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Ariane 5

Ariane 5 is a European expendable launch system designed to deliver payloads into geostationary transfer orbit or low Earth orbit.

It is manufactured under the authority of the European Space Agency (ESA) and the Centre National d'Etudes Spatiales (CNES), with EADS Astrium Space Transportation (Astrium) as prime contractor, leading a consortium of sub-contractors. The rocket is operated and marketed by Arianespace as part of the Ariane programme. Astrium builds the rockets in Europe and Arianespace launches them from the Guiana Space Centre.

It succeeded Ariane 4, but does not derive from it directly. Its development took 10 years and cost €7 billion. Ariane 5 has been refined since the first launch in successive versions, G, G+, GS, ECA, and most recently, ES. ESA originally designed Ariane 5 to launch the manned mini shuttle Hermes, and thus intended it to be "human rated" from the beginning. After ESA cancelled Hermes, the rocket became a purely robotic launcher.

Two satellites can be mounted using a SYLDA carrier (SYstème de Lancement Double Ariane). Three main satellites are possible depending on size using SPELTRA (Structure Porteuse Externe Lancement TRiple Ariane). Up to eight secondary payloads, usually small experiment packages or minisatellites, can be carried with an ASAP (Ariane Structure for Auxiliary Payloads) platform.

By mid 2007, Arianespace has ordered a total of 99 Ariane 5 launchers from Astrium. The first batch ordered in 1995 consisted of 14 launchers, while the second - P2 - batch ordered in 1999 consisted of 20 launchers . A third - PA - batch consisting of 25 ECA and 5 ES launchers was ordered in 2004. The latest batch ordered in mid 2007 consist of another 35 ECA launchers. Through these orders, the Ariane 5 will be the workhorse of Arianespace at least through 2015.

Components

Ariane 5’s cryogenic H158 main stage (H173 for Ariane 5 ECA) is called the EPC (Étage Principal Cryotechnique - Cryotechnic Main Stage). It consists of a large tank 30.5 metres high with two compartments, one for 130 tonnes of liquid oxygen and one for 25 tonnes of liquid hydrogen, and a Vulcain engine at the base with thrust of 115 tonnes-force (1.13 meganewtons). This part of the first stage weighs about 15 tonnes when empty.

Attached to the sides are two solid propellant EAP, P238 (P241 for Ariane 5 ECA), each weighing about 277 tonnes full. Each delivers a thrust of about 630 tonnes-force (). These EAP can be recovered with parachutes, like the Space Shuttle Solid Rocket Boosters. They may have been retrieved for examination on early missions, but are not reused.

The second stage is on top of the main stage and below the payload. The Ariane 5G used the EPS (Étage à Propergols Stockables - Storable Propellant Stage), which is fueled by monomethylhydrazine (MMH) and nitrogen tetroxide, whereas the Ariane 5 ECA uses the ESC (Étage Supérieur Cryotechnique - Cryogenic Upper Stage), which is fueled by liquid hydrogen and liquid oxygen.

The payload and all upper stages are covered at launch by a fairing, which splits off once sufficient altitude has been reached. Ariane 5G+ used and Ariane 5 GS and ES use an improved EPS upper stage. The EPS upper stage is capable of re-ignition, which has been demonstrated twice. The first demonstration occurred 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 into a circular parking orbit. Following spacecraft separation, a third burn took place to de-orbit the upper stage.

Variants

  • The original version is dubbed Ariane 5G (Generic) with a launch mass of 737 tonnes. Its payload capability to Geostationary transfer orbit (GTO) was initially specified as , but was increased after the qualification flights to .
  • The Ariane 5G+ had an improved second stage, with a GTO capacity of for a single payload. It flew three times in 2004.
  • It was replaced in 2005 by the Ariane 5GS, with the same solid EAP as the Ariane 5 ECA and a modified first Stage with a Vulcain 1B engine. It can carry a single payload of to GTO.
  • The Ariane 5 ECA (Evolution Cryotechnique type A) has a GTO launch capacity of for dual payloads or for a single payload. This variant uses a new Vulcain 2 first-stage engine, and an ESC-A (Etage Supérieur Cryogénique-A) second stage, powered by an HM-7B engine, weighing and carrying of cryogenic propellant. The second stage was previously used as the third stage of Ariane 4; in ECA use, the tanks are modified to shorten stage length. The revised Vulcain has a longer, more efficient nozzle with more efficient flow cycle and denser propellant ratio. The new ratio demanded length modifications to the first-stage tanks. Also, the solid EAP casings have been lightened with new welds, and packed with more propellant. The ESC-A cryogenic second stage does not improve the performance to Low Earth orbit compared to Ariane 5G, and for this reason the Ariane 5 ECA will not be used to launch the Automated Transfer Vehicle (ATV).
  • The Ariane 5 ES-ATV (Evolution Storable-) is used to launch the Automated Transfer Vehicle. It includes all the performance improvements of Ariane 5 ECA on EPC (Etage Principal Cryogénique - main stage) and EAP (Etage d'Accélération à Poudre - solid rocket booster) stages while the second stage is the EPS (Etage à Propergols Stockable) used on Ariane 5GS variants. It is estimated that the Ariane 5 ES-ATV can put up to in LEO. The first such launch occurred at 04:03 GMT on 9 March 2008.

Comparable rockets: Delta IV - Atlas V - Chang Zheng 5 - GSLV Mk.III - Angara - Proton - Falcon 9 - H-IIB

Future developments

Ariane 5 ECB development hold

Ariane 5 ECB was planned to have an ESC-B upper stage using a new Vinci expander cycle type engine. The GTO capacity was to increase to , but ECB was put on hold due to budget cuts.

At an ESA conference (December 2005) in Berlin there was no decision to restart or cancel the program, meaning it is currently on hold. The Vinci engine, which is designed to power the Ariane 5 ECB upper stage, is still being developed, though at a lower pace. Consequently, a restart of the ESC-B program is not impossible at the ESA conference in 2008, but seems very unlikely.

Etage d'accélération à poudre

Work on the Ariane 5 EAP motors have been continued in the Vega programme. The Vega 1st stage engine - the P80 engine - is a shorter derivation of the EAP. The P80 booster casing is made of filament wound graphite epoxy, much lighter than the current stainless steel casing. A new composite steerable nozzle has been developed while new thermal insulation material and a narrower throat improve the expansion ratio and subsequently the overall performance. Additionally, the nozzle now has electromechanical actuators which have replaced the heavier hydraulic ones used for thrust vector control.

These developments will probably later make their way back into the Ariane programme. The incorporation of the ESC-B with the improvements to the solid motor casing and an uprated Vulcain engine would deliver 27,000kg to LEO. This would be developed for any lunar missions but the performance of such a design may not be possible if the higher Max-Q for the launch of this rocket poses a constraint on the mass delivered to orbit.

Launch history

Ariane 5's first test flight (Ariane 5 Flight 501) on 4 June 1996 failed, with the rocket self-destructing 37 seconds after launch because of a malfunction in the control software, which was arguably one of the most expensive computer bugs in history. A data conversion from 64-bit floating point to 16-bit signed integer value had caused a processor trap (operand error). The floating point number had a value too large to be represented by a 16-bit signed integer. Efficiency considerations had led to the disabling of the software handler (in Ada code) for this trap, although other conversions of comparable variables in the code remained protected.

The second test flight, L502 on 30 October 1997 was a partial failure. The Vulcain nozzle caused a roll problem, leading to premature shutdown of the core stage. The upper stage operated successfully but could not reach the intended orbit.

A subsequent test flight on 21 October 1998 proved successful and the first commercial launch occurred on 10 December 1999 with the launch of the XMM-Newton X-ray observatory satellite.

Another partial failure occurred on 12 July 2001, with the delivery of two satellites into an incorrect orbit, at only half the height of the intended GTO. The ESA Artemis telecommunications satellite was able to reach its intended orbit on 31 January 2003, through the use of its experimental ion propulsion system.

The next launch did not occur until 1 March 2002, when the Envisat environmental satellite successfully reached an orbit above the Earth in the 11th launch. At , it was the heaviest single payload until the launch of the first ATV on March 9, 2008 (~9000kg).

The first launch of the ECA variant on 11 December 2002 ended in failure when a main booster problem caused the rocket to veer off-course, forcing its self-destruction three minutes into the flight. Its payload of two communications satellites (Stentor and Hot Bird 7), valued at about EUR 630 million, was lost in the ocean. The fault was determined to have been caused by a leak in coolant pipes allowing the nozzle to overheat. After this failure, Arianespace SA delayed the expected January 2003 launch for the Rosetta mission to 26 February 2004, but this was again delayed to early March 2004 due to a minor fault in the foam that protects the cryogenic tanks on the Ariane 5.

On 27 September 2003 the last Ariane 5 G boosted three satellites (including the first European lunar probe, SMART-1), in Flight 162. On 18 July 2004 an Ariane 5 G+ boosted what was at the time the heaviest telecommunication satellite ever, Anik F2, weighing almost .

The first successful launch of the Ariane 5 ECA took place on 12 February 2005. The payload consisted of the XTAR-EUR military communications satellite, a 'SLOSHSAT' small scientific satellite and a MaqSat B2 payload simulator. The launch had been originally scheduled for October 2004, but additional testing and the military requiring a launch at that time (of an Helios 2A observation satellite) delayed the attempt.

On 11 August 2005, the first Ariane 5GS (featuring the Ariane 5 ECA's improved solid motors) boosted Thaïcom-4/iPStar-1, the heaviest telecommunications satellite to date at , into orbit.

On 16 November 2005, the third Ariane 5 ECA launch (the second successful ECA launch) took place. It carried a dual payload consisting of Spaceway-F2 for DirecTV and Telkom-2 for PT Telekomunikasi of Indonesia. This was the rocket's heaviest dual payload to date, at more than .

On 11 March 2006, the fourth Ariane 5 ECA launch boosted another dual payload to orbit. This payload consisted of Hot Bird 7A for Eutelsat (a replacement for the Hot Bird 7 satellite lost in the first Ariane 5 ECA launch), and SPAINSAT, a Spanish government telecommunications satellite for HISDESAT.

On 27 May 2006, an Ariane 5 ECA rocket set a new commercial payload lifting record of 8.2 tonnes. The dual-payload consisted of the Thaicom 5 and Satmex 6 satellites.

On 4 May 2007 the Ariane 5 ECA set another new commercial record, lifting into transfer orbit the Astra 1L and Galaxy 17 communication satellites with a combined weight of 8.6 tonnes, and a total payload weight of 9.4 tonnes. This record was again broken by another Ariane 5 ECA, launching the Skynet 5B and Star One C1 satellites, on 11 November 2007. The total payload weight for this launch was .

On 9 March 2008, the first Ariane 5 ES-ATV was launched to deliver the first ATV called Jules Verne to the International Space Station.

On 18 April 2008, an Ariane 5ECA launched Star One C-2, and Vinasat-1, Vietnam's first satellite.

Ariane 5 flights

Date
& Time (UTC)
Flight (Vol) 5G, 5G+,
5GS
ECA ES Serial number Payload Result #
04.06.1996 12:34:06 V-89 5G 501 Cluster Failure 1
30.10.1997 13:43:00 V-101 5G 502 MaqSat H & TEAMSAT, MaqSat B, YES Partial failure 2
21.10.1998 16:37:21 V-112 5G 503 MaqSat 3, ARD Success 3
10.12.1999 14:32:07 V-119 5G 504 XMM-Newton Success 4
21.03.2000 23:28:19 V-128 5G 505 INSAT 3B, AsiaStar Success 5
14.09.2000 22:54:07 V-130 5G 506 Astra 2B, GE 7 Success 6
16.11.2000 01:07:07 V-135 5G 507 PAS 1R, Amsat P3D, STRV 1C, STRV 1D Success 7
20.12.2000 00:26:00 V-138 5G 508 Astra 2D, GE 8 (Aurora 3), LDREX Success 8
08.03.2001 22:51:00 V-140 5G 509 Eurobird 1, BSat 2a Success 9
12.07.2001 22:58:00 V-142 5G 510 Artemis, BSat 2b Partial failure 10
01.03.2002 01:07:59 V-145 5G 511 Envisat Success 11
05.07.2002 23:22:00 V-153 5G 512 Stellat 5, N-Star c Success 12
28.08.2002 22:45:00 V-155 5G 513 Atlantic Bird 1, MSG 1, MFD Success 13
11.12.2002 22:22:00 V-157 5ECA 517 Hot Bird 7, Stentor, MFD A, MFD B Failure 14
09.04.2003 22:52:19 V-160 5G 514 Insat 3A, Galaxy 12 Success 15
11.06.2003 22:38:15 V-161 5G 515 Optus C1, BSat 2c Success

16
27.09.2003 23:14:46 V-162 5G 516 Insat 3E, eBird 1, SMART-1 Success 17
02.03.2004 07:17:44 V-158 5G+ 518 Rosetta Success 18
18.07.2004 00:44:00 V-163 5G+ 519 Anik F2 Success 19
18.12.2004 16:26:00 V-165 5G+ 520 Helios 2A, Essaim 1, 2, 3 and 4, PARASOL, Nanosat 01 Success 20
12.02.2005 21:03:00 V-164 5ECA 521 XTAR-EUR, Maqsat B2, Sloshsat Success 21
11.08.2005 08:20:00 V-166 5GS 523 Thaicom 4 - iPStar Success 22
13.10.2005 22:32:00 V-168 5GS 524 Syracuse 3A, Galaxy 15 Success 23
16.11.2005 23:46:00 V-167 5ECA 522 Spaceway F2, TELKOM-2 Success 24
21.12.2005 22:33:00 V-169 5GS 525 Insat 4A, MSG 2, MFD C Success 25
11.03.2006 22:32:50 V-170 5ECA 527 Spainsat, MFD C, MFD C, Hot Bird 7A Success 26
26.05.2006 21:08:50 V-171 5ECA 529 Satmex 6, Thaicom 5 Success 27
11.08.2006 22:15:00 V-172 5ECA 531 JCSat 10, Syracuse 3B Success 28
13.10.2006 20:56:00 V-173 5ECA 533 DirecTV-9S, Optus D1, LDREX-2 Success 29
08.12.2006 22:08:00 V-174 5ECA 534 WildBlue 1, AMC 18 Success 30
11.03.2007 22:03 V-175 5ECA 535 Skynet-5A, Insat-4B Success 31
04.05.2007 22:29 V-176 5ECA 536 Astra 1L, Galaxy 17 Success 32
14.08.2007 23:44 V-177 5ECA 537 Spaceway F3, BSAT-3A Success 33
05.10.2007 22:02 V-178 5GS 526 Intelsat 11, Optus D2 Success 34
14.11.2007 22:06 V-179 5ECA 538 Skynet 5B, Star One C1 Success 35
21.12.2007 21:41 V-180 5GS 530 RASCOM-QAF 1, Horizons 2 Success 36
09.03.2008 04:03 V-181 ES ATV 528 Automated Transfer Vehicle 1 - "Jules-Verne" Success 37
18.04.2008 22:17 V-182 5ECA 539 Star One C2, Vinasat-1 Success 38
12.06.2008 22:05 V-183 5ECA 540 Turksat 3A, Skynet-5C Success 39
07.07.2008 21:47 V-184 5ECA 541 BADR-6, ProtoStar I Success 40
14.08.2008 20:44 V-185 5ECA 542 AMC-21, Superbird 7 Success 41

Upcoming flights

Date Flight Model Serial number Payload Result
2008-11-28 V-186 Ariane-5ECA 543 Eutelsat W2M / Hot Bird 9 Planned
2009-02 V-187 Ariane-5ECA 544 Herschel / Planck Planned

There is one Ariane 5 GS unit left (532) to be launched

See also

References

External links

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