Ariane’s Makeover

A new version of the Ariane 5 should be brought to life around 2015. At least if the member states of the European Space Agency decide to launch studies aimed at evolving of the European launcher. This measure will reassure those who worry that the launcher Ariane 5 may not be able to keep up with changes in the satellite launching market.

Is Ariane going to disappear? Will the European launcher lag behind when it comes to new constraints in the satellite launching market and be unable to satisfy clients’ demands? These were the fears expressed this summer by former top spatial managers in Europe in statements published in the press… (see chapter 1)

All this aside, Ariane 5 in its current condition (a model known as ECA, standing for type A cryotechnical evolution, whose first successful launch took place in February 2005), the star launcher in Europe, experiences great success today.  “Since the beginning of the year, we have launched half of all commercial satellites (offering commercial services, such as the television, for example) sent into space from all over the world, and we have gained eight new contracts, half of which have been signed on an international scale”, Jean-Yves Le Gall explains, manager of Arianespace, the company in charge of commercializing the European launcher. So, the order book seems quite full, with 40 satellites to be launched, insuring more than three years of business.
 
Today, Ariane 5 continues to fulfill its commercial clients’ needs, allowing it to partially finance itself. Therefore, it can still carry out the mission that justifies its existence: enabling the Old Continent to send its own institutional satellites, without depending on the goodwill of a third party state. Ariane 5 has brought meteorological satellites, interplanetary probes, scientific observation equipment for Earth and Universe, and a freight transport vehicle safe and sound to the International Spatial Station (ISS).  Not to mention, of course, military, observational and telecommunications satellites. In the near future the launcher will also be in charge of transporting the Galileo satellites which will provide greater precision than that of the GPS to users of positioning services.

This does not mean that changes should not be foreseen. European space ministers are going to focus on the matter on the 25th and 26th of November 2008 at The Hague during their annual meeting. On the agenda of the discussions between member countries of the European Space Agency (ESA) will be the future of Ariane. A decision might be made to finance preparatory studies aimed at creating a more powerful version of Ariane 5 that would be available around 2015 (see chapter 2). Named Ariane 5 ME (standing for Midlife Evolution) it will make it possible to send 12 tons of material (this is called payload) into geostationary transfer orbit instead of the possible 9.5 tons today. This enables the professionals in the sector to look ahead to the future with a little more serenity, until a radically different version comes out around 2025 (chapter 3). In the spatial domain, the latest creations quickly become obsolete.  

01.Ariane 5: subject of debate

2008 summer turned out to be quite eventful on the spatial front: publications in the press’ comments columns, an open letter, public accusations… Those responsible for setting off this debate are ten former top European spatial managers. "Ariane is clearly in serious danger of decline due to a lack of future planning and determination”, worries one of them, Frédéric d’Allest, Arianespace director from 1980 to 1990, in a letter published in the newspaper Le Monde, on the 6th June 2008. For the first time since Ariane’s first launch in December 1979, the launcher finds itself limited in its capacity without a more powerful version being developed to take over”. For them, it is extremely urgent to switch over to a more powerful version of Ariane.

Not so fast, answers Michel Eymard, launcher director at the National Centre of Spatial Studies (CNES). “Today, the current launcher has reached its maturity, ten years after its inaugural launch. The Ariane 5 program was the result of huge investment from European states: approximately €8m, half of which was paid for by France, leader in this sector. In this case, it seems only natural to want to use this launching system, which is one of the most efficient in the world, to its full potential”, he explains. “One of our concerns is to hold on to our market share”, confirms Jean-Yves Le Gall, director of Arianespace. “And, to do so, we would like to keep the launcher in its current state, without any modifications.”

Indeed, today, the Ariane 5 launcher is considered by satellite operators as being both reliable and inexpensive. Inexpensive, meaning €150 million per launch, due to its capacity to send two satellites at the same time and thus, allowing any two clients to share some of the costs between them. Reliable, because it has had a total of 27 consecutive launches carried out without fail.

Changing a launching system that works well and fulfills market demands seems quite risky. Especially if we recall the difficulties Europe has experienced in getting to this stage. In 1996, the very first version of Ariane 5 was blown to pieces in a spectacular explosion, the pictures of which were shown all over the world. Six years later, the first Ariane 5 in its current version, called ECA (type A cryotechnic evolution), exploded in the skies over Guyana.

The only problem is that Ariane 5 will have to be updated some day. This is due to the fact that the satellite mass is tending to increase year on year, at the steady rate of 130 kilos per year. In the future, the launch capacity of Ariane 5 will be too weak to continue carrying out double launches. The only question is when.

02.Ariane 5 ME, the update

Ariane 5’s achievements, insufficient in the long term to send satellites with ever-increasing masses into space, is not the only problem facing the launcher. It also lacks a reignitable engine on its “second stage” (called the upper stage by specialists) in order to give it more “flexibility”.

This new engine will allow Ariane 5 to send satellites destined for geostationary orbit, at 36 000 km of altitude, directly to their final path. Currently the European launcher injects them into an intermediary orbit, called “transfer”, in an elliptic shape. It is then up to the satellite itself, using its own engines to “circulate” the orbit as soon as it passes an altitude of 36 000km. With this new engine, Ariane 5 would be able to offer the satellites it carries the possibility to save its precious fuel and would therefore appear more attractive on the market.

But, reigniting a cryogenic engine, i.e. working with propellants (the equivalent of fuel) such as liquid hydrogen and oxygen is not that easy. In mid flight, the different parts of the engine heat up.  And yet, when the engine on the upper stage of Ariane 5 is reignited, all these will transmit their heat onto the propellants, which should, on the other hand, stay at a temperature of -240°C for liquid hydrogen and --180°C for liquid oxygen at each blast-off. If not, the engine will go "hiss!"…

What is the solution to overcome these two challenges? First of all to continue studying Ariane 5 as it is now. With each launch, engineers understand a little better the way in which the whole system of Ariane works and manage to improve it. “We play with the mix of hydrogen and oxygen, for instance, or on the combustion speed of the powder propulsive unit. By optimizing these settings, we should be able to increase the launch capacity from 300 to 400kg in the next two years,” explains Michel Eymard.

In additional, on the 25th and 26th November 2008 at The Hague, the space ministers of the member countries of the ESA should decide – except if there are some surprises – to finance studies on Arian 5 ME (Midlife Evolution). In 2011, when this work comes to an end, they will be able to order its construction so that it can soar up into the skies for the first time in 2015 from the spaceport of Kourou, in French Guyana. For the signatories of the open letter sent to the directors of the ESA this summer, it will be too late. “If a political push from high up is not given quickly by France, the outcome - the decline of Ariane in the next three to four years and its disappearance from the commercial market in a short number of years - will be irrefutable”, they explain in Le Monde. On the other hand, the professionals ruling feel that the planned schedule is adapted to the situation.

Ariane 5 ME will not differ hugely from the current version, Ariane 5, except on one crucial point. The future launcher will have a new superior stage, built around a new engine, called Vinci. This engine works along the same principle as the current HM7B that equips the superior stage of Ariane 5 – the mix of flammable liquid oxygen and hydrogen provide the propulsion - the Vinci engine will produce a much stronger thrust that will allow the launcher to send masses of 11.5 to 12 tons into geostationary orbit transfer, compared to 9.5 tons today. And it can be reignited. This would be if all the thermal problems have been solved in the meantime…

France, which has always had a training role in the sector of satellite launching in Europe, should pay for almost half of the expenses connected to the research to be carried out on Ariane 5 ME – the amount of the budget has not yet been made public. It will therefore, obviously be from France, and more precisely from the Paris region, where the head offices of the CNES and the ESA are located, that the project will be steered and carried out all over Europe by industrials such as EADS Astrium or Snecma, which will possibly one day result in the launching of the new version of Ariane 5.

03.Ariane 6 for 2025?

In about 2025, the version A5ME will, in turn, be nearing its end. And the Ariane 5 system as a whole will hardly be able to be improved, the experts predict. In order to make the launcher more efficient its global architecture will need to be entirely rethought. In such a situation, all the spatial engineers wonder the same thing: reusable or consumable? A launcher whose various stages could return gently to the ground once their mission has finished would have the advantage of being able to be sent into space again, they dream. This would allow substantial savings to be made.

However, on this point, Christophe Bonnal, a senior CNES expert has some bad news: “Studies have shown that a launcher that could be entirely reusable would cost a colossal amount of money, between €13bn and €19bn, and its recurrent cost would be the same as that of the current Ariane…” In other words, it would present no economic interest. Such a system would involve costly studies and major infrastructure to be implemented (landing runways, specialized maintenance workshops, etc.) Even a semi-reusable launcher, where only its boosters equipped with wings would come back to earth, would only mean savings of 10% on recurring costs… provided that the engineers manage to grasp the necessary technology.

The FLPP (Future Launcher Preparatory Program) itself consists of almost no studies on reusable stages. This is an ESA research program which prepares the new generation of launchers, benefitting from more than €300 million for the 2005-2009 period. However the future Ariane 6 is sure to present some surprises: “One of the solutions being studied at the moment involves an engine that uses methane, as a replacement for hydrogen, and oxygen”, outlines Guy Pilchen, FLPP program director at ESA. “The advantage of this technology is the small volume of methane used compared to that of hydrogen, which means that a smaller launcher could be used, which would be lighter and therefore able to send satellites with bigger masses.” In this way, the launcher’s structure would no longer be made up of aluminum but of an alloy of aluminum and lithium, providing identical strength with a smaller volume. In addition, for some missions needing a lot of thrust, three main stages, which are commonly called the “first stage” of a rocket, could be attached to each other in order to have a thrust that is three times stronger.

On its end, the CNES is carrying out its own work. The French spatial agency could launch a program called Aldebaran which would lead to what Michel Eymard calls “a real breakthrough”. The aim is to come up with “a launcher just as reliable as Ariane 5, that is nevertheless twice as cheap and implemented during launching campaigns that are four times shorter.” How could such a result be obtained? By carrying out all the necessary new technological tests on a micro-launcher, which remains to be built.

Over the last two years, the CNES, which has been working in association with the German and Spanish spatial agencies on this project, have been thinking about such a “technological demonstrator” which would send small volumes, from 50 to 300kg into space. It could have a methane-hydrogen engine, but also electronics capable of diagnosing itself in such a way as to prevent breakdowns likely to affect it. Its equipment box, the guiding instruments of the rocket, could weight a mere 15kgs (compared to one ton for the current Ariane 5) thanks to the use of a feather weight electron and batteries…Maybe it would also have reusable parts, capable of coming back to earth to be reused on future flights.

The general architecture of this little piece of equipment is still to be defined. The CNES and its partners have thought about drawing it from an aircraft in order to benefit from the altitude acquired. In this way, before the engines have ignited, it would be carried into the air by a giant balloon, or on the back of an Airbus A380, or even under a giant drone or a Rafale fighter plane …

In two years from now, the CNES will be able to put its very innovative micro-launcher forward for financing from the states. If its construction goes ahead, the European engineers will be able to test new “breakthrough” technology, from which the Ariane 6 could also benefit.

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