Interview: Jean-Yves Le Gall, CNES President

Jean-Yves Le Gall, president of CNES, tells Aviation Week’s Thierry Dubois about the agency’s progress on reusable launchers and other programs in conjunction with International Astronautical Congress 2020.




- [Thierry Dubois] Jean-Yves Le Gall, you are the president of the French space agency Centre National D'Etudes Spatiales.  Thank you for taking some time with us. Where is Europe, and in particular, the French industry, in preparing for the development of a reusable launcher?


- In fact, we decided already a few years ago to start the development of a reusable engine, because when you deal with a reusable launcher, you need to have a reusable engine, and this is why in early 2016, we decided to trigger the development of Prometheus.Prometheus is a very interesting engine, because the objective is to have a very low-cost engine, roughly 10 times cheaper than the current Vulcan engine of Ariane 5 and more, and 6.

And in addition, Prometheus should be reusable.And so, this development is ongoing, and we plan to have the first test of Prometheus next year, and in parallel, we also develop small vehicles to learn to recover a vehicle, and, in the second step, to make it reusable.And so, with JAXA in Japan, the DLR in Germany, and CNES, we developed the Callisto launch vehicle, which will fly in two years from French Guiana to learn to recover this small vehicle, and later on, we will develop Themis, which will be kind of Callisto, but with the Prometheus engine, for, to have the first step of a reusable launch vehicle.


- [Dubois] Do you mean that Themis will be larger than Callisto?


- Themis will be a little bit larger than Callisto, but Themis will use the Prometheus engine, when Callisto will use Japan engine, which is foldable.


- [Dubois] So Callisto will be launched for the first time in two years from now. What about Themis' schedule?


- Themis will be a little bit later. If we aim at 2022 for Callisto let us say that the first flight of Themis should arrive in a late '23, or '24.


- [Dubois] For a long time, Europe's reluctance to go ahead with reusable launcher technology was explained by the remaining uncertainty about the business model. Are you still wondering about a reusable launcher being profitable?


- Today, the question is upon taking into account the global business in Europe, which is very, very specific.But nevertheless, we decided that we must master this technology, and so this is why we decided to process with Prometheus, Callisto and Themis.


- [Dubois] What are the other technologies you think will be shaping the space sector over the coming years?


- I think that for the satellites, the biggest trend is miniaturization.And what is the very, very impressive is that the first environment satellite launched by Europe was only sent about 20 years ago. It was a seven-ton satellite.

Now, the success of the Envisat, or the Copernicus satellites, which are under 1 ton, and for the future, it is clear that the mass will continue to decrease.

And so, it is really a game-changer, because when you have such a decrease of the mass, without decreasing the performance, it is because these are in fact a progress of the technology, but the cost of satellites decreased as well.

And at the end of the day, many people use satellites, which was not the case 20 years ago.


- [Dubois] Can you name a current, or planned exploration mission in which you think this has a particularly relevant role?


- As you know, we put the SuperCam camera on Perseverance, which has been launched by NASA on the 30th of July, and if everything is going well, it will land on Mars on the 18th of February, 2021, and with SuperCam, we will start the process for the Mars Sample Return, which will occur within 10 years from now.

But definitely, the French scientific community is excellent for all what is related to Mars.It is why we are selected to provide instruments for most of the Mars missions, and we will be instrumental in this mission, Mars Sample Return, and it will occupy our scientists for the next 10 years.


- [Dubois] Can you describe SuperCam?


- SuperCam in fact is a camera with a laser, which shoots on the Mars rocks, and with these laser shots, you can analyze the composition of the rocks that you selected, and it's very, very interesting, because it will allow us to have an in-depth knowledge of the composition of the soil of Mars.


- [Dubois] Thank you. Can we talk a bit about defense, French defense? France is renewing its military observation capacity with the CSO constellation of satellites, three satellites.

You said early this year that CSO 1 has changed the way satellite images are used for strategic purposes. How?


- Because in fact CSO capitalize on the success of the Helios family, Helios 1A, 1B, 2A, 2B, and there are some other capabilities which have been added to CSO.

So CSO is much more than the Helios, and with those capabilities, in particular infrared observation, it's really a state-of-the-art satellite, and in my opinion, it's probably one of the most advanced Earth observation satellites ever launched.


- [Dubois] What does infrared allow?


- Infrared gives you the kind of dynamic of the images, which is not possible with classical images.


- [Dubois] The French Air Force is now the Air and Space Force. Can you describe CNES' role in the creation of the Space Command?


- It is clear that the Space Command is excellent news for France, and for the space community, because it gives a new impetus to our space defense policy.

And so, it has been decided to use the expertise which has been developed by CNES for many, many years, because the CNES program is by essence a dual program, and this is why the Space Command, the French Space Command is now going to be implemented in our Toulouse Space Center, and it will give the opportunity to our teams to work in very close connection with the teams of the Space Command, and I think that at the end of the day, it will be a win-win situation when CNES, we take advantage of the developments made by, for the defense, and vice versa.


- [Dubois] So rather than transfer that, rather than knowledge transfer, it's cooperation?


- It's a cooperation, and it is rather than creating a kind of military CNES, in fact it has been preferred to have a CNES working for the defense.


- [Dubois] Thank you. One question about climate, you often say that CNES can be seen as the space agency for climate. Green activists say we are hyper-informed spectators. So do we really need to learn more to act against climate change?


- Yes, because as you know, when you speak about the climate, it has been decided to use 50 essential climate variables, and out of these 50 variables, 26, more than half, can be observed only with satellites. These are the satellites which observe the increase of the average temperature of the globe.

These are the satellites, and in particular, the French-US satellite TOPEX/Poseidon, and Jason, which showed that we have an increase of the level of the oceans, and in the future, there will be a satellite which will observe the concentrations of carbon dioxide or methane. And so, space is very, very important to tackle climate change, and this is why we decided to create the Space Climate Observatory.

Up to now, we have a total of 27 space agencies, plus some international organizations which are a member of this SCO, and it will be a very important tool in the future to have a better understanding of climate change, and to help populations to tackle the effects of climate change.


- [Dubois] Thank you very much for your time.


- Thank you.

Thierry Dubois

Thierry Dubois has specialized in aerospace journalism since 1997. An engineer in fluid dynamics from Toulouse-based Enseeiht, he covers the French commercial aviation, defense and space industries. His expertise extends to all things technology in Europe. Thierry is also the editor-in-chief of Aviation Week’s ShowNews.