Rollon and Skyward for the launch of a sounding rocket

Rollon and Skyward Experimental Rocketry – a student association of the Politecnico di Milano, – will collaborate for the third consecutive year on the launch of a sounding rocket during the European Rocketry Challenge. The Lyra rocket, star of the 2024 edition of the competition, will mount linear guides supplied by Rollon on its aerobrakes. But the collaboration does not stop there: this year Rollon also supplied a linear guide for a new test bench.

For the third year running, Rollon and Skyward Experimental Rocketry – a multi-disciplinary student association bringing together engineers from different faculties of the Politecnico di Milano, – will collaborate on the design of a rocket that will be launched during the 2024 edition of the European Rocketry Challenge (EuRoC), Europe’s first university rocket launch competition.

Skyward will participate in EuRoC 2024 with the Lyra rocket. It is a hybrid rocket in that the two reactants in the combustion process – the oxidant and the fuel – are in two different phases of matter. Specifically, the nitrous oxide used as an oxidant is in the liquid state, while the fuel grain composed of a mixture of paraffin wax and ABS is in the solid state. The fuel grain is precisely one of the main technological innovations introduced with Lyra. In fact, the pure paraffin grain is mechanically reinforced by an ABS reinforcement, ensuring even greater performance.

As in previous years, the rocket will mount linear guides supplied by Rollon on the aerobrakes, which will help to ensure the correct functioning of these fundamental components. During the competition, Lyra’s engine will have to propel the rocket as close as possible to the target altitude of 3,000 metres, although it is in fact designed to go beyond this altitude. To succeed, it is necessary to be able to control speed – a task delegated to the aerobrakes, which are regulated by the rocket’s control system. The extraction and re-entry of the aerobrakes are made possible by the linear movement of the Rollon^® guides, which, thanks to their robustness and load-bearing capacity, work together to guarantee the perfect functioning of the mechanism at a speed of 1000 km/h and under a sustained force of around 20 kg each.

Linear guides supplied by Rollon help to ensure the correct functioning of the aerobrakes.

A novelty that opens up future prospects

The year 2024 brings with it a novelty. Rollon has supplied Skyward with an additional linear rail – specifically a Compact Rail Plus – for a new test bench for measuring the mass of the rocket tank.

“The Lyra engine was experimentally validated through ten Static Fire Tests, i.e. tests in which the engine is anchored to the ground and firing is simulated. To fix the engine, a structure called Test Stand, is required. It also has the function of supporting the oxidant tank, a feature that is very important to us,” explains Andreas Oberrauch of the Skyward team. “In fact, to be able to evaluate the various parameters and process the data, we need to know the history of the oxidant mass over time. To do this, we use a load cell positioned below the tank itself, and it is crucial that the tank is only vertically constrained by the load cell itself. In our first tests, the clamping system consisted of two clamps concentric to the tank, which bound the tank to the test stand but did not allow us to measure the mass independently of the clamping system. The reading was therefore incorrect”.

With the Compact Rail Plus linear guide supplied by Rollon, it was possible to solve this problem. In fact, fixing the tank with clamps directly to the slider of the guide allowed sliding only on the vertical translation degree of freedom, used by the load cell for measurement. In addition, the Compact Rail Plus guides can compensate for misalignment, which is essential for this operation as they ensure that there is no friction during measurement that would alter the load cell’s reading. In addition, the Plus version helps to ensure greater rigidity and load support.

The new Test Stand mounts Rollon’s Compact Rail Plus guides for tank mass measurement.

“This configuration proved to be very effective as well as comfortable in the tests conducted,” Oberrauch says.

This opens up new perspectives for the future. “We are considering the possibility of using this configuration to also measure engine thrust in the future. The situation is, in fact, analogous to measuring the mass of the oxidant: to measure the engine thrust, we have to place a load cell on one end of the combustion chamber, thus keeping the degree of freedom of the horizontal movement constrained only by the load cell itself. In this way, the thrust measurement would be derived directly, without the fastening system altering the measurement,” explains the Skyward team.

When Manufacturing meets STEM

2024 marks the third consecutive year of collaboration with Skyward. The partnership began two years ago, when the Skyward team triumphed at the 2022 EuRoC with the Pyxis rocket; it continued in 2023 with the Gemini rocket, which earned the team the Technical Award; and was consolidated this year, with the addition of an interesting new project.

The partnership with Skyward fits perfectly into the objectives of supporting the territory and research that Rollon has always pursued. In particular, it underlines Rollon’s commitment to supporting innovation, research and the development of advanced technologies in the field of aerospace engineering, a sector in which Rollon has been providing expertise and know-how for years.

“Rollon has always been at the forefront of providing linear motion solutions, and to be able to collaborate with an association like Skyward represents a unique opportunity for us to see our products used in such an exciting sector,” says Alberto De Giorgi, Business Developer Aerospace at Rollon. “We are proud to support young talent that contributes to technological innovation and the growth of engineering culture in Italy.”

The 2024 edition of EuRoC will take place from 9-15 October in Constância, Portugal and the official launch, which will be held at the Santa Margarida military camp, can be followed live.

Rollon: Motion Technology for All Types of Automation

Founded in 1975, for over 45 years Rollon has specialized in the production and development of linear motion systems. Since 2018, Rollon has been a part of The Timken Company, representing the linear motion unit within the Industrial Motion division of Timken. Rollon’s solutions are globally adopted in industrial automation, aerospace, medical equipment, material handling, and other sectors where product performance, efficiency and reliability are essential. With the acquisition by The Timken Company of Nadella, Chiavette Unificate, Durbal, Shuton-Ipiranga, and Rosa Sistemi, Rollon is now able to offer its customers an even more comprehensive product range – from linear components, actuators and systems to ball screws and rotational units.

Skyward Experimental Rocketry

Skyward Experimental Rocketry is a student association of Politecnico di Milano founded in 2012 that now has more than one hundred members from different faculties (aerospace, mechanics, computer science, and electronics). Created with the intention of enabling students to get real practice with the theoretical knowledge learnt in class, it has achieved the goal of launching probe rockets beyond 1,000 meters.

The European Rocketry Challenge

Organized by the Portuguese space agency, the European Rocketry Challenge began in 2020 as the first European competition among student associations involved in rocket design and launching. Each year, teams from all over Europe come to Portugal to compete in a precision launching competition in two categories – 3,000 and 9,000 meters. Points are earned by getting closest to the altitude target and, later, retrieving the falling rocket at a specific location. Other awards are also given during the event to acknowledge the best technical report, best teamwork, best design and best flight performance.