of H-IIA. At the result of such enhancement, the H-IIB needs propellant 1.7 times more than the former.
Clustering several engines, whose performance is already fixed, has the advantage in shortening the period and reducing the cost for its development.

2.For Effective Development

At the time of launching HTV, the H-IIB will use a special fairing for HTV. However, in other parts, it will take over most of the specifications and structures of on-board equipments and ground systems already used for the H-IIA. These efforts are designed to reduce development risk and cost. Moreover, it will share the launch facility with the H-IIA and be launched from Yoshinobu Launch Pad of the Tanegashima Space Center.

At the time of launching HTV, the H-IIB will use a special fairing for HTV. However, in other parts, it will take over most of the specifications and structures of on-board equipments and ground systems already used for the H-IIA. These efforts are designed to reduce development risk and cost. Moreover, it will share the launch facility with the H-IIA and be launched from Yoshinobu Launch Pad of the Tanegashima Space Center.

Major Characteristics

Major Characteristics (H-IIB Test Flight)

Length (m)	56.6
Mass (t)	531 (without payload mass)
Guidance Method	Inertial Guidance Method

Large Image

Item
	First Stage	Solid Rocket Booster (SRB-A)	Second Stage	Payload Fairing(5S-H)
Height (m)	38	15	11	15
Outside diameter (m)	5.2	2.5	4.0	5.1
Mass (t)	202	306 (for four SRB-As in total)	20	3.2
Propellant mass (t)	177.8	263.8 (for four SRB-As in total)	16.6	-
Thrust (kN)^*1	2,196	9,220	137	-
Combustion time (s)	352	114	499	-
Propellant type	Liquid oxygen/hydrogen	Polybutadiene composite solid propellant	Liquid oxygen/hydrogen	-
Propellant supply system	Turbo pump	-	Turbo pump	-
Impulse to weight ratio (s)^*1	440	283.6	448	-
Attitude control method	Gimbal	Movable nozzle	Gimbal gas jet system	-
Major onboard avionics	Guidance control equipment Telemetry transmitter	-	Guidance control equipment Radar transponder Telemetry transmitter Command destruct system	-

*1	In vacuum. Solid rocket booster's thrust is set to the maximum value.

H-IIB Launch Vehicle Launch Capacity

Orbit for HTV (Inclination:51.6 degrees)350km-460km16.5t
Orbit	Altitude	Payloads

Large Image

Launch Records

Flight No.	Launch Date	Payload
F9	5/21/2020	H-II Transfer Vehicle "KOUNOTORI9" (HTV9)
F8	9/25/2019	H-II Transfer Vehicle "KOUNOTORI8" (HTV8)
F7	9/23/2018	H-II Transfer Vehicle "KOUNOTORI7" (HTV7)
F6	12/9/2016	H-II Transfer Vehicle "KOUNOTORI6" (HTV6)
F5	8/19/2015	H-II Transfer Vehicle "KOUNOTORI5" (HTV5)
F4	8/4/2013	H-II Transfer Vehicle "KOUNOTORI4" (HTV4)
F3	7/21/2012	H-II Transfer Vehicle "KOUNOTORI3" (HTV3)
F2	1/22/2011	H-II Transfer Vehicle "KOUNOTORI2" (HTV2)
TF1	9/11/2009	H-II Transfer Vehicle "KOUNOTORI" (HTV Demonstration Flight)