Date of Award

Fall 12-16-2022

Level of Access Assigned by Author

Open-Access Thesis

Degree Name

Master of Science (MS)


Civil Engineering


William Davids

Second Committee Member

Andrew Young

Third Committee Member

Eric Landis


The Hypersonic Inflatable Aerodynamic Decelerator is a stack of concentric, inflated rings (tori) being developed by NASA for landing spacecraft. This research will build on work previously done at UMaine to understand the structural behavior of the HIAD by examining the response of two tori paired together. A test fixture previously used to test single tori was analyzed and modified to withstand the estimated forces from testing paired tori. Two single tori of different sizes were tested separately on the fixture at various inflation pressures. The tests consisted of displacing the tori equally at 16 discrete points using cables attached to individual actuators. The actuators were synchronized using a modified version of the control code used previously. Noncontact photogrammetry data, as well as the forces in each cable, were collected throughout each test. The photogrammetry data will also be used to determine the displaced shapes of the specimens. The testing was repeated with a paired specimen consisting of two tori of the same sizes as tested previously. A finite element model of the paired tori was developed and verified using data collected from the physical tests.