Figure 4 - The ESA Academy's Concurrent Engineering Workshop - May 2018 participants(credit ESA)

One week at ESA

Blog post by Florian Vidal, REVOLVE Fellow

It has been a while since my last post! Don’t worry I didn’t suffocate under research papers and on the contrary, my work is progressing fine. Today I’m going to focus on an event I participated in which was a workshop organized by ESA. ESA stands for European Space Agency and its role is to provide, for exclusively peaceful purposes, cooperation among European states in space research and technology and their space applications. It also promoting space with outreach (follow their mascot Paxi!) Furthermore, ESA is involved in state-of-the art project such as Galileo, the European GPS.

The topic of the workshop I attended was about concurrent engineering, the art of combining several engineering fields to find an optimal design. I am going to present to you the process we went through to design a spacecraft to go to the moon.

Figure 1 - Redu position in Europe

Figure 1 – Redu position in Europe

The workshop took place in ESA’s European space Security and Education Centre (ESEC) in Redu, a remote Belgian village 2 hours from Brussels. This place was chosen years ago by ESA to minimize interference for satellite operations while remaining in the center of Europe. When I arrived to the hotel I was really surprised by the diversity of nationalities amongst the participants. We were 20 university students, Spanish, German, Polish, Dutch, Italian, Romanian, Portuguese, English and French. Moreover 2 system engineers from ESA were there to support us during this week.

Figure 2 - ESA-ESEC site in Redu, Belgium

Figure 2 – ESA-ESEC site in Redu, Belgium

We were welcomed by ESA staff at ESA Academy’s Training and Learning Centre. There, we were presented ESA and ESA Education Programme, and our mission for the following days: designing a low-cost spacecraft to bring a rover to the moon using ESA Educational Concurrent Engineering Facility (CDF). The name of the mission was LIAR (Lunar Impactor And Rover). The mission consisted in a spacecraft that would impact the moon instead of landing softly. That way we would use less fuel hence a lighter spacecraft. This spacecraft would bring a rover to the moon for an observation mission (taking pictures).


Figure 3 - ESA's Educational Concurrent Engineering Facility (CDF) (credit ESA)

Figure 3 – ESA’s Educational Concurrent Engineering Facility (CDF) (Credit:ESA)

The team was composed of several sub-teams divided by subsystems: thermal; communications/data handling; structures; trajectory; configuration;  propulsion; and, power. I was working on communication and data handling subsystems with another student. Concretely our work consisted in finding a/some ground station(s), designing the communication module to enable control, telemetry, and the downlink of the pictures the rover would take on the moon.

Figure 4 - The ESA Academy's Concurrent Engineering Workshop - May 2018 participants(credit ESA)

Figure 4 – The ESA Academy’s Concurrent Engineering Workshop – May 2018 participants (credit: ESA)

We also had the opportunity to visit ESEC facilities. For example, we went into the Proba Operations Control Room. Proba satellites are 3 Belgian observation satellites: Proba-1 is observing Earth; Proba-2 the sun; and, Proba-V vegetation. Their information is precious and can be used for agricultural, weather or scientific purposes.

Figure 5 - Photo of the sun taken by Proba-2 (credit: ESA)

Figure 5 – Photo of the sun taken by Proba-2 (credit: ESA)

During the last 2 days of the Workshop we worked hard to find an optimal solution. It was really challenging in the way all the subsystems interact with other subsystems. For example, as I was working on communications, trade-offs between the number of pictures we can send and the power required on the spacecraft were to be made. It was hard negotiations! The tools provided by ESA and the fact that we were all in the same room were essential to iterate quickly to cross out non-feasible solutions.

In the end I was really surprised by the result of our work. I honestly thought that we could not achieve anything in 4 days for such complex mission but finally the solution we reached seemed not too far-reached! Many thanks to ESA Education Office team for this exciting week!










Linked to a Satellite!

Imagine you are lost in one of the most remote place in Antartica or in the Amazonian jungle, it seems like all hope is gone and your life is about to reach an end… Except if you are properly linked to a satellite!


Figure 1 – Telephone linked to the satellite constellation Iridium manufactured by Thales Alenia Space

Then you can call anywhere on the earth and connect to anyone in a snap. The problem is to figure out how the satellite will know when and where to help you and that’s the moment my project comes into place. Louis described the ears of the satellite with mind-boggling antennas, I consider my work has more to do with the brain of the satellite: it must know in which region on earth it must focus its ears. To use specific words, my work is on satellite payload. But why adding a load on a satellite ? This payload is the brain of the satellite, it points the antenna and gives proper amount of power in the correct direction so you can for example communicate or surf the Internet. The payload shares these services with all the people who pays to use the satellite. This may seem easy but sometimes enabling a lot of people to use the satellite at the same time is a problem to pull one’s hair out. Just remember that time you wanted to send a text or make a call at New Year’s Eve. If the network is crowded you must find some way out, it is the same with satellite network so the focus of satellite’s resources must be on the busiest regions. On the contrary, steering the antenna towards Sahara desert would be quite pointless…

Moreover in the case you want to serve a busy area, interference between users becomes a serious problem you must take into account. If you want to have an idea of what interference is, imagine a meeting where everybody is speaking at the same time, the voice of each other would jam the conversation and it would result in a joyful cacophony. Exactly the same phenomena happens in some cases when either the satellite speaks to users on the ground or users on the ground to the satellite. Mitigating these effects is also part of my work.

To wrap it up, my work is to make satellites’ architectures smarter, more flexible to any situation that may occurs whether you are in Antartica at the brink of death or if you just want to wish a happy new year to your loved ones. The video presenting Thales Alenia Space constellation Iridium with worldwide coverage is below: