Session: 02-01-02: Dynamic Loads, Response, Vibration and Alleviation of Aerospace Structures - II

Paper Number: 110259

110259 - Experimental Validation of Cubesat On-Orbit Vibration Data via Ground Tests 

Thin-ply composite laminates are widely used in deployable space structures for small satellites due to their low mass and high packing efficiency. However, there is a significant knowledge gap in terms of the effect that these deployments have on the chassis of the satellite. As the size of deployable structures increases, this information becomes all the more important. Ut ProSat-1(UPS-1), a 3U cubesat, led by a student team from Virginia Tech, aims to passively self-deploy a bistable composite boom on orbit. This boom has an IMU at its tip and another one near its root inside the chassis. It also has copper traces running through it for transferring power and data to and from the payload control module. These two IMUs together will measure the frequency response of the structure in terms of the transverse acceleration due to the deployment of the boom. Here, we present the results of ground tests that were designed to validate the on-orbit data from this mission. In accordance with the system level philosophy of “test as you fly and fly as you test”, these experiments were devised to resemble the environmental conditions experienced by UPS-1 in space. In order to replicate the thermal effects, a “day in the life” simulation was performed in an environmental chamber under a pressure of 10^-3 Torr and with temperature cycling from -30 to 60°C. In a second set of experiments, to mitigate the effect of gravity on the results, the cubesat chassis was suspended from the ceiling with the help of an overhead crane and nylon strings. Soft springs were connected to the strings to allow deployment of the boom with negligible stiffness interference. The boom was repeatedly deployed and retracted in different orientations and the acceleration response was measured in both the tests. As these tests could not be performed simultaneously, exact replication of the space environment could not be achieved. As a solution, it was decided to have sufficient margin on the design parameters for the flight mission. Any difference between the flight and ground test data was noted and has been presented here. 

Presenting Author: Deven Mhadgut Virginia Tech

Presenting Author Biography: Deven is a PhD student at Virginia Tech working with Prof. Jonathan Black and Dr. Sheyda Davaria. He has previously obtained an MS in Aerospace Engineering at the University of Colorado, Boulder. His current work involves study of experimental dynamic characterization of thin composite booms for space applications.

Authors:

Deven Mhadgut Virginia Tech
Austin Phoenix Virginia Tech
Jonathan Black Virginia Tech
Gustavo Gargioni Virginia Tech
Robert Engebretson Virginia Tech