Ariane 4
Encyclopedia
Ariane 4 was an expendable launch system
Expendable launch system
An expendable launch system is a launch system that uses an expendable launch vehicle to carry a payload into space. The vehicles used in expendable launch systems are designed to be used only once , and their components are not recovered for re-use after launch...

, designed by the Centre National d'Etudes Spatiales and manufactured and marketed by its subsidiary Arianespace
Arianespace
Arianespace SA is a French company founded in 1980 as the world's first commercial space transportation company. It undertakes the production, operation, and marketing of the Ariane 5 rocket launcher as part of the Ariane programme....

. Ariane 4 was justly known as the ‘workhorse’ of the Ariane family. Since its first flight on 15 June 1988 until the last, on 15 February 2003, it made 113 successful launches. It was known to be an extremely versatile launcher.

The Ariane 4 proved ideal for launching communications and Earth observation satellite
Earth observation satellite
Earth observation satellites are satellites specifically designed to observe Earth from orbit, similar to reconnaissance satellites but intended for non-military uses such as environmental monitoring, meteorology, map making etc....

s as well as those for scientific research. During its working life, Ariane 4 captured 50% of the market in launching commercial satellites, demonstrating Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

's ability to compete in the commercial launch sector.

History

In 1973 eleven countries, called together by the European Space Agency
European Space Agency
The European Space Agency , established in 1975, is an intergovernmental organisation dedicated to the exploration of space, currently with 18 member states...

 (ESA), decided to take Europe down its own path in the space field: and so the Ariane programme was born. Six years later in 1979, Ariane 1 was launched from Kourou
Kourou
Kourou is a commune in French Guiana, an overseas region and department of France located in South America.Kourou is the location of the Guiana Space Centre, France and ESA's main spaceport.-Geography:...

. Following development work on variants 1, 2 and 3, Ariane 4 was able to draw on the experience gained from these earlier variants.

The development program began in 1983 and the first successful launch was on 15 June 1988. The system became the basis for a European satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....

 launches with a record of 113 successful and three launch failures. Ariane 4 provided a payload increase from 1700 kg for Ariane 3 to a maximum of 4800 kg to geostationary transfer orbit
Geostationary transfer orbit
A geosynchronous transfer orbit or geostationary transfer orbit is a Hohmann transfer orbit used to reach geosynchronous or geostationary orbit....

 (GTO). The record for Ariane 4 to GTO was 4946 kg.

The Ariane 4 Launch Team was awarded the Space Achievement Award by the Space Foundation
Space Foundation
The Space Foundation is a nonprofit organization that supports the global space industry through information and education programs. It is a resource for the entire space community - industry, national security organizations, civil space agencies, private space companies and the military around the...

 in 2004.

Vehicle Description

The Ariane 4 was the ultimate development from the Ariane 1,2,3. Compared with the Ariane 2/3, the Ariane 4 featured stretched first (61%) and third stages, a strengthened structure, new propulsion bay layouts, new avionics, and the SPELDA (Structure Porteuse Externe de Lancement Double Ariane) dual-payload carrier. The basic 40 version used no strap-on motors, while the Ariane 42L, 44L, 42P, 44P, and 44LP versions used various combinations of solid and liquid propellant strap-on motors. Development was authorised in January 1982, with the objective of increasing payload by 90%. Total development cost 476 million 1986 ECU's.

Originally designed to place 2-4.2 tonne payloads in geostationary orbit, the six Ariane 4 variants, aided by strap-on boosters, enabled the launch of payloads in excess of 4.9 tonnes on several occasions.

Variants

The rocket was used in a number of variants - it could be fitted with two or four additional solid
Solid rocket booster
Solid rocket boosters or Solid Rocket Motors, SRM, are used to provide thrust in spacecraft launches from the launchpad up to burnout of the SRBs. Many launch vehicles include SRBs, including the Ariane 5, Atlas V , and the NASA Space Shuttle...

 (PAP - Propulseurs d'Appoint à Poudre) or liquid
Liquid Rocket Booster
A Liquid Rocket Booster is similar to a solid rocket booster attached to the side of a rocket to give it extra lift at takeoff. A Liquid Rocket Booster has fuel and oxidiser in liquid form, as opposed to a solid rocket or hybrid rocket....

 fueled booster rockets (PAL - Propulseurs d'Appoint à Liquide). The launcher included a satellite payload carrier system called Spelda (Structure Porteuse Externe de Lancement Double Ariane, French for 'External carrying structure for Ariane double launches') for launching more than one satellite at a time. The rocket captured nearly 60% of the world’s commercial launch services market, serving both European and international clients.

Ariane 4 AR 40 was the basic version, with three stages: 58.4 m high, a diameter of 3.8 m, a liftoff mass of 245 t and a maximum payload of 2100 kg to GTO or 5000 kg to Low Earth orbit
Low Earth orbit
A low Earth orbit is generally defined as an orbit within the locus extending from the Earth’s surface up to an altitude of 2,000 km...

 (LEO). Main power was from four Viking 2B motors
Viking (rocket engine)
The Viking rocket engines were members of a series of bipropellant engines for the first and second stages of the Ariane 1 through Ariane 4 commercial launch vehicles, using storable, hypergolic propellants, N2O4/UH 25...

 each producing 667 kN of thrust. The second stage had a single Viking 4B motor, and the third stage had an HM7-B liquid oxygen/liquid hydrogen motor. AR 44L, with the maximum additional boost of four liquid fuel rocket strap-ons, was four-stage, weighed 470 t and could transfer a payload of 4730 kg to GTO or 7600 kg to LEO.
Model PAL PAP Payload to GTO, kg Launches Successes Failure date
AR 40
-
-
2100
7
7
-
AR 42P
-
2
2930
15
14
1 December 1994
AR 42L
2
-
3480
13
13
-
AR 44L
4
-
4720
40
39
22 February 1990
AR 44LP
2
2
4220
26
25
24 January 1994
AR 44P
-
4
3460
15
15
-

Launches

The inaugural flight of Ariane 4 took place in 1988. Since then has accomplished 116 flights with a success rate of more than 97%. The final launch of Ariane 4 rocket occurred on 15 February 2003, placing Intelsat
Intelsat
Intelsat, Ltd. is a communications satellite services provider.Originally formed as International Telecommunications Satellite Organization , it was—from 1964 to 2001—an intergovernmental consortium owning and managing a constellation of communications satellites providing international broadcast...

 907 into geosynchronous orbit
Geosynchronous orbit
A geosynchronous orbit is an orbit around the Earth with an orbital period that matches the Earth's sidereal rotation period...

.

Retirement

Ariane 4 was phased out in favour of Ariane 5
Ariane 5
Ariane 5 is, as a part of Ariane rocket family, an expendable launch system used to deliver payloads into geostationary transfer orbit or low Earth orbit . Ariane 5 rockets are manufactured under the authority of the European Space Agency and the Centre National d'Etudes Spatiales...

 and, eight years later, the Soyuz ST. Spacecraft launched by the Soyuz reuse the payload platform and dispenser originally designed for the Ariane.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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