Space Machines Company: Satellite Vibration Testing

Challenge

The UTS team was engaged to perform vibration testing on SMC’s Optimus vehicle, which is set to launch on a SpaceX Rideshare mission in 2024. The protoqualification tests, run to SpaceX Rideshare protocols, were performed on the mission-ready satellite to ensure it can withstand launch conditions. The “Static Load” sine burst test was completed on the Multi-Axial-Simulation-Table (MAST) based at UTS Tech Lab.

The testing conditions presented a number of unique challenges to the team:

• The high load conditions required the UTS Multi-Axis Simulation Table (MAST) be utilized to 90% of its capacity.
• A bespoke fixture was required to hold the spacecraft in a specific orientation to reach the spacecraft lateral acceleration levels, the main contributor for the first case.
• For the second case, with spacecraft axial acceleration levels as main load contributors, the UTS MAST was programmed to excite the structure in both the axial and lateral directions.
• Effective MAST control system tuning was important for this mass/load combination scenario, as the fixture and structure-under-test were both dynamic, non-linear systems, presenting unique challenges.

Solution

The UTS team, in collaboration with Space Machines Company, developed a completely bespoke solution to meet SMC and SpaceX requirements. The solution delivered:

• The design, manufacture, and modal test of a bespoke fixture to orient Optimus in position to complete the testing.
• Collaboratively developing and testing a “dummy spacecraft” structure (similar mass properties – mass and mass center) for initial testing (bespoke fixture validation) and tuning purposes to validate the test operations and safety procedure for Optimus satellite protoqualification testing.
• Designing and implementing a series of sine burst tests to meet the SpaceX Rideshare Payload Users Guide vibration testing program.
• Collecting acceleration data from the MAST, from locations on the bespoke fixture and from the spacecraft itself (18 locations in three planes with transducers in Lateral and Axial spacecraft orientations) throughout the duration of the testing campaign.
• Processing digitized data using custom software applications to enable the peak acceleration loadings to be determined, with those at the locations of primary importance to SpaceX used to confirm that the spacecraft had been subjected to the necessary peak loadings without failure occurring.
• Collecting high-speed, high frame rate video data simultaneously for quantitative evaluation of the MAST, fixture, and spacecraft performance during all four vibration scenarios.