scholarly journals Granular flow experiment using artificial gravity generator on International Space Station

2021 ◽  
Author(s):  
Shingo Ozaki ◽  
Genya Ishigami ◽  
Masatsugu Otsuki ◽  
Hirdy Miyamoto ◽  
Koji Wada ◽  
...  
Keyword(s):  
Bulk Density ◽  
International Space Station ◽  
Granular Flow ◽  
Granular Media ◽  
Space Station ◽  
Artificial Gravity ◽  
Low Gravity ◽  
International Space ◽  
Flow Experiment ◽  
Reliable Design

Abstract Studying the gravity-dependent characteristics of regolith, fine-grained granular media covering extra-terrestrial bodies is essential for the reliable design and analysis of landers and rovers for space exploration. We performed a granular flow experiment under stable artificial gravity conditions generated by a centrifuge on the International Space Station. We also performed a discrete element simulation of the granular flow in both artificial and natural gravity environments. The simulation results verified that the granular flows in artificial and natural gravity are consistent. Further, regression analysis of the granular flow results revealed that the mass flow rate quantitatively follows a well-known physics-based law with some deviations under low-gravity conditions, implying that the bulk density of the granular media decreases with gravity. This insight also indicates that the bulk density considered in simulation studies of space probes under low-gravity conditions needs to be tuned for their reliable design and analysis.

Active Mass Auto-Balancing System for Centrifuge Rotor Providing an Artificial Gravity in Space

2001 ◽  
Author(s):  
Koichi Ohtomi ◽  
Fumio Otsuki ◽  
Hirohiko Uematsu ◽  
Yasuhiro Nakamura ◽  
Yuichi Chida ◽  
...  
Keyword(s):  
International Space Station ◽  
Centrifugal Force ◽  
Life Science ◽  
Space Station ◽  
Artificial Gravity ◽  
Experimental Facility ◽  
Test Results ◽  
Active Mass ◽  
International Space ◽  
Centrifuge Rotor

Abstract The Centrifuge Rotor (CR) is an artificial gravity generator, which is aiming at launch in 2006 as a portion of the life science experimental facility of the International Space Station (ISS). The CR rotates habitats located radially around the axis and generates centrifugal force, imposing artificial gravity of arbitrary magnitude up to 22.0 m/s2 (about 2.2 g) on the specimens housed in the habitats. The imbalance is caused by the asymmetry of two habitats opposite each other, which brings about change in the mass of the habitats as well as the quasi-static change of the CG of plants and fluids and the dynamic rodent motions in the habitats. The active mass Auto-Balancing System (ABS) is provided for automatic canceling of the above-mentioned imbalance of the rotor. This paper presents the concept and the test results of the ABS.

Pool Boiling Heat Transfer on the International Space Station: Experimental Results and Model Verification

2012 ◽  
Vol 134 (10) ◽  
Author(s):  
Rishi Raj ◽  
Jungho Kim ◽  
John McQuillen
Keyword(s):  
Heat Transfer ◽  
International Space Station ◽  
Boiling Heat Transfer ◽  
Pool Boiling ◽  
Space Station ◽  
High Quality ◽  
Low Gravity ◽  
International Space ◽  
Pool Boiling Heat Transfer ◽  
Poor Understanding

The relatively poor understanding of gravity effects on pool boiling heat transfer can be attributed to the lack of long duration high-quality microgravity data, g-jitter associated with ground-based low gravity facilities, little data at intermediate gravity levels, and a poor understanding of the effect of important parameters even at earth gravity conditions. The results of over 200 pool boiling experiments with n-perfluorohexane as the test fluid performed aboard the International Space Station (ISS) are presented in this paper. A flat, transparent, constant temperature microheater array was used to perform experiments over a wide range of temperatures (55 °C < Tw < 107.5 °C), pressures (0.58 atm < P < 1.86 atm), subcoolings (1 °C ≤ ΔTsub ≤ 26 °C), and heater sizes (4.2 mm ≤ Lh ≤ 7.0 mm). The boiling process was visualized from the side and bottom. Based on this high quality microgravity data (a/g<10−6), the recently reported gravity scaling parameter for heat flux, which was primarily based on parabolic flight experiments, was modified to account for these new results. The updated model accurately predicts the experimental microgravity data to within ±20%. The robustness of this framework in predicting low gravity heat transfer is further demonstrated by predicting many of the trends in the pool boiling literature that cannot be explained by any single model.

Human factors assessment of International Space Station (ISS) medical equipment packs

2005 ◽  
Author(s):  
Danielle Paige Smith ◽  
Vicky E. Byrne ◽  
Cynthia Hudy ◽  
Mihriban Whitmore
Keyword(s):  
Human Factors ◽  
International Space Station ◽  
Medical Equipment ◽  
Space Station ◽  
International Space

Dose Tracker Application for Collecting Medication Use Data from International Space Station Crew

2020 ◽  
Vol 91 (1) ◽  
pp. 41-45 ◽  
Author(s):  
Virginia. E. Wotring ◽  
LaRona K. Smith
Keyword(s):  
Data Collection ◽  
International Space Station ◽  
Sleep Disturbances ◽  
Space Station ◽  
Medication Use ◽  
International Space ◽  
Flight Data ◽  
Open Questions ◽  
Share Data ◽  
Usability Feedback

INTRODUCTION: There are knowledge gaps in spaceflight pharmacology with insufficient in-flight data to inform future planning. This effort directly addressed in-mission medication use and also informed open questions regarding spaceflight-associated changes in pharmacokinetics (PK) and/or pharmacodynamics (PD).METHODS: An iOS application was designed to collect medication use information relevant for research from volunteer astronaut crewmembers: medication name, dose, dosing frequency, indication, perceived efficacy, and side effects. Leveraging the limited medication choices aboard allowed a streamlined questionnaire. There were 24 subjects approved for participation.RESULTS: Six crewmembers completed flight data collection and five completed ground data collection before NASA’s early study discontinuation. There were 5766 medication use entries, averaging 20.6 ± 8.4 entries per subject per flight week. Types of medications and their indications were similar to previous reports, with sleep disturbances and muscle/joint pain as primary drivers. Two subjects treated prolonged skin problems. Subjects also used the application in unanticipated ways: to note drug tolerance testing or medication holiday per research protocols, and to share data with flight surgeons. Subjects also provided usability feedback on application design and implementation.DISCUSSION: The volume of data collected (20.6 ± 8.4 entries per subject per flight week) is much greater than was collected previously (<12 per person per entire mission), despite user criticisms regarding app usability. It seems likely that improvements in a software-based questionnaire application could result in a robust data collection tool that astronauts find more acceptable, while simultaneously providing researchers and clinicians with useful data.Wotring VE, Smith LK. Dose tracker application for collecting medication use data from International Space Station crew. Aerosp Med Hum Perform. 2020; 91(1):41–45.

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