“The first time ESA introduced the project to us, I was thinking how challenging projects in the space research domain are and how great would it be to contribute to them.”
PDEng ST trainee Dmitriy Kondrashov definitely was not the only one who accepted this challenge. No less than 14 TU/e PDEng ST and ASD/MSD trainees enrolled for the project at the European Space Research and Technology Centre (ESTEC), the technical heart of ESA. Eight weeks later, they all gathered at Noordwijk for one final meeting; in a crowded room with the curtains closed, to present their work to the staff of the Software Systems Division.
“We have been in contact with ESA for a while to find the right project that fits our PDEng programs”, says dr. Yanja Dajsuren, Program director of the PDEng ST program. Marcel Verhoef, software engineer at ESTEC, adds: “Usually we invite individual students and young graduates at ESTEC, to make the new generation of engineers familiar with our field of work. We now found a project that gave us the opportunity to define a group assignment, which also had a multidisciplinary character.”
This project Dajsuren and Verhoef are talking about, was all about simultaneously controlling several UAV’s (unmanned aerial vehicles). The objective for the PDEng trainees was as follows: Demonstrate three quadcopters flying in formation, modeled with TASTE — ESA’s open source toolset for model-driven software engineering — in order to demonstrate the role of software in spacecraft.
From five to three drones in eight weeks
It may sound easy, but PDEng ST Program director dr. Ad Aerts assures this is not the case: ”A quadcopter has four propellers, which are controlled by separate motors and a complex set of algorithms. It is challenging to make the quadcopter fly steady enough to allow formation flying.” He continues: “Many different factors affect the stability of the quadcopter. For example, the remaining battery power has impact on the maximum acceleration of the propellers.” Some of these properties had to be discovered by trial and error. This also reflects in the project’s equipment. Aerts: “We started the project with five quadcopters, including spare parts. After eight weeks, only three of them were left…”
However, trying to make the quadcopters fly was not the first step of the project. It all started with a training day at ESTEC, to master modeling with TASTE. In the weeks afterwards, the system design, simulation, prototype, and positioning system were developed during various sprints. First of all, these sprints helped developing the technical skills of the trainees. But Dmitriy Kondrashov gained something more: “As a project manager, I also learned how to smoothen the work process, create a good work environment, and establish a strong connection between our team and ESA.”
Ready for industry
Yanja Dajsuren complements the words of Kondrashov: “Our postgraduate PDEng Software Technology (ST — formerly known as OOTI) and PDEng Automotive Systems Design/Mechatronic Systems Design (ASD/MSD) programs prepare trainees for an elite career in industry. Not only by increasing their scientific and technological knowledge, but also by developing other professional skills they will need in their future careers.”
The two-year salaried programs of the Department of Mathematics and Computer Science can be followed after gaining a Master’s degree in one of several technological fields. After carrying out three in-house training projects and a final graduation project, the trainees will receive a Professional Doctorate in Engineering degree.
The final presentation at ESTEC was a success. The PDEng trainees managed to make three drones fly in formation, and even demonstrated this on the spot. Marcel Verhoef: “The goal was very ambitious and it was difficult to estimate in advance how far the trainees would get within the limited time of the project. Having the quadcopters fly in formation within eight weeks, is a good achievement.”
The next goal for ESA is to demonstrate the three flying quadcopters during the open days of ESTEC in October. Verhoef: “The demonstrator will be further developed for the purpose of instruction, demonstration, and research purposes of our TASTE toolset.” Some points of attention in further development are the prevention of in air collisions between quadcopters, and making the demonstrator tolerant to changes in ambient light levels, so we can open the curtains…
Taking the software to outer space
One last question remains unanswered: Why is ESA interested in formation flying? Many of the next generation space missions rely on multiple spacecraft to work closely together in order to meet their mission objectives. For example, for LISA, the Laser Interferometer Space Antenna; three spacecraft are going to fly in a triangular formation separated by 2.5 million kilometers, bouncing a laser beam between them, in order to detect gravitational waves. Or the Proba-3 spacecraft, consisting of two parts that will be performing a very accurate formation flying mission to observe the corona of the Sun. Kondrashov concludes: “The members of our project team are very proud to have contributed to a project that could be having major future impact.”