Damping And Vibrations Experiment
California Polytechnic State University, San Luis Obispo

Satellite	Status	NORAD	Uplink	Downlink	Beacon	Mode	Callsign	Reports	Info	IARU freq coord	Telemetry Decoder
CP-7 (DAVE)	ACTIVE	43615			437.150	9k6 FSK AX.25	WI2XNR-1	latest report	details	YES

The DAVE mission implements a payload to evaluate a mechanical damping technology in microgravity. This technology, called particle damping, exploits the
dynamics of multiple constrained particles to dissipate vibration energy. Terrestrial applications demonstrate particle damping performance to be largely unaffected by extreme environments yet simple and cheap to implement. This feature set makes particle damping an attractive technology for applications in spacecraft, where dampers are needed to steady sensitive instrumentation and inhibit destructive structural resonant modes.
In orbit, DAVE provides a low cost and low-risk platform to acquire data to characterize unknown particle damper microgravity behavior. Simultaneously, the mission achieves flight heritage for particle damper technology. The completion of these objectives overcomes barriers currently inhibiting the employment of particle dampers in space.

Particle dampers

Particle dampers are mechanical damping devices that consist of an enclosed cavity filled with particles. When the particles are subjected to vibration the momentum exchanges and frictional forces of these particles create a damping effect that can be optimized to suit a number of applications over a broad frequency and amplitude range. In space-based applications, these particle dampers could potentially serve as a robust and simple device to eliminate jitter in optical assemblies or other sensitive scientific equipment. However, particle dampers have never been tested in a microgravity environment, and modeling their performance in microgravity proves problematic, as their effectiveness is highly nonlinear and dependent on orientation with gravity. The proposed experiment provides data to characterize two variations of these dampers under microgravity conditions. Their performance will be compared to a control and ground-based test. The experimental set up consists of the two particle damper configurations and one mass model control, each fixed to a cantilever beam. These beams are driven over a frequency range centered on their first mode resonant frequency. Through the observation of their steady-state response, a mathematical model is used to assess the damper performance. By repeating this test under a range of input amplitudes, the degree of nonlinearity in the dampers is ascertained. The conclusions of this experiment will determine the feasibility of using particle dampers in space and provide reliable models on which to base further investigation or actual space-based applications.

Telemetry

CP7 DAVE RF spectrum

ELFIN-B High-Speed SoundModem by UZ7HO – Ver 0.18b – FSK G3RUH 9600bd

2018-09-17 16:21:17.960 UTC: from WI2XNR-1 
000 > C0 00 00 00 00 00 00 00 00 AE 92 64 B0 9C A4 03 03 CC 45 00 
020 > 00 F6 00 00 40 00 01 11 84 89 81 41 93 2B E0 00 00 01 C3 50 
040 > 00 02 00 E2 C3 2A 01 D1 D1 D0 D7 4D 8A 37 6A 00 6B 00 00 00 
060 > 00 00 00 00 6A 00 00 8B FE 26 4E 8B 01 23 65 CC 8A 00 B7 8A 
080 > 03 CD 8A 02 F3 8A 01 AA 00 01 1D FA 00 15 CB 4B 00 04 09 D6 
100 > 00 F6 98 7C 00 00 72 31 00 01 00 00 00 00 9B 64 00 00 07 F8 
120 > 00 00 FD 4C 00 0D B8 00 00 04 25 B4 00 0A DF B8 00 35 56 80 
140 > 02 6F 5E 9B 56 24 00 00 09 80 4E 1B 4B 3F F9 FF 4B 3D 3A ED 
160 > 02 BF 00 10 00 08 00 01 00 00 00 1C 00 00 57 79 00 00 04 C8 
180 > 00 89 4D 4C 00 00 00 00 00 00 00 00 00 00 30 00 00 00 00 00 
200 > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
220 > 00 00 00 00 00 0B C6 A8 FF F3 74 BD 00 03 D7 0A FF DD B3 34 
240 > 00 52 0A 3D 00 0F D1 EB 00 00 0D 4C 00 00 1A 98 00 00 61 64 
260 > 00 00 00 00 C0