Deep-space motion control expertise

The German Mittelstand manufacturer offers standard and custom designed products and systems covering stepper motors, linear actuators, precision mechanics, feedback systems, power electronics, and motion controls. Phytron’s application expertise covers many fields of industry and sciences for earth-based motion systems where numerous environmental challenges arise, but the most demanding applications are found in deep-space exploration craft and satellite systems. Phytron’s phySPACE range of space-certified drives are meticulously engineered to deliver optimal robustness, withstand intense vibration, resist radiation exposure, tolerate high operating temperatures, and perform with complete reliability in ultra-high vacuum.

One of the latest phySPACE space-certified applications has been recently delivered to the University of Bern, Switzerland, where specially engineered stepper motors are used on a high-precision laser-based mass spectrometer scheduled to land near the Moon’s south pole in 2029. The instrument is part of the payload for the Blue Ghost Mission 4, by Firefly Aerospace (USA) which encompasses NASA’s Commercial Lunar Payload Services (CLPS) initiative that enables the delivery of scientific payloads to the Moon. The spectrometer will examine the lunar south pole’s surface for chemical and isotopic composition. This research aims to advance our knowledge of the Moon’s geochemistry and foster an increased understanding of the solar system's origins and resources for future missions.

As part of the design requirements Phytron provided the stepper motor housings in precision machined titanium alloy with a PVD (Physical Vapour Deposition) gold coating applied by the University of Bern’s research team. This gold layer is more than just an attractive feature—it plays a crucial thermal role by preventing excessive radiated heat transfer from the motor to nearby assemblies that require optical stability. Consequently, most of the heat is carried away through conduction rather than radiation, helping to protect sensitive neighbouring systems.

Space-bound motors and actuators must operate reliably within a range of harsh environmental conditions. These demanding settings can be defined by one, or a combination, of the following factors:

• Extreme Temperatures: The operating environment may expose the motor to extremely low temperatures as low as -270⁰C, or extremely high temperatures reaching up to +300⁰C
• Ultra-High Vacuum: Motors must withstand vacuum levels that can reach 10-11 Torr. Such conditions require careful consideration for undesired gas emissions from materials and components
• Ionising Radiation: Drive systems are subject to ionising radiation, which may deteriorate materials and mechanisms. Exposure levels can be as high as 108 Rad
• Aggressive Environmental Conditions: Certain applications require motors or actuators to be hermetically sealed to protect against contamination and ensure operational integrity
• Minimal weight: In addition to their resilience, phySPACE drive designs are optimised for size and weight, contributing to overall mission payload efficiency.

These challenges define the rigorous requirements for motion control systems used in space exploration, demanding the highest standards of engineering and manufacturing to ensure dependable performance throughout mission lifetimes. Phytron’s products and processes meet strict European Cooperation for Space Standardisation (ECSS) requirements confirming they can withstand space flight environments.

Whether harsh industrial, extreme, or space application environments, microstepping motors stand out as the primary technological drive solution for Phytron. Their unique design, which eliminates direct contact between the rotor and stator components, results in minimal wear and ensures ongoing reliability. The motors operate flawlessly with digital open-loop controls, and the capability to verify position using robust and non-contacting resolvers or encoders further enhances their suitability for demanding environments. These benefits make stepper motors the preferred choice for tasks requiring precision, durability and long-term reliability. For Phytron, stepper motors are employed both as stand-alone units, or as integrated assemblies with precision gearboxes and/or mechanics as part of complete linear or rotary positioning solutions - paired with complementary drives and motion controls for single or multi-axis applications.

For decades, Phytron has been renowned for delivering high-precision motion solutions that thrive in the most extreme environments, from cryogenic particle accelerators to ambitious interplanetary missions. Phytron’s story in space technology began in 1985 with ESA’s Giotto mission – one of Europe’s pioneering deep-space probes. Giotto captured the world’s attention with its close encounter with Halley’s Comet in March 1986 and later with Comet Grigg–Skjellerup in 1992. During these landmark missions, Phytron played a vital role by providing custom-developed actuator systems that precisely control position and movement that is essential for adjusting scientific instruments in space, ensuring accuracy and reliability in unforgiving conditions. These early achievements marked a turning point in European space history and has set the stage for future innovation.

Building on its pioneering work with ESA’s Giotto mission, Phytron has continually advanced its technology to meet new challenges, these include the ROSETTA space probe, NASA’s Mars Rover, the James Webb Telescope, the Chandrayaan-3 moon mission, and numerous navigation and scientific satellites. Culminating in this latest lunar endeavour, Phytron’s drives continue to demonstrate their reliability in countless scientific and space applications.

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