NASA/TM-2010-216132

C-9 and Other Microgravity Simulations

Summary Report

Report prepared by

Space Life Sciences Directorate

Human Adaptation and Countermeasures Division

NASA Johnson Space Center, Houston

 

 

 

 

September 2010

National Aeronautics and

Space Administration

Johnson Space Center

Houston, TX 77058
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NASA/TM-2010-216132

C-9 and Other Microgravity Simulations

Summary Report

Report prepared by

Space Life Sciences Directorate

Human Adaptation and Countermeasures Division

NASA Johnson Space Center, Houston

 

 

 

 

 

 

September 2010

National Aeronautics and

Space Administration

Johnson Space Center

Houston, TX 77058
PREFACE

This document represents a summary of medical and scientific evaluations conducted aboard the

C-9 and other NASA-contracted aircraft from June 2009 to June 2010. Included is a general 

overview of investigations manifested and coordinated by the Human Adaptation and 

Countermeasures Division. A collection of brief reports that describes tests conducted aboard 

NASA-sponsored aircraft follows the overview. Principal investigators and test engineers 

contributed significantly to the content of the report, describing their particular experiment or 

hardware evaluation. Although this document follows general guidelines, each report format 

may vary to accommodate differences in experiment design and procedures. This document 

concludes with an appendix that provides background information concerning the NASA Reduced 

Gravity Program.

Acknowledgments

The Space Life Sciences Directorate gratefully acknowledges the work of Sharon Hecht, 

Jacqueline M. Reeves, and Elisabeth Spector for their outstanding editing support and contributions to the overall quality of this annual summary report.

Available from:

NASA Center for AeroSpace Information National Technical Information Service

7115 Standard Drive 5285 Port Royal Road

Hanover, MD 21076-1320 Springfield, VA 22161

Phone: 301-621-0390 or 703-605-6000

Fax: 301-621-0134

This report is also available in electronic form at http://ston.jsc.nasa.gov/collections/TRS/
i
ii

Contents 

 Page 

Overview of Reduced Gravity Flight Activities Sponsored by the 

Human Adaptation and Countermeasures Division......................................................................1

Medical and Scientific Evaluations during Parabolic Flights.......................................................2

Education Outreach Program – Effects of Altered Gravity on Cellular Function.....................3

High-Accuracy Eye-movement Monitor .................................................................................12

FASTRACK Program – Antimicrobial Polymers Project.......................................................16

Education Outreach Program – Space Motion Sickness and the Semicircular

Canals of the Inner Ear ......................................................................................................33

Appendix.................................................................................................................................. A-1

Background Information about the C-9 and NASA Reduced Gravity Program .................. A-2
iii

Acronyms 

ACS American Chemical Society

AFRL Air Force Research Laboratory

Ag silver

AgF silver fluoride

AMME-TEDP Antimicrobial Materials for Microgravity Environments Test Equipment Data 

Package

AMPP Advanced Materials Processing Program

AO acridine orange

AODC acridine orange direct count

ASTM American Society for Testing and Materials

ATP adenosine triphosphate

AWRSDF Advanced Water Recovery System Development Facility

BRIC Biological Research in a Canister

BRIC-LED Biological Research in a Canister-Light-emitting Diode

BSC biological safety cabinet

CDC change data capture

CO2 carbon dioxide

CPHS Committee for the Protection of Human Subjects

Cr chromium

DNA deoxyribonucleic acid

ECLS environmental control and life support

ERI engineered roughness index

ESEM environmental scanning electron microscopy

EtO ethylene oxide

FAST Facilitated Access to Space Environment for Technology Development and 

Training

fPOSS fluorodecyl polyhedral oligomeric silsesquioxanes

HPC heterotrophic plate count

ICP-AES inductively coupled plasma atomic emission spectroscopy

IPP integrated phase planning

IRB Institutional Review Board

ISK inverse SharkletTM

ISS International Space Station

JSC Johnson Space Center

KSC Kennedy Space Center

L/D live/dead

LSSC launch services support contract

MESA mathematics, engineering, science, and achievement

MPDFU modified Petri dish fixation unit

Na2CrO4 sodium chromate

NSTA National Science Teachers Association

P pilin peptide

PBS phosphate buffered saline

PC polycarbonate
iv

PDFU Petri dish fixation unit

PDMS polydimethylsiloxane

PE polyethylene

PET polyethylene terephthalate

POSS polyhedral oligomeric silsesquioxanes

ppb parts per billion

QGATM Quench-Gone Aqueous

RGO Reduced Gravity Office

SAS space adaptation syndrome

SEM scanning electron microscopy

SM smooth

SMS space motion sickness

SPDFU standard Petri dish fixation unit

SS stainless steel

Ti titanium

TSB TrypticaseTM Soy Broth

USM University of Southern Maine

UV ultraviolet

WAD work authorization document
1

Overview of Reduced Gravity Flight Activities 

Sponsored by the Human Adaptation and Countermeasures Division 

As a summary for the year, 4 weeks were specifically reserved for flights sponsored from June

2009 to June 2010. Seven flights with approximately 32 parabolas per flight were completed and 

the average duration of each flight was 2.1 hours. The Reduced Gravity Program coordinator 

assisted principal investigators and test engineers of 7 different experiments and hardware

evaluations in meeting the necessary requirements for flying aboard the C-9 or another NASAcontracted aircraft and in obtaining the required seating and floor space. Support was provided to

the Education Outreach Program during weeks in June and August 2009 and in April 2010. A

large ground crew from the respective academic institutions supported the in-flight experiments.

The number of seats supported and number of different tests flown by flight week are provided 

below:

Flight Week Seats No. Tests Flown Sponsor

2009

June 11–12 6 1 Education Outreach Program

August 11–14 35 4 FASTRACK

2010

April 29–30 10 2 Education Outreach Program

Further flights will be added throughout the remainder of calendar year 2010 to accommodate 

customers as needs arise.
2

Medical and Scientific Evaluations during Parabolic Flights 
3

TITLE 

Education Outreach Program –

Effects of Altered Gravity on Cellular Function

FLIGHT DATES 

June 11–12, 2009

PRINCIPAL INVETIGATOR 

John Pierce Wise, Sr., PhD, University of Southern Maine (USM), Portland, ME

COINVESTIGATORS

John P Wise, USM

Michael Browne, USM

Jane McKay, USM

Jennifer Brown, USM

Matthew Braun, USM

James Wise, USM

Catherine Wise, USM

Ryan Duffy, USM

Eben Estell, USM

Sandra Wise, USM

Kellie Joyce, USM

Michael Mason, PhD, USM
4

GOAL

To determine the effects of altered gravity on cellular function.

OBJECTIVES 

To determine how altered gravity affects cellular function, we looked at three specific objectives:

1. Determine whether human genotoxic agents cause more damage to cells and deoxyribonucleic acid (DNA) in altered gravity than in normal gravity. The effects of altered 

gravity on the potency of human genotoxicants are not well understood. Last year we found 

that altered gravity increases damage induced by genotoxic chromate. Thus, this specific 

objective is to confirm the effects of altered gravity on DNA damage in comparison to

normal gravity using an assay for chromosome damage.

2. Determine whether the change in the amount of chromosome damage is due to an increase in

cellular uptake of chemicals by facilitated diffusion and phagocytosis in altered gravity: The 

ability of cells to take up chemicals in altered gravity is not well understood. This objective is 

to determine the effects of altered gravity on facilitated diffusion and phagocytosis using 

assays for ion uptake and particle internalization.

3. Determine whether the change in the amount of chromosome damage is due to inhibition of

DNA repair mechanisms by altered gravity. The effects of altered gravity on DNA repair 

mechanisms are not well understood. This objective is to determine the effects of altered 

gravity on DNA repair relative to normal gravity, using an assay for DNA double-strand 

breaks.

METHODS AND MATERIALS 

Overview

This hypothesis was tested by measuring the effects of known genotoxic chemicals in altered 

gravity (flight), and comparing the results to identical tests conducted in normal gravity (ground).

To keep the cells alive, we took a mini-oven (kept at human body temperature 37°C [98°F]) on 

board the plane with us. The mini-oven was secured to the floor of the plane using a structure designed by SpaceWorks, Inc. (Grand Junction, CO). A cooler was 

attached on top of this structure to stop a few experiments at the 

end of flight. We used this cooler on our first flight but decided 

it was not important for this year’s experiment. Our task on 

board the plane was to monitor the temperature and power.

Collectively, the cooler-oven system (figure 1) worked very 

well for our experiments.

 

Figure 1. The “ rig” used to maintain the cells in flight. 

 

 

Cells and Cell Culture

The human lung cells were developed in the Wise Laboratory

(Blankenship et al., 1997). These cells are fibroblasts immortalized with telomerase. The 

telomerase serves to extend the fibroblasts’ life spans, but the cells otherwise function normally 
5

and maintain normal responses to metals (Blankenship et al., 1997). The cells, which were maintained as adherent subconfluent monolayers (figure 2), were seeded 

48 h before treatment to allow them to settle and resume normal growth.

For our experiments the cells were grown in T-25 flasks (figure 3A) and

on sealed slide chambers (figure 3B). All experiments were conducted

on logarithmically growing cells. There is little concern for the lack of 

carbon dioxide (CO2) gas exchange (an essential compound for cell 

growth) during the flight because the length of time without CO2

exchange is insignificant.

Treatments 

Sodium chromate (Na2CrO4) (CAS #7775-11-3, American Chemical Society (ACS) reagent 

minimum 98% purity) was used as a soluble hexavalent chromium salt, Cr(VI). Solutions of 

Na2CrO4 were prepared by: (1) measuring the desired amount of Na2CrO4; (2) dissolving the 

Na2CrO4 in double distilled water; and (3) filtering the solution through a 0.2-μm filter to sterilize

the solution. We used 5 to 20-μM concentrations of Na2CrO4 as our laboratory has employed

these methods with success (Xie et al., 2004).

We treated cells for varying times, as indicated under each specific objective. All treatments 

were done at the Bioscience Core Laboratory at the NASA Johnson Space Center before flight.

Our experiments focused on using vitamin C and cold temperature to stop the treatments. For 

repair experiments, we used vitamin C to stop the Na2CrO4 treatment, allowing the cells’ repair 

mechanisms to begin, because Na2CrO4 is a form of Cr(VI). Cr(VI) ions can enter the cell with 

the help of a protein in the plasma membrane (Wise et al., 2004). By contrast, trivalent chromium 

Cr(III) ions cannot enter the cell (Wise et al., 2004). By adding vitamin C, the Cr(VI) ions are 

reduced to Cr(III) ions outside the cell, thus preventing further chromium (Cr) uptake. Therefore, 

vitamin C prevents Cr ions from getting into the cell and causing more DNA damage (Xie et al., 

2005; Crawford-Young, 2006; Tischler and Morey-Holton, 1993). Not only does this approach 

prevent uptake, but our laboratory has shown that this approach also prevents chromosome 

damage after Na2CrO4 exposure (Crawford-Young, 2006; Tischler and Morey-Holton, 1993). 

Vitamin C was dissolved in double distilled water before it was sterilized by filtering through a 

0.2-μm filter. We used a 2-μM vitamin C co-treatment as our laboratory found that this 

concentration maximizes the amount of chromate reduction without inducing cytotoxicity

(Crawford-Young, 2006).

Figure 2. Human lung fibroblast cells under microscope. 

 

A – Flask 

 

B – Slide chamber 

Figure 3. Pictures of cell culture tools. 
6

The results of these experiments have implications for protecting the health of astronauts going 

on extended missions to the International Space Station (ISS), the Moon, and, eventually, the outer

reaches of the universe. These results will help determine how occupational exposure limits to 

hazardous materials in reduced gravity compare to the occupational exposure limits in normal 

gravity. Further, the results may impact how NASA engineers design future space equipment 

and stations (ie, with or without the same materials, and in the same or different amounts to limit 

exposure).

Specific Objective 1 

Our first specific objective was to determine whether human genotoxic agents damage cells and 

DNA more in altered than in normal gravity. The focus of this objective was to measure the 

effects of altered gravity on DNA damage caused by exposure to chemicals. We considered the 

ability of chemicals to induce chromosome damage in normal, hyper-, and microgravity. By 

treating cells according to the schedule in Table 1, we measured the amount of chromosomal 

abnormalities produced in metaphase cells after Na2CrO4 exposure using the Wise Laboratory’s 

published methods for chromosome damage (Xie et al., 2004). We measured the amount of DNA 

double-strand breaks using immunofluorescence of H2A.X foci, as each focus is considered to 

represent one DNA double-strand break. We also used the Wise Laboratory’s published methods 

for H2A.X foci formation.

Cells were treated on the ground and then harvested shortly after landing, as described in Table

1. After the experiments were completed and the cells harvested, the cells were prepared to be 

sent back to Maine for microscopic analysis in the Wise Laboratory. We are analyzing 100 

metaphases per dose, and the results will be expressed as percentage of metaphases with damage 

and total damage in 100 metaphases. We predict that altered gravity will result in an increase in 

the amount of DNA damage and the percentage of metaphases with damage. For DNA doublestrand breaks, cells were harvested at the cessation of the experiments and preserved for foci 

formation measurement before they were shipped to the Wise Laboratory for analysis on a

confocal microscope. We will analyze 50 cells per dose and the results will be expressed as 

average number of foci per cell. We predict that altered gravity will increase the level of DNA

double-strand breaks.

Specific Objective 2 

Our second specific objective was to determine whether the change in the amount of 

chromosome damage is due to an increase in the cellular uptake of chemicals by facilitated 

diffusion and phagocytosis in altered gravity. We tested the effects of altered gravity on cellular 

uptake of chemicals. We measured ion uptake and particle internalization in normal and altered 

Table 1. Outline of Experiments for Specific Objective 1 

Experiment Purpose Treatment Procedure

Chromosome

damage

Confirm that 

chromosome damage 

is increased by altered 

gravity

Na2CrO4 (0, 5, 10, 

20 μM)

• Treat cells 1 h before takeoff

• Allow cells to incubate in warm environment 

on plane

• Harvest 1 h after landing

DNA doublestrand breaksDetermine whether

DNA breaks are also 

increased by altered 

gravity

Na2CrO4 (0, 5, 10, 

20 μM)

• Treat cells 1 h before takeoff

• Allow cells to incubate in warm environment 

on plane

• Harvest 1 h after landing
7

gravity, and treated cells according to the schedule in Table 2. We then measured the amount of 

Cr ion inside the cell after a 4-h exposure to Na2CrO4 using the Wise Laboratory’s published 

methods for inductively coupled plasma atomic emission spectroscopy (ICP-AES) (Holmes et al., 

2005). Cells were treated on the ground and harvested shortly after landing, as described in Table 

2. After the experiments were completed, cells were frozen and shipped to the Wise Laboratory.

There, cells will be analyzed for uptake using ICP-AES (ion uptake) or transmission electron 

microscopy. Data will be presented as μM Cr in the intracellular and extracellular environment 

and percentage of cells with internalized particles. We predict that altered gravity will result 

increase the uptake of ions, thereby increasing the frequency of DNA and chromosome damage.

Table 2. Outline of Experiments for Specific Objective 2

Experiment Purpose Treatment Procedure

Cr ion uptake Determine the effects of 

altered gravity on the uptake 

of Cr ions to compare with 

the DNA damage studies in 

Specific Objective 1

Na2CrO4

(0, 5, 10, 20 μM)

• Treat cells 1 h before takeoff

• Allow cells to incubate in warm 

environment on plane

• Harvest 1 h after landing

Specific Objective 3 

Our third specific objective was to determine whether the change in the amount of chromosome 

damage is due to an inhibition of DNA repair mechanisms by altered gravity. In this objective,

we tested the effects of altered gravity on DNA repair mechanisms in an altered gravity 

environment. We measured DNA double-strand breaks using the immunofluorescence of H2A.X 

foci, as each focus is considered to represent one DNA double-strand break. We treated cells and

allowed for a repair time according to the schedule in Table 3. We then measured the average 

number of H2A.X foci per cell after Na2CrO4 exposure using the Wise Laboratory’s published 

methods for H2A.X foci formation. After the experiments were complete, the cells were harvested

and preserved for foci formation measurement before they were shipped to the Wise Laboratory 

for analysis by confocal microscope. We will analyze 50 cells per dose and the results will be 

expressed as average number of foci per cell. We predict that altered gravity will inhibit DNA 

repair mechanisms, resulting in a higher number of DNA double-strand breaks.

Table 3. Outline of Methods of Specific Objective 3

Experiment Purpose Treatment Procedure

DNA repair:

4-h treatment 

preflight

Determine amount of damage in 

cells before flight

Na2CrO4

(0, 5, 10, 20 μM)

• Treat 5 h before takeoff

• Harvest 1 h before flight

DNA repair:

4-h treatment 

preflight

+

4-h repair 

recovery

Determine effects of altered 

gravity on recovery of DNA 

damage

Equal treatment/recovery 

time intervals

Na2CrO4

(0, 5, 10, 20 μM)

• Treat 5 h before takeoff

• Add vitamin C 1 h before 

takeoff

• Keep in incubator for flight 

duration

• Harvest 1 h after landing

DNA repair:

4-h treatment 

preflight

+

24-h repair 

recovery

Determine effects of altered 

gravity on recovery of DNA 

damage after 4-h treatment 

interval over standard recovery 

interval, beginning on flight

Short treatment time; 

standard recovery time, 

beginning in altered gravity

Na2CrO4

(0, 5, 10, 20 μM)

• Treat 5 h before take-off

• Add Vitamin C 1 hour 

before takeoff

• Keep in incubator for flight 

duration

• Store in incubator for 22 h

• Harvest after 24-h recovery

 
8

RESULTS 

We do not have completed data from this year’s experiments because it takes several weeks 

(sometimes months) to complete data analysis and we are currently analyzing our data. The 

results shown in figures 4 and 5 are based on last year’s experiments. We anticipate similar 

results from this year’s experiment.

Figure 4. Chromosome damage resulting from Na2CrO4 treatments. The data show there 

is a much higher incidence of chromosome damage in flight than on the ground. For 

example; at 10 μM, there are 43 chromosome aberrations per 100 metaphases on the ground 

and 92 in flight. 

Figure 5. Cr uptake resulting from Na2CrO4 treatments at varying concentrations. Unlike 

what we expected to find, the data show there is a much lower Cr uptake in flight than on 

the ground. For example: at 10 μM, the uptake is 1,773 μM in flight and 4,874 μM on the 

ground. 

Now, if we take the intracellular Cr concentrations that we found in the uptake experiments and

graph them against the total amount of chromosome damage, we can more accurately demonstrate 

the effects of altered gravity, as shown in figure 6.

0

20

40

60

80

100

120

0 5 10 15 20 25

Concentration (uM)

Total Damage in 100 Metaphases

Flight

Ground

0

1000

2000

3000

4000

5000

6000

0 5 10 15 20 25

Concentration (uM)

Intracellular Concentration (uM)

Flight

Ground
9

Figure 6. Chromosome damage resulting from the intracellular Cr concentration. The 

graph illustrates the following: (1) flight increases the rate at which chromosome damage 

occurs; (2) there is much more damage in flight than on the ground (eg, at 1773 μM, there 

are approximately 23 aberrations in the ground experiments; in flight, there are 92). 

DISCUSSION

Based on the results from our chromosome damage experiments, a combination of hyper- and 

microgravity causes an increase in the number of chromosomal aberrations induced by Na2CrO4.

We used three concentrations of Na2CrO4 (5, 10, and 20 μM) and a negative control (0 μM) to 

consider a dose response. Our results showed that altered gravity dramatically increased chromosome damage inducing two to three times the total amount of damage present in 100 metaphase 

cells and in the percentage of metaphase cells with damage. Analyzing the data, we observed that 

the total amount of chromosome damage and the percentage of damaged metaphase cells in 

altered gravity drops at doses between 10 and 20 μM, which is most likely due to an increase in 

cell death removing severely damaged cells from the population.

Results from our experiments to determine the effects of altered gravity on cellular uptake of 

chemicals indicate there is less uptake of chemicals in flight than on the ground. Again, we used

three concentrations of Na2CrO4 (5, 10, and 20 μM) and a negative control (0 μM). Unlike our 

hypothesis, our results indicated that altered gravity inhibited a cell’s ability to take up Cr(VI) 

ions. We used ICP-AES to analyze our samples, and found the normal gravity samples had 

approximately twice the number of Cr ions as the altered gravity samples. We observed a drop 

between the 10 and 20 μM treatments (similar to what we saw in the chromosome damage 

experiments), and believe this drop to be a result of altered gravity increasing the occurrence of 

apoptosis.

Last year’s results to determine the effects of hyper- and microgravity on DNA repair mechanisms are incomplete because the antibody needed to analyze these slides failed. During DNA 

repair, a protein called H2A.X responds by accumulating around damaged DNA strands and initiating the repair process. We detected the H2A.X by adding an antibody that binds only to the 

protein; this antibody is fluorescent and can be detected using a green light filter under a microscope. We conducted similar experiments at our laboratory to determine how long it would take 

for DNA repair to occur. After treating cells with 10-μM Na2CrO4 for 4 h before co-treating then 

with vitamin C for 4, 6, and 24 h, we observed approximately half of the foci after a 4-h repair 

0

20

40

60

80

100

120

0 1000 2000 3000 4000 5000 6000

Concentration (uM)

Total Damage in 100 Metaphases

Flight

Ground
10

period. We did the same set of experiments with a 20-μM treatment, but did not see any repair 

until after 24 h. Thus, we expect to be able to find some significant results from this year’s 

experiments.

CONCLUSION 

Our hypothesis predicted that due to the known morphological alterations cells undergo in zero

gravity (Crawford-Young, 2006; Tischler and Morey-Holton, 1993), the altered-gravity environment that astronauts experience will have implications on cellular function, such that chemically 

induced genotoxicity will be exacerbated. We hypothesized that this effect would result from an

increase in cellular uptake of chemicals and/or inhibition of DNA repair mechanisms. After analyzing the results from our chromosome damage experiments, we confirmed our hypothesis that 

altered gravity exacerbates chemically induced genotoxicity. However, altered gravity does not 

increase the amount of background damage, which means that flight alone is not genotoxic. Our results indicate that crewmembers exposed to genotoxic chemicals in flight could be at greater risk

than expected. We predicted this effect would be a result of the increased cellular uptake of ions, 

but our data proved our hypothesis incorrect. Instead, we found the cellular uptake of ions to be

drastically inhibited. We anticipate the data from this year’s experiment to show the same results,

and indicate whether the exacerbated genotoxicity is due to inhibited DNA repair mechanisms or

some other unknown factor.

REFERENCES 

1. Wise SS, Elmore LW, Holt SE, et al. Telomerase-Mediated Lifespan Extension of Human 

Bronchial Cells Does Not Affect Hexavalent Chromium-Induced Cytotoxicity or Genotoxicity.

Mol Cell Biochem, 2004;255:103-111.

2. Wise JP Sr, Wise SS, Little JE. The Cytotoxicity and Genotoxicity of Particulate and Soluble 

Hexavalent Chromium in Human Lung Cells. Mutat Res. 2002;517:221-229.

3. Costa M, Klein CB. Toxicity and Carcinogenicity of Chromium Compounds in Humans. Crit 

Rev Toxicol. 2006; 36.2:155-163.

4. Blankenship LJ, Carlisle DL, Wise JP Sr, Orenstein JM, Dye LE III, Patierno SR. Induction 

of Apoptotic Cell Death by Particulate Lead Chromate: Differential Effects of Vitamins C 

and E on Genotoxicity and Survival. Toxicol Appl Pharmacol. 1997;146:270-280.

5. Xie H, Holmes AL, Wise SS, Gordon N, Wise JP Sr. Lead Chromate-Induced Chromosome 

Damage Requires Extracellular Dissolution to Liberate Chromium Ions but Does Not Require

Particle Internalization or Intracellular Dissolution. Chem Res Toxicol. 2004;17.10:1362-1367.

6. Wise SS, Holmes AL, Ketterer ME, et al. Chromium Is the Proximate Clastogenic Species 

for Lead Chromate-Induced Clastogenicity in Human Bronchial Cells. Mutat. Res. 2004;560:

79-89.

7. Xie H, Wise SS, Holmes AL, et al. Carcinogenic Lead Chromate Induces DNA DoubleStrand Breaks in Human Lung Cells. Mutat. Res. 2005;586(2):160-172.

8. Crawford-Young SJ. Effects of Microgravity on Cell Cytoskeleton and Embryogenesis. Int J 

Dev Biol. 200650:183-191.

9. Tischler ME, Morey-Holton E. Space Life Sciences Research: The Importance of Long-Term 

Space Experiments. Washington, DC: NASA Headquarters; 1993; NASA-TM-4502.

10. Holmes AL, Wise SS, Xie H, Gordon N, Thompson WD, Wise JP Sr. Lead ions do not 

cause human lung cells to escape chromate-induced cytotoxicity. Toxicol Appl Pharmacol.

2005;203:167-176.
11

PHOTOGRAPHS 

JSC2009E135194 to JSC2009E135197

JSC2009E137325

JSC2009E137316

JSC2009E137339

JSC2009E137558 to JSC2009E137559

JSC2009E137577 to JSC2009E137578

JSC2009E137598 to JSC2009E137600

JSC2009E137631 to JSC2009E137649

VIDEO 

• Zero G flight week 6/5 – 6/12, 2009 Master: 743649

Videos are available from Imagery and Publications Office (GS4), NASA Johnson Space Center 

(JSC).

CONTACT INFORMATION 

John P. Wise, Jr.

john.p.wise@maine.edu

Dr. John P. Wise, Sr.

john.wise@maine.edu

Dr. Michael Mason

mmason@umche.maine.edu
12

TITLE 

High-Accuracy Eye-Movement Monitor

FLIGHT DATES 

August 11–12, 2009

PRINCIPAL INVESTIGATOR 

Mark Shelhamer, Johns Hopkins University, School of Medicine, Baltimore, MD

COINVESTIGATORS 

Kara Beaton, Johns Hopkins University, School of Medicine, Baltimore, MD

Aaron Wong, Johns Hopkins University, School of Medicine, Baltimore, MD

Dale Roberts, Johns Hopkins University, School of Medicine, Baltimore, MD

Michael Schubert, Johns Hopkins University, School of Medicine, Baltimore, MD
13

GOAL AND OBJECTIVES 

To validate, in a realistic space analog environment, the performance of a device for accurate 

high-resolution measurements of eye movements during head and body motions. This device can 

aid future research programs into human sensorimotor adaptation to spaceflight.

INTRODUCTION

The control of eye movements represents one of the most basic and fundamental motor control

systems of the human brain, combining information from both low-level motion transducers in 

the inner ear (the vestibular system) and high-level visual information. The measurement of eye 

movements thus can provide important information on many forms of sensorimotor processing.

Long-duration spaceflight has been shown to adversely affect many aspects of sensorimotor function, which can have serious implications on manually controlled tasks and piloting performance, 

especially during maneuvers involving transitions in G-level. Therefore, the ability to measure 

eye movements with high spatial and temporal precision, during natural head and body motions, 

can be a valuable aid to monitoring these effects.

METHODS AND MATERIALS

The technology tested in this project is an improved version of the standard scleral search-coil 

method, the current “gold standard” for measurement of eye movements. An annular contact lens

that sits on the eye contains a passive resonant coil/capacitor circuit. A transmitter coil and small 

(2.5 cm) cubes of receiver coils are placed near the eye on a headset and connected to associated 

electronics. The transmitter coils are pulsed to generate bursts of magnetic field energy that stimulate the resonant coil in the contact lens. After each burst of pulses, the receiver coils act as directional antennae, transducing the electromagnetic field radiated by the resonant scleral coils. A 

dedicated processing unit then amplifies, digitizes, and determines the magnitudes of the received

waveforms, which depend on the orientation of the resonant coils on the eye relative to the set of 

receiver coils. By using this magnitude information, we can determine the orientation of the coil 

(and eye). The contact lens assembly is based on a commercial lens in widespread use that we 

modified by attaching a resonating capacitor (figure 1).

For this study an engineering evaluation of

this device is performed in parabolic flight

during which a test subject, wearing the device, makes head and body movements. A 

rate-sensor/accelerometer package on the

headset measures head movements. Testing

in parabolic flight is critical when validating

the device for later use in spaceflight (and 

further parabolic-flight experiments) to assess any shifting of the headset on the head 

and any changes in overall comfort and 

effectiveness in different gravity levels.

Figure 1. Wireless coil. 
14

Information on position as well as orientation (with respect to the headset) of an 

eye coil is obtained using multiple receiver

coils (figure 2); this allows measurement 

of headset motion relative to the head by 

taping an “eye coil” to the head as a 

reference.

RESULTS 

At the time of the flights, we did not have

the JSC’s Committee for the Protection 

of Human Subjects (CPHS) approval to

place a contact lens on the subject’s eye 

while the subject was in flight. We are

working to resolve this problem, which we expect to accomplish in the near future (the Johns 

Hopkins Institutional Review Board [IRB] has approved this project for use in parabolic flight). 

Therefore, we evaluated several engineering aspects of the device besides its ability to measure 

eye movements. These aspects are: robustness and ease of use of the hardware and software, signal quality and noise level, comfort of the head unit, and slip of the head unit during movements 

at different gravity levels. This engineering evaluation consisted of having one of the investigators 

wear the head unit while making natural movements. A rate-sensor/accelerometer package on the 

head unit measured head movements, as did, for comparison, a similar set of sensors on a 

biteboard.

Testing revealed satisfactory usability of hardware and software, although work remains to be done

on a real-time graphical display that will show signal and noise levels. Signal quality and head 

slip appear adequate, although we have not yet processed these data fully. The head unit was found 

to be prone to wiring damage during stowage. This damage, which was found before the first 

flight, was fixed on site although it recurred during the second flight, thus limiting the overall data 

return. Subject comfort (and, to some extent, head-unit stability) was limited by the cabling from 

the head unit to the electronics package. This umbilical was almost 2 cm in diameter and not 

very flexible, which required that it be clamped to the subject’s flight suit in several places for 

strain relief, thereby limiting comfort and freedom of movement.

DISCUSSION/CONCLUSION 

Development of this device continues, with special attention paid to the shortcomings revealed

during the flights, as noted above. Specifically, a user-friendly software interface will be developed; more robust electrical wiring will be implemented; and smaller, more flexible umbilical

wiring will be considered. We anticipate that after making these changes, we will obtain CPHS

approval for actual eye-movement recording, integrate the device with a set of visual stimuli for 

sensorimotor testing, and test this integrated and improved package during flights in the 2010 

Facilitated Access to Space Environment for Technology Development and Training (FAST)

program.

Figure 2. Head-mounted assembly, showing multiple sets of 

receiver coils. 
15

REFERENCES 

1. Roberts D, Shelhamer M, Wong A. A new “wireless” search-coil system. In: Proceedings of

the Eye Tracking Research & Applications Symposium, Savannah, Georgia, 26-28 March 

2008;197-204.

2. Robinson DA. A method of measuring eye movement using a scleral search coil in a 

magnetic field. IEEE Trans Biomed Eng. 1963;10:137-145.

VIDEO 

• Zero G flight week 8/11 – 8/14, 2009 Master/TSR: 103823

Videos are available from Imagery and Publications Office (GS4), NASA JSC.

ACKNOWLEDGEMENT 

This work was supported by the NASA FAST Program.

CONTACT INFORMATION 

Mark Shelhamer

Johns Hopkins University, School of Medicine

210 Pathology Bldg.

600 N. Wolfe St.

Baltimore, MD 21287

mjs@dizzy.med.jhu.edu

410-614-6302
16

TITLE 

FASTRACK Program – Antimicrobial Polymers Project

FLIGHT DATES 

August 10–14, 2009

PRINCIPAL INVESTIGATORS 

Luke Roberson, Kennedy Space Center, FL

Mike Roberts, Dynamac Corporation, Kennedy Space Center, FL

David Makufka, Kennedy Space Center, FL

Amy Hitabel, AP Solutions, Glenn Research Center, OH
17

GOALS 

To develop test methods and generate microbiological data to be used in the verification of the

antimicrobial efficacy of materials and biocides in wetted systems.

INTRODUCTION/BACKGROUND 

The vision for human space exploration requires integrated technologies to collect, store, 

recycle, and disinfect water for use and reuse in environmental control and life support systems

(ECLSS) for spacecraft missions. In addition to maintaining water quality for crew use, these 

systems must minimize mass, power, and resupply requirements. Microbial control 

technologies currently employed by NASA for spacecraft potable water systems require the use 

of a residual chemical biocide such as silver (Ag) or iodine and one or more physical disinfection 

devices to reduce the microbial burden. None of these chemical biocides are completely effective 

against all microorganisms, however, and all have limitations for long-term use because they 

do not provide an absolute barrier to microbial growth, become inactive over time, require 

repeated additions, and/ or pose risks to human health with prolonged use. An antimicrobial 

solution is needed that improves microbial control and provides a safe, long-lasting, and nonleaching antimicrobial surface useful for long-duration spaceflight applications.

A recent approach to resisting surface microbial colonization is to modify the surface roughness to

emulate naturally occurring anti-fouling surfaces. SharkletTM, developed by Sharklet Technologies, Inc. (Alachua, FL), is a highly specific, micron-scale surface pattern inspired by the surface

roughness associated with the skin of sharks. The SharkletTM micro-pattern may be engineered into

new or existing material surfaces to inhibit microorganism growth (Schumacher, 2007A; Schumacher 2007B; Carman, 2006) and delay the formation of bacterial biofilm (Chung, 2007). As the 

surface micro-patterning technique adds no new material to the surface, the surface maintains its

original chemistry and material properties. This purely physical approach to inhibiting biofilm 

formation does not rely on the incorporation of antimicrobial agents, thus sidestepping the 

problems associated with reduced antimicrobial activity and health risks.

The development of antimicrobial coating methods stems from the commonly held belief that

bioadhesion is primarily influenced by the chemical composition and activity of the surface.

While this is an important factor, the influence of surface topography can be a dominant variable in

predicting bioadhesion. It has long been known that surface roughness affects wettability, which has 

motivated the study of the physical modification of a material surface with topography as a

means to control bioadhesion (Schmidt, 1991; den Braber, 1996; den Braber, 1998; van Kooten,

1998; van Kooten, 1999). While surface topography has been explored in a trial-and-error fashion

for randomly roughened surfaces and some ordered topographies, only recently has the interrelationship of topography, wettability, and bioadhesion been investigated (Carman, 2006). These

studies have indicated that engineered topographies—particularly geometries of ordered features

designed with unique roughness properties—do elicit specific, predictable biological responses.

This strategy for controlling bioadhesion represents a paradigm shift in the current methods using antimicrobial agents. Applying a surface topography instead of antimicrobial agents relies on

controllably changing the surface energy so as to affect bioadhesion.

Polymer surface micro-patterning is an area of research and development that has expanded 

significantly in both the private sector and academia. Several methods for accomplishing this 
18

exist, and all methods rely on the use of a master or mold and are derived by altering parameters

such as heat, ultraviolet (UV) exposure, and pressure. They include photolithography, soft lithography (including micro-contact printing, replica molding, micro-transfer molding, micromolding 

in capillaries, and solvent-assisted micromolding) (Xia, 1998; del Campo, 2008; Gates, 2005), soft

molding (Kim, 2001; Choi, 2004), polymer casting (Gates, 2005), hot embossing (Chang, 2003), 

UV imprint lithography (Bailey, 2002; Cheng, 2008; Haatainen, 2008; Kim, 2003; and Rudschuck,

2000), ion beam proximity patterning, and focused ion beam writing. These methods have been 

widely used and perfected for replicating micron-scale features into flat substrates; several 

demonstrate feasibility for large-area printing—a necessity for manufacturing scale production 

(Suho, 2006; Suho, 2007; Kunnavakkam, 2003; Makela, 2008; Gates, 2005; and Xia, 1998). A 

few of these methods (eg, hot embossing and micro-contact printing) have been studied for 

application to curved surface patterning (Chang, 2005; Cheng, 2006; Choi, 2004; Makela, 2008; 

Tanaka, 2007; and Paul, 2003).

An engineered roughness index (ERI) model has been previously described (Schumacher, 

2007A) for predicting the biological response to micro-patterns. The model predicts the wetting 

and de-wetting potential of a particular surface roughness and can be used to develop patterns with 

optimized roughness (Schumacher, 2008; Schumacher, 2007B; Carman, 2006). The dimensionless 

ratio allows for characterization of engineered roughness that expands on traditional definitions 

of roughness for topography:

ERI = (r * df) / fD

The ERI is a function of three variables associated with the geometry, size, and spatial 

arrangement of the topographical features: Wenzel roughness factor (r), depressed surface 

fraction (fD), and degrees of freedom (df). The ERI is based on the hypothesis that increased 

tortuosity, or the dimensionality and orientation of the spacing between features in the surface 

topography, renders the surface less favorable for organism adhesion. Larger ERI values imply 

reduced settlement of biological microorganisms (Schumacher, 2007A).

Aspect ratio, including feature height and feature width, can be adjusted to improve ERI values; 

for example, increased feature height increases surface area, leading to a higher ERI. A variation 

of the SharkletTM micro-pattern with the same spatial arrangement of features but with depressed 

recesses instead of protruding features, called inverse SharkletTM (ISK), would decrease fD, 

resulting in an increased ERI.

In combination with non-leaching antimicrobial additives, SharkletTM would provide persistent,

long-term biological protection to polymeric and metal surfaces against a broad spectrum of

bacteria, fungi, and protozoa without need for biocide re-application. To verify that the microbial

control technology is effective in maintaining high purity water requirements from vehicle loading

through mission operations, antimicrobial materials for use in spacecraft ECLSS were first

evaluated for the impact of variable gravity environments on cellular adhesion. In this study, the

ISK and SharkletTM micro-patterns were evaluated in different material compositions for the

ability to resist colonization in lunar gravity and microgravity conditions.
19

METHODS AND MATERIALS 

Pre-travel Procedure 

Sharklet Technologies, Inc. provided NASA with 30 coupons for ground testing and a further 110 

coupons for reduced-gravity flight operations, as described below. They provided 15 PDMS 

(polydimethylsiloxane) elastomer coupons with the SharkletTM pattern, 15 PDMS coupons with 

ISK pattern, and 15 PDMS coupons without a pattern. NASA personnel performed change data 

capture (CDC) bioreactor testing on the SharkletTM PDMS coupons following methods defined in 

ASTM (American Society for Testing and Materials) E 2562-07, as previously conducted at

KSC, to compare the extent of biofilm formation on new materials with that previously observed.

Additionally, Sharklet Technologies, Inc. supplied ISK-patterned PDMS coupons for NASA to 

apply a peptide coating to a subset of materials to include in CDC reactor testing. NASA also 

included additional material coupons from the Air Force Research Laboratory (AFRL) (WrightPatterson Air Force Base, Dayton, OH) for CDC reactor testing.

NASA personnel tested a subset of material coupons in the BRIC (biological research in a canister)

flight hardware containing either a standard Petri dish fixation unit (SPDFU) or a modified Petri 

dish fixation unit (MPDFU) for verification of ground- and flight-test procedures to determine 

antimicrobial activity within the duration of reduced-gravity parabolic flight operations.

Flight Hardware 

BRIC-LED (biological research in a canister light-emitting diode) flight hardware is an 

anodized-aluminum container capable of providing illumination and fixation capability for the 

cultivation of small biological specimens in a complement set of flight hardware, the Petri dish 

fixation unit (PDFU) (figure 1). Each BRIC-LED canister can accommodate as many as six

PDFUs. Each PDFU contains a single 60 × 15-mm Petri dish and a fluid reservoir for on-orbit

activation and/or chemical fixation of biological samples in the PDFU. The SPDFU contains a

single-chamber reservoir for the addition of one fluid during flight operations. The MPDFU 

contains a dual-chamber reservoir for the addition of two fluids during flight operations.

Figure 1. Flight hardware: A. The BRIC and 

B. The PDFU. 

Pre-flight Procedure at KSC 

Sharklet Technologies, Inc. provided NASA with 110 polycarbonate (PC) coupons without 

pattern, 90 PC coupons with the ISK pattern, 110 PDMS coupons without pattern, and 90 PDMS 

coupons with both SharkletTM and ISK patterns. In addition, Sharklet Technologies, Inc. supplied 

low-density polyethylene (PE) coupons with and without the ISK pattern. NASA provided 80 

A B 
20

stainless-steel (SS) and 80 titanium (Ti) coupons. All coupons were 12 mm in diameter and had 

an adhesive backing for mounting into BRIC PDFUs.

NASA personnel treated all coupons by ethylene oxide (EtO) sterilization for payload integration 

with flight hardware treated by autoclave sterilization and assembled by the Flight Payloads 

Group (Bionetics Corporation, Yorktown, VA) at KSC per procedures contained in the 

Antimicrobial Polymer Project Work Authorization Document (LSSC-WAD-AMPP [launch 

services support contract-work authorization document-Advanced Materials Processing 

Program]). Sterile test coupons and either ionic Ag biocide (400 μg•L-1 AgF) (Sigma-Aldrich, 

St. Louis, MO) or cell fixative (1% formalin, Sigma Aldrich) were aseptically loaded into the 

flight hardware in a laminar flow bench or biological safety cabinet (BSC) for shipment by 

government van in sealed flight hardware shipping containers to the JSC Advanced Water 

Recovery System Development Facility (AWRSDF) in Building 7B. An agar streak plate of the 

test microorganism, Pseudomonas aeruginosa strain ERC1 (ATCC 700888), was prepared at 

KSC for shipment to JSC in a separate container. The bacterial inoculum for reduced-gravity 

testing was prepared as a broth culture in BBLTM TrypticaseTM Soy Broth (TSB) (BD, Franklin 

Lakes, NJ) from the agar streak plate ≥12 h before flighteach flight day and loaded into the flight 

hardware at JSC in a BSC.

In total across two flight days, 70 treatments––comprised of seven identical coupons affixed to

the bottom of a 60-mm Petri dish housed in a PDFU mounted inside of each BRIC (ie, seven

coupons per PDFU, six PDFUs per BRIC, six BRICs per flight day)––were performed, except as

noted. After each flight day, MPDFUs were removed from the BRIC units and stored at 4°C for

return to KSC. SPDFUs were de-integrated from their BRIC and the coupons were aseptically transferred from each Petri dish to sterile containers for analysis at JSC or KSC. At JSC on each flight 

day, two coupons were sampled for heterotrophic plate count (HPC) on R2 agar (BD, Franklin

Lakes, NJ), two coupons for LIVE/DEAD® BacLightTM (Invitrogen, Carlsbad, CA) direct count 

live/dead (L/D), and one coupon for ATP (LuminUltra Technologies Ltd., Fredericton, New Brunswick, Canada) quantification. For coupons from each SPDFU to be sampled at KSC, one coupon 

was fixed in 1% formalin using the acridine orange direct count (AODC) (Sigma Aldrich) technique and one coupon was suspended in sterile phosphate buffered saline (PBS) (Sigma Aldrich) 

for scanning electron microscopy (SEM). In addition to coupon samples, bulk fluid from each PDFU

was assayed at JSC by HPC, L/D, AODC, and ATP.

The HPC test, also called the total count or plate count, provided an estimate of the total number of

bacteria that developed into colonies during a period of incubation on a nutrient-rich agar (eg,

R2A) in a sample. This test, which can detect a broad group of bacteria including non-pathogens, 

pathogens, and opportunistic pathogens, often does not accurately sample all of the bacteria in the

water sample examined. For example, bacterial biofilms, injured bacteria, and/or viable but nonculturable bacteria may not form colonies on the selected nutrient medium. In some cases, samples

required serial dilution for enumeration. The results were averaged and the standard deviation was

calculated for both the HPC and the AODC sample data. For direct counts of cells the formalinfixed water samples were sonicated, diluted into 0.2-μm filtered deionized water, stained with

acridine orange (AO), and filtered onto 25-mm (dia.), 0.2-μm black polycarbonate filters for enumeration on an Axioskop 2 epi-fluorescent microscope (Carl Zeiss Micromalging, Inc., Thornwood, 

NY) at 1,000× magnification (Bloem, 1995; Hobbie et al., 1977). The LIVE/DEAD® BacLight
21

bacterial viability kit (Invitrogen) had previously been used to determine the percentage of viable 

organisms found in a urine sample (Boulos et al., 1999; Gregori et al., 2001). Viability, as determined by BacLightTM assay and that equates with cells that have intact cell membranes, tends to 

overestimate living cells in most environmental matrices.

Adenosine Triphosphate Procedure 

Bulk Fluid Adenosine Triphosphate Procedure Assay Protocol 

The following are instructions for the Quench-Gone Aqueous (QGATM) test kit:

• Remove the plunger from a 60-mL syringe (provided by manufacturer)

• Add a filter (provided by manufacturer) to the 60-mL syringe

• Vortex each sample for 5 s

• Pipette 3 mL of sample with a 5-mL serological pipette into the syringe with filter

• Replace the plunger

• Slowly filter the sample into a 1-L beaker (waste receptacle)

o Filter all fluid through, but allow the filter to remain wet

• Detach the filter and remove the plunger

• Reattach the filter to the syringe

• Add 1 mL of UltraLyse 7 to the barrel

• Collect the extract fluid in a dilution tube until the filter is dry

• Add 9 mL of UltraLute to the extract with a 10-mL serological pipette (10 mL total volume)

• Cap and invert three times to mix

• Pipette 100 μL of diluted extract into a well of the black-and-white Isoplate

• For the control well, add 100 μL of UltraCheck 1 (two drops)

• Add 100 μL of room-temperature Luminase (two drops) to all wells containing samples

• Swirl gently five times to mix

• Load into the PerkinElmer VICTORTM X2 plate reader (PerkinElmer, Covina, CA) and run 

luminescence assay (×3)

Modified Coupon Adenosine Triphosphate Procedure Assay Protocol 

The following are instructions for the modified coupon ATP assay protocol:

• Place a sample in a 15-mL extraction tube containing 1 mL of UltraLyse 7

o Ensure the coupon is completely immersed

• Cap and vortex for 5 s

• Incubate sample for 5 min at room temperature

• Transfer the contents of the extraction tube to a dilution tube containing the UltraLute/resin 

mixture

• Cap and invert three times to mix

• Pipette 100 μL of diluted extract into a well of the black-and-white Isoplate

• For the control well, add 100 μL of UltraCheck 1 (two drops)

• Add 100 μL of room-temperature Luminase XL (two drops) to all wells containing samples

• Swirl gently five times to mix

• Load into the PerkinElmer VICTORTM X2 plate reader and run luminescence assay (×3)

 
22

Microgravity Flight (Reduced-gravity Flight Day 1 – 6 BRICs) 

BRIC A – C: 17 MPDFUs containing an inoculum and 400 μg L-1 AgF (silver fluoride) biocide

BRIC A: 6 control materials (PC SM [smooth], PE SM, PDMS SM, SS, Ti, and PET 

[polyethylene terephthalate]/Ag)

BRIC B: 4 SharkletTM patterned materials (PDMS ISK, PDMS SK, PC ISK, PE ISK)

2 AFRL POSS [polyhedral oligomeric silsesquioxanes] samples (*PC/FD8T8, 

*PC/[NMe4]

+

FD8T8)

*3 coupons per PDFU

BRIC C: 5 Peptide (PC SM P [pilin peptide], PC ISK P, SS P, Ti P, and PET/Ag P)

BRIC D – F: 18 SPDFUs containing only inoculum

BRIC D: PC SM, PC SM P, PC ISK, PC ISK P, PE SM, PE ISK

BRIC E: PDMS SM, PDMS SK, PDMS ISK, SS, SS P, PET/Ag

BRIC F: Ti, Ti P, **PC/AFRL, **PC/FD8T8, **PC/[NMe4]

+

FD8T8, **PC/Me4NF

**4 coupons per PDFU for microgravity flight; **3 coupons per PDFU for lunar-G flight

Lunar-gravity Flight (Reduced-gravity Flight Day 3 – 6 BRICs) 

BRIC a / BRIC b / BRIC c

17 MPDFUs containing inoculum and formalin with the same material distribution as in the 

microgravity flight

BRIC d / BRIC e / BRIC f

18 SPDFUs containing inoculum with the same material distribution as in the micro gravity

flight.

Table 1 provides the active mean surface area by coupon material type, and figure 2 depicts the 

BRIC test plan coupon arrangement for both microgravity and lunar gravity experiments.

Table 1. Active Mean Surface Area by Coupon Material Type 

Material

Mean Coupon

Diameter (mm)

Mean Coupon Thickness 

(mm)

Mean Surface

Area (mm2)

PC ISK 12 0.1778 119.80

PC SM 12 0.1778 119.80

PC/control 12.7 1.4986 186.47

PC/treatments 12.7 1.7272 195.59

PDMS ISK/SK 12 0.0762 115.97

PDMS SM 12 0.1016 116.93

PE ISK 12 0.1016 116.93

PE SM 12 0.3048 124.59

PET/Ag 12 square 0.0762 147.66

SS 12.7 3.8608 280.72

Ti 12.7 3.6322 271.60
23

Zero Gravity Flight 

8/11/2009

A

B

C

D

E

F

housing BRIC

Modified PDFU

coupon

inoculum

AgF AgF

silver 

AgF

AgF

AgF

AgF

PC SM

PE SM

PDMS SM

SS

Ti

PET/Ag

AgF AgF

AgF

AgF

AgF

AgF

PDMS ISK

PDMS SK

PC ISK

PC/FD8T8

PC/[NMe4]+FD8T8

PE ISK

AgF AgF

AgF AgF

AgF

PC SM P

PC ISK P

SS P

Ti P

PET/Ag P

Standard PDFU

PDMS SM 

PDMS SK

PDMS ISK

SS

SS P

PET/Ag

PC SM

PC SM P

PC ISK

PC ISK P

PE SM

PE ISK

Ti

Ti P

PC/AFRL

PC/FD8T8

treatment name

1

2

3

4

5

6

1

2

3

4

5

6

1

2

3

4

5

1

2

3

4

5

6

1

2

3

4

5

6

1

2

3

4

5

6

PC/[NMe4]

+FD8T8

PC/Me4NF

6

Lunar Gravity Flight 

8/13/2009

a

b

c

d

e

f

housing BRIC Modified PDFU

coupon

inoculum

AgF AgF

silver 

AgF

AgF

AgF

AgF

PC SM

PE SM

PDMS SM

SS

Ti

PET/Ag

AgF AgF

AgF

AgF

AgF

AgF

PDMS ISK

PDMS SK

PC ISK

PC/FD8T8

PC/[NMe4]+FD8T8

PE ISK

AgF AgF

AgF AgF

AgF

PC SM P

PC ISK P

SS P

Ti P

PET/Ag P

Standard PDFU

PDMS SM 

PDMS SK

PDMS ISK

SS

SS P

PET/Ag

PC SM

PC SM P

PC ISK

PC ISK P

PE SM

PE ISK

Ti

Ti P

PC/AFRL

PC/FD8T8

treatment name

1

2

3

4

5

6

1

2

3

4

5

6

1

2

3

4

5

1

2

3

4

5

6

1

2

3

4

5

6

1

2

3

4

5

6

PC/[NMe4]+FD8T8

PC/Me4NF

6

Figure 2. BRIC test plan coupon arrangement for microgravity (top) and lunar-gravity (bottom) experiments. 

 
24

Preflight Procedure at Johnson Space Center 

KSC ground support personnel loaded the PDFU fixation reservoirs at JSC (AWRSDF, Building

7B) with an inoculum on the morning of each flight day containing the test microorganism P.

aeruginosa strain ERC1 (ATCC 700888) at a cell density of approximately 1E5 CFU•mL-1 (ie, 

100,000 cells/mL). Each SPDFU had a single fixation reservoir with a fill volume of 

approximately 13 to 14 mL while the MPDFU had two fixation reservoirs, each with a fill 

volume of approximately 8 to 10 mL. The second fixation reservoir in each MPDFU was filled to 

capacity (~8 to 10 mL) with either an AgF ionic biocide solution (400 μg•L-1 AgF for the microgravity flight) or 1% formalin fixative (for the lunar-gravity flight) during hardware integration

and assembly at KSC as outlined above. BRICs were loaded into foam inserts in a tray at JSC for

transport to nearby Ellington Field and integration into a Shuttle middeck locker for attachment 

to the plane frame with straps for reduced-gravity flight operations, as described in the antimicrobial materials for microgravity environments test equipment data package (AMME-TEDPRevA).

In-flight Procedure 

Microgravity

Before the first parabola was executed, all BRICs (A-F) were manually engaged, thereby

exposing the coupons to the microbial inoculum containing [1E5] challenge bacteria in 10% 

TSB. The samples remained in the inoculum throughout the duration of the reduced-gravity

flight. At the end of the last parabola, each BRIC unit containing an MPDFU with Ag biocide 

solution was engaged again to inject the fluid at the end of the last parabola.

Lunar Gravity 

Before the first parabola was executed, all BRICs (a-f) were manually engaged, thereby

exposing the coupons to the microbial inoculum containing [1E5] challenge bacteria in 10% 

TSB. The samples remained in the inoculum throughout the duration of the reduced-gravity

flight. At the end of the last parabola, each BRIC unit containing an MPDFU with 1% formalin 

fixative was engaged again to inject the fluid at the end of the last parabola.

Post-flight Procedure 

After each flight day BRICs containing MPDFUs were stored, as is, in coolers with ice packs for

return shipment to KSC by ground transport. All MPDFUs were de-integrated from BRICs and 

processed at KSC for sample analysis to quantify antimicrobial efficacy and cell attachment.

BRICs containing SPDFUs were de-integrated from the BRIC units and processed at JSC in the 

Building 7B. AWRSDF for sample analysis to quantify antimicrobial efficacy and cell attachment.

All de-integrated and integrated BRIC and PDFU hardware was packed for return shipment to 

KSC in accordance with the antimicrobial polymer project work authorization document (LSSCWAD-AMPP) and under the supervision of flight quality assurance.

A series of treatments similar to the reduced-gravity testing was performed as a ground control at 

KSC after completion of the micro and lunar parabolic flight experiments.

RESULTS/DISCUSSION 

The duration between inoculation and harvest of the SPDFUs was approximately 4.5 h. The 

duration between fixation and harvest of the MPDFUs was 1 week. HPC results of the bulk fluid

samples indicated that experiment and flight hardware performance was nominal (figure 3). The 
25

microgravity flight had an increase of Log10 CFU/mL = 0.33; the lunar gravity flight had an increase of Log10 CFU/mL = 0.38; and the ground testing had an increase of Log10 CFU/mL = 0.41. 

The HPC results of the bulk fluid samples indicated that variability between PDFUs was minimal 

for both the flight and the ground experiments (figure 4). HPC data for bulk fluid and coupon

samples were unobtainable from MPDFUs after fixation with either 400 ppb ionic Ag or 1% 

formalin.

Figure 3. HPC comparison between experiments indicating growth 

throughout the duration of experiment. 

 

Figure 4. HPC comparison between experiments indicating variation between 

bulk fluid samples at the time of harvest. 

Microscopy data supported the results found from the plate counts for the bulk fluid samples, 

demonstrating minimal variability between flight experiments. However, the AO and L/D counts

were below the limit of detection for coupons recovered for both microgravity and lunar gravity 

conditions from the MPDFUs and the SPDFUs. During the BacLightTM L/D assay, it was found

that 88% to 92% of the cells found in the bulk fluid samples were alive; this result was optimal.

The L/D total counts were similar to those found during HPC analysis (figure 5). L/D data for

bulk fluid samples was unobtainable from MPDFUs after fixation with either 400-ppb ionic Ag

or 1% formalin. Although there were slight variations between the AO samples based on fixation

method, these variations were not statistically significant (figure 6). No cells were observed on 

coupon surfaces during environmental scanning electron microscopy (ESEM).

5.2

5.3

5.4

5.5

5.6

5.7

5.8

5.9

Inoculation Harvest

Log (10) CFU/mL

Ground Lunar Zero 

1

2

3

4

5

6

7

Ground (n=3) Lunar (n=18) Zero (n=18)

Log (10) CFU/mL
26

Figure 5. L/D comparison between flights indicating variation in bulk fluid samples. 

Figure 6. AO comparison between flights indicating variation in bulk fluid based on fixation type. 

A standard curve was generated using the LuminUltraTM QGATM test kit with the P. aeruginosa

strain ERC1 (ATCC 700888) at a high range of cellular density (figure 7) and a low range of 

cellular density (figure 8); both ranges showed a positive correlation between the number of cells 

and the amount of ATP/mL of sample. Cellular concentrations were verified by optical density, 

AO direct counts, and HPCs. ATP analysis of the bulk fluid samples showed that after 1 week,

the microgravity flight produced a 1.6 log reduction after Ag fixation while the lunar gravity 

flight produced a 2.3 log reduction after formalin fixation. This pattern was repeated to a lesser 

degree during ground testing in which there was approximately a 1 log reduction in adenosine 

triphosphate (ATP)/mL with 1% formalin fixation and a > 0.5 log reduction with 400 ppb ionic Ag 

fixation (figure 9). These results indicate that the formalin has an increased negative impact on 

cellular metabolism over the Ag.

1

2

3

4

5

6

7

Lunar (n=18) Zero (n=18)

Log (10) cells/mL

1

2

3

4

5

6

7

Lunar Zero

Log (10) cells/mL

MPDFU (n=17) SPDFU (n=18)
27

Figure 7. High ATP standard curve (n=9). 

Figure 8. Low ATP standard curve (n=9). 

 

Figure 9. Bulk fluid ATP results. 

The previously established benchmark for healthy cells exposed to terrestrial gravity is 

Escherichia coli pg ATP/cell ≈1.00E-03 (Crombrugge and Waes, 1991). This shows that the 

amount of ATP in the P. aeruginosa cells during ground testing resembled the metabolic state of 

the benchmark samples. More ATP/cell was in those samples experiencing short-duration 

microgravity exposure than in those during ground testing (Table 2). This effect was previously 

seen in a study with plants in which cells exposed to short-term microgravity experienced an 

increased metabolic rate and then, after long-term exposure to microgravity, went into a relaxed 

y = 518901e-2.408x

R2 = 0.9933

1.E+01

1.E+02

1.E+03

1.E+04

1.E+05

1.E+06

1.E+08 1.E+07 1.E+06 1.E+05

pg ATP/mL

cells/mL

y = 38.423e-0.815x

R2 = 0.9959

1.E+00

1.E+01

1.E+02

1.E+04 1.E+03 1.E+02 1.E+01

pg ATP/mL

cells/mL

1

10

100

1000

10000

Ground (n=21) Lunar (n=51) Zero (n=51)

pg ATP/mL

Standard Formalin Silver
28

metabolic state lower than even experienced in terrestrial gravity (Hampp et al., 1997). In the cells 

that were not exposed to a fixative, there appeared to be more ATP/cell in the lunar gravity flight 

samples than in those that experienced microgravity. After fixation in the MPDFUs for 1 week 

with either ionic Ag or formalin, there was a 2 log reduction in pg ATP/cell; however, during 

ground testing this effect was a 1 log reduction in pg ATP/cell.

Table 2. Bulk Fluid pg ATP/Cell Results 

Without fixative 1% Formalin 400 ppb Silver

Ground (n=21) 1.10E-03 ± 3.81E-04 1.38E-04 ± 3.31E-05 2.81E-04 ± 8.83E-05

Lunar (n=51) 2.70E-03 ± 6.05E-04 2.82E-05 ± 5.57E-06 N/A

Micro (n=51) 2.02E-03 ± 5.75E-04 N/A 2.30E-05 ± 9.07E-06

The HPC of the PDMS SK and ISK over the SM decreased in both the lunar and the microgravity flight coupon samples (figures 9 and 10). This effect was more pronounced in the lunargravity flight samples (< 1 log reduction). There was a decrease in the HPC of the Ag-coated

PET samples over the controls in both the lunar-gravity and the microgravity samples. This effect

was more pronounced in the microgravity flight samples (~1 log reduction). During initial coupon

ATP testing, the recommended protocol of using a QuenchGone21 wastewater (QG21W) extraction tube with 2 mL of UltraLyse and then adding the sample to a QG21W dilution tube with 8 mL

of UltraLute was below the limit of detection for the luminescence assay. The protocol was thus 

modified to use 1 mL of UltraLyse and 1 mL of UltraLute to lower the dilution factor and produce

a response above background due to the low number of cells on the coupons as verified by HPCs.

However, this could have made the reaction too alkaline, which could cause inhibition of the 

Luminase and produce a less-specific reaction.

Figure 10. HPC comparison between coupons during the microgravity parabolic flight (n=2). 

0

1

2

3

4

Log (10) CFU/cm2
29

Figure 11. HPC comparison between coupons during the lunar-gravity parabolic flight (n=4). 

CONCLUSION 

Analysis methods indicated that the flight hardware performed nominally and that minimal 

variability occurred between flight and ground experiments. The short-term duration of the 

microgravity and lunar-gravity parabolic flights was not conducive to the advancement of biofilm

formation. However, there was a slight decrease in cellular adhesion to the coupons with PDMS 

with both the SharkletTM and the ISK pattern over the unpatterned surface. There was also a 

decrease in cells on the coupons containing an Ag coating over the control samples. Although the 

ATP/cell for the P. aeruginosa healthy terrestrial samples was similar to the anticipated 

benchmark for E. coli, exposure to short-term variable gravity caused the amount of ATP/cell to 

more than double––an effect that was greater in the lunar-gravity flight samples. As anticipated, the 

amount of ATP per cell decreased when exposed to either formalin or Ag fixation. For both flight 

and ground experiments, fixing with formalin had an increased negative impact on cellular 

metabolism over Ag fixation.

Further evaluation will be conducted on optimizing the ATP method for coupon surfaces and to 

confirm whether the increased ATP found in the lunar-gravity flight over the microgravity flight 

is specific to flight conditions or time dependent. Further experiments need to be performed at

longer durations of reduced gravity to extrapolate the microgravity and 2-gravity segments of the 

parabolic data. New materials will be developed and tested in 1-gravity environments using ASTM 

methods to improve the materials’ antimicrobial response.

ACKNOWLEDGEMENTS 

The principal investigators would like to thank the integrated phase planning (IPP) FAST program 

for providing them an opportunity to perform reduced-gravity experiments aboard the Zero-G

aircraft. We would also like to thank the KSC IPP office for its financial support for funding the 

use of shuttle flight hardware for the experiment.

This report is submitted as part of a requirement of the NASA IPP FAST Reduced Gravity 

Program.

The following table describes the materials in this article as well as provides the materials’ 

source/vendor.

0

1

2

3

Log (10) CFU/cm2
30

Materials Description Source/Vendor

PC SM Polycarbonate, smooth Sharklet Technologies, Inc.

PC SM P PC with pilin peptide, smooth Sharklet Technologies, Inc.

PC ISK PC with inverse SharkletTM pattern Sharklet Technologies, Inc.

PC ISK P PC with inverse SharkletTM pattern and pilin peptide Sharklet Technologies, Inc.

PC/AFRL Polycarbonate (AFRL) Air Force Research Laboratory

PC/FD8T8 PC + [10% fluorodecyl polyhedral oligomeric 

silsesquioxane] (ie, polycarbonate with fPOSS)

Air Force Research Laboratory

PC/[NMe4]

+

FD8T8 PC + [10% Me4N+ fPOSS(F-)] (ie, polycarbonate 

with caged fPOSS)

Air Force Research Laboratory

PC/Me4NF PC + [0.25% Me4N+ F-] (ie, polycarbonate with 

cage but no fPOSS)

Air Force Research Laboratory

PDMS SM polydimethylsiloxane elastomer, smooth Sharklet Technologies, Inc.

PDMS SK PDMS with SharkletTM pattern Sharklet Technologies, Inc.

PDMS ISK PDMS with inverse SharkletTM pattern Sharklet Technologies, Inc.

PE SM Polyethylene, smooth Sharklet Technologies, Inc.

PE ISK PE with inverse SharkletTM pattern Sharklet Technologies, Inc.

PET/Ag Silver-coated polyethylene terephthalate Georgia Tech Research Institute

PET/Ag P Silver-coated PET with pilin peptide Georgia Tech Research Institute

SS Stainless steel 316 BioSurfaceTechnologies Corporation 

(Bozeman, Mont.)

SS P Stainless steel 316 with pilin peptide BioSurface Technologies Corporation

Ti Titanium 6Al-4V BioSurface Technologies Corporation

Ti P Titanium 6Al-4V with pilin peptide BioSurface Technologies Corporation

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PHOTOGRAPHS 

None available.

VIDEO 

• Zero G flight week 8/11 – 8/14, 2009 Master/TSR: 103823

Videos are available from Imagery and Publications Office (GS4), NASA JSC.

CONTACT INFORMATION 

Luke Roberson, PhD

Research Scientist

Mail Code: NE-L6-P

NASA Kennedy Space Center, FL 32815
33

TITLE 

Education Outreach Program –

Space Motion Sickness and the Semicircular Canals of the Inner Ear

PRINCIPAL INVESTIGATORS 

Matthew Allner

Rich Simonsen

COINVESTIGATOR 

Paul Uranga, NASA Johnson Space Center, Houston, TX, Mentor

FLIGHT DATES 

April 26–30, 2010
34

GOAL 

Fluids of different viscosities flow at different rates in a 1-gravity environment. This 

investigation will attempt to determine whether these same fluids flow at different rates while in 

a simulated microgravity environment.

OBJECTIVES 

This experiment was designed by students at Fox Meadow Middle School in Colorado Springs, 

CO. The students were learning about space adaptation syndrome (SAS)/space motion sickness 

(SMS) in their NASA space science class and wanted to better understand why so many astronauts

experience SMS symptoms during their first few days of spaceflight. These students thought that

building a model of the inner ear and the semicircular canals would allow them to better visualize

what really happens with endolymph fluid movement. Students were also curious whether fluids of

different viscosities would flow differently through semicircular, canal-shaped tubes when 

exposed to a reduced-gravity environment.

The question these students wanted answered was: What implication does the experiment have 

for understanding the astronaut’s inner ear? The endolymph fluid of the semicircular canals of 

the inner ear moves in 1 G as the head is moved in all three axes (x, y, and z). In microgravity,

this fluid moves freely due to the altered state of gravity, thus contributing to the Conflict Theory 

that causes SMS (Churchill, 1997; Connors, Harrison, and Akins, 2005). Our flight experiment 

design will allow us to collect data on how three different liquids (of differing viscosities) move 

in a simulated space environment. We feel that the fluid that is probably most like the endolymph 

fluid is vegetable oil because it tends to move more freely than the other two fluids. However, 

the reason for us investigating the other two fluids (dish soap and syrup) is that we are curious as 

to whether the endolymph fluid viscosity of astronauts, who will be living permanently in alteredgravity environments, will change to allow their bodies to adapt to the environment in which 

they will be living. We think this fluid could thicken in time; hence, we are also studying two 

other fluids that are slightly more viscous than endolymph fluid.

METHODS AND MATERIALS

We anticipate that by using clear plastic tubing that is calibrated and mounted in various positions, we will be able to measure flow rates during periods of microgravity as well as the rate of 

return (resettling of the liquid) during hypergravity.

The original design is a model of the three axes of rotation and the semicircular canals of the 

inner ear (figure 1). To generate sufficient post-flight data analysis, two more experiments were

built: the primary experiment, which will be designed for the flight (figure 2), and a second experiment, which will serve as a prototype to allow us to test the fluids and collect data in the

classroom (figure 3). The data collected from the in-class experiment will then be cross-analyzed

with data collected during the flight in an effort to provide a post-flight analysis and lessons 

learned.
35

We will be measuring the distance that three different fluids (vegetable oil, dish soap, and syrup) 

will flow through 0.5-in. vinyl tubing. Assuming the fluids will move when in microgravity/zero 

gravity, the maximum length of tubing that any one fluid can move will be 28 cm. We will be 

calibrating the tubing to record the amount of movement of each liquid; using periods of 

microgravity, we will be recording the time it takes for the liquids to either flow all the way to 

the opposite end or the time it takes for the parabola to be completed.

We anticipate that the flow rates of the three selected liquids will vary when tested on Earth. The

flow rate of each liquid will remain consistent in microgravity, but the distances the liquids may 

travel and their velocities in the tubing may vary. Our assumption was based on the premise that 

in positive gravity, downward force and the acceleration rate of an object are constant. Since a 

small amount of gravitational force is still present in microgravity we feel the flow rates will 

remain in the same order as tested on Earth, but will be slower due to the reduction of gravitational force.

Again, one side of our experiment will be for the data collection portion and the other will be a

model of the semicircular canals of the inner ear, displaying three tubes with one in each of the

three axes (x, y, and z). Each of these three tubes will have vegetable oil in them (simulating the 

endolymph fluid).

The following is a list of the equipment to be brought on board the aircraft. All equipment will be 

stowed in a Reduced Gravity Office (RGO) glove box for takeoff and landing. The camera pole 

used for mounting the video camera will be in place and bolted to the floor during takeoff and 

Figure 1. SMS FOX FT 2 – flight experiment. Figure 2. SMS FOX FT 2 – in-flight experiment. 

 

Figure 3. SMS FOX FT 1 – class 

experiment. 

 
36

landing; but the camera itself will be attached after takeoff. The total weight of all experiment 

components is approximately 13 lb, not including the RGO glove box.

Space Motion Sickness Fluid Tester (SMS-FOX-FT 2) 

The following comprise the parts of the figure 1 flight experiment:

1. Experiment assembly

• 12 hose barb adapter caps

• 12 hose barb adapters (3/8 in. × 1/4 in.)

• 9 vinyl plastic tubing pieces

• 40 small plastic zip ties (10 cm)

• 6 drain cock valves (1/4 in.)

• 3 fluids for testing Dawn® dish soap (Proctor & Gamble, Cincinnati, OH), vegetable oil, 

syrup

• 18 pieces of plumber’s tape (each 17-cm long)

• Peg board

• One 4-in. metal hinge

• 2 wing nuts

• Wood-threaded shaft

• Grooved piece of maple wood (for the divider)

• Various small scraps of pine wood

• 30 wood screws

• Two 1/4-in. nuts and bolts with 2 washers each

• 18 hose clamps

2. Three camera mounts, attached preflight

3. Two digital video cameras

4. One digital camera (ie, still camera)

5. RGO glove box

6. One spinning top, 1 U.S. penny, and 1 Slinky® (POOF-Slinky, Inc., Plymouth, MI) –

Educational outreach experiment

7. Three spare batteries

All equipment was stowed in the RGO glove box for takeoff and landing. The flight team will

ensure that all equipment is properly secured and stored within the crates before takeoff and 

landing. The glove box attachment will be inspected before takeoff and landing to ensure it is 

correctly fastened to the aircraft floor.

SMS FOX FT2 – In-flight (1 G) 

1. During zero-g – Flier 1 will be positioned on the hinge side (ie, the bottom) of the 

experiment, and Flier 2 will sit to either side of the experiment. Flier 1 will watch the 

movement of the liquids and the distance the liquids travel. He/she will also note both the 

time and the distance the liquids are moving and this information will be recorded in a data 

table. Flier 2 will run the stop watch for the first half of the testing (seven parabolas); his/her

job will be to (1) call out the test number as the test begins and (2) give Flier 1 the time at which

Flier 1 sees a liquid has reached the end of the tubing. After the seventh parabola, Flier 1 and 

Flier 2 will switch places and will continue collecting data the same as before, but for eight

more parabolas.
37

2. During hypergravity, the board will always be set back at 90 deg to assist with fluid resettling. On receiving a call (announcement) that they will be coming out of hypergravity, 

Flier 1 and Flight 2 will then readjust the board back to the desired angle. Flier 1 will sit as 

still as possible but will monitor the board to see how much of the liquids resettle.

3. At least 15 parabolas will be used to collect data; we would like to set the adjustable peg 

board at the following three angles: 0, 45, and 90 deg. We plan on running five trials during 

which the board is at each angle.

4. During each test, a video camera will be set up to tape both sides of the experiment. Thus, if

any data are miscalculated or unobserved, we can catch the miscalculation or unobserved 

occurrence on film during the post-flight review with students.

RESULTS

Classroom Data 

Results from our classroom experiment prototype were first collected in the classroom; these are 

shown in figures 4a and 4b.

Microgravity Simulation (8-deg decline) 

Blue

Liquid Flow Distance Time (sec) Avg Time

(cm) Trial 1 Trial 2 Trial 3 Trial 4 Trial 5

Veg. Oil 53 34.28 29.44 24.84 29.72 34 30.456

Syrup 53 190.01 300 403 271 364 305.602

Dish Soap 53 262 231 221 238 200 230.4

Red

Liquid Flow Distance Time (sec) Avg Time

(cm) Trial 1 Trial 2 Trial 3 Trial 4 Trial 5

Veg. Oil 54 34.6 40.61 40.61 29.37 54.81 40

Syrup 54 277.03 468.72 557.59 495.79 783.97 516.62

Dish Soap 54 428.69 263.22 243.57 206 241.03 276.502

Figure 4a. Microgravity simulation data (8-deg decline). Classroom data were collected from two separate 

student groups (Blue Team and Red Team), 
38

Earth (1 G) Data Collection 

Blue

Liquid Flow Distance Time (sec) Avg Time

(cm) Trial 1 Trial 2 Trial 3 Trial 4 Trial 5

Veg. Oil 53 5 8 5.38 7.25 5.16 6.158

Syrup 53 53 38 32.5 53.85 41.63 43.796

Dish Soap 53 25 31 25 31 21.84 26.768

Red

Liquid Flow Distance Time (sec) Avg Time

(cm) Trial 1 Trial 2 Trial 3 Trial 4 Trial 5

Veg. Oil 54 4.84 2.88 6.38 7.25 5.25 5.32

Syrup 54 62.25 88.03 64.96 87.13 60.56 72.586

Dish Soap 54 22.9 25.6 24.91 28.71 22.44 24.912

Figure 4b. 1g classroom data. Liquids movement was measured when experiment board was in a 90-deg 

angle, perpendicular to the ground. 

In Earth-based analyses conducted on humans, bed rest studies have provided numerous useful 

insights into many of the physiological responses humans would have in the space environment 

(Connors, Harrison, and Akins, 2005). Such studies involve using human subjects and placing

them in a head-down tilt position for various lengths of time while physiological processes were

monitored and countermeasures were implemented in efforts to better learn how to best improve 

astronaut health while in the microgravity environment of space. Following this idea of a bed rest 

study, we hypothesized that an 8-deg downward tilt (decline) would possibly produce results that 

would be similar to those obtained in bed rest studies as well as in a microgravity environment.

Students recorded data from two separate experiment test boards. Five trials were completed by

each student group. Figure 4a indicates movement of all three liquids, with syrup moving the 

slowest and vegetable oil moving the fastest after five trials. Looking at the data in figure 4b, the 

same pattern exists in that syrup moved the slowest and vegetable oil moved the fastest.

Flight Day 1 Data 

Results from our flight experiment design were collected on two separate flights and shown in 

figures 5a through 5e (Flight Day 1) and figures 6a and 6b (Flight Day 2). Unfortunately, due to 

the lack of movement during both flights, it was difficult to collect significant data to support our 

hypothesis, as well as to accumulate data in which to engage in any sort of intelligent discussion 

and formulation of conclusions.

RGO Flight (90-deg incline) 

Parabola Tests 1, 2, and 3

Liquid (Microgravity) Hypergravity

Distance (cm) Time (sec) Distance (cm) Time (sec)

Veg. Oil 5 5 0 15 5 5 0 15

Syrup 2 2 0 15 2 2 0 15

Dish Soap 3 3 0 15 3 3 0 15

Figure 5a. Flight Day 1 – Parabola Test 1, 2, and 3 (90-deg incline). 
39

RGO Flight (45-deg incline) 

Parabola Tests 1, 2, and 3

Liquid (Microgravity) Hypergravity

Distance (cm) Time (sec) Distance (cm) Time (sec)

Veg. Oil 5 5 0 15 5 5 0 15

Syrup 2 2 0 15 2 2 0 15

Dish Soap 3 3 0 15 3 3 0 15

Figure 5b. Flight Day 1 – Parabola Test 1, 2, and 3 (45-deg incline). 

RGO Flight (0-deg incline) 

Parabola Test 1

Liquid (Microgravity) Hypergravity

Distance (cm) Time (sec) Distance (cm) Time (sec)

Veg. Oil 8 10 2 15 8 12 4 15

Syrup 10 11 1 15 11 12 1 15

Dish Soap 9 11 2 15 9 12 3 15

Figure 5c. Flight Day 1 – Parabola Test 1 (0-deg incline). 

Parabola Test 2

Liquid (Microgravity) Hypergravity

Distance (cm) Time (sec) Distance (cm) Time (sec)

Veg. Oil 9 12 3 15 8 11 3 15

Syrup 11 12 1 15 11 13 2 15

Dish Soap 10 14 4 15 11 14 3 15

Figure 5d. Flight Day 1 – Parabola Test 2 (0-deg incline). 

Parabola Test 3

Liquid (Microgravity) Hypergravity

Distance (cm) Time (sec) Distance (cm) Time (sec)

Veg. Oil 11 16 5 15 15

Syrup 6 9 3 15 15

Dish Soap 6 17 9 15 15

Figure 5e. Flight Day 1 – Parabola Test 3 (0-deg incline). 

Flight Day 2 Data 

Results from Flight 2 tests produced the results shown in figures 6a and 6b.

RGO Flight (90-deg incline) 

Parabola Tests 1 and 2

Liquid (Microgravity) Hypergravity

Distance (cm) Time (sec) Distance (cm) Time (sec)

Veg. Oil 5 5 0 15 5 5 0 15

Syrup 2 2 0 15 2 2 0 15

Dish Soap 3 3 0 15 3 3 0 15

Figure 6a. Flight Day 2 – Parabola Tests 1 and 2 (90-deg incline). 
40

Parabola Test 3

Liquid (Microgravity) Hypergravity

Distance (cm) Time (sec) Distance (cm) Time (sec)

Veg. Oil 5 2 0 15 5 5 0 15

Syrup 2 2 0 15 2 6 4 15

Dish Soap 3 3 0 15 3 3 0 15

Figure 6b. Flight Day 2 – Parabola Test 3 (90-deg incline). 

The comparison of data from figures 4a and 4b to those of figures 5a through 5e and 6a and 6b

indicates differentiation in fluid movement. Figures 5a through 5e indicate that the only movement

in any liquid occurred when the board was set in the 0-deg setting (figures 5c, 5d, and 5e). How 

much of this movement was due to simple displacement as opposed to any change in gravity is

questionable, however. Further analysis of why no movement took place during the 45- and 90-

deg settings was hypothesized as being due to the fact that the tube pressure was not vented on 

reaching the flight experiment cruising altitude. Following Flight Day 1, the fliers discussed this 

possibility and decided on Flight Day 2 to vent all six tubes on the hinge side of the pegboard.

Results of the venting (figures 6a and 6b) led to more fluid movement, but the movement was not

continuous and consistent as anticipated and as observed during the classroom tests, especially

with the dish soap. During the 90-deg setting, while fluid movement was seen in the soap, what

was visible in the tube was separated by pockets of air, which made it difficult to accurately

measure displacement. Interestingly, during hypergravity any movement of the soap that did

occur resulted in a lack of complete resettling back to the starting point of the liquid. It was 

difficult to say, from the data we were able to collect, that one liquid tended to move farther than

another liquids. Data results were very inconsistent.

DISCUSSION 

Analysis of our data showed that while we were able to collect some relevant data after modifications following Flight Day 1, the data results were not similar to those we collected in the 

classroom. Although our experiment did work after venting the tubes, the movement of liquid 

was still much less in microgravity than in the simulated microgravity setting (ie, the 8-deg 

downward tilt) we created in the classroom.

CONCLUSION

From our hypothesis and efforts in this investigation, we conclude that our experiment was a

success. Although it did not work the way we had predicted, we considered the experiment a 

success because of the results we were able to collect. Although inconsistent, the data collected 

in flight showed us how unpredictable fluid movement can be in a microgravity (or simulated

microgravity) environment. It is also possible that the lack of fluid movement in the experiment 

during both days of flight might have provided some evidence of the conflict theory. By this we 

mean that our test subject reported that during flight his body consistently would sense the simulated microgravity environment each time a parabola was flown, while sensing the hypergravity 

environment as well. However, the test subject did not recall anything out of the ordinary with

regards to visual changes or disturbances providing any input out of the ordinary. Assuming that 

the fluid in the inner ear either moves or does not move much (as in our experiment), a conflict 

of information could have been taking place during simulated microgravity flights such as RGO;

this may have resulted in differences in information being sent to the brain, as opposed to what it 
41

is accustomed to receiving for input in a 1-gravity environment. This would most likely explain 

why a conflict takes place between the inner ear and the brain during spaceflight, leading to the 

development of SMS (Churchill, 1997).

BIBLIOGRAPHY 

1. Churchill SE. Fundamentals of Space Life Sciences. Malabara, FL: Krieger Publishing 

Company, Inc., 1997;pp. 167-168.

2. Connors MM, Harrison AA, Akins FR. Living Aloft. Honolulu, HA: University Press of the

Pacific, 2005;36:21-25.

PHOTOGRAPHS 

J SC2010E060420 to JSC2010E060423

J SC2010E060436 to JSC2010E060438

JSC2010E060847 to JSC2010E060853

JSC2010E060856 to JSC2010E060857

JSC2010E060873

JSC2010E060883 to JSC2010E060885

JSC2010E060893 to JSC2010E060895

J SC2010E060897

VIDEO 

• Zero G flight week 23 – 30 April, 2010 Master: 882773, 882774, 882775

Videos are available from Imagery and Publications Office (GS4), NASA JSC.

ACKNOWLEDGEMENTS 

We would like to thank the following individuals and organizations for their support with the

development and flight of our project: The mathematics, engineering, science, and achievement

(MESA) program at Harrison School District; all MESA participants (David Davidson, Darius 

Casaus, Steven Varney, Selena Quintanilla, Rebecca Cos, Melissa Arnold, Natalie and Marselino 

Padilla, Amy Shrieves, Brandee Lantz, James Hoovestol, and Preston Bolyard); Fox Meadow 

Middle School; The Home Depot, Inc. (Atlanta, GA); the NASA Explorer School Program; the 

National Science Teachers Association (NSTA); our NASA Mentor Mr. Paul Uranga; and our 

MESA coordinators Mr. Allner and Mr. Simonsen.

CONTACT INFORMATION 

Paul Uranga

Paul.uranga1@nasa.gov
42
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Appendix 
A-2

Background Information about the C-9 and the Reduced Gravity Program 

The Reduced Gravity Program, operated by NASA JSC, provides engineers, scientists, and 

astronauts alike a unique opportunity to perform testing and training in a weightless environment

but without having to leave the confines of the Earth’s orbit. Given the frequency of space shuttle

missions and the construction and habitation of the ISS, the Reduced Gravity Program provides an

ideal environment in which to test and evaluate space hardware and experimental procedures 

prior to launch.

The Reduced Gravity Program was established in 1959 to investigate the reactions of humans 

and hardware during operations in a weightless environment. A specially modified turbojet that 

flies parabolic arcs produces periodic episodes of weightlessness lasting 20 to 25 s. The aircraft 

is sometimes also flown to provide short periods of lunar (1/6) and Martian (1/3) gravity. Over 

the last 50 years, in excess of 100,000 parabolas have been flown in support of the Mercury, 

Gemini, Apollo, Skylab, Space Shuttle, and ISS Programs.

Excluding the C-9 Flight Crew and the Reduced Gravity Program Test Directors, NASA’s C-9

aircraft accommodates seating for a maximum of 20 other passengers. The C-9’s cargo bay 

provides a test area that is approximately 45 ft long, 104 in. wide, and 80 in. high.

NASA has also transitioned to using Zero G Corporation’s (Vienna, VA) 727 aircraft, which will

hold up to 30 investigators. Zero G Corporation’s 727 is nearly identical in size and volume to 

the KC-135 aircraft previously used by NASA to support the Reduced Gravity Program. The 

Zero G Corporation’s Boeing 727 has a larger cargo door than the KC-135 that accommodates

large payloads and provides a test areas that is approximately 70 ft long, 140 in. wide, and 86 in.

high.

Both aircraft are equipped with electrical power for test equipment and photographic lights. When

requested, professional photography and video support can be scheduled to document activities 

in flight.

A typical flight lasts 2 to 3 h and consists of 30 to 40 parabolas. The parabolas are flown in succession or with short breaks between maneuvers to allow time for reconfiguration of test equipment.

For additional information concerning flight weeks sponsored by JSC’s Human Adaptation 

Countermeasures Division or other Reduced Gravity Program opportunities, please contact:

Todd Schlegel, MD Dominic Del Rosso

Technical Monitor, Human Adaptation Test Director

and Countermeasures Division NASA Lyndon B. Johnson Space Center

NASA Lyndon B. Johnson Space Center Reduced-Gravity Office, Ellington Field

Mail Code: SK Mail Code: CC43

Houston, TX 77058 Houston, TX 77034

Telephone: (281) 483-9643 Telephone: (281) 244-9113

Explore the Zero Gravity Experiments and Aircraft Operations Web pages at:

http://zerog.jsc.nasa.gov/

http://jsc-aircraft-ops.jsc.nasa.gov

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September 2010 Technical Memorandum

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C-9 and Other Microgravity Simulations – Summary Report

6. AUTHOR(S)

Space Life Sciences Directorate, Human Adaptation and Countermeasures Division, NASA 

Johnson Space Center

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13. ABSTRACT (Maximum 200 words)

This document represents a summary of medical and scientific evaluations conducted aboard the C-9 and other NASA-sponsored 

aircraft from June 2009 to June 2010. Included is a general overview of investigations manifested and coordinated by the Human 

Adaptation and Counter-measures Division. A collection of brief reports that describe tests conducted aboard the NASA-sponsored 

aircraft follows the overview. Principal investigators and test engineers contributed significantly to the content of the report, 

describing their particular experiment or hardware evaluation. Although this document follows general guidelines, each report format 

may vary to accommodate differences in experiment design and procedures. This document concludes with an appendix that provides 

background information concerning the Reduced Gravity Program.

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weightlessness; weightlessness simulation; parabolic flight; zero gravity; aerospace 

medicine; astronaut performance; bioprocessing; space manufacturing 56

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