Session
Poster Session 1
Location
Salt Palace Convention Center, Salt Lake City, UT
Abstract
Increased industry demand for microsatellite missions calls for aggressive project timelines without sacrificing intricate development practices. Delivering missions at a faster pace relies strongly on both assembly processes, and ground support equipment, used through mission development cycles. Procedural challenges often arise in positioning larger spacecraft within the laboratory environment for various testing campaigns. Deployable mechanism, vibration, thermal vacuum, and electromagnetic compatibility testing often require spacecraft to be held under multiple orientations. Dual-axis rotation devices offer a means to position spacecraft in any orientation, proving a versatile spacecraft assembly, integration, and testing platform.
The development of a low-cost dual-axis rotation device is presented for use in microsatellite assembly, integration, and testing. The Test Workstation for Integration of Spacecraft Technology and Rotation (TWISTR) will enable functional and environmental testing of a 60-kg microsatellite mission. As such, the device is designed and tested to meet applicable ground support system requirements for use at various launch vehicle integration sites.
TWISTR facilitates dual-axis rotation using a crossed roller bearing mounted orthogonally to an automotive engine stand. Primary axis rotation is driven by a worm gear within the engine stand assembly to prevent back driving. Secondary axis rotation is accomplished by operator intervention on the unconstrained bearing, and the angle can be fixed in discrete increments using a spring-loaded tapered pin. A cradle structure enables the crossed roller bearing to be mounted orthogonally to the engine stand. The cradle structure is designed with members dedicated to supporting orthogonal bending modes associated with various orientations. This allows for future design scalability, as the structural design performance can be adjusted through the sizing of only six structural members.
Finite element analysis is conducted to verify the sizing of the cradle structure for a 60-kg satellite with consideration for future missions. The pin taper angle of the secondary axis locking mechanism is selected such that the mechanism cannot slip out of engagement regardless of the mass or mass center of the spacecraft. Sizing of the taper pin is accomplished through leveraging stress concentration factors in literature to compute contact stresses at the tip and root of the pin.
Proof load testing is conducted with loads in excess of the baselined 60-kg microsatellite, as to certify the design for use with future missions. Testing methodologies and justification is presented herein.
Document Type
Event
TWISTR: A Scalable, Low-Cost Microsatellite Rotation Device for Spacecraft Assembly Integration and Testing
Salt Palace Convention Center, Salt Lake City, UT
Increased industry demand for microsatellite missions calls for aggressive project timelines without sacrificing intricate development practices. Delivering missions at a faster pace relies strongly on both assembly processes, and ground support equipment, used through mission development cycles. Procedural challenges often arise in positioning larger spacecraft within the laboratory environment for various testing campaigns. Deployable mechanism, vibration, thermal vacuum, and electromagnetic compatibility testing often require spacecraft to be held under multiple orientations. Dual-axis rotation devices offer a means to position spacecraft in any orientation, proving a versatile spacecraft assembly, integration, and testing platform.
The development of a low-cost dual-axis rotation device is presented for use in microsatellite assembly, integration, and testing. The Test Workstation for Integration of Spacecraft Technology and Rotation (TWISTR) will enable functional and environmental testing of a 60-kg microsatellite mission. As such, the device is designed and tested to meet applicable ground support system requirements for use at various launch vehicle integration sites.
TWISTR facilitates dual-axis rotation using a crossed roller bearing mounted orthogonally to an automotive engine stand. Primary axis rotation is driven by a worm gear within the engine stand assembly to prevent back driving. Secondary axis rotation is accomplished by operator intervention on the unconstrained bearing, and the angle can be fixed in discrete increments using a spring-loaded tapered pin. A cradle structure enables the crossed roller bearing to be mounted orthogonally to the engine stand. The cradle structure is designed with members dedicated to supporting orthogonal bending modes associated with various orientations. This allows for future design scalability, as the structural design performance can be adjusted through the sizing of only six structural members.
Finite element analysis is conducted to verify the sizing of the cradle structure for a 60-kg satellite with consideration for future missions. The pin taper angle of the secondary axis locking mechanism is selected such that the mechanism cannot slip out of engagement regardless of the mass or mass center of the spacecraft. Sizing of the taper pin is accomplished through leveraging stress concentration factors in literature to compute contact stresses at the tip and root of the pin.
Proof load testing is conducted with loads in excess of the baselined 60-kg microsatellite, as to certify the design for use with future missions. Testing methodologies and justification is presented herein.
