![[The Ariane Family]](graphics/ariane.gif)
Probably the most successful and reliable space launch vehicle in the world.
Many people believe there have only been five of these rockets, the fifth exploding due to a fault in the navigation computer. This is entirely untrue. The number refers not to the craft but to its design. So the first version was Ariane 1, which was used for many years. It was then redesigned to produce Ariane 2 and so on.
The rocket which exploded was the first of a new design, Ariane 5. The problem was that when converting the navigation software from Ariane 4 to Ariane 5 it was not updated to take into account that the new rocket was bigger and heavier.
Since that unfortunate incident there have been a number of succesul launches of the Ariane 5 design.
The first pan-european space launch vehicle was named Europa
. Its first
stage was a British Blue Streak
nuclear warhead delivery ballistic
missile. The second stage was French and the third German. This project was
plagued with difficulties due to unreliability in this third stage. In the
end the project was scrapped without a single successful launch to its name
when the British pulled out.
Europa was replaced by Ariane 1
which in turn was based on a replacement
design for Europa. The maiden flight of this new rocket was the 24th of
December 1979. Ariane 2 was the same as its forbear but had a stretched
third stage. Ariane 3 added solid rocket booster motors to the design and
first took to the air in 1984.
Ariane 4 had a stretched first stage as well. A choice of solid and liquid propellant boosters where used with this version since a fully fuelled Ariane 4 rocket is unable to lift off without the aid of such boosters. It has been in service since 1988.
Obviously the original design had been taken just about as far as it would go so it was felt to be time for a re-design. To this end Ariane 5 has been designed and built. This is the current European heavy lift launch vehicle taking overfrom Ariane 4 in 1996.
One of the reasons for Ariane's cheapness (relatively speaking) and reliability is the fact that it is not a manned space craft. This means it does not require heavy and expensive life support equipment. It also means that the odd explosion is a pain in the neck, not to mention the wallet, but never fatal.
Although the Ariane rockets are attributed to ESA (European Space Agency) the rockets themselves are almost entirely a French endevour.
Ariane 5 is technically a two stage rocket. It has two solid fuel strap on boosters which count as stage 0. These provide 93% of thrust on lift off. They are jettisoned after a burn time of 123 seconds.
Stage 1 uses liquid oxygen and liquid hydrogen as fuel to the Vulcain
engine. This is jettisoned after 431 seconds of burn.
Finally, stage 2 consists of another liquid fuel engine, the L7
. This
burns nitrogen peroxide and monomethylhydrazine. Not the sort of thing you'd
want to put in your tea but ideal if you want something to ignite in a
vacuum. All this tom-foolery with stages allows Ariane 5 to deliver a
payload of up to 18 tonnes to low earth orbit or 6.8 tonnes to a
geosynchronous transfer trajectory.
At the date of writing there have been three launches of the Ariane 5 design. One went spectacularly wrong to great media coverage. The other two have performed excellently with no serious mishaps or media coverage.
Arianes 1-4 have been possibly the most commercially successful launch vehicles in the world. While super sexy space craft such as the Shuttle have stolen all the lime light Airane has been soldiering away doing the bread and butter launch work. Many of the worlds communications satellites, weather satellites and scientific satellites have been placed in orbit by an Ariane rocket. Quite a record for Ariane 5 to live up to.
Ariane 5 is not just cool by itself however. One of the reasons why it was decided to go ahead with this project back in 1987 was that a heavy lift vehicle such as this would be required if the Hermes spaceplane was ever to be successfully launched. Of course Hermes doesn't exist at the moment but now there is a launch vehicle capable of carrying it into space we might just see it some time.
There are no great downers on the technical side of the Ariane rocket. The main problem is again one of public perception. No one really knows what a good job it is doing. Then again I suspect this is mostly because people aren't really interested in unmanned flights. The US Titan rockets suffer much the same fate. These are also unmanned satellite launch platforms which are regularly launched putting many satellites in orbit but they very rarely get even a mention on the news.
Ariane rockets are launched from a site in French Giana.
Well ESA of course.