Ang mga sasakyan sa paglunsad ng Ariane European

Ariane, pamilya ng paglulunsad ng mga sasakyan na binuo bilang isang paraan ng nakasalalay na pag-access sa puwang para sa European Space Agency (ESA) at bilang isang launcher para sa mga komersyal na payload. Kabilang sa maraming mga satellite satellite na inilunsad ni Ariane ay si Giotto, ang probe sa Halley's Comet; Hipparcos, ang stellar na pagsukat ng distansya ng satellite; Rosetta, isang comet rendezvous mission; at Envisat, isang malaking satellite na nagmamasid sa Earth.

Matapos ang kabiguan ng mga pagsisikap sa panahon ng 1960 upang makabuo ng isang sasakyan sa paglunsad ng espasyo sa pamamagitan ng kooperasyon sa pagitan ng ilang mga bansang European, hinimok ng Pransya ang mga kasosyo sa Europa na bigyan ito ng pangunahing papel sa isang bagong programa upang lumikha ng tulad ng isang sasakyan, na pinangalanan pagkatapos ni Ariadne (Ariane sa Pranses), ang alamat ng prinsesa na Cretan na tumulong sa Theus na tumakas mula sa Labyrinth. Ang ahensya ng espasyo ng Pransya, Center National d'Études Spatiales (CNES), ay pinamamahalaan ang pag-unlad at pag-upgrade ng Ariane sa ilalim ng mga auspice ng ESA, kasama ang isang bilang ng mga bansang Europa na nag-aambag sa badyet ng programa at nagsasagawa ng isang bahagi ng pag-unlad at gawaing paggawa.

Ang unang paglulunsad ng sasakyan ng Ariane 1 ay naganap noong Disyembre 1979. Ang Ariane 1 ay 50 metro (164 talampakan) ang taas at nagkaroon ng thrust sa pag-angat ng 2,400 kilonewtons (550,000 pounds), na pinayagan itong maglunsad ng 1,850-kg (4,070- pounds) satellite sa geostationary orbit. Ang Ariane 1 ay likido na tinatapon; orihinal na ito ay gumamit ng isang halo ng unsymmetrical dimethylhydrazine (UMDH) at nitrogen tetroxide. Gayunpaman, pagkatapos ng isang launcher na sumabog noong Mayo 1980, ang pinaghalong gasolina ay binago sa mas matatag na halo ng UMDH at hydrazine.

Ang mga pinahusay na bersyon ng Ariane ay binuo noong 1980s; ang unang sasakyan ng Ariane 3 ay inilunsad noong Agosto 1984, ngunit ang unang Ariane 2 (na may parehong disenyo ng paglulunsad ng sasakyan bilang Ariane 3 ngunit nang wala ang dalawang solidong gasolina na strap-on na nagpapalaki) ay pinasimulan noong Mayo 1986. Ariane 3, higit pa malakas sa dalawang bagong modelo, ay may isang tulak na 4,000 kilonewtons (900,000 pounds), na maaaring magdala ng isang 2,700-kg (5,900-pounds) satellite sa geostationary orbit.

The first Ariane 4 vehicle was launched in June 1988. Ariane 4 was even more powerful than Ariane 3. With a thrust of 5,700 kilonewtons (1.3 million pounds), it could place a 4,800-kg (11,000-pound) satellite in geostationary orbit. The first two stages of Ariane 2–4 were fueled by a mixture of UMDH and hydrazine, with nitrogen peroxide as an oxidizer; the third stage used cryogenic fuel. The first four generations of Ariane shared the same basic design but achieved increased performance and flexibility through modifications of that design; by the end of its 15-year-long career, Ariane 4 had achieved over 97 percent reliability.

In 1985 the ESA decided to develop the more powerful Ariane 5 launcher with a totally new design based on a cryogenically fueled first stage, flanked by two large solid-fuel boosters, and having a second stage fueled by monomethylhydrazine with nitrogen peroxide as the oxidizer. A strong impetus for developing the more powerful Ariane 5 was the ESA’s ambition to launch a manned space glider named Hermes. However, the Hermes project was canceled in 1992. Since then, Ariane 5 has launched only unmanned satellites.

With a much more powerful upper stage than previous Ariane models, the Ariane 5 is capable of carrying a 10,500-kg (23,100-pound) satellite to geostationary orbit. The first test launch of the Ariane 5, in June 1996, was a spectacular failure, but in subsequent years the vehicle operated reliably. Since the Ariane 4 was retired from service in 2003, all ESA launches have used Ariane 5, and there has been a continuing effort to lower its costs and improve its reliability and performance, particularly its ability to launch two communications satellites to geostationary orbit. The Ariane 5 ECA version can launch two satellites with a combined weight of 9,600 kg (21,000 pounds) to that orbit. The Ariane 5 has achieved 89 percent reliability.

In January 1980 the ESA decided to entrust Arianespace—an organization owned by both public and private sector entities—with the management of Ariane production and launch for government use and also with the marketing of the vehicle to commercial customers. Arianespace succeeded in establishing the Ariane family as the single largest provider of commercial launch services in the world.

The Ariane launch site is in Kourou, Fr.Guia., just 5 degrees north of the Equator. This location allows launches to take full advantage of the velocity imparted by Earth’s rotation, meaning that the spacecraft’s onboard fuel can be conserved, thus extending orbital life. This is a particular advantage for revenue-producing commercial satellites, which can get an extra year or more of life from being launched near the Equator.