Ariane 3

Ariane 3 was a European expendable carrier rocket, which was used for eleven launches between 1984 and 1989. It was a member of the Ariane family of rockets. The principal manufacturer for the Ariane 3 was Aérospatiale, while the lead agency for its development was the Centre National d'Etudes Spatiales (CNES).

Development of the Ariane 3 was authorised in July 1979, months prior to the Ariane 1's first flight. Drawing heavily upon both the design and infrastructure of the Ariane 1, the new launcher was concurrently developed alongside the Ariane 2, with which it shared much of its design. It represented an advancement of the Ariane 1 rather than a replacement, but was capable of lifting even heavier payloads into Geostationary transfer orbit (GTO) as well as launching two satellites via one launch. Developed largely within a two year window, the Ariane 3 performed its maiden flight on 4 August 1984, actually flying in advance of its Ariane 2 sibling. During its brief service life, having performed its final launch on 12 July 1989, the Ariane family had become increasingly commercially competitive, becoming the market leading heavy launch vehicle in the world by the late 1980s.

Development

In 1973, eleven nations decided to pursue joint collaboration in the field of space exploration and formed a new pan-national organisation to undertake this mission, the European Space Agency (ESA).Harvey 2003, pp. 161-162. Six years later, in December 1979, the arrival of a capable European expendable launch system was marked when the first Ariane 1 rocket launcher was successfully launched from the Guiana Space Centre at Kourou, French Guiana.Harvey 2003, p. 169. The Ariane 1 soon became considered to be a capable and competitive launcher in comparison to the rival platforms offered by the Soviet Union and the United States of America. However, even prior to the launcher having entering service, there was a strong desire to quickly produce improved derivatives that would be able to handle even greater payloads than Ariane 1 could. These desires would result in the creation of both the Ariane 2 and Ariane 3.Harvey 2003, pp. 172-174.

While the initiative was first proposed in 1978, prior to the Ariane 1's first flight, approval to commence the first phase of development was not received until July 1979.Harvey 2003, p. 174. The bulk of development work on the new launcher occurred between 1980 and 1982. The Ariane 3 was designed to satisfy the future demand for the delivery of two tonne payloads into a Geosynchronous transfer orbit (GTO). According to aerospace historian Brian Harvey, in spite of the numbering sequence adopted, the Ariane 3 was the direct successor to the Ariane 1, rather than the Ariane 2,as could be logically assumed.Harvey 2003, p. 174. The principal agency behind the development of the Ariane 3 was the Centre National d'Etudes Spatiales (CNES), while the lead company for its production was the French aerospace manufacturer Aérospatiale.Harvey 2003, p. 214.

In order to keep costs down, CNES directed that only tested technologies could be implemented in the launcher's improvements; in fact, no budget was provided for new test series to be performed. Furthermore, it was restricted to using the existing launch pad and handling facilities established for the Ariane 1, and that there was to be no allowance for retooling of the Ariane production line. However, one new piece of infrastructure that was permitted was the establishment of tracking equipment in the Ivory Coast; the existing infrastructure based in Brazil used by the Ariane 1 was less suitable due to the increased performance of the Ariane 3, which flew a different ascent profile that reached 250km, rather than 200km before coasting into orbit.Harvey 2003, p. 215. Performance boosts were achieved via several different ways, such as the elongated third stage fuel tanks to carry 30 percent more fuel, elevated combustion pressure in multiple stages, a new intertank structure that supported the addition of solid-fuel boosters, and the adoption of a new fuel mixture.Harvey 2003, pp. 214-215.

The finalised Ariane 3 followed the same basic design as the earlier Ariane 1, but incorporated numerous modifications that had been made for the Ariane 2. Unlike the Ariane 2, two solid-fuelled PAP strap-on booster rockets were used to augment the first stage at liftoff.Harvey 2003, pp. 216-217. The core of the Ariane 3 was essentially identical to that of the Ariane 2. The first stage was powered by four Viking 2B bipropellant engines, burning UH 25 (25% straight hydrazine, 75% UDMH) in a dinitrogen tetroxide oxidiser. The second stage was powered by a Viking 4B, which used the same fuel-oxidiser combination. The third stage used a cryogenically fuelled HM7B engine, burning liquid hydrogen in liquid oxygen. On some flights, a Mage 2 kick motor was flown as a fourth stage. One atypical modification for the era was the revised satellite deployment system, which could facilitate the launch of two smaller satellites as well as one larger one.

The Ariane 3's design heavily influenced that of its successor, the Ariane 4; while the design team considered various approaches for achieving such a launcher, one of the studied concepts had involved the addition of a fifth engine to an enlarged first stage of the Ariane 3.Harvey 2003, p. 179. However, this was determined to have involved a very high level of redesign work; an alternative approach was