Metallic Envelopes for LTA Technology: Interview with Tankers

Metallic Envelopes for LTA Technology: Interview with Tankers

We had the chance to interview Mickael Frotin, engineer at CNRS (French National Centre for Scientific Research) in France since 2008. Expert in the team of Nathalie Leborgne, he is experienced with particles in CERN and involved with calorimetry. He has worked at the astrophysics laboratory in Paris where he tried to find a flight solution for telescopes for many years. Here, the idea for founding Tankers evolved:

“The major problem is that telescopes can currently not stay airborne for longer than six months. We therefore tried to find a solution for a material that could hold gas for longer. After having studied simulations for many materials, we finally hit upon the solution of a metallic envelope which gave very good results (ability to stay airborne for four to five years). Following upon this discovery, we found a solution to assemble the metallic envelope. Applying the new data, we determined the suitability.

Of course, our solution is heavier than using a plastic envelope but with the metallic envelope, we can fly at stratospheric conditions (altitude of 25 km). Another advantage is that the envelope is recyclable since new sheet could be built from the old material in the event of crash.”

During the interview we also learned that the metallic envelope is an excellent solution to resist UV and gamma radiation, which are commonly encountered in large quantities at stratospheric altitudes, and which can be difficult conditions for plastic envelopes. Besides the positive aspects, of course also some disadvantages arise when using metallic envelopes.

“It is more difficult to bend than plastic, the material needs to be created as-is, which is a problem that conventional planes also have.”

Since the envelope is metallic, it is already compatible with hydrogen gas; further study is needed for use with liquid hydrogen, due to the very low temperatures involved. There is a design being developed to store liquid hydrogen in a tank for over ten hours in a static way. Compared to other storage solutions, the weight of Tankers’ material is 25% less than aluminium, making it particularly useful for aviation applications. The leakage rates are also much lower than when a plastic material is used.

Frotin explained that the metallic envelope is also useful for integrating solar panels on the surface, which is a challenge for other airships with conventional envelopes. Using this envelope, an autonomous airship powered by photovoltaics becomes much more viable.

Mickael Frotin

“A test is already organised with a laboratory, to be undertaken by Tankers in July or August 2022 – we expect to create a small tank to store helium at an altitude of one kilometre, and equipped with four solar cells, to create a small quantity of hydrogen from a small quantity of water onboard the airship. The hydrogen shall be stored in a separate tank and be used to create electricity using a fuel cell onboard the airship. The total payload would be around three kilograms. This would be done to compare the electricity produced at high altitude with the electricity produced on the ground. The ultimate aim would then be to fly at five kilometres altitude, in order to increase efficiency of PV power (eliminate cloud cover problem).”

Tankers’ team consists of five committed people with different backgrounds:

Logo Tankers

Nathalie Leborgne – CEO of Tankers,

Mickael Frotin – Expert Engineer of Mechanical Projects,

Julien Prudent – Expert Mechanical Study Department,

Maxime Mauguet – Expert Scientific Researcher Multiphysics Simulation Specialist,

Jean-Louis Lequeux – highly experienced with new project and technology creation – worked with Thales, Airbus, SAFRAN and created two start-ups.

Why was the name Tankers chosen?

“A tank needed to be created, whether to fly, or for storage. In addition, the principal function of a balloon is to act as a “tank” for the lift gas, ultimately a “tank” needed to be produced. It felt that the name “Tankers” is ambitious and fits the goal of the company. We want to bring an impact to many people.”

With their research, development, and production of a new envelope, Tankers aims at having a very low level of gas leakage and to be able to fly for several years without refilling and therefore increase the time that the airship can remain airborne. Using Tankers’ envelope material, the flight time under stratospheric conditions (25 kilometres altitude) increases up to four years (compared to about six months).

Tankers is now trying to find a suitable financial partner to help in the construction of Tankers’ first demonstrator at Plateau of Paris Saclay, at Polytechnique School. Furthermore, Tankers is already in contact with other countries to develop solutions for continuous, long-term (relative to drones) surveillance using a tethered balloon. Also, for our platform, their technology could be interesting.

“Partners of the U-LTA platform can collaborate with Tankers if they need a new envelope for their airship operations (including tethered balloons from one to five kilometres altitude) with a low leakage rate, that is reusable, and can also be used in stratospheric conditions. Another possibility could be if a developer would need an onboard hydrogen tank for their airships.”

Thank you, Mickael, for this interview. We are looking forward to future collaboration!

To find out more about Tankers, please feel free to contact us (; we will be happy to put you in contact.