Sometime soon NASA will send its fifth rover to Mars, where its main mission will be to collect soil samples that will be analysed on Earth once they have been collected by a future mission. Interestingly, n this mission the rover will also carry a helicopter that will perform the first flights on the Red Planet, and maxon's precision DC and BLDC motors are being used for numerous critical tasks on the project.
maxon's drive systems are already omnipresent on Mars, because the electric motors from Switzerland have been used in virtually every successful robotic mission there over the last three decades. There are now more than 100 of them on the Red Planet and there are likely to be more soon as the launch window for NASA's next mission nears on July 17. An Atlas V rocket will send the new Perseverance rover on its way to Mars, where it will seek signs of former life on the planet. However, its most important job remains the taking of multiple soil samples, sealing them in containers and depositing them on the surface of the planet so that a future mission can return them to Earth.
Several maxon motors will be used to handle the samples inside the rover. For example, DC motors are installed in the robotic arm which moves the samples from station to station, and maxon motors will also be used for sealing and depositing the sample containers. NASA's Jet Propulsion Laboratory (JPL), which is carrying out the mission, has contracted maxon to produce 10 drives for the rover. As with almost all previous Mars missions, these drives are based on standard products from maxon's catalogue but have been modified.
For the first time, NASA chose brushless DC motors: nine EC 32 flat and one EC 20 flat in combination with a GP 22 UP planetary gearhead. Working closely with JPL specialists, maxon engineers developed the drives over several years and tested them thoroughly to achieve the highest standards of quality. Robin Phillips, head of the maxon SpaceLab says: "We've learned a lot from this exciting project. We now have very broad expertise in space applications and have established quality assurance processes that meet the expectations of the industry. Customers from other industries such as the medical sector, where requirements are often similar, also benefit from this know-how".
Space missions place the highest demands on drive systems. These include vibrations during the rocket launch, vacuum during the journey, impacts on landing, and harsh conditions on the surface of Mars, where temperatures fluctuate between -125 and +20degC and dust penetrates everywhere.
The Perseverance rover is expected to land on Mars on February 18, 2021 - but it won't be alone, because a drone helicopter called Ingenuity will be attached to its underside. It weighs 1.8kg, is solar powered and will perform several short flights, as well as take overhead images. The main goal of this experiment is to test the concept for further drones of this kind in the Martian environment. Once again, drive specialist maxon is involved, with six brushed DCX motors (each with a diameter of 10mm) controlling the tilt of the rotor blades and therefore the direction of flight.
The drives are very light, dynamic and energy-efficient, properties which are crucial because every gram counts on the Mars helicopter. Flying on Mars is unlikely to be easy: the atmosphere is extremely thin, roughly comparable to the conditions on Earth at an altitude of 30km. The drone helicopter has already flown in a simulated test environment in the JPL laboratory and whether or not it will lift off on Mars remains to be seen. First, other obstacles, such as the rocket launch, must be overcome. maxon CEO Eugen Elmiger says: "We hope that everything goes well and that we'll soon see our drives in action on Mars. We're all keeping our fingers crossed".
Learn more about maxon drives at www.maxongroup.co.uk.