What is a CubeSat?
CubeSats are small satellites built to standard dimensions and launched as auxiliary payloads. They are sent into space with large and expensive equipment, such as a telecommunications satellite, or fit into extra space on a resupply mission to the International Space Station.
Vibration testing verifies a level of confidence that the test item will withstand the highest payload and function afterward if needed.
Vibration Testing Systems
Perform shock and random testing with a complete testing system from Vibration Research (VR), including the controller, shaker, and software. The VR controller hardware features 26,000 lines of resolution for low-frequency control and a low noise floor for a greater dynamic range.
VR9500 I/O Unit
Vibration Research’s best-selling control hardware for vibration and shock testing. Scalable to 128 channels and compatible with all electrodynamic and servo-hydraulic shakers. Features include up to 200kHz sample rate and 2 outputs.
VR10500 I/O Unit
Vibration Research’s high channel count control hardware for vibration and shock testing. Scalable to 512 channels and compatible with all electrodynamic and servo-hydraulic shakers. Features include up to 256kHz sample rate and 4 outputs for multiple shakers.
Vibration Controller Systems
The controller hardware is compatible with all electrodynamic and servo-hydraulic shakers. The VR electrodynamic shaker systems consist of a shaker and a matching linear direct-coupled power amplifier. Additional components may be added to the basic system for a customized system. The systems have been designed and manufactured with shakers and matching amplifiers in-tandem.
Mount the device under test in the three linear directions or employ multi-axis testing to run all three directions at once. Three-axis testing is accomplished by random vibration testing along each axis using identical or individualized test profiles. The three-axis configuration creates a more realistic test compared to traditional single-axis testing.
The VibrationVIEW software allows 2 to 3 test profiles and 2 to 3 control loops to be performed on the x, y, or z-axis.
Commercially available technology such as the tested spectrometer is effective for staying within budget constraints. Space-qualified spectrometers are on the order of $100K each while off-the-shelf spectrometers cost significantly less.
However, maintaining a budget is meaningless without the confidence that the off-the-shelf technology can survive a launch. Vibration testing is required to establish mission viability.
For a spectrometer vibration test, engineers can implement NASA-STD-7001B, a standard that verifies the survivability of spaceflight payload hardware. NASA-STD-7001B is defined for payload testing when the launch vehicle has not yet been determined. When the launch vehicle is known, a test profile specific to that launch vehicle is used for testing.
CubeSat Project with WMU
In 2019, Vibration Research engaged with a team of students from Western Michigan University (WMU) to assist with CubeSat Vibration Testing. The team ran the initial set of tests on an off-the-shelf spectrometer.
Easily Customizable Test Setup
Perform random vibration testing with standard test specifications or a user-defined test profile.
- Enter frequency/amplitude breakpoints in an easy-to-read, tabular format.
- Control constant or ramped acceleration, velocity, or displacement.
- Automatically calculate and enter the frequency of intersection between any combination of constant acceleration, velocity, or displacement lines.
- Enter over 9,999 separate frequency/amplitude breakpoints to meet virtually any test specification.
Short Duration Random Testing
Aerospace facilities often test high-value equipment at extremely high levels of random vibration for a brief period. The goal is to run a test that will identify any reliability issues without damaging the equipment. Ideally, the test engineers want to see a smooth control trace on the PSD that remains within an established tolerance range.
Short duration random vibration tests typically have very tight tolerances (+/- 1.5dB). The statistics of averaging FFT power values limit the possibility that all lines will be within tolerance in a short timeframe. Instant Degrees of Freedom® (iDOF) calculations are a statistically valid way to provide smooth lines and an in-tolerance PSD in a brief testing period.
Access the most common synthetic shock pulses in the industry and fulfill requirements from test standards. Alternatively, select the user-defined transient option to upload a recorded waveform. With the Shock software, repeat a pulse from 1 to more than 2 billion times with a configurable repetition rate. Tests can be configured to run pulses at different amplitude levels.
With the Shock Response Spectrum (SRS) software, define the parameters and synthesize a pulse to meet a specified SRS curve. The package includes a variety of waveform synthesis generation techniques.
Sine Resonance Track & Dwell (SRTD) Control
Manually change SRTD settings during a test and receive feedback on current test settings in the SRTD Controls dialog box. The time-based SRTD graphs display long-term changes in the resonance frequency due to fatigue or product temperature. The phase-based SRTD graphs have a custom layout.
Peak tracking in VibrationVIEW automatically shifts resonances by finding and maintaining the peak transmissibility between two channels. It oscillates the phase between the two channels and observes increases or decreases to the peak transmissibility. As more data is collected, the phase change becomes narrower in frequency and slower in time. This change limits the amount of oscillation while accurately tracking the peak.
This powerful feature minimizes the need for precise detection during the sine sweep so the user can sweep faster. Most importantly, it maintains peak transmissibility throughout the tracked dwell portion of the test.