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Analysis of Vibratory Data Collected by the Space Acceleration Measurement System (SAMS) on Blue Origin, June 19, 2016

Kevin McPherson
Kevin McPherson
, 
Eric Kelly
Eric Kelly
, 
Jennifer Keller
Jennifer Keller
, 
Ajeeth Ibrahim
Ajeeth Ibrahim
, 
Erika Wagner
Erika Wagner
 oraz 
Kenneth Hrovat
Kenneth Hrovat
   | 21 lip 2020
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Article Category: Research Article
Data publikacji: 21 lip 2020
Zakres stron: 2 - 10
DOI: https://doi.org/10.2478/gsr-2017-0006
Słowa kluczowe
© 2017 Kevin McPherson et al., published by Sciendo
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Figure 1

SAMS sensor location within the New Shepard vehicle. (A) The New Shepard vehicle, showing the capsule on top. (B) A top-down cross-sectional view of the capsule with six payload stacks uniformly distributed around its perimeter; the payload locker that housed SAMS was at about the 8 o’clock, position #3. (C) A perspective view of the SAMS payload locker. (D) A top-down view of the SAMS sensor mounted within its payload locker with cabling for power and data.
SAMS sensor location within the New Shepard vehicle. (A) The New Shepard vehicle, showing the capsule on top. (B) A top-down cross-sectional view of the capsule with six payload stacks uniformly distributed around its perimeter; the payload locker that housed SAMS was at about the 8 o’clock, position #3. (C) A perspective view of the SAMS payload locker. (D) A top-down view of the SAMS sensor mounted within its payload locker with cabling for power and data.

Figure 2

Per-axis plot of SAMS acceleration measurements up to 204.2 Hz versus time for three main periods. Note that the mean value computed during the Microgravity Period is subtracted off. The colored bands at the top represent flight periods. The pink band (top) demarks the Separation Period, which was ~2.8 min in duration from 1 s after the Separation event to the Coast End event. The blue band (middle) indicates the Coast Period, which was ~2.2 min in duration from the Coast Start event to the Coast End event. The green band (bottom) marks the very quiet Microgravity Period, which was ~46.8 s in duration from 521.86 s to 568.61 s.
Per-axis plot of SAMS acceleration measurements up to 204.2 Hz versus time for three main periods. Note that the mean value computed during the Microgravity Period is subtracted off. The colored bands at the top represent flight periods. The pink band (top) demarks the Separation Period, which was ~2.8 min in duration from 1 s after the Separation event to the Coast End event. The blue band (middle) indicates the Coast Period, which was ~2.2 min in duration from the Coast Start event to the Coast End event. The green band (bottom) marks the very quiet Microgravity Period, which was ~46.8 s in duration from 521.86 s to 568.61 s.

Figure 3

Spectrogram computed from SAMS measurements and Blue Origin flight information. This three-dimensional plot shows the acceleration spectrum via color-mapped power spectral density (PSD) magnitude versus frequency on the vertical axis, and versus time on the horizontal axis. The PSD color scale was chosen for emphasis during free fall and represents the squared deviation of the acceleration with respect to the mean acceleration during free fall. Although a Hanning window was used to reduce spectral leakage for each of the constituent PSDs in this spectrogram (k = 918), the strong signal near zero frequency should be disregarded as attributable to spectral leakage from sensor bias.
Spectrogram computed from SAMS measurements and Blue Origin flight information. This three-dimensional plot shows the acceleration spectrum via color-mapped power spectral density (PSD) magnitude versus frequency on the vertical axis, and versus time on the horizontal axis. The PSD color scale was chosen for emphasis during free fall and represents the squared deviation of the acceleration with respect to the mean acceleration during free fall. Although a Hanning window was used to reduce spectral leakage for each of the constituent PSDs in this spectrogram (k = 918), the strong signal near zero frequency should be disregarded as attributable to spectral leakage from sensor bias.

Figure 4

A cumulative RMS acceleration versus frequency plot for the three main periods of interest. The Post-Separation Period (red) and Coast Period (blue) mostly track each other, and the New Shepard Microgravity Period stays well below 1 mg RMS up to the sensor cutoff frequency.
A cumulative RMS acceleration versus frequency plot for the three main periods of interest. The Post-Separation Period (red) and Coast Period (blue) mostly track each other, and the New Shepard Microgravity Period stays well below 1 mg RMS up to the sensor cutoff frequency.

Figure 5

Comparison of RMS acceleration levels below 10 Hz versus microgravity duration for several different types of platforms (Ross, 2001).
Comparison of RMS acceleration levels below 10 Hz versus microgravity duration for several different types of platforms (Ross, 2001).

Root-mean-square accelerations calculated for the Coast Period.

Root-Mean-Square Acceleration (mg)
FrequencyX-AxisY-AxisZ-AxisTotal
Below 50 Hz0.321.231.001.23
Below 200 Hz10.104.137.0311.14

Five-number statistical summary of acceleration magnitudes during the Microgravity Period.

Acceleration Magnitude (mg)
PercentileX-AxisY-AxisZ-AxisTotal
25th0.100.060.070.25
50th0.220.140.160.36Median
75th0.370.240.270.52
97.5th0.760.480.560.94
MAX2.271.181.452.77

Five-number statistical summary of acceleration magnitudes during the Post-Separation Period.

Acceleration Magnitude (mg)
PercentileX-AxisY-AxisZ-AxisTotal
25th0.280.170.200.47
50th1.450.620.923.37Median
75th8.603.075.0111.91
97.5th51.1110.2516.9254.75
MAX230.48143.29178.41276.18

Root-mean-square accelerations calculated for the Microgravity Period.

Root-Mean-Square Acceleration (mg)
FrequencyX-AxisY-AxisZ-AxisTotal
Below 50 Hz0.010.070.030.08
Below 200 Hz0.320.200.230.45

Root-mean-square accelerations calculated for the Post-Separation Period.

Root-Mean-Square Acceleration (mg)
FrequencyX-AxisY-AxisZ-AxisTotal
Below 50 Hz0.250.940.751.23
Below 200 Hz8.603.666.0611.14

Five-number statistical summary of acceleration magnitudes during the Coast Period.

Acceleration Magnitude (mg)
PercentileX-AxisY-AxisZ-AxisTotal
25th0.290.180.210.47
50th2.380.911.465.13Median
75th10.293.515.8113.68
97.5th57.3410.5617.6459.93
MAX230.48143.29178.41276.18
eISSN:
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Język:
Angielski
Częstotliwość wydawania:
2 razy w roku
Dziedziny czasopisma:
Life Sciences, other, Materials Sciences, Physics
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