View source for N-I (rocket)

{{Short description|Booster}}
{{about|the Japanese rocket|the Soviet rocket|N1 (rocket)}}
{{Use dmy dates|date=October 2020}}
{{Infobox Rocket
|name = N-I
|image=N-I.svg
|caption = The N-I rocket<ref name="EA">{{cite web|url=http://www.astronautix.com/lvs/delta.htm|title=Delta|first=Mark|last=Wade|publisher=[[Encyclopedia Astronautica]]|access-date=3 September 2008|url-status=dead|archive-url=https://web.archive.org/web/20130817180906/http://astronautix.com/lvs/delta.htm|archive-date=17 August 2013|df=dmy-all}}</ref>
|function       =  [[Carrier rocket]]
|manufacturer   =  [[McDonnell Douglas]] (design)<br>[[Mitsubishi Heavy Industries]] (production)
|country-origin =  United States (design)<br>Japan (production)
|height       =  {{convert|34|m|ft}}<ref name="EA" />
|diameter     =  {{convert|2.44|m|ft}}
|mass         =  {{convert|131330|kg|lb}}<ref name="EA" />
|stages       =  2 or 3
|capacities =  
{{Infobox Rocket/Payload
|location =  [[Low Earth orbit|LEO]]
|kilos    =  {{convert|1200|kg|lb}}<ref name="EA" />
}}
{{Infobox Rocket/Payload
|location =  [[Geosynchronous transfer orbit|GTO]]
|kilos    =  {{convert|360|kg|lb}}<ref name="EA" />
}}
|family      =  [[Delta rocket|Delta]]
|status   =  Retired
|sites    =  [[Tanegashima Space Center|Tanegashima]], [[Osaki Launch Complex|Osaki]]
|launches =  7
|success  =  6
|partial = 1
|first    =  9 September 1975
|last     =  3 September 1982

|stagedata    = 
{{Infobox Rocket/Stage
|type       =  booster
|name       =  [[Castor (rocket)|Castor 2]]
|number     =  3<ref name="JAXA-archive" />
|engines    =  1 [[TX-354-3]]
|thrust     =  {{convert|258.9|kN|lbf}}
|SI         =  262 sec
|burntime   =  37 seconds
|fuel       =  [[Solid rocket|Solid]]
}}
{{Infobox Rocket/Stage
|type       =  stage
|stageno    =  First
|name       =  [[Thor (rocket)|Thor-ELT]]
|engines    =  1 [[MB-3-3]]
|thrust     =  {{convert|866.7|kN|lbf}}
|SI         =  290 sec
|burntime   =  270 seconds
|fuel       =  [[RP-1]]/[[LOX]]
}}
{{Infobox Rocket/Stage
|type       =  stage
|name       =
|stageno    =  Second
|engines    =  1 [[:ja:LE-3|LE-3]]
|thrust     =  {{convert|52.9|kN|lbf}}
|SI         =  290 sec
|burntime   =  246 seconds
|fuel       =  [[Dinitrogen tetroxide|NTO]]/[[Aerozine 50|A-50]]
}}
{{Infobox Rocket/Stage
|type       =  stage
|name       =  [[Star-37N]]
|stageno    =  Third
|diff       =  optional
|engines    =  1 [[solid rocket|solid]]
|thrust     =  {{convert|45|kN|lbf}}
|SI         =  290 sec
|burntime   =  42 seconds
|fuel       =  [[solid rocket|Solid]]
}}
}}
[[File:Rocket-Namba.jpg|thumb|200px|Mock up of N-1]]
The '''N-I''' or '''N-1''' was a derivative of the American [[Thor-Delta]] rocket, produced under license in Japan. The N stood for "Nippon" (Japan). It used a [[Thor (rocket)|Long Tank Thor]] first stage, a [[Mitsubishi Heavy Industries]]-designed [[:ja:LE-3|LE-3]] engine on the second stage,<ref>{{cite web|url=https://www.jstage.jst.go.jp/article/jjsass1969/32/362/32_362_127/_pdf/-char/ja|title=N-Iロケット開発の歩み|publisher=Yukihiko Takenaka, NASDA|access-date=10 February 2011}}</ref><ref name="MHInagoya">{{cite web|url=http://202.228.55.2/ngpsw/introduction/history/index.html|title=三菱重工 名古屋誘導推進システム製作所 事業所紹介 沿革|publisher=Mitsubishi Heavy Industries|access-date=10 February 2011|url-status=dead|archive-url=https://web.archive.org/web/20110704102309/http://202.228.55.2/ngpsw/introduction/history/index.html|archive-date=4 July 2011}}</ref><ref>{{cite web|url=http://www.mext.go.jp/b_menu/hakusho/html/hpaa198201/hpaa198201_2_030.html|title=第1部 創造性豊かな科学技術を求めて 第2章 自主技術開発への展開 第3節 先導的・基盤的科学技術分野における自主技術開発の展開 2.宇宙開発|publisher=Ministry of Education, Culture, Sports, Science and Technology|access-date=10 February 2011|archive-url=https://web.archive.org/web/20080615025750/http://www.mext.go.jp/b_menu/hakusho/html/hpaa198201/hpaa198201_2_030.html|archive-date=15 June 2008|url-status=dead}}</ref> and three [[Castor (rocket)|Castor]] SRMs.<ref name="JAXA-archive">{{cite web|url=http://jda.jaxa.jp/jda/p1_e.php|title=JAXA Digital Archives|publisher=Japan Aerospace Exploration Agency|access-date=1 October 2009|url-status=dead|archive-url=https://web.archive.org/web/20090909144812/http://jda.jaxa.jp/jda/p1_e.php|archive-date=9 September 2009}}</ref><ref name="GSP">{{cite web|url=http://space.skyrocket.de/doc_lau_det/n-1.htm|title=N-1|first=Gunter|last=Krebs|publisher=Gunter's Space Page|access-date=31 August 2008}}</ref> Seven were launched between 1975 and 1982, before it was replaced by the [[N-II (rocket)|N-II]]. Six of the seven launches were successful, however on the fifth flight, there was recontact between the satellite and the third stage, which caused the satellite to fail.

On 29 February 1976, the second N-I conducted the only orbital launch, as of 17 February 2024, to occur on a [[leap day]].<ref name="x">{{cite web|url=https://www.space.com/32093-space-station-leap-day-spaceflight-history.html|title=Space Station Command Change Is One Giant Leap (Day) for Space History|first=Robert|last=Pearlman|date=29 February 2016 |publisher=[[Space.com]]|access-date=2 November 2017}}</ref>

==Launch history==
{| class="wikitable plainrowheaders"
|-
! scope="col" | Flight No.
! scope="col" | Date / time ([[Coordinated Universal Time|UTC]])
! scope="col" | Launch site
! scope="col" | Payload<ref>{{Cite web |title=JAXA {{!}} N-I Launch Vehicle |url=https://global.jaxa.jp/projects/rockets/n1/ |access-date=2024-02-18 |website=JAXA {{!}} Japan Aerospace Exploration Agency |language=en}}</ref>
! scope="col" | Payload mass
! scope="col" | Orbit
! scope="col" | Launch <br /> outcome
|-
! scope="row" rowspan = 2 style="text-align:center;|1(F)
| 9 September 1975<br>05:30<ref name="JSR">{{cite web|url=http://planet4589.org/space/lvdb/launch/Thor|title=Thor|first=Jonathan|last=McDowell|work=Orbital and Suborbital Launch Database|publisher=[[Jonathan's Space Report]]|access-date=31 August 2008|archive-date=1 August 2020|archive-url=https://web.archive.org/web/20200801135201/http://planet4589.org/space/lvdb/launch/Thor|url-status=dead}}</ref>
|[[Tanegashima Space Center|Tanegashima]]
| Engineering Test Satellite I "KIKU-1"(ETS-I)
| 82.5kg<ref name=":0">{{Cite web |title=JAXA {{!}} Engineering Test Satellite I "KIKU-1" (ETS-I) |url=https://global.jaxa.jp/projects/sat/ets1/ |access-date=2024-02-18 |website=JAXA {{!}} Japan Aerospace Exploration Agency |language=en}}</ref>
| [[Low Earth orbit|LEO]]
| {{Success}}
|-
| colspan="6" |
|-
! scope="row" rowspan = 2 style="text-align:center;|2(F)
| 29 February 1976<br>03:30<ref name="JSR" />
|[[Tanegashima Space Center|Tanegashima]]
| Ionosphere Sounding Satellite "UME"(ISS)
| 139kg<ref name=":1">{{Cite web |title=JAXA {{!}} Ionosphere Sounding Satellite "UME" (ISS) |url=https://global.jaxa.jp/projects/sat/iss/ |access-date=2024-02-18 |website=JAXA {{!}} Japan Aerospace Exploration Agency |language=en}}</ref>
| [[Low Earth orbit|LEO]]
| {{Success}}
|-
| colspan="6" |
|-
! scope="row" rowspan = 2 style="text-align:center;|3(F)
| 23 February 1977<br>08:50<ref name="JSR" />
|[[Tanegashima Space Center|Tanegashima]]
| Engineering Test Satellite II "KIKU-2"(ETS-II)
| 130kg<ref name=":2">{{Cite web |title=JAXA {{!}} Engineering Test Satellite II "KIKU-2" (ETS-II) |url=https://global.jaxa.jp/projects/sat/ets2/ |access-date=2024-02-18 |website=JAXA {{!}} Japan Aerospace Exploration Agency |language=en}}</ref>
| [[Geosynchronous transfer orbit|GTO]]
| {{Success}}
|-
| colspan="6" |3rd stage used
|-
! scope="row" rowspan = 2 style="text-align:center;|4(F)
| 16 February 1978<br>04:00<ref name="JSR" />
|[[Tanegashima Space Center|Tanegashima]]
| Ionosphere Sounding Satellite "UME-2"(ISS-b)
| 141kg<ref name=":1" />
| [[Low Earth orbit|LEO]]
| {{Success}}
|-
| colspan="6" |
|-
! scope="row" rowspan = 2 style="text-align:center;|5(F)
| 6 February 1979<br>08:46<ref name="JSR" />
|[[Tanegashima Space Center|Tanegashima]]
| Experimental Communications Satellites "Ayame"(ECS)
| 130kg<ref name=":3">{{Cite web |title=JAXA {{!}} Experimental Communications Satellites "Ayame" (ECS) |url=https://global.jaxa.jp/projects/sat/ecs/ |access-date=2024-02-18 |website=JAXA {{!}} Japan Aerospace Exploration Agency |language=en}}</ref>
| [[Geosynchronous transfer orbit|GTO]]
| {{Partial failure}}
|-
| colspan="6" |3rd stage used; Recontact between satellite and upper stage.
|-
! scope="row" rowspan = 2 style="text-align:center;|6(F)
| 22 February 1980<br>08:35<ref name="JSR" />
|[[Tanegashima Space Center|Tanegashima]]
| Experimental Communications Satellites "Ayame-2"(ECS-b)
| 130kg<ref name=":3" />
| [[Geosynchronous transfer orbit|GTO]]
| {{Success}}
|-
| colspan="6" |3rd stage used; Satellite failed shortly after separation.
|-
! scope="row" rowspan = 2 style="text-align:center;|9(F)
| 3 September 1982<br>05:00<ref name="JSR" />
|[[Tanegashima Space Center|Tanegashima]]
| Engineering Test Satellite III "KIKU-4"(ETS-III)
| 385kg<ref name=":4">{{Cite web |title=JAXA {{!}} Engineering Test Satellite III "KIKU-4" (ETS-III) |url=https://global.jaxa.jp/projects/sat/ets3/ |access-date=2024-02-18 |website=JAXA {{!}} Japan Aerospace Exploration Agency |language=en}}</ref>
| [[Low Earth orbit|LEO]]
| {{Success}}
|-
| colspan="6" |
|-
|}

== Payload Descriptions ==

=== Engineering Test Satellite I "KIKU-1" (ETS-1) ===
ETS-1 was the first satellite launched by the [[National Space Development Agency of Japan|NASDA]]. It had the objective of acquiring information on N-series launch vehicles, orbit injection, and tracking and control.<ref name=":0" /> It ceased operations on 28 April 1982. 

=== Ionosphere Sounding Satellite "UME" (ISS) ===
UME was Japan's first Ionosphere Sounding Satellite.<ref name=":1" /> It was used to monitor radio waves in the ionosphere and forecast conditions for shortwave communications. A power supply issue caused Ume to stop functioning one month after launch.<ref>{{Cite web |title=ISS a, b (Ume 1, 2) |url=https://space.skyrocket.de/doc_sdat/iss-a.htm |access-date=2024-02-18 |website=Gunter's Space Page |language=en}}</ref> 

=== Engineering Test Satellite II "KIKU-2" (ETS-2) ===
KIKU-2 was NASDA's first satellite launched to GEO.<ref name=":2" /> It was intended to gather data on geostationary satellite launch, tracking, control, orbit maintenance, and attitude control as well as carrying out experiments on communications equipment. KIKU-2 ceased operations on 10 December 1990, leaving GEO. 

=== Ionosphere Sounding Satellite "UME-2" (ISS-b) ===
UME-2 had similar goals to the original UME satellite, but was much more successful in carrying them out. While it was originally intended to gather data for only a year and a half, UME-2 ceased operations on 23 February 1983.

=== Experimental Communications Satellites "Ayame/Ayame-2" (ECS/ECS-b) ===
Both ECS satellites were unsuccessful in completing their mission. During the first ECS launch, the third stage rocket collided with the satellite shortly after separation. During the ECS-2 launch, the satellite stopped transmitting shortly after separation. The satellites had the intention of conducting millimeter wave experiments. The JAXA website states that "we learned some valuable lessons on satellite separation technology and apogee engine from this experience".<ref name=":3" />

=== About Engineering Test Satellite III "KIKU-4" (ETS-III) ===
KIKU-4 was developed to acquire data on designing earth observation satellites with high power requirements.<ref name=":4" /> KIKU-4 completed testing of three-axis attitude control, deployable solar panels, movable heat control, and ion engine operation. On 8 April 1985, the satellite ran out of fuel and ceased operation. 

==See also==
* [[Comparison of orbital launchers families]]
*[[Delta rocket]]
*[[H-I]]
*[[H-II]]
*[[H-IIA]]
*[[N-II (rocket)]]
*[[PGM-17 Thor]]

==References==
{{reflist|colwidth=30em}}

{{Mitsubishi Heavy Industries}}
{{Expendable launch systems}}
{{Japanese launch systems}}
{{Thor and Delta rockets}}

[[Category:Mitsubishi Heavy Industries space launch vehicles]]
[[Category:Thor (rocket family)]]
[[Category:Vehicles introduced in 1975]]
[[Category:Japan–United States relations]]