Editing Ariane 5 (section)

== Vehicle description ==
=== Cryogenic main stage ===
[[File:SNECMA Vulcain II.jpg|thumb|upright|left|[[Vulcain (rocket engine)|Vulcain engine]]]]

Ariane 5's [[Cryogenics|cryogenic]] H173 main stage (H158 for Ariane 5G, G+, and GS) was called the EPC (''Étage Principal Cryotechnique'' — Cryotechnic Main Stage). It consisted of a {{cvt|5.4|m}} diameter by {{cvt|30.5|m}} high tank with two compartments, one for [[liquid oxygen]] and one for [[liquid hydrogen]], and a [[Vulcain (rocket engine)|Vulcain 2]] engine at the base with a vacuum thrust of {{cvt|1390|kN}}. The H173 EPC weighed about {{cvt|189|t|lb}}, including {{cvt|175|t|lb}} of propellant.<ref name=a5dsslr>{{cite web|title=Ariane 5 Data Sheet|url=http://www.spacelaunchreport.com/ariane5.html|publisher=Space Launch Report|access-date=8 November 2014|archive-url=https://web.archive.org/web/20141108044627/http://www.spacelaunchreport.com/ariane5.html|archive-date=8 November 2014|url-status=usurped}}</ref> After the main cryogenic stage runs out of fuel, it re-entered the atmosphere for an ocean splashdown.

=== Solid boosters ===
Attached to the sides were two P241 (P238 for Ariane 5G and G+) [[solid rocket booster]]s (SRBs or EAPs from the French ''Étages d'Accélération à Poudre''), each weighing about {{cvt|277|t|lb}} full and delivering a thrust of about {{cvt|7080|kN}}. They were fueled by a mix of [[ammonium perchlorate]] (68%) and aluminium fuel (18%) and [[hydroxyl-terminated polybutadiene|HTPB]] (14%). They each burned for 130 seconds before being dropped into the ocean. The SRBs were usually allowed to sink to the bottom of the ocean, but, like the [[Space Shuttle Solid Rocket Booster]]s, they could be recovered with parachutes, and this was occasionally done for post-flight analysis. Unlike Space Shuttle SRBs, Ariane 5 boosters were not reused. The most recent attempt was for the first Ariane 5 ECA mission in 2009. One of the two boosters was successfully recovered and returned to the Guiana Space Center for analysis.<ref name="FranceScience">{{cite web|url=http://www.france-science.org/spip.php?article399#3-ARIANE-5-ECA-BOOSTER-RECOVERED|title=France in Space #387|publisher=Office of Science and Technology Embassy of France in the USA|url-status=dead|archive-url=https://web.archive.org/web/20090125213207/http://www.france-science.org/spip.php?article399#3-ARIANE-5-ECA-BOOSTER-RECOVERED|archive-date=25 January 2009}}</ref> Prior to that mission, the last such recovery and testing was done in 2003.{{Citation needed|date=January 2022}}

The French [[M51 (missile)|M51]] [[Submarine-launched ballistic missile|submarine-launched ballistic missile (SLBM)]] shared a substantial amount of technology with these boosters.<ref>{{cite news|title=French Navy SSBN 'Le Téméraire' Test Fired M51 SLBM In Operational Conditions|author=Xavier Vavasseur |date=12 Jun 2020|url=https://www.navalnews.com/naval-news/2020/06/french-navy-ssbn-le-temeraire-test-fired-m51-slbm-in-operational-conditions/|website=navalnews.com|access-date=March 27, 2023}}</ref>

In February 2000, the suspected [[nose cone]] of an Ariane 5 booster washed ashore on the [[South Texas]] coast, and was recovered by [[Beachcombing|beachcombers]] before the government could get to it.<ref>{{cite web |url=http://www.foxnews.com/etcetera/022900/space.sml |archive-url=https://web.archive.org/web/20010224100038/http://www.foxnews.com/etcetera/022900/space.sml |date=29 February 2000 |agency=Associated Press |publisher=Fox News |title=Government Loses Unidentified Floating Object |archive-date=24 February 2001 }}</ref>

=== Second stage ===
[[File:Ariane 5 EPS Upper Stage.jpg|thumb|upright|left|EPS Upper Stage used on Ariane 5ES]]

The second stage was on top of the main stage and below the payload. The original Ariane — Ariane 5G — used the EPS (''Étage à Propergols Stockables'' — Storable Propellant Stage), which was fueled by [[monomethylhydrazine]] (MMH) and [[nitrogen tetroxide]], containing {{cvt|10000|kg}} of [[storable propellant]]. The EPS was subsequently improved for use on the Ariane 5G+, GS, and ES.

The EPS upper stage was capable of repeated ignition, first demonstrated during flight V26 which was launched on 5 October 2007. This was purely to test the engine, and occurred after the payloads had been deployed. The first operational use of restart capability as part of a mission came on 9 March 2008, when two burns were made to deploy the first [[Automated Transfer Vehicle]] (ATV) into a circular parking orbit, followed by a third burn after ATV deployment to de-orbit the stage. This procedure was repeated for all subsequent ATV flights.

Ariane 5ECA used the ESC (''Étage Supérieur Cryotechnique'' — Cryogenic Upper Stage), which was fueled by liquid hydrogen and liquid oxygen. The ESC used the [[HM7B]] engine previously used in the Ariane 4 third stage. The propellent load of 14.7 tonne allowed the engine to burn for 945 seconds while providing 6.5 tonne of thrust. The ESC provided roll control during powered flight and full attitude control during payload separation using hydrogen gas thrusters. Oxygen gas thrusters allowed longitudinal acceleration after engine cutoff. The flight assembly included the Vehicle Equipment Bay, with flight electronics for the entire rocket, and the payload interface and structural support.<ref>European Space Agency, "Ariane 5ECA": http://www.esa.int/Enabling_Support/Space_Transportation/Launch_vehicles/Ariane_5_ECA2 Discussed in context of other launch vehicles in Gérard Maral, Michel Bousquet, and Zhili Sun, ''Satellite Communications Systems: Systems, Techniques and Technology'', sixth edition, London: Wiley, 2020 {{ISBN|9781119382072}}</ref><ref>[https://www.arianespace.com/?popup=ariane-5-4 ESC-A – Cryogenic upper stage], accessed December 27, 2021</ref>

=== Fairing ===
The payload and all upper stages were covered at launch by a fairing for aerodynamic stability and protection from heating during supersonic flight and acoustic loads. It was jettisoned once sufficient altitude has been reached, typically above {{cvt|100|km}}. It was made by [[RUAG Space|Ruag Space]] and since flight VA-238 it was composed of 4 panels.<ref>{{cite web|author1=ESA|title=Ariane 5 launch proves reliability and flies new fairing|url=https://www.esa.int/Enabling_Support/Space_Transportation/Ariane_5_launch_proves_reliability_and_flies_new_fairing|access-date=27 February 2020}}</ref>{{clarify|that's fine for explaining what fairings do, generally. But who makes the Ariane fairing? At what cost? What are any of it's design specifications or design characteristics?|date=September 2019}}