National Aeronautics and Space Administration (NASA) Glenn Research Center

Microgravity Environmentat EXPRESS Rack 1 (ER1)

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Kevin McPhersonEric Kelly

Jennifer KellerKen Hrovat

National Aeronautics and Space Administration (NASA) Glenn Research Center

1.Microgravity Environment Components

2.SAMS/MAMS Sensor Locations

3.Vibratory Characterization of EXPRESS Rack 1

4.Quasi-Steady Characterization of EXPRESS Rack 1

5.Roadmaps for the Microgravity Environment

6.Brief Characterization of Some Disturbances

7.Some Things to Consider

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Outline

National Aeronautics and Space Administration (NASA) Glenn Research Center

Microgravity Environment Components

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MAMSGlobal (rigid body)

SAMSMore Localized with Increasing Frequency

a generic label not intended to quantitatively characterize

platform

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Sensor Locations on the ISS

SAMSSE F02, MSG upper left seat track

SE F03, ER2 lower Z panel

SE F04, ER1 lower Z panel

SE F05, ER4 drawer 2

SE F08, ER3 seat track

TSH-ES05, CIR

TSH-ES06, FIR

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MAMS in ER1 (OSS and HiRAP)

National Aeronautics and Space Administration (NASA) Glenn Research Center

Vibratory Characterization of EXPRESS Rack 1

Comparison of GMT 06-Jun-2013 to 07-Jun-2013 (f < 200 Hz):

• Each plot on the left is spectral summary for that day.

• The black-shaped annotations highlight the portion of acceleration spectrum where you will see most significant changes (~90-105 Hz) for ER1.

• To see this in more detail, view the following link (a 30-page PDF) in flipbook fashion and focus on the frequency range from about 90 Hz to about 105 Hz:

http://pims.grc.nasa.gov/plots/user/etchells/2013_06_30_121f04_pcss_roadmaps500.pdf

• For lower frequency concerns, where the changes are much more subtle, see analogous summary at this link:

http://pims.grc.nasa.gov/plots/user/etchells/2013_06_30_121f04one_pcss_roadmaps142.pdf

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Frequency (Hz)5

National Aeronautics and Space Administration (NASA) Glenn Research Center

Quasi-Steady Characterization of EXPRESS Rack 1

MAMS Quasi-Steady Measurements for June 2013:

• X-, Y-, and Z-axis components of quasi-steady (below 0.01 Hz) acceleration vector vs. time for the entire month.

• The red, mean values show mean values derived from ISS rates/angles data for the month:

X = 0.006 ug, Y = -0.141 ug, Z = -0.180 ug

• To see this in more detail, view the link below (a 1-page PDF):

http://pims.grc.nasa.gov/plots/user/etchells/2013_06_one_month_ossbtmf_radgse_map2er1.pdf

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National Aeronautics and Space Administration (NASA) Glenn Research Center

Consider the following timeline:

Web-Based “Roadmap” Resources

• ARCHIVE (lags real-time by 2 days): See roadmap spectrograms for SAMS ER1 Sensor (121f04) at:

http://pims.grc.nasa.gov/roadmap Navigate PIMS roadmaps with calendar view for last ~12 years!

• BUFFER (most recent 48 hours): Roadmap Spectrograms for SAMS JEM Sensor (121f05) at:

http://pims.grc.nasa.gov/plots/user/buffer Browse most recent 2 days of screenshots from real-time.

• REAL-TIME (most recent ~2 hours): Roadmap Spectrogram for SAMS JEM Sensor is updated at:

http://pims.grc.nasa.gov/html/121_f04/PIMS_ISS_color.html This automatically refreshes in browser.

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National Aeronautics and Space Administration (NASA) Glenn Research Center

Brief Characterization of Some Disturbances

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Source Brief Characterization Notes

Progress Reboost* duration = 11.4 minutes, x-axis step = 0.4 mg* mean values based on 24 reboosts

ATV3 Reboost duration = 7.0 minutes, x-axis step = 0.3 mg

Mode One~0.1 Hz, fund. mode of main trussmonitored daily by loads and dynamics teamUSL < 2 ugRMS, COL & JEM < 3 ugRMS (Sept. 2012)

GLACIER Ops two narrowband spectral peaks:(1) 162 ugRMS @ 60 Hz, (2) 112 ugRMS @ 120 Hz

Ku-Band Antenna 5 to 17 Hz, nom. < 500 ugRMS with orbital period variations

MSG Ops broadband, step up 536 ugRMS for f < 200 Hz

Robonaut Ops narrowband peak: 50 ugRMS @ ~47 Hz

ARIS Attenuation 0.01 to 20 Hz, step down from ~100 to ~10 ugRMS (FIR ops)

CCAA fan: ~57 Hz or ~95 Hz, ~510 ugRMSwater separator: ~98 Hz, ~234 ugRMS

Crew Sleep/Wake

difference primarily below about 6 Hz:USL during sleep ~11.8 ugRMS, during wake ~23.9 ugRMSJEM during sleep ~15.2 ugRMS, during wake ~34.6 ugRMSCOL during sleep ~17.3 ugRMS, during wake ~37.7 ugRMS

National Aeronautics and Space Administration (NASA) Glenn Research Center

• Spatial: EXPRESS Rack 1!

• Temporal: scheduling (crew sleep vs. wake)?

• Spectral: any resonances or sensitivities?

Backup slides: misc info on microgravity environment at:

http://pims.grc.nasa.gov/plots/user/etchells/backup_slides.pptx

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Some Things to Consider