Session
Next on the Pad Research & Academia
Location
Salt Palace Convention Center, Salt Lake City, UT
Abstract
The 40-kg class micro solar sail “PIERIS,” equipped with a 25 m² reflective membrane, will be launched in 2027. This paper explains PIERIS’s mission design, the unique challenges of this satellite system and their solutions, and the current development status. PIERIS will be launched into LEO at approximately 600 km altitude to demonstrate two novel technologies for addressing significant disturbance torques acting on its large membrane surface.
First, it will demonstrate a technology that actively adjusts the offset between the center of action of external torques and the satellite's center of mass to control these torques. PIERIS connects the bus structure and sail structure using a single motor, allowing the relative position between them to be changed, thereby generating external torques in desired directions. This demonstrates the feasibility of “Integrated Attitude-Orbit Control,” where the sail is oriented to an attitude suitable for orbit control while controlling the external torque through relative position changes on the bus structure.
Second, it demonstrates a technology that applies tension to the sail membrane surface to suppress membrane deformation caused by external forces, thereby reducing disturbance torque caused by deformation. This approach focuses not only on adjusting the tether length connecting the boom and sail but also on the fact that shape errors in the boom caused by coil set due to storage and initial manufacturing errors can affect membrane tension. Therefore, PIERIS uses a metal boom that ensures shape reproducibility before and after deployment. Additionally, a pyramid-shaped sail configuration is adopted to improve attitude stability after deployment.
Realizing these two technologies will significantly expand the applicability of propellant-free orbital and attitude control, from Earth orbit to deep space exploration. Implementing these demonstrations as a compact, lightweight system presents unique design challenges specific to PIERIS. Specifically, a hold-and-release mechanism is required to hold the motor and sail structure during launch, and dimensional design is needed to prevent interference between the bus structure and sail structure during motor operation after release. Therefore, an extendable connection arm was adopted, and harness routing was designed to avoid obstructing arm extension and motor rotation. Additional challenges arise during sail deployment: the tension applied to the membrane creates forces that prevent boom extension. To address this, the center tether of the sail is connected to a constant spring, and the stiffness at the boom root is partially increased, improving extendibility.
Currently, we are advancing the design of the engineering model while conducting sail deployment tests to implement further improvements. This project has been selected for the JAXA Small Satellite Rush Program, with a launch scheduled for FY2027.
Document Type
Event
Engineering Model Development of the Micro Solar Sail PIERIS: Single-Motor External-Torque Control and High-Accuracy Sail-Shape Realization
Salt Palace Convention Center, Salt Lake City, UT
The 40-kg class micro solar sail “PIERIS,” equipped with a 25 m² reflective membrane, will be launched in 2027. This paper explains PIERIS’s mission design, the unique challenges of this satellite system and their solutions, and the current development status. PIERIS will be launched into LEO at approximately 600 km altitude to demonstrate two novel technologies for addressing significant disturbance torques acting on its large membrane surface.
First, it will demonstrate a technology that actively adjusts the offset between the center of action of external torques and the satellite's center of mass to control these torques. PIERIS connects the bus structure and sail structure using a single motor, allowing the relative position between them to be changed, thereby generating external torques in desired directions. This demonstrates the feasibility of “Integrated Attitude-Orbit Control,” where the sail is oriented to an attitude suitable for orbit control while controlling the external torque through relative position changes on the bus structure.
Second, it demonstrates a technology that applies tension to the sail membrane surface to suppress membrane deformation caused by external forces, thereby reducing disturbance torque caused by deformation. This approach focuses not only on adjusting the tether length connecting the boom and sail but also on the fact that shape errors in the boom caused by coil set due to storage and initial manufacturing errors can affect membrane tension. Therefore, PIERIS uses a metal boom that ensures shape reproducibility before and after deployment. Additionally, a pyramid-shaped sail configuration is adopted to improve attitude stability after deployment.
Realizing these two technologies will significantly expand the applicability of propellant-free orbital and attitude control, from Earth orbit to deep space exploration. Implementing these demonstrations as a compact, lightweight system presents unique design challenges specific to PIERIS. Specifically, a hold-and-release mechanism is required to hold the motor and sail structure during launch, and dimensional design is needed to prevent interference between the bus structure and sail structure during motor operation after release. Therefore, an extendable connection arm was adopted, and harness routing was designed to avoid obstructing arm extension and motor rotation. Additional challenges arise during sail deployment: the tension applied to the membrane creates forces that prevent boom extension. To address this, the center tether of the sail is connected to a constant spring, and the stiffness at the boom root is partially increased, improving extendibility.
Currently, we are advancing the design of the engineering model while conducting sail deployment tests to implement further improvements. This project has been selected for the JAXA Small Satellite Rush Program, with a launch scheduled for FY2027.
