This topic page covers shock testing of spacecraft and component sub-assemblies or parts. Shocks are very short and high intensity loads (i.e., high peak acceleration and high frequency content) caused by separation and deployment events that can damage spacecraft hardware. Shock testing either involves the application of a shock pulse or a shock response spectrum (SRS) vibration at the mechanical interface of the test article. This testing ensures that the spacecraft will survive the shocks present in the launch environment and can provide response accelerometry for validation and refinement of structural analysis models.
Resources in this topic area are primarily standards which provide parameters and methodologies for defining shock test loading and case studies documenting shock testing of spacecraft hardware.
Conduct comprehensive inspection and functional testing on the test article before and after vibration testing and compare results to detect damage. For electronics, functional testing at hot and cold temperatures following vibration testing is a good way to identify broken wires and solder joints which may not be detected with an ambient post-shock functional test.
Carefully plan for shock testing and document these plans in detail. Review your test plan with key stakeholders on your team and, if applicable, with test facility personnel. Facility specific equipment and processes can significantly impact these plans (e.g., accelerometry positioning, test fixture design, etc.) and should be carefully considered in advance.
Accelerometer data from vibration testing can be an powerful tool for validation and refinement of structural analysis models. Carefully plan out shock test accelerometer positioning to validate both (1) the excitation close to structural interfaces and (2) response at locations where your modeling predicts relatively high response in modes within the applied shock response spectrum.
If it is not required by your launch provider, carefully consider whether shock testing is necessary. The attenuated shock response spectrum may be bounded by the random vibration spectrum.
In many CubeSat deployers, the spacecraft is allowed to translate small distances between the the CubeSat and deployer rails. These impacts can create substantial shocks during launch. If your spacecraft includes shock-sensitive components (e.g. crystal or ceramic parts) and dampening is not present at these interfaces, consider including conservative shock testing in your test plan.
This website provides in-depth tutorials and software tools for structural analysis. This includes sections ... on vibration response spectrum, damping, shock and shock response spectrum, random vibration, and many other topics relevant to the structural analysis of space hardware. This is a good place to go to improve your understanding of the fundamental principles and assumptions behind structural analysis methods. Some content can be accessed without a subscription, but a subscription is required for full access.
Section A.3.2 provides guidance on the attenuation of the shock response spectrum (SRS) with distance ... from the source (i.e. system-level interface) and with the interfaces between the source and the subassembly or component being analyzed.
This handbook "provides guidance for laying out a mission success approach for CubeSat missions." Section ... 2.3.3 Mechanical Shock Environment, provides guidance for both subsystem and payload mechanical shock tests at a high level.
Satellites experience large shocks during separation from the launch vehicle. This article details a ... methodology for estimation of the shock response spectrum (SRS) due to satellite separation and makes comparisons to experimental data to validate the simulated results. This provides a valuable example of application of test data to validation of shock simulation results and presents a method for estimating the SRS imposed on a small satellite upon separation.
This article introduces spacecraft pyroshock analysis and testing methods and then addresses important ... and practical issues regarding pyroshock attenuation. This information is useful because shock attenuation modeling has a very significant impact on test conditions. In addition, the testing described here could serve as a useful introduction to time (Section 3) and frequency-domain (Section 4) shock excitation.
This standard provides environmental and structural ground testing requirements for space hardware. This ... is a very comprehensive and traditional requirements document not appropriate for determining requirements for most smallsat projects; however, it provides definitions, baseline requirements, and specific methodologies for each type of test and can serve as a valuable reference to inform smallsat testing. This section titled "Unit Shock Test" provides shock test requirements and reasons to waive the requirement for shock testing.
This handbook provides in-depth guidance on testing of space vehicles. This is a dated but comprehensive ... source of space hardware test environments and processes that could be used to inform test planning and execution for smallsat projects. This section covers pyrotechnic shock testing of space vehicles.