In satellite communication antenna Earth-scanning, solar array Sun-tracking, space station robotic arm operations, and high-precision servo turntables, rotating mechanisms need to continuously transmit power and control signals under long-term unmanned maintenance conditions. Traditional fixed cables will twist, fatigue, and suffer contact failures under continuous rotation, leading to power interruptions and signal loss. Therefore, space systems typically use slip rings as the “rotary electrical interface” between stationary structures and rotating structures.
Ingiant has developed a 65-circuit space-grade slip ring for aerospace missions, custom-designed for the aforementioned on-orbit scenarios.
I. Channel Architecture: Power and Signal Subsystem Isolation
This slip ring adopts a 65-circuit hybrid configuration:
- · 25 power rings: For high-power circuits such as main power supply, solar wing drive, and actuator power.
- · 40 signal rings: 0.5A per circuit, used for CAN, RS422/485, telemetry, remote control, encoder feedback, low-speed data, and sensitive instrument signals.
Power and signals are physically partitioned in the ring arrangement, with signal rings adding shielding and grounding isolation to reduce crosstalk from high-current switching to low-level signals. For aerospace applications, power rings focus on current-carrying temperature rise, insulation distance, and vacuum dielectric strength, while signal rings focus on contact resistance stability, noise, and bit error rate.
II. Vacuum Compatibility and Low-Outgassing Materials
Space slip rings must operate long-term in a high vacuum. The vacuum environment causes organic materials to outgas and lubricants to volatilize, forming condensation contamination on cold surfaces; meanwhile, without convective cooling in a vacuum, electrical heating relies more on conduction and radiation.
This model is designed for vacuum compatibility at 1×10⁻⁵ Pa. Insulation, potting, bonding, and surface treatment materials prioritize low-outgassing solutions. Aerospace material screening often refers to ASTM E595, using Total Mass Loss (TML) ≤1% and Collected Volatile Condensable Materials (CVCM) ≤0.1% as admission thresholds; for optical proximity or high-voltage areas, requirements can be further tightened. Contact parts can use precious metal alloys according to the project to reduce oxidation and wear products, lowering vacuum contamination risks.
III. Wide Temperature Range and Thermal Cycling Adaptability
Orbital operations involve alternating sunlight and shadow, so slip rings experience rapid transitions between high and low temperatures. The 65-circuit model targets a temperature range of -155°C to +100°C, focusing on three issues:
- · Matching the thermal expansion coefficients of different metals, insulating materials, and packaging materials to avoid ring gap drift.
- · Insulating materials must not crack at low temperatures or soften at high temperatures; aerospace-grade dielectrics such as alumina ceramics and special polyimides are prioritized.
- · Contact pressure must remain stable throughout the entire temperature range to avoid low-temperature jamming or high-temperature contact resistance rise.
Thermal design requires simulation based on rated current, duty cycle, and installation thermal paths, rather than just nominal current at room temperature.
IV. Insulation, Voltage Withstand, and Partial Discharge Control
Insulation performance differs in a vacuum compared to atmospheric pressure; high-channel-density, high-voltage slip rings especially need to control partial discharge. Design points include:
- · Using ceramic/high-temperature polymer composite insulation between rings and layers.
- · Determining ring spacing and potting thickness based on orbital voltage, creepage distance, and vacuum dielectric strength.
- · Factory testing for insulation resistance, dielectric strength, partial discharge, and dynamic contact resistance.
- · Adding differential transmission, filtering, and single-point grounding for shielded layers for sensitive signals.
For next-generation high-voltage satellite platforms, the industry already has verified cases of 400–500V, 8A-class vacuum slip rings, indicating that high-voltage slip rings require separate breakdown and plasma risk assessments in the vacuum to critical pressure range.
V. Low Speed, Long Lifespan, and Launch Mechanics
This model has a maximum speed of 10 RPM, targeting low-speed scenarios such as solar array drives, antenna turntables, and servo positioning. Its design life exceeds 10 years, with a cumulative operation of no less than 20,000 hours. Long lifespan relies on:
- · Low-wear precious metal contact pairs.
- · Constant-force brush wires or fiber brush structures.
- · Vacuum-compatible solid lubrication or non-volatile lubrication solutions.
- · Bearing preload and thermal deformation compensation.
The launch phase must withstand random vibration, sine vibration, and shock. Therefore, the structure is optimized for overall rigidity, and the slip ring, flange, bearing housing, and cable outlet are unified for modal analysis to avoid resonance causing brush wire deviation or insulation cracking.
VI. Lightweight and On-Orbit Maintainability
Space products are sensitive to mass and volume. The slip ring housing uses aviation-grade aluminum alloy with special surface treatment, balancing strength, thermal conductivity, and weight. The 65-circuit high-density layout can reduce axial and radial dimensions, adapting to SADA (Solar Array Drive Assembly), antenna mounts, robotic arm wrists, or payload turntables.
Since on-orbit maintenance is impossible, the design adopts redundant channels, condition monitoring, and derating: critical power supplies can be dual-ring paralleled, critical signals can have dual-channel backup, and contact resistance, temperature, and insulation resistance data can be integrated into the satellite health management system.
VII. Typical Application Scenarios
- · LEO constellations: Continuous rotation of spaceborne antennas, power supply and data return for phased array turntables.
- · GEO communication satellites: Long-term transmission of high-stability power + telemetry signals.
- · Solar Array Drive Assembly (SADA): Power slip rings replace flexible harnesses to achieve continuous solar panel Sun-tracking rotation.
- · Space station robotic arms and adapter joints: Hybrid transmission of multi-channel power, video, and control signals.
- · High-precision aerospace servos: Low-speed positioning, absolute feedback, and holding torque coordination.
Ingiant can provide customized solutions from contact materials, circuit numbers, shaft diameters, vacuum levels to lead wire directions, and cooperate with technical specifications, environmental test outlines, and NDA reviews. If you need the 65-circuit prototype specification sheet or SADA adaptation suggestions, please contact their Aerospace Engineering Team directly for detailed parameters.
Post time: Sep-08-2026