Pushing back the limits of technology in the conquest of space
A driver of continuous progress, the space industry is currently undergoing a renaissance; a profound transformation into a more competitive environment as it enters the commercial era. Private companies can understand the wonderful challenges and rewards that space provides, so they are among the primary contributors to this dynamic. They are focusing on the production of telecommunications data (internet, GPS, etc.), terrestrial imaging (digital agriculture, smart cities, smart energy, etc.), climate observation, and the prevention of natural risks.
Air Liquide is ready to meet the challenges of this new chapter in the history of space. After more than 50 years of technological developments on the Ariane, Melfi, Planck, Herschel, Curiosity, and ExoMars programmes, we have the ambition, the will and the expertise to engage in all the major new international challenges: electric propulsion, more competitive launch vehicles, the constellation of satellites, life in space, and more.
We were involved in the design phase for Ariane 1 to Ariane 5's cryogenic propellant tanks, and right up to the point that they were fitted onto the European rockets. The development of these tanks, as well as the insulation of certain equipment, like the Pressure Control Units or the level gauges, has enabled us to make spectacular technological advances. We now work alongside the European Space Agency (ESA) in our capacity as cryogenics expert. With Euro Cryospace, a strategic partnership between Air Liquide and Airbus Defence and Space, we offer innovative solutions that are a taste of the concepts of the future Ariane 6 launch vehicle, which will have reignition capability.
The number of objects in orbit is set to increase over the coming decade. As well as 400 new satellites dedicated to Earth observation and 300 others dedicated to telecommunications, people are already talking about launching over 1,000 additional satellites, making the largest constellation ever to orbit the Earth!
Thanks to its expertise in orbital cryogenics, storage systems and gas distribution, Air Liquide will be part of this revolution. The group has already been able to meet a wide variety of needs like the preservation of biological samples in the International Space Station’s MELFI cryo-freezer, the observation of the universe's background thermal radiation with the Planck and Herschel satellites, and the cooling of observation satellites' infrared detectors. By providing our expertise and adding our technologies to the Curiosity and ExoMars rovers, we are also part of the effort to explore Mars.
Air liquide has been preparing, testing, and optimizing the installation and connections of cryogenic lines for launch pads since the 1980s. We operate on the space launch sites of Kourou in Guyana, in Cape Canaveral in the USA, Tanegashima in Japan, as well as Xichang and Wenchang in China.
We supplied the liquid hydrogen and oxygen plants that produce the cryogenic fluids for launch vehicles in Kourou. Several Air Liquide employees are based on the Guiana Space Center in order to supply liquid hydrogen and oxygen for the launch vehicles' propulsion, liquid nitrogen for inerting, and the helium that is indispensable for pressurization, cool-down, and cleaning. They also deal with equipment maintenance for Arianespace and the CNES.
We also offer HELIAL helium and HYLIAL hydrogen liquefiers for these space centers. The HELIAL in Kourou, for example, liquefies helium gas vapor that evaporates during storage.
Moreover, we have designed simulation chambers and testbeds on the ground that reproduce the extreme space conditions that satellites and their components are subjected to.
Air Liquide offers industrial and scientific customers the use of a test center that is unique in Europe, with the expertise of a dedicated team at their disposal. This 6-hectare site, located near Grenoble, was built in order to test, inspect, and qualify equipment for the needs of the space industry. Our team has acquired a high level of expertise in all kinds of studies, from the characterization of materials, to thermal cycle analysis, cryogenic trials, and the simulation of thermal conditions on the ground, during take-off, and in space…
Air Liquide also conducts trials outside its test center, as was the case with the pulse tube cryocooler, which was inspected in an ultra-clean room. Sometimes experiments can even take place very far from Sassenage, like with Cryofenix trials, which were carried out within the polar circle, in Sweden.
Setting up a base and living in space is no longer just a pipe dream. The European Space Agency may have plans to set up a permanent base on the moon, which could eventually replace the International Space Station and be used as a stepping-stone to Mars. Solutions for putting this incredible project into action already exist. What would we need in order to live far from Earth? We would need to produce and store energy, to purify air, and to produce fuel to enable spacecraft to return to Earth…
At Air Liquide, we are thinking seriously about how we can contribute to establishing human life in space. We have already developed all the technological building blocks required for this new adventure for terrestrial applications: fuel cells, air purification units, propellant production systems, etc. All that remains is to adapt them for use in space. Thanks to more than 50 years' experience in the conquest of space, we are up to the challenge. We have all the necessary expertise, recognized the world over, and are ready to test these technologies on the “Lunar Analogue” facility, under construction at the European Astronaut Centre in Germany. Today, living on the moon is much more than just a dream. Tomorrow, it will become a reality.
All Ariane 5 rockets feature a spherical cryogenic storage tank called the LHESS, which supplies the helium circuit that pressurizes lower-stage liquid oxygen tank. We designed this unique supercritical helium cryostat to meet the launch vehicles' need for compactness and efficiency, as well as the mechanical strength imposed by take-off. The most complex technical challenges are this tank's perfect leak-tightness and exemplary thermal insulation. And these are challenges we have met!
Liquid methane could replace hydrogen in the future. There are two reasons for this. Firstly, methane has a significantly higher condensation temperature than hydrogen. It is close to that of oxygen, which makes it easier to use. Moreover, methane has a higher density than hydrogen, which makes it possible to use smaller tanks. Thanks to this expertise, we are already planning new trials: a HX2 demonstrator and a Cryofenix 2 sounding rocket.
Since the start of the Ariane program, Air Liquide has been involved in the evolution of successive generations of launch vehicles in close collaboration with the European Space Agency and the Centre National d’Etudes Spatiales (French National Space Studies Center). We are responsible for the launch vehicles' liquid hydrogen and oxygen storage tanks, from their design to their integration.
Today, Air Liquide Advanced Business & Technologies produces Ariane 5's second stage liquid oxygen tanks in Sassenage. EuroCryospace, a partnership between Air Liquide and Airbus Defence & Space, produces the first stage propellant tanks and the second stage liquid hydrogen tanks in Les Mureaux.
Tomorrow, Ariane 6 will head into space. We will pursue the adventure through innovation, studies, and experiments. Our objective? To guarantee the ideal conditions for the launch vehicle's future engine to shut down and reignite after a ballistic phase. That's the aim of the Cryofenix sounding rocket flight, which analyzed the behavior of liquid hydrogen in microgravity, and tests on the HX demonstrator. This will result in the approval of 14 technologies developed by Air Liquide and EuroCryospace!
Pressure Control Units have a key role in getting Ariane launch vehicles into space. The mechanical performance of liquid hydrogen and oxygen tanks, the supply of fuel to the cryogenic engine at constant flow and pressure, control of the hydrogen/oxygen ratio, and the activation of pneumatic valves on the cryogenic stage. Not only does Air Liquide produce the Pressure Control Units, we are also general contractor for the tanks' pressurization trials. That makes all the difference!
Without the thermal insulation of tanks, cryogenic liquid propellants would vaporize before the rocket even takes off. The insulation we developed has all the features required for space launch vehicles: including thermal efficiency, of course, as well as lightness, mechanical strength, and resistance to aerothermal flows.
As an expert in cryogenic equipment, Air Liquide has achieved something that had never been done on a spacecraft! For the International Space Station, we designed the MELFI turbo-engine, which cools biological samples to – 80°C and has been operational for 10 years. This is quite an achievement when you bear in mind it was only intended to run for two years!
We fitted out Planck and Herschel, the most complex satellites ever produced in Europe. We developed and qualified a dilution refrigerator at 0.1 Kelvin for Planck, which later produced a map of the universe's cosmic background microwave radiation. We produced a huge helium tank to cool the powerful Herschel telescope. Since then, Herschel has produced results that explain how the stars were born. One of our biggest challenges with these satellites was the absolute necessity to avoid leaks, which required high-precision welding work.
Air Liquide is also developing an innovative pulse tube cooling technology. For satellites, where there is a limited amount of space for equipment, active cooling technology is the most appropriate.
Did you know? The Planck and Herschel telescope's detectors are cooled to a temperature close to absolute zero, allowing it to scan regions of space where temperatures don't exceed 3 Kelvin.
By 2022, a quarter of satellites in geostationary orbit will use electric propulsion. The principle behind this is that xenon ions are ejected from the engine by an electric and/or magnetic field powered by the satellite's solar panels. By using a gas like xenon as fuel, we can cut the satellites' weight in two.
Air Liquide supplies the gas and the satellites' filling cart. We have also developed a micro-valve for regulating the flow of xenon. We exploited this technology to regulate helium flow in ExoMars rover's chromatograph. The technology is being developed with the CNES to adapt it to the challenge of electric propulsion. Weighing just a few grams, these micro-flow regulators, which operate by thermal expansion, are a miniaturization challenge.
"The microvalves developed for ExoMars are perfectly leak-tight. We can't afford to lose a single molecule of Xenon. At tens of thousands of euros per normal cubic meter, it's vital.”
Our expertise has led us to take part in exploration projects and the search for life on planet Mars. Indeed, we worked on the Curiosity rover's gas phase chromatograph, as well as that of the ExoMars exploration robot, in order to separate the compounds found on Mars before analysis. We manufactured several of this device's components (helium tanks, valves, etc.), as well as assembling the chromatograph's capillary tubes with high-precision brazing.
And that's not all. Our gas management expertise has allowed us to be involved in other projects. The law now requires defunct satellites to re-enter Earth's atmosphere to be disintegrated. For the Microscope satellite, which has been in space since 2016, we designed a system that ejects nitrogen gas to empty the satellite's tanks and inflate the IDEAS structure's two large masts, which accelerates Microscope's re-entry.
But before this, the innovative gas propulsion system guides the ultra-sensitive accelerometer on board the Microscope satellite, with the aim of explaining Newton’s law of universal gravitation.
Air Liquide's HELIAL and HYLIAL liquefiers enable the production of liquid helium and hydrogen respectively, directly on the launch pad.
Ariane 5's cryogenic stage requires huge quantities of helium: two fixed storage tanks with a capacity of 100,000 liters each were installed by Air Liquide in Kourou, in order to clean, condition, and to pressurize the rocket's tanks and cryogenic lines on the ground, before filling them with oxygen or liquid hydrogen. To prevent the loss of helium, which is highly volatile, the Kourou Space center boasts a HELIAL that recovers cool helium vapor in the tanks on the ground in order to reinject it in liquid form. HELIAL also helps to depressurize helium transportation tanks, to limit losses during transfer from the trailer to the storage tank.
Several space centers have acquired our HYLIAL to supply launch vehicles with liquid hydrogen. The Xichang center, in the Province of Sechuan, and the Wenchang center, on Hainan island, both acquired hydrogen liquefiers, allowing them to produce liquid hydrogen on site. Previously, the cryogenic fuel was transported to the space centers in special convoys over thousands of kilometers.
Distributing liquid propellants to heights of several dozen meters and loading the launch vehicle up to five seconds prior to launch: that's what the dedicated cryogenic lines, built and installed by Air Liquide, can do on Ariane 5's launch pad tower in Kourou.
Over the years, we have designed, produced, and installed the cryogenic equipment for all four launch tables on the Kourou base. The Ariane ELA2 launch complex, for example, had no less than six tanks, with capacities ranging from 20 to 100 m3, related equipment and 1,100 meters of vacuum-insulated lines, including 650 m for transferring liquid hydrogen. For ELA3, Air Liquide supplied 630 meters of lines and nine tanks, including five 360 m3 tanks intended for storing hydrogen three kilometers from the launch pad! ELA4, meanwhile, is still in the design phase, and is due to be operational as of 2020. Intended to launch the future Ariane 6 launch vehicle, it will be similar to the ELA3.
And that's not all: Air Liquide's on-site teams are responsible for the full maintenance of cryogenic equipment, in particular the super-insulated vacuum lines, which we produced, as well as the reconditioning of all tubes that connect the launch vehicle to the launch tower.
Did you know? Filling the tanks with liquid propellants is one of the last operations prior to a launch
Ionic propulsion can be used to control satellites in orbit, while reducing their mass and extending their useful life. Air Liquide has developed a fully automated, mobile, leak-tight, lightweight, and compact system for filling and emptying xenon tanks, as well as conducting pressure tests on ionic propulsion systems: the automatic Xenon loading cart. This system can fill a satellite's tank with 99.999%-pure xenon, at a pressure of 180 bar, in a record time (16 hours) while controlling the flow and the mass of xenon loaded.
Air liquide designs and manufactures space simulation chambers to test satellites' reliability by reproducing extreme space conditions on the ground: a vacuum at 85K, brutal variations in temperature from 100K to 400K, intense vibrations on takeoff, and cosmic radiation.
We work with Thales Alenia Space, among others, helping to create a simulated space environment in its space simulation chambers. The main difficulty is obtaining and maintaining a high vacuum. We therefore supply thermal panels that produce cold using liquid or gaseous nitrogen.
Beyond these components, we can also deliver complete, turnkey, integrated simulation chambers.
Every generation of the Ariane launch vehicle's tanks were tested at Air Liquide's test center. The test center, which is one of a kind in Europe, was built for the specific requirements of space cryogenics and has progressed as the cryogenic stages’ have become more efficient. This secure zone has several testbeds, vacuum chambers, and containment systems, to help research institutes and industry to test the reliability of their own technological developments. The use of this infrastructure can lead to major advances. For example: we designed a 1:2 scale demonstrator of the Ariane tanks as part of the HX program, in order to develop new technologies for the launch vehicles of tomorrow. Tests on this HX demonstrator have led to the approval of 14 new technologies!
Did you know? Air Liquide can design bespoke testbeds for specific needs, like the TVT (Thermal Vacuum Test) testbed, a real mini-space simulation chamber
Air Liquide has already helped put astronauts in orbit, on board the International Space Station, by supplying NASA with the MELFI, a turbo engine that cools its laboratory freezer for preserving biological samples at -80°C. Our experience suggested that turbo-Brayton technology would be suitable. Our experts took great care to avoid mechanical wear and tear: the compressor wheel and the centrifugal turbines are mounted on a tungsten carbide shaft in suspension on a nitrogen film.XXX This was an excellent precaution to have taken when you bear in mind that the MELFI, which was initially due to have an operating life of two years, is still working perfectly a decade later and should last until at least 2020: hundreds of thousands of hours later!
This success was the very first experiment with a turbo-Brayton engine in space. Today, Air Liquide is building a turbo engine capable of supplying 400 times more cooling power. A new challenge!
What Air Liquide has developed for marine applications can be adapted for use in space. Air Liquide has recognized know-how and technologies for marine applications. We have developed, for example, a gas generation unit that produces 99.5%-pure oxygen and nitrogen for the French navy's Charles de Gaulle aircraft carrier. Spanish air-independent propulsion submarines also boast cryogenic liquid oxygen storage tanks designed by Air Liquide. We developed an innovative solution combining cryo-trapping of Volatile Organic Compounds (VOCs) and pulse tube cryocoolers. For years, we have been working with ship-builders to design systems for providing breathable air to submarine crews. These same technologies could be used for crews in space. The idea has already come a long way: we have started working with the European Space Agency and Airbus Defence & Space to develop a decarbonation unit suitable for use in space.
The pulse tube cryocoolers developed for space applications are used in equipment that produces breathable air for submarine crews. This technology could also help create breathable atmospheres for astronauts.
Hydrogen, oxygen, and methane are all fuels capable of powering vehicles on other planets. Sources of these gases exist in space. We know that there is water hidden on the dark side of the moon, and therefore hydrogen and oxygen, as well as methane.
As for the technological building blocks required to produce and store them, Air Liquide has developed cutting-edge expertise in this field. The group is capitalizing on 50 years' experience in the liquefaction of cryogenic fluids for a wide range of applications: scientific research, biology, electronics, fuels cells, and the space industry, among others. We designed and built all Ariane's cryogenic propellant tanks since the very first launch vehicle took off from Kourou in 1979. We have also developed an exclusive industrial methane purification solution.
All these technologies can be easily adapted for use on the moon or on Mars. We are motivated by the challenge and we are no novices. By innovating and continuously pushing back technological frontiers, we are helping to define the world of tomorrow..., on Earth and beyond.
We have worked on all the developments for the European launch vehicle, Ariane, as well as numerous international projects, including the International Space Station; the Planck, Herschel, and Microscope satellites; and the Curiosity and ExoMars exploration rovers, among others.
Our employees are passionate about their work. Our results-minded approach and wealth of expertise have allowed us to make great strides and are now leading us to even more ambitious technological challenges, from launch vehicles with reignition capability and electric propulsion for satellites, to life on Mars...
Our innovation teams rely on Air Liquide's expertise and close collaborations with public research laboratories, like the CEA, the CNRS, and the Grenoble University Space Center.