Editing JAXA (section)

== Rockets ==
[[File:H-II series.png|180px|right|thumb|H-IIA & H-IIB]]
JAXA uses the [[H-IIA]] (H "two" A) rocket from the former NASDA body as a [[medium-lift launch vehicle]]. JAXA has also developed a new medium-lift vehicle [[H3 (rocket)|H3]]. For smaller launch needs, JAXA uses the [[Epsilon (rocket)|Epsilon]] rocket. For experiments in the upper atmosphere JAXA uses the [[SS-520]], [[S-520]], and [[S-310]] [[sounding rocket]]s.

Historical, nowadays retired, JAXA orbital rockets are as follows: [[Mu (rocket family)|Mu rocket family]] ([[M-V]]) and [[H-IIB]].

=== Launch development ===
[[File:H-IIA_F19_launching_IGS-O4.jpg|thumb|H-IIA F19 launch]]
[[File:HTV-1 approaches ISS.jpg|thumb|[[H-II Transfer Vehicle]]]]
Japan launched its first satellite, [[Ohsumi (satellite)|Ohsumi]], in 1970, using ISAS' [[Lambda (rocket)|L-4S]] rocket. Prior to the merger, ISAS used small [[Mu (rocket family)|Mu rocket family]] of solid-fueled launch vehicles, while NASDA developed larger liquid-fueled launchers. In the beginning, NASDA used licensed American models.<ref name = "jstage291221"/>

The first model of liquid-fueled launch vehicle developed domestically in Japan was the [[H-II]], introduced in 1994. NASDA developed the H-II with two goals in mind: to be able to launch satellites using only its own technology, such as the ISAS, and to dramatically improve its launch capability over previous licensed models. To achieve these two goals, a [[staged combustion cycle]] was adopted for the first stage engine, the [[LE-7]]. The combination of the [[liquid hydrogen]] two-stage combustion cycle first stage engine and [[solid rocket booster]]s was carried over to its successor, the H-IIA and H-IIB and became the basic configuration of Japan's liquid fuel launch vehicles for 30 years, from 1994 to 2024.<ref name = "jstage291221">{{Cite news
  |url=https://www.jstage.jst.go.jp/article/jhts/33/5/33_229/_pdf/-char/ja
  |title=History and Prospect of Liquid Rocket Engine Development in Japan
  |date=|accessdate=21 February 2024|publisher=J Stage
  |archiveurl =https://web.archive.org/web/20211229131449/https://www.jstage.jst.go.jp/article/jhts/33/5/33_229/_pdf/-char/ja|archivedate = 29 December 2021}}</ref>

In 2003, JAXA was formed by merging Japan's three space agencies to streamline Japan's space program, and JAXA took over operations of the [[H-IIA]] liquid-fueled launch vehicle, the [[M-V]] solid-fuel launch vehicle, and several observation rockets from each agency. The H-IIA is a launch vehicle that improved reliability while reducing costs by making significant improvements to the H-II, and the M-V was the world's largest solid-fuel launch vehicle at the time.<ref name = "jstage291221"/>

In November 2003, JAXA's first launch after its inauguration, H-IIA No. 6, failed, but all other H-IIA launches were successful, and as of February 2024, the H-IIA had successfully launched 47 of its 48 launches. JAXA plans to end H-IIA operations with H-IIA Flight No. 50 and retire it by March 2025.<ref name = "nikkei240112">{{Cite news
  |url=https://www.nikkei.com/article/DGXZQOUC116OJ0R10C24A1000000/
  |title=H2Aロケット48号機打ち上げ成功 情報収集衛星を搭載
  |date=12 January 2024|accessdate=21 February 2024|publisher=Nikkei
  |archiveurl =https://web.archive.org/web/20240213153235/https://www.nikkei.com/article/DGXZQOUC116OJ0R10C24A1000000/|archivedate = 13 February 2024}}</ref>

JAXA operated the [[H-IIB]], an upgraded version of the H-IIA, from September 2009 to May 2020 and successfully launched the [[H-II Transfer Vehicle]] six times. This [[cargo spacecraft]] was responsible for resupplying the [[Kibō (ISS module)|Kibo Japanese Experiment Module]] on the [[International Space Station]].<ref name="mynavi Corporation20200909pdf">{{Cite news|url=https://news.mynavi.jp/techplus/article/htv-3/
  |title=「こうのとり」ミッションの集大成、そして未来へバトンをつないだ最終号機
  |date=9 September 2020|accessdate=21 February 2024|publisher=Mynavi Corporation
  |archiveurl =https://web.archive.org/web/20230226091727/https://news.mynavi.jp/techplus/article/htv-3/|archivedate = 26 February 2023}}</ref>

To be able to launch smaller mission on JAXA developed a new solid-fueled rocket, the [[Epsilon (rocket)|Epsilon]] as a replacement to the retired [[M-V]]. The maiden flight successfully happened in 2013. So far, the rocket has flown six times with one launch failure.

In January 2017, JAXA attempted and failed to put a miniature satellite into orbit atop one of its SS520 series rockets.<ref>{{cite news |last=Kyodo|date=15 January 2017|title=JAXA fails in bid to launch world's smallest satellite-carrying rocket|url=http://www.japantimes.co.jp/news/2017/01/15/national/science-health/japan-launches-worlds-smallest-satellite-carrying-rocket/#.WH00OlMrJEY|newspaper=The Japan Times|access-date=16 January 2017}}</ref> A second attempt on 2 February 2018 was successful, putting a four kilogram CubeSat into Earth orbit. The rocket, known as the SS-520-5, is the world's smallest orbital launcher.<ref>{{cite news |date=2 February 2018|title=Souped-up sounding rocket lifts off from Japan with tiny satellite|url=https://spaceflightnow.com/2018/02/02/ss-520-5-tricom-1r-test-launch/|newspaper=Spaceflight Now|access-date=7 February 2018}}</ref>

In 2023, JAXA began operating the [[H3 (rocket)|H3]], which will replace the H-IIA and H-IIIB; the H3 is a liquid-fueled launch vehicle developed from a completely new design like the H-II, rather than an improved development like the H-IIA and H-IIB, which were based on the H-II. The design goal of the H3 is to increase launch capability at a lower cost than the H-IIA and H-IIB. To achieve this, an [[Expander cycle#Expander bleed cycle|expander bleed cycle]] was used for the first time in the world for the first stage of the engine.<ref name = "mynavi1507151">{{Cite news
  |url=http://news.mynavi.jp:80/series/jaxa_h3/001/
  |title=新型基幹ロケット「H3」の挑戦 1/5
  |date=15 July 2015|accessdate=21 February 2024|publisher=Mynavi Corporation
  |archiveurl =https://web.archive.org/web/20170912011650/http://news.mynavi.jp:80/series/jaxa_h3/001/|archivedate = 12 September 2017}}</ref><ref name = "mynavi1507152">{{Cite news
  |url=http://news.mynavi.jp:80/series/jaxa_h3/002/
  |title=新型基幹ロケット「H3」の挑戦 2/5
  |date=22 July 2015|accessdate=21 February 2024|publisher=Mynavi Corporation
  |archiveurl =https://web.archive.org/web/20170928031914/http://news.mynavi.jp:80/series/jaxa_h3/002/|archivedate = 28 September 2017}}</ref><ref name="jaxa20150702pdf">{{Cite press release
  |url=https://www.jaxa.jp/press/2015/07/files/20150702_rocket_j.pdf
  |title=新型基幹ロケットの開発状況について
  |date=2 July 2015|accessdate=21 February 2024|publisher=JAXA
  |archiveurl =https://web.archive.org/web/20230106005035/https://www.jaxa.jp/press/2015/07/files/20150702_rocket_j.pdf|archivedate = 6 January 2023}}</ref>