Sherpa Acceptance Vibe Testing: Success/Complete

We hit another critical/important milestone as we prepare for our next mission with our latest generation Sherpa-OTV, Sherpa LTC. We conducted testing on the primary Sherpa structure, the Configurable Annex Base (CAB), putting it through environmental testing to clear its use for flight on SpaceX’s Transporter-3 no earlier than January 2022. The completion of this testing clears Sherpa to start customer integration and the final configuration for flight. We are pleased that all is going smoothly and all systems are go!

The ride to space is not a benign environment, and preparatory testing is a must. We do this to ensure not only that Sherpa will survive — and thrive, but there are no failures that can impact our customers’ spacecraft or our launch vehicle provider. That’s why we subject Sherpa to an environment and load testing more severe than it would see in flight. We take the effort to do the rigorous analysis to ensure that the environments we provide to our customers represent as close as the flight loads as possible.

Our testing was completed at NTS facility in Santa Clarita and included acceptance vibe testing for the Sherpa-FX3 and LTC1 CAB. This testing included:

• Perform Sherpa-FX3 Vibration Acceptance Testing (y-axis)
  • Pre-test baseline sine sweep to characterize the structure
  • Quasi Static Sine Burst test, Sine Vibration test, Random Vibration test
• Complete testing on FX3 unit in the second horizontal axis
• Reconfigure shaker table to test vertical axis
• Complete FX3 Testing in the vertical axis
• Swap out the FX3 unit for the LTC1 test unit
• Instrument Sherpa-LTC1 test unit. Same 10 triaxial accelerometer setup as FX3.
• Begin Testing on LTC1 Vehicle. Rinse & Repeat.
• Complete Sherpa-LTC1 vibration acceptance testing in all axis
• Data review and procedure closeout for both test units

Basic vibration engineering tells us that the loads our customers experience will not be exactly that of the launch vehicle, Sherpa does change things. So this is not only a validation of those customer loads, but also an opportunity for us to refine our analysis techniques for the next mission.

Chief Engineer at Spaceflight Adam Hadaller agrees, adding: “We’re breaking new ground at Spaceflight through applying a standardized test campaign on all Sherpa vehicles to verify launch environmental compatibility and fully characterize load transfer through our vehicle to customer payload interfaces. Our test approach proves vehicle robustness while developing environmental loading for our customers’ spacecraft to ensure the highest level of mission assurance.”

At Spaceflight, our Sherpa OTV system allows us to offer unprecedented flexibility for our customers, and must pass the most rigorous of testing to make sure that it can take customers’ spacecraft to orbit as efficiently and as cost-effectively as possible. We’re happy to report that it has passed all tests with flying colors so far!