Date: April 10, 2011

Title: Ariane Rockets

Podcaster: Lycée Henri Moissan

Organization: The Henri Moissan High School in France – http://www.lycee-moissan.ac-creteil.fr/

Description: In today’s podcast, we are going to speak about Ariane rockets and especially Ariane 5, one of the world’s leading heavy-lift launchers. After a brief history of the project and mission, we‘ll get an overview of its characteristics and greatest successes. However, we’ll also have to talk about the satellites that never made it into orbit. To finish with, we’ll take a look at what Arianespace as in store for the future.

Bio: As part of an English school project, we decided to record a podcast for the 365 daysofastronomy. We are French students in 11th grade aged from 15 to 17 in a high school located in Meaux, next to Paris. Our specialty is science and that’s why we chose a scientific topic. However, this is the first time we work on an astronomic subject in details. Thanks to our English teacher, we discovered the 365 daysofastronomy podcast and we thought it would be nice to contribute,hoping to inspire other students. We hope you’ll enjoy our podcast.

Today’s sponsor: This episode of “365 Days of Astronomy” is sponsored by John Sandlin. The Sandlin Family wishes you all Clear Skies.

Transcript:

Welcome to the 365 days of astronomy podcast. We are eleventh graders from France and we decided to present you a great and influential European project named Ariane.

Ariane rockets are a family of civil European satellite launchers whose project was born in 1973 and developed by the European Space Agency, ESA after the failure of the Europa’s project in 1971. Its main goal was to give Europe access to its own heavy-lift vehicle. The first launch was realized on December, 24th 1979 from Kourou, French Guyana. This site was chosen because of its location near the equator where the Earth rotates the fastest and thus saving fuel to reach the Earth orbit. Arianes launchers received many improvements throughout its 5 generations. This pharaonic project has cost about 2,000 billion Euros shared between many European countries such as Germany, Sweden and Switzerland. France is still the biggest contributor to this program with its National Center for Space Research.

Now, let’s have a look at the Arianes’ rockets technical characteristics, especially the difference between the first and latest versions, Ariane1 and Ariane5. Firstly, Ariane 1 was 48 meters high, weighted 210 tons and was composed of 3 stages: the first stage had 4 Viking engines; the second and third stage had one engine each. It needed 186 tons of fuel to lift 1ton of payload into orbit. Ariane 5 is better, higher and more powerful than its predecessors. It is 52 meters high, has got only 2 stages and only one Vulcain engine. It needs 158.5 tons of fuel to carry up to 2 satellites at the same time or almost 10 tons into Earth orbit. The second, third and fourth Generation weren’t too different from Ariane 1 but this latest version is a rocket revolution and a huge investment. To launch one rocket they need 700,000 hours of work, 6.9 billion Euros and there are 1100 industrial participants.

Here are the steps leading to the launch. Twenty-two days before the rocket launch, it is assembled for 13 days. Then, it takes about one week to put the satellites into the cap. The cap and satellites within are taken by plane to Kourou, Guyana where they are subjected to a thorough inspection. Finally, the tanks are filled and pressurized. And it is lift-off day. Two minutes and a half after launch, the solid booster rockets are detached and fifty seconds later, the cap is detached. Nine minutes after launch sees the upper stage being separated and its engine blast off in order to reach orbit while the lower stage falls into the ocean. Twenty-six minutes after lift-off, the satellite is separated from the upper stage and put into orbit. Finally, twenty-four hours after lift-off, he technicians maneuver for the orbit adjustment.

Since its beginning, Ariane has sent almost 200 satellites to space, for many different nations and uses: military, telecommunications and of course to study the environment. Here are some of them:

Some of military satellites sent by Ariane 4 and 5 were the “Helios” type. The first one was launched on July, 7th 1995 and others in 1999, 2004 and 2009. The goal is to observe countries without violating air-space and inform militaries on what’s going on the Earth, with high resolution.

There are many satellites to observe things like natural disasters or global warming. First, it was “Météosat”, bought by ESA and sent in 1977 by Ariane 1, which observed the evolution of the climate. Secondly, “Spot”, a satellite for the National Center for Space Study, was launched in 1986 by Ariane 2 before being reinforced by newer versions with improved image quality. Part of the “Spot” satellite, is a little satellite, “Vegetation 1 & 2” to keep an eye on the biosphere and cultures. But Ariane also sent space probe, the most recent and famous ones, launched together by Ariane 5, were the Planck Surveyor, to study the cosmic microwave background, and Hershel, to study how stars and galaxies formed. However, despite all these successes, Ariane has had its failures too.

For their first commercial target missions, Ariane’s manager, ESA had failures. On September the 10th, 1982, a turbo pump problem was noticed on the third floor leading to a crash in the Atlantic. Later, another failure occurred on September the 12th, 1985 when a gate was not watertight enough on the third floor. Hopefully, the problem was spotted before launch and it was aborded. On May the 31st, 1986 the Ariane3 project started but a new problem happened on the third floor again: an engine starter didn’t work which forced the rocket to remain sixteen months on the ground. On the 23rd of February 1990, during their 36th launch, the rocket exploded. This explosion didn’t cause any damage, except the rocket, since it happened far from the Guyanese coasts. There was a fuel leak. As for Ariane 5, on December the 11th 2002, a flow in the coding system stalled the launch for six months. Nevertheless, Ariane is a very reliable and high-performance launcher.

And Arianespace hasn’t said its last word yet. A new rocket, the successor of Ariane5 is planned for 2025. Guess what they’ll call it: Ariane6. The two main targets are to improve the reliability by limiting the launch failures and to lower the costs to be able to meet its competitors such as the Japanese H2, the Russian Proton and the American Delta4. We can guess that even if Ariane6 has the same success as its predecessors, it won’t be the last one to go to space.

Recently, on March 13th, 2011 SpaceX, a private company announced an agreement to launch a satellite in collaboration with Arianespace. There are about to present a heavy launcher in 2013 and it may be a direct competitor to Ariane5.

We hope you enjoyed this podcast. Thanks for listening.

End of podcast:

365 Days of Astronomy
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