John B. McQuillen, Terri L. McKay, and DeVon W. Griffin

Glenn Research Center, Cleveland, Ohio

Dan F. Brown and John T. Zoldak

ZIN Technologies, Inc., Cleveland, Ohio 

Final Report for Intravenous Fluid Generation 

(IVGEN) Spaceflight Experiment

NASA/TM—2011-217033

July 2011
NASA STI Program . . . in Profile

Since its founding, NASA has been dedicated to the 

advancement of aeronautics and space science. The 

NASA Scientific and Technical Information (STI) 

program plays a key part in helping NASA maintain 

this important role.

The NASA STI Program operates under the auspices 

of the Agency Chief Information Officer. It collects, 

organizes, provides for archiving, and disseminates 

NASA’s STI. The NASA STI program provides access 

to the NASA Aeronautics and Space Database and 

its public interface, the NASA Technical Reports 

Server, thus providing one of the largest collections 

of aeronautical and space science STI in the world. 

Results are published in both non-NASA channels 

and by NASA in the NASA STI Report Series, which 

includes the following report types:

• TECHNICAL PUBLICATION. Reports of 

completed research or a major significant phase 

of research that present the results of NASA 

programs and include extensive data or theoretical 

analysis. Includes compilations of significant 

scientific and technical data and information 

deemed to be of continuing reference value. 

NASA counterpart of peer-reviewed formal 

professional papers but has less stringent 

limitations on manuscript length and extent of 

graphic presentations.

• TECHNICAL MEMORANDUM. Scientific 

and technical findings that are preliminary or 

of specialized interest, e.g., quick release 

reports, working papers, and bibliographies that 

contain minimal annotation. Does not contain 

extensive analysis.

• CONTRACTOR REPORT. Scientific and 

technical findings by NASA-sponsored 

contractors and grantees.

• CONFERENCE PUBLICATION. Collected 

papers from scientific and technical 

conferences, symposia, seminars, or other 

meetings sponsored or cosponsored by NASA.

• SPECIAL PUBLICATION. Scientific, 

technical, or historical information from 

NASA programs, projects, and missions, often 

concerned with subjects having substantial 

public interest.

• TECHNICAL TRANSLATION. Englishlanguage translations of foreign scientific and 

technical material pertinent to NASA’s mission.

Specialized services also include creating custom 

thesauri, building customized databases, organizing 

and publishing research results.

For more information about the NASA STI 

program, see the following:

• Access the NASA STI program home page at 

http://www.sti.nasa.gov

• E-mail your question via the Internet to help@

sti.nasa.gov

• Fax your question to the NASA STI Help Desk 

at 443–757–5803

• Telephone the NASA STI Help Desk at

443–757–5802

• Write to:

 NASA Center for AeroSpace Information (CASI)

 7115 Standard Drive

 Hanover, MD 21076–1320
John B. McQuillen, Terri L. McKay, and DeVon W. Griffin

Glenn Research Center, Cleveland, Ohio

Dan F. Brown and John T. Zoldak

ZIN Technologies, Inc., Cleveland, Ohio 

Final Report for Intravenous Fluid Generation 

(IVGEN) Spaceflight Experiment

NASA/TM—2011-217033

July 2011

National Aeronautics and

Space Administration

Glenn Research Center

Cleveland, Ohio 44135
Available from

NASA Center for Aerospace Information

7115 Standard Drive

Hanover, MD 21076–1320

National Technical Information Service

5301 Shawnee Road

Alexandria, VA 22312

Available electronically at http://www.sti.nasa.gov

Trade names and trademarks are used in this report for identification 

only. Their usage does not constitute an official endorsement, 

either expressed or implied, by the National Aeronautics and 

Space Administration.

Level of Review: This material has been technically reviewed by technical management. 
NASA/TM—2011-217033 iii

Contents

Summary.......................................................................................................................................................1

1.0 Introduction and Background...............................................................................................................1

1.1 Standards.....................................................................................................................................2

1.2 Spacecraft Potable Water............................................................................................................4

2.0 Previous Spaceflight Experiment: Sterile Water for Injection System ................................................5

3.0 IVGEN Trade Studies ..........................................................................................................................6

3.1 Mixing Studies............................................................................................................................6

3.2 Water Purification Studies..........................................................................................................8

3.2.1 Distillation..................................................................................................................... 9

3.2.2 Osmosis......................................................................................................................... 9

3.2.3 Deionization................................................................................................................ 11

3.2.4 Microwave .................................................................................................................. 11

3.2.5 KSC Clearwater System.............................................................................................. 13

3.2.6 Cartridge Sizing for IVGEN ....................................................................................... 14

4.0 Design of IVGEN...............................................................................................................................15

4.1 Accumulator..............................................................................................................................15

4.2 Purifier ......................................................................................................................................17

4.3 Mixer Assembly........................................................................................................................18

5.0 Procedure............................................................................................................................................20

6.0 Results................................................................................................................................................21

6.1 Hydrodynamic Characterization ...............................................................................................22

6.2 Conductivity..............................................................................................................................24

6.2.1 Purification.................................................................................................................. 24

6.2.2 Mixing Uniformity...................................................................................................... 27

6.3 Post-Flight Analysis..................................................................................................................29

7.0 Plans...................................................................................................................................................31

7.1 Testing ......................................................................................................................................31

7.2 Operational System Design.......................................................................................................31

8.0 Conclusion..........................................................................................................................................32

References...................................................................................................................................................32

Appendix A.—Acronyms and Abbreviations.............................................................................................35

Appendix B.—Test Results ........................................................................................................................37

B.1 Bag 1, Normal Saline................................................................................................................37

B.2 Bag 2, Normal Saline................................................................................................................41

B.3 Bag 3, Purified Water ...............................................................................................................44

B.4 Bag 4, Purified Water ...............................................................................................................46

B.5 Bag 5, Purified Water ...............................................................................................................49

B.6 Bag 6, Purified Water ...............................................................................................................51

Appendix C.—Investigation Results for Out-of-Specification Saline Concentration ...............................55

C.1 Completed Test Plan.................................................................................................................55

C.2 Chemical Analysis Results of Bag Contents (Performed by Precision Analytical)..................66

C.3 Conversion Analysis.................................................................................................................72

NASA/TM—2011-217033 1

Final Report for Intravenous Fluid Generation (IVGEN)

Spaceflight Experiment

John B. McQuillen, Terri L. McKay, and DeVon W. Griffin

National Aeronautics and Space Administration

Glenn Research Center

Cleveland, Ohio 44135

Dan F. Brown and John T. Zoldak

ZIN Technologies, Inc.

Cleveland, Ohio 44135

Summary

NASA designed and operated the Intravenous Fluid Generation (IVGEN) experiment onboard the 

International Space Station (ISS), Increment 23/24, during May 2010. This hardware was a demonstration

experiment to generate intravenous (IV) fluid from ISS Water Processing Assembly (WPA) potable water 

using a water purification technique and pharmaceutical mixing system. The IVGEN experiment utilizes a 

deionizing resin bed to remove contaminants from feedstock water to a purity level that meets the 

standards of the United States Pharmacopeia (USP), the governing body for pharmaceuticals in the United 

States. The water was then introduced into an IV bag where the fluid was mixed with USP-grade 

crystalline salt to produce USP normal saline (NS). Inline conductivity sensors quantified the feedstock 

water quality, output water purity, and NS mixing uniformity. Six 1.5-L bags of purified water were 

produced. Two of these bags were mixed with sodium chloride to make 0.9 percent NS solution. These 

two bags were returned to Earth to test for compliance with USP requirements.

On-orbit results indicated that all of the experimental success criteria were met with the exception of 

the salt concentration. Problems with a large air bubble in the first bag of purified water resulted in a 

slightly concentrated saline solution of 117 percent of the target value of 0.9 g/L. The second bag had an 

inadequate amount of salt premeasured into the mixing bag resulting in a slightly deficient salt 

concentration of 93.8 percent of the target value. The USP permits a range from 95 to 105 percent of the 

target value.

The testing plans for improvements for an operational system are also presented.

1.0 Introduction and Background

The Vision for Space Exploration (Ref. 1) outlined a new direction for NASA, consisting of missions 

to return astronauts to the Moon and test the technologies required for Mars missions. The International 

Space Station (ISS) will also be used as a test bed for some of these new technologies. NASA’s 

Exploration Systems Architecture Study (Ref. 2) presented several Design Reference Missions (DRMs) 

that were used to facilitate the derivation of various requirements for the essential technologies such as

the Environmental Control and Life Support Systems (ECLSS), spacecraft power and propulsion, and 

communications. These DRMs included ISS expeditions, Lunar Sorties lasting 7 days, a Lunar Outpost

with crew exchanges once every 6 months, and various options for a trip to Mars. With the exception of 

the ISS expeditions, there is limited capability for emergency medical evacuations because of the distance 

from Earth and their associated return timelines. The ability to stabilize and treat patients on exploration 

missions will depend on access to needed consumables. IV fluids have been identified as required 

consumables. Miller et al. (Ref. 3) reviewed the ISS Patient Condition Database (PCDB), which lists over 

400 medical conditions that could require treatment during ISS missions. These conditions are a subset of 

possible conditions that could be encountered during long-duration, Extravehicular Activity (EVA)

intensive, exploration missions. Of the 442 conditions, approximately 115 could require medical 
NASA/TM—2011-217033 2

Figure 1.—Advanced life support pack.

fluids during the course of treatment. Terrestrial treatment would typically include fluids such as normal 

saline (NS, 0.9 percent NaCl), 5 percent dextrose, Lactated Ringer’s, or blood products. Watkins (Ref. 4) 

provided a condition list, the Space Medicine Exploration Medical Condition List (SMEMCL), for the 

Exploration Medical Capabilities Element of the Human Research Program that examined seven DRMs 

and listed the breakdown of various medical conditions and treatment priorities.

Currently, the ISS stocks a large complement of diagnostic medical equipment and supplies for the 

purpose of both biomedical research and treatment of injuries and illnesses among the crewmembers. The 

philosophy for life-threatening and severe cases is to provide initial treatment to stabilize the patient and 

evacuate the patient back to Earth in a timely fashion. To implement this philosophy, the Advanced Life 

Support Pack (ALSP), shown in Figure 1, contains IV fluid of 0.5-L bags of dextrose solution and 0.5-

and 1-L bags of 0.9 percent NS solution for a total of 4.5 L. Due to shelf life considerations, each of the 

contents of the ALSP is replaced at least every 18 months (Ref. 5).

Operational constraints such as mass limitations and lack of refrigeration may limit the type and 

volume of such fluids that can be carried onboard the spacecraft. Consequently, the objective of the 

IVGEN experiment was to develop, design, and validate the necessary methodology to purify spacecraft 

potable water into a NS solution thus reducing the amount of IV fluids that are included in the launch 

manifest. 

1.1 Standards

The United States Pharmacopeia (USP) is the authoritative source for medicine and healthcare 

product standards. These standards are in place to improve public health by ensuring the quality and 

safety of products. As such, the USP has developed monographs detailing standards for drug products,

including various types of water to be used for pharmaceutical purposes. The monographs for these water

products include a cascade of multiple techniques and requirements as illustrated in Figure 2. The 

classification for the final products depends not only on the preparation method, but the usage and 

packaging as well. For example, “Sterile Water for Irrigation” (SWFI) and “Sterile Water for Injection” 

(SWI) may be prepared identically, but SWFI is packaged “in bulk” or in sterile containers that hold more 

than 1 L of fluid while SWI must be packaged in containers no larger than 1 L.

Some monographs include process-oriented descriptions, that is, they describe a series of operations 

or procedures that are not verified directly via measurements of quantifiable values, such as a 

concentration, for all possible contaminants. As an example, the USP standard for purified water requires 

that source water meet Environmental Protection Agency (EPA) National Primary Drinking Water 

Regulations (NPDWR). To meet USP requirements for water for irrigation (WFI) distillation, reverse 

osmosis, or an equivalent or superior process is acceptable; however, there are no quantifiable values for 

assessment.
NASA/TM—2011-217033 3

Figure 2.—Process for manufacturing water for injection.

The EPA does not have limits on all possible contaminants, such as iodine and silver because these 

biocides, which are generally used in space vehicle water, are not normally present in public water 

systems. Biocides are not allowed in SWI and must be removed. Bagdigian et al. (Ref. 6) discuss in detail 

the various agencies and regulations governing water quality and allowed contaminant levels in water to 

be used for different purposes.

It should also be noted that there are additional stipulations listed within the USP National Formulary

(Ref. 7) that are imposed upon these processes that are not readily apparent otherwise. For example, with 

regards to distillation, provisions need to be incorporated that eliminate the possibility of evaporator 

flooding and mist carryover. Furthermore, during periods of system nonusage, provisions need to 

incorporate the ability to drain and dry the distillation apparatus to minimize the possibility of microbial 

infiltration and growth. Finally, there needs to be a process to validate and periodically inspect the process 

to assure that quality standards are being met.

Cascading requirements and procedures are not limited only to the preparation of WFI. Per the USP 

National Formulary, the specification for NS solution, “Sodium Chloride Injection,” is 0.9 weight percent

concentration of sterile sodium chloride in WFI. Therefore, a NS solution must meet the EPA 

requirements for potable water; and the USP requirements for purified water, WFI, sodium chloride 

injection and sterility. The USP monographs may be found at their online website.
NASA/TM—2011-217033 4

1.2 Spacecraft Potable Water 

NASA potable water must meet requirements defined in the Spacecraft Water Exposure Guidelines 

(SWEGs) (Ref. 8) in NASA Space Station Program (SSP) 41000 (Ref. 9) and CxP 20024 (Ref. 10), if 

they are different than EPA NPDWR standards. While there is some overlap in the two standards, 

NASA’s standards cover contaminants specific to spacecraft water. Furthermore, the SWEGs establish 

limits based on exposure durations that include 1, 10, 100, and 1000 days. These standards reduce the 

acceptable concentration as the exposure duration increases. Some contaminant standards, such as 

manganese salts, are not addressed by the NPDWR, while the SWEGs establish a limit.

While using the vehicle’s potable water for the SWI source is an obvious choice, other potential 

sources do exist. Short-duration missions could use fuel cells, such as those in the shuttle, to generate 

high-purity water. Moderate-duration missions feed potable water into an additional deionizing bed to 

remove the iodine biocide before feeding the water into an electrolysis unit to generate oxygen. The feed 

water into the electrolysis unit could also be used to generate SWI. A generic emergency water source to 

be used for oxygen generation, medical emergencies, or replenishing potable water stores may be a viable 

option for moderate- to long-duration missions. Water obtained from in situ resource utilization would 

presumably go through processing to bring quality up to potable water standards. In addition, other 

sources of nonpotable water (SSP 57020 (Ref. 11)), such as the ISS technical water, which is water 

generated from fuel cells without any effective biocide additive, exist and might be usable provided 

sufficient treatment could be assured of the water supply.

During initial phases of assembly for the ISS, water was either supplied directly from terrestrial 

sources or the shuttle fuel cells. Water from the space shuttle or Space Transportation System (STS), was 

stored in multiple Contingency Water Containers (CWCs) and emptied as needed. The CWCs were 

treated with a silver biocide and could store 44 L of fluid, much larger than the 1 L of fluid required for a 

normal IV bag. CWCs were replaced by Contingency Water Container Iodine (CWC–I) that used iodine 

as the biocide. While shuttle fuel cells do have the ability to provide relatively high purity water, additives 

were used to adjust the taste and prevent bacterial growth. Subsequently, as part of the ECLSS, the Water 

Processing Assembly (WPA) was launched. Drinking water for the astronauts from the WPA is dispensed 

via the Potable Water Dispenser (PWD). Samples from both the STS potable water source and the WPA 

were periodically returned to Earth and their water quality was tested. Some results (Ref. 12) are 

presented in Table 1 and show that the purity standards that are required are met with ample margin.

TABLE 1.—ISS WPA POTABLE WATER SAMPLING RESULTS

Parameter

Total organic 

carbon, 

mg/L

Ethanol, 

mg/L

Acetone, 

mg/L

Conductivity, 

μmhos/cm

Nickel,

mg/L

pH Iodine, 

mg/L

Maximum contaminant 

level (MCL)

4 ---- -------- -- 0.3 4.5 to 8.5 6/0.2

Maximum contaminant 

level source

41000 ---- -------- -- SWEG and 

41000

41000 b41000

November 22, 2008a 1.05 <0.1 0.174 6 1.69 7.7 0.21

November 25, 2008 0.35 <0.1 0.031 3 0.42 7.48 1.40

November 26, 2008 0.23 <0.1 0.011 3 0.05 7.06 1.89

November 26, 2008 0.19 <0.1 0.009 3 0.13 7.43 1.90

December 8, 2008 0.23 <0.1 0.016 9 0.10 7.79 2.41

February 9, 2009 0.12 <0.1 <0.002 3 0.11 6.91 2.54

February 27, 2009 0.12 <0.1 <0.002 3 0.25 6.82 2.70

March 10, 2009 0.09 <0.1 <0.002 3 0.12 6.49 2.70

March 25, 2009 0.09 <0.1 <0.002 3 0.04 6.03 2.71 a

Represents primarily residual water in the WPA at launch, not processed water

b

Total I max/total I at point of consumption
NASA/TM—2011-217033 5

2.0 Previous Spaceflight Experiment: Sterile Water for Injection System 

In the late 1980s and early 1990s, NASA conducted a detailed investigation to determine the 

possibility of producing IV fluids on orbit as part of the Health Maintenance Facility for the Space Station 

Freedom Program. The NASA Johnson Space Center (JSC) led this effort, which included contracts with 

Krug International, Sterimatics, and Baxter, and culminated in a flight experiment on STS–47 from 

September 12, 1992, through September 20, 1992. Part of that decision was based on the ability to rapidly 

return ill crewmembers to Earth, an option that becomes increasingly more difficult as the time duration 

of exploration missions and the distance from Earth increases.

As part of the SWIS effort, Creager of Krug Life Sciences (Ref. 13) evaluated six scenarios requiring 

fluids for medical treatment. Fluid volumes were calculated for each scenario using seven types of 

solutions. The volume required to treat a particular scenario ranged from 11 to 90 L, averaging 37 L. The 

total volume required to treat all individual scenarios envisioned for a mission and the minimum volume 

required to any single scenario in a mission were also calculated. The total volume of the seven types of 

solutions required to cover one incident of all of the scenarios was 220 L, while 141 L was the maximum 

required to cover any single scenario. (The report suggested that the minimum was 123 L but there was an 

18 L error in the calculations for the minimum amount of NS required.)

Krug International, as lead contractor for the Health Maintenance Facility on Space Station Freedom, 

subcontracted with Sterimatics Corporation to develop a Sterile Water for Injection System (SWIS) to 

produce IV fluids. The SWIS was a filter/adsorption-based technology to produce SWI. The design goal 

was to convert ISS “hygiene water,” which has a lower quality than ISS potable water, to SWI. System 

requirements included producing at least 6 L of SWI at 6 L/hr with a sterile shelf life of 90 days utilizing 

a filter with a minimum shelf life of 1 year. As developed, the SWIS had a dry mass of 2 kg and produced 

9 L of SWI from water-containing contamination levels 10 times the ISS potable water specification.

Testing indicated that at least 20 L of SWI could be produced from potable water. 

As part of the SWIS project, Baxter worked on developing methods to mix both powders and 

concentrates, but was unable to overcome problems in mixing powders (Ref. 14) even in a normal gravity 

environment. The development was constrained by a requirement to mix “passively” by utilizing only 

water pressure. Baxter conducted experiments with a dyed concentrate and observed a low degree of 

mixing, with the heavier, dyed concentrate located on the bottom of the bag in 1g testing. No quantitative 

mixing studies were completed in normal or microgravity. Subsequent analysis and tests have 

demonstrated that these mixing techniques can easily be gravity-driven and care must be taken not to 

interpret those results as a testament to their effectiveness in microgravity (Ref. 15).

The SWIS was flown on STS–47 in September 1992 as part of the Fluid Therapy System (FTS) on 

the Spacelab–J (Spacelab–Japan). The test plan called for a purge sample of approximately 350 to 

400 mL of liquid to purge the SWIS cartridge, followed by an assortment of 1-L bags of four sterile 

water samples, three 5 percent dextrose samples, and three NS solution samples. Problems were 

encountered with the system including the following (Ref. 16):

• Small bubbles were present in all of the filled bags.

• Air was detected in the IV line.

While post-flight microbiological analysis indicated that all of the samples were sterile (Ref. 17), 

there were some problems that the chemical analysis detected (Ref. 18):

• The saline concentration for two of the three bags was slightly higher than allowable tolerances 

per the USP specifications.

• The Total Organic Carbon (TOC) content for both ground testing and spaceflight testing was 

considerably above USP specifications.
NASA/TM—2011-217033 6

Based on these results and vehicle constraints, NASA decided not to produce sterile water or IV 

fluids on Space Station, but to use prepackaged IV fluids. No flight-ready hardware was fabricated for 

sterile water production.

3.0 IVGEN Trade Studies

Several trade studies were performed as part of the effort to develop the IVGEN experiment to 

evaluate different aspects for the design. Mixing techniques were evaluated in a manner in normal gravity 

that minimized natural convection due to density differences between the solvent and the solution 

mixture. The selected mixing technique was then verified in low gravity aboard the C–9 aircraft.

A second series of trade studies were performed to select water purification techniques and included 

both analysis and testing. After the selection of the water purification technique, a secondary study was 

performed to size the cartridge. 

3.1 Mixing Studies

In their 2006 trade study, Niederhaus and Miller (Ref. 15) evaluated several different mixing 

techniques. Their evaluation criteria were qualitative and included the following:

• Efficiency or minimal power consumption

• Ability to maintain sterility

• Flexibility to accommodate both powders and concentrates

• Overall system mass

• Confidence that the technique could be adapted to use in the microgravity environment

• Amount of crew time required to set up and operate the system coupled with degree of difficulty

The mixing techniques included the following:

• Recirculation within the IV bag that is generated via a peristaltic pump attached to a tubing 

appendage on the IV bag

• Mixing cartridge with the powdered pharmaceutical placed in the inlet flow path to IV bag; 

dissolution and/or mixing would occur as the water passes through the cartridge and enters the 

bag

• Magnetic stir bar prepositioned within the bag

• Impeller mixing with a rotating shaft that penetrates the IV bag walls

• A rod that penetrates the IV bag walls and vibrates ultrasonically

• IV bag deformation or kneading

• Vibrating surface in external contact with IV bag wall

• High frequency acoustic emitter placed in external contact with IV bag wall

Niederhaus and Miller assessed each mixing technique an adjectival rating of “High,” “Medium,” or 

“Low” for every evaluation criteria listed above. Numerical scores were assigned to the adjectival rating 

and summed and then ranked in Table 2 (Ref. 15). Based on their results, the magnetic stir bar and 

vibrating wall methods were selected for normal gravity testing. They used Planar Laser-Induced 

Fluorescence (PLIF) and schlieren were used to determine mixing times.

PLIF utilizes a laser beam shaped to be narrow in one dimension and 5 to 6 centimeters wide in the 

orthogonal direction, thus illuminating a plane. In this case, Niederhaus and Miller doped the fluid with 

particles that would fluoresce under laser illumination. A video camera perpendicular to the plane of 

illumination captures a time sequence of images of the particles in the flow, thus mapping out the mixing 

process as a function of time. 
NASA/TM—2011-217033 7

TABLE 2.—EVALUATION OF MIXING METHODS ACCORDING TO SELECTION CRITERIA Efficiency Sterility Flexibility Equivalent system mass

μg confidence

OperationsDevelopment easeUnweighted scoreRelative ranking

Recirculation loop H M H H M M M 17 4

Inline mixer M H L M L M L 12 8

Magnetic stirrer bar H H H M H H M 19 1

Shaft with impeller H M H M H M M 17 4

Vibrating rod M M H M L M L 13 7

Shape change L H H M M M M 15 6

Vibrating surface M H H H H H M 19 1

Acoustic streaming M H H H H H L 18 3

A schlieren system passes collimated light from a point source through a test section of interest, where 

the object under test must have refractive index differences, which in the case of mixing, are produced by 

density differences. After passing through the test section, the light is focused with a knife edge in the focal 

plane obscuring half of the focal spot. A camera that is focused on the test section is placed after the focal 

spot. By using this arrangement, the camera records images of density differences in the test section that 

appear as shadows moving across the field of view. This system records the mixing process without the 

need to dope the fluid. Alternatively, the optical configuration for schlieren is much more complicated and 

less compact than PLIF, so each has its advantages. By using both techniques, Niederhaus and Miller were 

able to ensure that they had the best possible technique to collect the mixing data.

While Niederhaus and Miller demonstrated that both mixing techniques showed promise, the presence 

of an air bubble in the IV bag greatly enhanced the mixing efficiency for the vibrating wall technique 

whereas the stir bar technique did not require such assistance. Tests of the vibrating wall technique that were 

conducted in single phase liquid with no air bubble exhibited mixing times that approximated mixing by 

diffusion, which means that the vibrating walls were producing essentially no mixing.

As shown in Figure 3, using 30- by 3-mm (length by diameter) and 35- by 3-mm stir bars at various 

angular velocities, mixing times were well under the 20 min target. For example, the data revealed that 

the 30-mm stir bar at 700 rpm could achieve a homogeneous solution for liquid-liquid mixing in less than 

2 min. The 30-mm stir bar at 700 rpm could aid in the dissolution of a solid and achieve thorough mixing 

in under 8 min (Ref. 19).

Following the 1g testing, Niederhaus and Miller conducted preliminary microgravity experiments in

the Glenn Research Center (GRC) 2.2-Second Drop Tower. Results indicated that faster spinner velocities 

are required to move bubbles away from the bag wall to prevent possible “dead zones” of no flow; 

however, not enough time was available to achieve a “steady-state” condition. Longer duration 

experiments were then performed aboard the NASA C–9 to examine concerns such as whether powder 

granules would collect in bag corners, and whether large bubbles would interfere with the mixing process.

Small nonsoluble polymer spheres (250 and 500 μm in diameter) were used as surrogates for 

pharmaceutical powders to track and analyze particle motion within various bag geometries during the 

mixing process. The use of a surrogate eliminates the regulatory issues associated with using actual 

pharmaceutical. These tests revealed that small particles do not become lodged in dead zones within the 

bag, such as fill ports and corners within the IV bag, and that bag shape does not prevent particles from 

being uniformly distributed. In microgravity, the mobility of the particles greatly increased as particles 

“rose” into the bulk fluid, rather than resting on or against, the bag “floor” as occurs in 1 g. Experiments 

demonstrated that air bubbles, some as large as 100 mL, did not interfere with the mixing process as the 

bubbles were sheared apart when contacting the rotating stir bar.
NASA/TM—2011-217033 8

Figure 3.—Mixing times from stir bars, sized 20 to

35 mm, at various rpms.

Bag filling tests were also conducted in microgravity. High liquid fill rates (1700 mL/min) produced a 

turbulent jet that dissolved the salt almost completely by the time the bag was full. However, low flow 

rates (~20 mL/min) did not aid rapid salt dissolution. Furthermore, the stir bar did not rotate easily when 

the bag contained very little water, and the stir bar became trapped within solid salt crystals. The 

dissolution of these salts crystals was limited because of the small amount of water within the bag. As the 

bag filled with water, the salt that trapped the stir bar dissolved and the stir bar would begin rotating.

3.2 Water Purification Studies 

The USP specifies both requirements and processes for generating SWI based on the concept that “the 

nature and robustness of the purification process is directly related to the resulting purity (Ref. 20).” As 

specified by the USP, distillation and reverse osmosis (RO) are the “acceptable” means of producing 

SWI; however, provisions are included to utilize other processes, provided that these processes deliver 

water of equivalent quality.

In addition to mixing, Niederhaus et al. (Ref. 21), examined several sterilization processes including 

the following:

• Distillation—Purification by phase change and collection of steam. Special provisions are needed 

to negate any liquid carryover in the form of droplet mists or boilover surges.

• Reverse osmosis—Osmotic pressure removes the contaminants by applying a pressure gradient 

across a semipermeable membrane.

• Adsorption—Impurities are chemically absorbed onto a packing material.

• Ultrafiltration—Water is purified by flowing through a filter medium with very small pore 

diameters that physically block the passage of impurities.

In addition, three recently developed techniques were examined as part of the current effort:

• Microwave—UMPQUA, Research Company, under a Small Business Innovative Research 

(SBIR) contract, examined the use of microwaving the water under pressure to kill any 

microorganisms. This technique would still need to be coupled with some filtering mechanism to 

remove impurities such as ions, organic carbon, and endotoxins.
NASA/TM—2011-217033 9

• Artificial kidney—Dr. Shuvo Roy, formerly an Assistant Staff member in the Department of 

Biomedical Engineering, Lerner Research Institute, Cleveland Clinic Foundation, and currently 

with the University of California, San Francisco, demonstrated the performance of a nanodevice 

prototype that should filter all impurities from input potable water.

• Forward osmosis—Several manufacturers now offer a device that can take unpurified and 

untreated water, pass it through an osmotic membrane in the forward direction and generate a 

sports drink from a syrup. The physical principles governing that process can be directly applied 

to generating a pharmaceutical mixture for IV administration.

Further discussion of these techniques, including analysis and some experimental evaluations, is 

discussed below.

3.2.1 Distillation

Purification by distillation relies on the evaporation and/or boiling of water and the flow of the water 

vapor to a separate location where the vapor is condensed. Sterilization is achieved by subjecting the 

water to sufficiently hot temperatures to kill any bacteria. Purification is accomplished by collecting the 

water condensate over a narrow range of temperature and pressure conditions whereby any compound 

that is more volatile than water is vented prior to collection and any compound less volatile than the water 

never vaporizes and flows into the condenser. Historically, this technique was the first acknowledged 

purification method and is still used today especially for the purification of large quantities of water.

It should be noted, however, that within the USP, there are several additional constraints placed upon 

the purification technique. Among these constraints are the following:

• Provisions must be made to demist the vapor flow, that is, liquid droplets cannot be present 

within the vapor stream as they are likely to contain impurities that would have remained behind.

• Provisions must be made to eliminate “boil-over.” A rapid increase in the amount of vaporization 

can result in the pockets of liquid mass drops and globules being carried over from the boiler/

evaporator to the condenser as the vapor surges in. These liquid slugs would be carrying 

impurities with it.

• The distillation system must be periodically inspected, drained, and cleaned for mineral deposits.

• During periods of nonusage, the system must be drained and dried.

Distillation is a purification technique that relies heavily on buoyancy forces to achieve separation 

between the purified vapor and the source liquid. Aboard the ISS, the Urine Processing Assembly (UPA)

utilizes a centrifuge operated at low pressure to achieve the evaporation and phase separation (Ref. 6).

Consequently, this ISS hardware is heavy and power intensive.

Given that some medical conditions within the SMEMCL involve burns, there is a possibility that the 

same event that caused the injury may have also damaged the spacecraft and thus limited the power 

production capability of the spacecraft.

Therefore, because of the numerous gravitational complications, large power demands, and mass and 

volume requirements incompatible with constraints on system size, distillation was discounted as a 

method to generate purified water in an emergency situation.

3.2.2 Osmosis

Osmosis is the process of a solvent diffusing across a semipermeable membrane from a region of low 

concentration to a region of higher concentration. This movement results in the dilution of the more 

concentrated region, and as a result, the local pressure adjacent to the membrane is higher on the 

concentrated side of the membrane. This process is known as forward osmosis. These membranes have a 

filtering capacity for removing particles larger than 0.1 μm. Filters that can sterilize water typically have a 

particle removing capacity of 0.2 μm or smaller.
NASA/TM—2011-217033 10

By applying a higher pressure to the concentrated solution side of the membrane, it is possible to 

reverse the flow and drive the solvent fluid from the solution side to the solvent side of the membrane

purifying it in the process. This technique is known as RO and was the other standard process recognized 

by the USP for purifying water.

Both osmotic processes, forward and reverse, will be discussed.

3.2.2.1 Reverse Osmosis

When reverse osmosis is used to purify water within a terrestrial application, typically the system is 

configured in a manner whereby only a portion of the feed stream is purified as it passes through the 

membrane (permeate) while some of the feed solution becomes more concentrated and exits the device 

without passing through the membrane (concentrate also known as retentate) (Ref. 22 and EPA/625/R–

96–009) as shown in Figure 4. Consequently, there is a significant amount of feed water that is “rejected” 

from the system. Nonetheless, it was decided to test the effectiveness of this technology at nearly 

complete conversion of the feed water.

For this testing, a thin-film composite (TFC) membrane, similar to that used in NASA Kennedy 

Space Center’s (KSC’s) Clearwater device (Refs. 23 and 24), was tested. Testing revealed that the RO 

filter (manufactured by General Electric’s Osmonics Desal, model 18 GPD TFC RO Membrane) failed to 

remove sufficient quantities of endotoxins, chloride ions, carbon dioxide, and oxidizable substances and 

failed sterility. It should be noted though, that the RO filter was included in the Clearwater system to meet 

the USP requirements at that time. The Clearwater system is discussed in greater detail in Section 3.2.5.

Ultimately, RO technology was rejected since it demonstrated that it was not possible to achieve the 

necessary purity without a substantial effluent flow of water.

Figure 4.—Simplified flow schematic of reverse osmosis process.
NASA/TM—2011-217033 11

3.2.2.2 Forward Osmosis

Osmostic membranes are used within sports drink bags that are marketed for those participating in 

outdoor wilderness activities that may not have access to a potable water source. Hydration Technology 

Innovation LLC’s X-pack can provide 1-L increments of a sports drink from a syrup and “muddy” water.

The syrup is poured into the concentrate side of the X-pack and the water is poured into the other side.

Analysis showed that the X-pack was able to meet the USP requirements; however, the flow rate was 

substantially lower than the requirements for the IVGEN experiment. Furthermore, there were concerns 

about the impact of liquid positioning within the X-pack in a low-gravity environment and its impact on 

X-pack performance. Specifically, if the liquid were in poor contact with the membrane, there would be 

insufficient transfer of purified liquid across the semipermeable membrane especially during the latter 

stages of purification.

3.2.3 Deionization

Deionization (DI) or demineralization uses ion-exchange resin particles to bind with mineral salts. A 

combination of different resin particles are used to remove cations such as sodium, potassium, etc., and 

anions, such as chloride and fluoride. Two different DI cartridges were tested: cartridges from the KSC 

Clearwater system and Prismedical Corporation’s MainStream (Ref. 25) device.

Two identical cartridges, Pentek Part Number PCF1–10MB, are used in the KSC Clearwater system.

These cartridges contain a “semiconductor-grade” deionizing resin. The cartridges are constructed with a 

hollow core so that flow through the resin beads is directed radially. The cartridges are typically installed 

in filter housings that permit flow through the annular region outside the cartridge, through the resin 

cartridge, and out the central core region inside the cartridge. Performance testing demonstrated that the 

cartridge was able to meet USP purity requirements for SWFI; however, because of the cartridge 

geometry, challenges were encountered with bubbles and unusual hydraulic characteristics during normal 

gravity testing as the flow direction with respect to the gravity vector was changed. This cartridge and its 

resin were not selected though, primarily due to a shelf life of 6 months that was posted on its package.

Prismedical developed for the Army, as part of the SBIR program, the MainStream system, Figure 5. 

The entire system was sealed within a foil-barrier envelope and contained a source water bag, the 

purification module, and a sterile receiver bag. The purification module contained both hydrophilic and 

hydrophobic filter material, as a means of removing any gas that either entered or was trapped in the 

system, and a ResinTech, Inc., deionizing resin. The system had a shelf life of 5 years. The MainStream 

could use any available source water, ranging from potable to contaminated, and produce up to 3 L of 

SWFI. The MainStream device did pass the USP requirements for SWFI but did not work when 

attempting to flow against gravity. The team conducted this test in an effort to identify gravity-related 

performance issues. An investigation revealed that an internal hydrophilic membrane did not allow the 

trapped gas present within the interstitial volume in the device to exit through the purified water exit port 

during the initial filling. The gas vent port is located adjacent to the water inlet port. The device was 

removed from consideration because of concerns with regards to flow in microgravity: the gas will coflow with the liquid and attempt to exit through the liquid exit port. Gas has not been observed to counterflow through porous media in microgravity.

3.2.4 Microwave

Under a SBIR contract to the NASA Glenn Research Center (GRC), UMPQUA Research Company, 

developed a system to produce medical-grade water using microwaves. The system immersed a 

microwave generator within a flow loop that sterilized and pyrolyzed the source water (Figure 6 and 

Ref. 26). Analyses and tests were conducted over a range of flow rates and power levels to determine the 

temperatures equivalent to autoclave conditions and sterilize the source water to meet acceptable 

standards. For example, typical steady-state operating conditions in experiments on this system included a 
NASA/TM—2011-217033 12

Figure 5.—Prismedical’s MainStream Device.

Figure 6.—UMPQUA’s Microwave Medical Water Generation System.
NASA/TM—2011-217033 13

single-phase liquid flow rate of 13 mL/min and a microwave power of 150 W, resulting in a sterilization 

temperature between 155 and 158 °C. Under these conditions, the system demonstrated effective 

sterilization and inactivation of endotoxins. While the technique was successful, this technique was 

discounted from further evaluation based on power consumption and the system mass and volume.

3.2.5 KSC Clearwater System

Components of the KSC Clearwater system, namely the RO and DI filters, were mentioned earlier.

The system as a whole was developed by NASA KSC with Tiger Purification Systems (Figure 7) using 

multiple filters to produce up to 300 L of WFI. The system features its own pumps, valves, and redundant 

flow paths (Figure 8). Source water first entered 5-μm sediment filters to remove particulate matter so 

that it would not burden filter elements downstream. A KDF–55 heavy metal and chlorine filter was used 

to remove some of the ions, particularly chloride ions, to prevent premature depletion of the reverse 

osmosis membrane that was located downstream. Waste water from the RO membrane was recycled back 

into the source water, but eventually all water was processed by the system. A deionizing resin filter was 

followed by a Posidyne ELD filter (Pall Corporation) primarily to remove any air bubbles from the flow. 

While the system could produce up to 300 L of WFI at a rate of 5.3 L/hr, the Clearwater system was 

removed from consideration for several reasons including the size of the system (52.5- by 28.4- by 

23.2-cm), dry weight of the system (19.5 kg) and the need for an electrically driven pump to supply the 

flow. Furthermore, each parallel leg could only be used once to generate the WFI for no more than 100 L. 

Once each leg had been used, the flow through that leg could not be reestablished without violating 

sterility protocols for Pall filter.

Figure 7.—Prototype Clearwater IV-Grade Water 

Filtration System.
NASA/TM—2011-217033 14

Figure 8.—Flow schematic of the KSC Clearwater System.

3.2.6 Cartridge Sizing for IVGEN

After completing the testing associated with the IVGEN trade study, the project team determined that

DI resin bed technology augmented with ultrafiltration would best meet medical operations, USP, and 

spaceflight requirements. As a result of that decision, the next tasks were to identify the best DI resin to 

produce USP WFI, and to determine the appropriate storage technology to ensure a resin lifetime long 

enough for exploration missions. During the course of this effort, system-level requirements needed to be 

established. Among these requirements included the following:

• Production rate of the WFI: It was assumed that a few bags of NS solution would be available for 

immediate use in the event of an emergency. After discussions, it was determined that a 

production of approximately 1 L/hr―would be sufficient to replenish consumed supplies.

• Production per cartridge: Terrestrially, the treatment protocol for a severe burn requires up to 

16 L per patient for the first 24 hr (Ref. 27). Additional amounts may be required during the 

subsequent days. However, 1 to 2 L per day may only be required for infusions of certain 

medications for treatment of infections and dehydration. Given that the USP requires that the 

distribution system be drained and dried during periods of prolonged nonuse, a balance between 

producing small quantities of fluid for slow consumption rates versus large quantities for faster 

consumption must be achieved. Furthermore, while only the DI resin is depleted during the 

purification, the packaging of the DI resin, the tubing, fittings, etc., consume the significant 

portion of the cartridge mass and size. It was decided to size the cartridge to produce up to 6 L of 

WFI from the shuttle potable water supply.

• Shelf life of DI resin: IV fluid is typically rotated through the ISS every 18 months, which 

corresponds roughly to recommended shelf life of most producers of IV fluid. The DRMs to Mars 

were as short as 18 months; however, some were projected to last up to 3 years.

The volume of the DI resin is one of the principal variables in determining the total amount of water 

that can be purified. The water flow rate into the cartridge also determines the amount of water that can be 
NASA/TM—2011-217033 15

purified as well as the level of purity achieved. The amount of time that the water spends in contact with 

the resin beads is known as the resonance time and is directly proportional to both the amount of water 

purified and the purity level. The resonance time is calculated by dividing the volume of the cartridge bed 

by the flow rate.

In normal gravity, packed bed reactors have been known to suffer from bed occlusion, in which a 

portion of the packing is blocked by the gas phase from reacting with the liquid phase. Motil et al.

(Ref. 28) found that two-phase flow through a packed bed of spherical beads in a microgravity 

environment tended to be well dispersed throughout the entire volume. They were operating at much 

higher flow rates than Holder and Parker (Ref. 29) who found regions of occlusion where there were no 

flow and liquid interaction with the nonspherical packing shapes, thus implying that there would be no 

chemical reaction or absorption in these regions. The required volumetric flow rates for this system are

similar to that of Holder and Parker, but the packing material is similar to Motil et al. Given the 

purification efficiency of the selected resin, the packing material density similar to Motil et al. is used and 

the inner diameter of the cartridge (1.27 cm) was sized to yield a “superficial” or empty tube velocity that 

was closer to Motil et al. than Holder and Parker.

The IVGEN hardware would ideally be manufactured and stored in such a way that a 5-year shelf life 

would be possible. As the deionizing resin degrades when exposed to oxygen, the storage would likely 

involve storing the hardware in a sealed manner to prevent such exposure. Initially, ResinTech Resin type 

MBD–10–NG or nuclear grade was purchased and tested because it met MIL–SPEC–DTL–24119D(SH). 

This MIL-SPEC outlines a storage standard for resin, which allows a life of at up to 5 years; however, the 

method of storage prescribed within the MIL–SPEC does not correspond to the desired method of storage 

for this NASA technology development. The MIL–SPEC is subject to export control laws; therefore, a 

more detailed description of the method outlined within the document will not be disclosed in this report. 

A second resin, Resin type MBD-10-Ultra, was purchased because the manufacturer had determined a 

method of storage that allowed for a storage life of up to 5 years. The method included using a heatsealing technique to enclose the resin a film with low permeability. As the outer most resin in a stored 

volume degrades the quickest, the shelf life is likely dependent on the volume of resin stored. 

Consequently, a test program was devised and is being implemented to evaluate the storage techniques for 

the both the MBD–10–NG and MBD-10-Ultra.

4.0 Design of IVGEN

The objective of the IVGEN experiment was to verify in a microgravity environment the ability to 

produce WFI and mix it with a predetermined amount of salt to produce a 0.9 percent NS solution. It 

should be noted that to verify the performance of this system, diagnostic instrumentation was placed in 

critical locations to measure hydraulic and purification characteristics. Thus, the design of an operational 

system should be much simpler with minimal diagnostics. Figure 9 shows the flow schematic for the 

system to verify the operational concept. The primary components include the accumulator, the purifier 

module, the mixing stand that holds both the mixing bag and transfer bag, and an avionics box. These 

components will be discussed in greater detail in the sections that follow. The design utilized video 

cameras, pressure transducers, thermocouples, conductivity sensors, and a flow meter to characterize onorbit system performance and provide forensic data, if needed. While these sensors characterized the 

relative mixing uniformity, demonstrating the compliance of the solution produced with USP 

requirements would have required such an extensive array of tests so two transfer bags of mixed saline 

were returned to Earth for USP testing by a certified laboratory.

4.1 Accumulator

The accumulator was designed to receive potable water from either the shuttle fuel cells via the 

CWCs or the ISS WPA (Figure 10). Two hoses that met the requirements for connecting to each water 

supply were fabricated with identical connections to the accumulator. The accumulator consisted of a 
NASA/TM—2011-217033 16

Figure 9.—IVGEN purification, mixing, and transfer flow schematic.

Figure 10.—Accumulator.

polycarbonate housing and an internal bag, or bladder that was filled with the liquid and was sized to 

accommodate 1.5 L of water. To pump the water from the bladder, the housing was pressurized using the 

gaseous nitrogen source provided within the Microgravity Science Glovebox (MSG). In the event that 

pressurized sources are not available or operational in a space vehicle, other pressure sources, such as a 

hand pump, may be used in an operational system.

To meet the concentration specification for NS solution, the liquid fill needed to be within 19 mL of 

the specified amount of water provided that the amount of salt was accurately measured to within 0.67 g. 

Estimates were made to account for the volume of the empty liquid transfer line between the WPA or 

CWC and the bladder. However, in the very late stages of flight hardware build and verification activities, 

ECLSS required that a filter be added to the IVGEN Accumulator Fill Hose for WPA (IVGEN Drawing 

Number 60112MFA1191) to prevent back-contamination into the WPA. The filter added significant air 

volume (55 mL) to the system. That air volume meant 55 mL less water in the saline solution resulting in 

a 3.8 percent increase in salt concentration. While the addition of the filter did not guarantee an out-ofspecification sample, it drastically reduced the allowable tolerance of other factors such as the amount of 

dry salt in the bag, air bubbles introduced by the WPA, and completeness of accumulator filling. This 

dramatically reduced the acceptable uncertainties required to meet the USP tolerance bound for salt 

concentration in the final product. Prior to the addition of the filter, the IVGEN system could tolerate a 

reasonable amount of error while still producing saline within USP specification. Consequently, the 

amount of residual air in this transfer line was larger than expected and the first filling of the accumulator 

did not have sufficient water.

The final flight configuration was tested prior to launch. Schedule constraints only allowed for the 

generation and analysis of two saline bags. One bag passed all USP tests while the other passed all but the 

saline concentration. The test results indicated that while the final flight configuration was capable of 
NASA/TM—2011-217033 17

producing USP NS, there was very little margin for error when it came to meeting the concentration 

specification. Due to the amount of time required to send the solution for test, testing time, and reporting 

time, the IVGEN team was not aware of the failure until after the hardware had been launched. Section 

6.3 provides a detailed summary of the post-flight investigation to determine the cause of the anomalies.

4.2 Purifier

The purifier module was the core of the experiment. It included the DI resin cartridge, air removal 

filters, and the instrumentation. An aluminum box with a transparent top housed the components in two 

layers (Figure 11). A Coriolis flow meter was used to provide the necessary accuracy to track the total 

amount of water that had passed through the system and the liquid flow rate for the hydraulic 

measurements, and also measured the density of the fluid flowing through the meter. Using this density 

measurement, it was possible to track whether gas or liquid was flowing from the accumulator into the 

purifier. A dual-ring conductivity probe was used to measure the baseline conductivity of the source water 

prior to purification. Because of the lack of conductivity for air, the probe also was able to detect bubble 

passage into the purifier. 

Two pairs of Supor filters (Pall Corporation) were used primarily to prevent air from entering the DI 

cartridge. These filters had a polyethersulfone membrane with a pore diameter of 1.2 μm in a 0.7 mL 

housing. As water began to flow through the system, the membrane would wet, thus permitting water 

passage while venting air bubbles through openings in the housing. In the event that the filters would plug 

due to particulate accumulation, each pair of filters had an isolation valve that could be used to divert 

flow from one pair of filters to the other pair or to a bypass line. 

The DI cartridge was machined from medical-grade polycarbonate into a hollow cylinder that had an 

outer diameter of 21.3 mm and an inner diameter of 15.9 mm with a length of approximately 170 mm. 

The outer diameter at each end was machined with threads to accept stainless steel end caps. 

Figure 11.—Top level of purifier module.
NASA/TM—2011-217033 18

The cartridge was loaded with DI resin from ResinTech. The specific resin used was MBD–10–

ULTRA and has the following characteristics:

• 60 percent anion

– Hydroxide form

– Type 1 strong-base gel

– R4N+OH (type 1 gel)

– 1.40 meq/mL min capacity (Clform)

• 40 percent cation

– Hydrogen form

– Strong acid

– Sulfonated gelular polystyrene

– RSO3-H+ (gel)

– 1.95 meq/mL min capacity (Na+ form) permit volume

This resin was certified by ResinTech to have a 5-year shelf life in a terrestrial environment. A space 

environment could impact the shelf life because of radiation, but this assessment was beyond the scope of 

this effort. The resin is retained in the cartridge by polyester felt filter discs that were positioned at each 

end of the cartridge and extended across the cross-sectional area of the tube. The discs had an average 

pore diameter of 1 μm.

To minimize settling of the resin particles, a procedure was developed to fill the cartridge with small 

amounts of resin beads and periodically compress the interstitial volume by gently tapping on the beads 

with a blunt rod. To prevent the formation of voids or empty spaces within the resin bed, a compressed 

spring was positioned between the upstream cap and filter disc. If additional compaction occurred due to 

vibrations, such as those imposed by launch, the spring would maintain a constant level of pressure on the 

bed to minimize the formation of voids. The spring was positioned between the end cap and the upstream

filter disc so that any decomposition of the spring could be absorbed by the DI resin.

A series of Posidyne ELD filters were used primarily to prevent air from entering the collection or 

saline bags. These filters use a nylon membrane with a pore diameter of 0.2 μm and also provide particle, 

bacteria, and endotoxin retention. This filter, like the Supor filter, permits water passage while air bubbles 

are vented through openings.

A flat plate sensor measured the conductivity of the purified water and also could provide an 

indication of the efficiency of the Pall filters in removing air bubbles. Using this and the inlet conductivity 

sensor, it is possible to determine the purification efficiency of DI cartridge.

Three absolute pressure transducers were plumbed into the system to measure the pressure loss across 

the two types of Pall filters and the DI cartridge and to provide a means of determining the density of any 

gas that would be present within the system.

The water would flow through the purifier out to the mixing assembly. After the salt dissolution was 

completed, the water would flow back into the purifier into a third conductivity sensor. This sensor was 

used to measure the uniformity of the salt concentration within the mixture before the solution flowed into 

the sterilized collection bag.

4.3 Mixer Assembly

The mixer assembly, Figure 12, consisted of two flat aluminum plates, a mixer motor and its 

controller, and the saline and collection bags. The mixer used two samarium cobalt rare earth magnets on 

a rotor driven by a direct current (DC) motor. The motor had a maximum speed of 900 rpm. The motor 

could be activated and its speed controlled remotely by the Data Acquisition and Control Unit (DACU), 

but there were provisions to locally control via a dial and switch. The rotor was visible through the bags 

to verify its functionality. 
NASA/TM—2011-217033 19

Figure 12.—Mixer assembly 

(without bags).

Both the collection and saline bags were multilayer bags manufactured from ethyl vinyl acetate. To 

prevent over-pressurization of the system, the accumulator was designed to supply only 1.5 L of water 

and the collection, saline, and transfer bag volumes were 2.0 L. Each bag had three ports: liquid inlet and 

outlet ports and a filling port. The filling port was used to place the salt and stir bar into collection bag 

and the port was then sealed. A 13.5 ± 0.67 g of USP-grade NaCl was specified to be introduced into each 

saline bag. 

The stir bar was Teflon (DuPont) resin coated and octagonal shaped. The bar measured 28.6 by 

7.9 mm and featured a molded-on pivot ring. The mixing tests conducted by Barlow indicated that the 

complete mixing could be achieved in shorter time periods using stir bars 30 mm or longer (see Figure 3). 

However, during prototype testing, the longer stir bars would snag on the ethyl vinyl acetate bag walls 

and decouple from the rotation of the stirring motor. It was necessary to shut off the stirring motor to 

reengage the stir bar. Additional prototype testing revealed that the 28.6-mm bar did not exhibit similar 

behavior within the ethyl vinyl acetate bag. 

Isolation valves were installed on the inlet and outlet bag ports and were used to maintain the integrity 

of the collection bag contents. The valves were opened and closed to accept or drain liquid into or from 

the bags as needed.

The transfer bags were constructed in a similar fashion as the collection bags; however, the transfer 

bags were gamma irradiated as part of the sterilization process and needed to be manufactured from 

polyethylene (PE) to avoid degradation due to the irradiation process.

Isolation valves were also used on the inlet and outlet ports of the transfer bags; however, a Pall 

Pediatric IV filter was spliced between the bag and the valves. This filter uses a Supor membrane with a 

pore diameter of 0.2 μm which is retentive of B. diminuta and meets USP 25/NF 20 requirements for a 

sterilizing-grade filter per American Society for Testing and Materials (ASTM) F838–83 test methods. 

Thus, as the salt solution flowed through this filter into the transfer bag, it was sterilized. The filters also 

vented any air that was entrained in the liquid from the collection bag to the transfer bag.
NASA/TM—2011-217033 20

5.0 Procedure

The MSG is a single rack facility onboard the ISS that provides power, thermal control, command 

and control, and imaging to scientific investigations (Ref. 30). The IVGEN hardware was designed to 

operate autonomously after the system was configured. IVGEN was installed into the MSG on May 4, 

2010. The installation included mounting the accumulator, the purifier module, and the mixer assembly to 

the MSG baseplate and the power converter and DACU to the MSG back wall. Cabling was connected for 

power, command, and control functions, and data between the MSG facilities and IVGEN. A hose to the 

MSG nitrogen port was installed to provide the pressurant to the accumulator housing to drive the flow of 

the water during the purification process from the accumulator bladder, through the purifier into the 

collection bag mounted on the mixing assembly. In addition, liquid hoses were installed between the 

accumulator and purifier, the purifier and the collections bag on the mixing stand and the purifier and the 

transfer bag on the mixing stand for each test.

Cameras were provided by MSG. One camera was focused on the parallel plate conductivity cell to 

verify that the cell was properly primed as flow through the purifier was initiated and later repositioned to 

view the Posidyne filters in the purifier. Another camera was positioned to view the Pall 1.2-μm Supor 

filters in the purifier module, and the last camera imaged the collection bag side of the mixer assembly.

Potable water was supplied from the WPA. IVGEN was required to install a sterilizing filter between 

the receiving container and the potable water reservoir (PWR) to prevent back contamination of the WPA 

via the PWR. After ensuring that the nitrogen supply was closed, the nitrogen hose was disconnected 

from the accumulator. The water hose between the accumulator and the purifier was also disconnected.

The accumulator was removed from the MSG and transported to the WPA where the accumulator was 

connected to the PWR. Potable water was transferred into the accumulator until it was filled. The 

accumulator was disconnected from the PWR and carried back to the MSG where the nitrogen and water 

hoses were reconnected to it.

Prior to the start of each test generating saline, the crewmember installed a new collection bag on the 

mixing stand, along with a new transfer bag. For those tests that did not generate saline, but merely tested 

filter capacity, the crewmember only installed a collection bag. The crewmember annotated unused 

videotapes with the recorder designation and date and loaded them into recorders in the MSG video 

drawer.

To flow water from the accumulator through the purifier to the collection bag, the accumulator was 

pressurized with nitrogen from the MSG gas supply. At the initiation of a test, the shutoff valve for the 

gaseous nitrogen supply in MSG was opened; however, the accumulator hand valve was left closed. Thus, 

the accumulator was not yet pressurized. To avoid degradation of the DI resin, the DI cartridge was 

isolated from the rest of the system by shutoff valves. The potable water shutoff valve on the purifier was 

also opened. After these steps had been completed, the hand valve on the accumulator was opened and 

liquid began to flow through the system.

During the purification, the astronaut crewmember watched for leaks and tracked the progression of 

liquid through the system. After about 1 min, the liquid had flowed to the collection bag inlet valve. Gas 

was vented through a Posidyne filter. The collection bag inlet valve was opened and liquid filled the bag.

The system was periodically surveyed for trapped bubbles and leaks.

The system was operated for six purification cycles. For the first two cycles, the purified water 

flowed into one of the collection bags containing the premeasured salt to test the mixing capability and to 

generate NS solution. For the remaining four cycles, the purified water flowed into empty collection bags 

to test the capacity of the DI resin cartridge. Two cycles were performed each day with no changeout of 

the DI cartridge.

For the NS generation cycles, after approximately 500 mL of liquid had been purified (based on flow 

meter readings), the magnetic stirrer was remotely started via the DACU. The operator would periodically 

check that the stir bar was still centered adjacent to rotor.
NASA/TM—2011-217033 21

Figure 13.—Collection bag inserted into blood pressure cuff.

For all cycles, after the water supply in the accumulator was exhausted, the operator verified that the 

collection bag was full. The MSG gaseous nitrogen supply valve, collection bag inlet valve, the purifier’s 

potable water shutoff and DI cartridge isolation valves were closed. 

Mixing continued for 20 min after the purification was completed for the first saline bag and only 5 min 

for the second saline bag. The actual mixing began shortly after purified water began to flow into the bag, 

thus the total mixing time was at least 30 min.

After mixing was completed, the operator verified that the stir bar had ceased rotating. The collection 

bag was removed from the mixer assembly and inserted into a blood pressure cuff (Figure 13). The outlet 

line was connected to the saline port on the purifier. The valves on the outlet port of the collection bag 

and the inlet port of the transfer bag were opened. The blood pressure cuff was inflated to pump water 

from the collection bag, through the conductivity sensor in the purifier and the 0.2-μm Supor sterilizing 

filter into the transfer bag. Periodically, the operator would check the flow and reinflate the blood 

pressure cuff if necessary to ensure that the liquid would continue to flow. After the liquid transfer had 

been completed, the valves on both bags were closed and the tubing ends were capped. The bags were 

stowed and returned to Earth for analysis on STS–132 in May 2010.

For the remaining four collection bags of purified water that were produced, there was no liquid 

transfer to other bags. The crew emptied these collection bags by transferring the water back into the ISS 

water reservoir. These bags and the saline bags were returned to Earth.

Upon return to Earth, the transfer bags containing NS were inspected, weighed, and photographed. 

They were shipped to Pace Analytical Services, Inc., Life Sciences for compliance with USP testing 

requirements. The collection bags were also inspected and were placed into bonded storage.

6.0 Results 

During operation of the IVGEN experiment, conductivity, temperature, flow rate, and pressure data 

were measured and recorded by the DACU via the appropriate sensors. These data were analyzed to 

assess the purification effectiveness, hydrodynamic performance, and the gas bubble removal 

effectiveness. For the sake of brevity, some representative plots will be shown here, with a tabulation of 

results from all the samples generated on the ISS within the body of this text. Plots of the remaining data 

are shown in Appendix B.

Video imaging provided evidence of the proper priming of the flat plate conductivity sensor and the 

type of flow into the collection bag. The video imaging also provided a qualitative assessment of the gas 

bubble removal in the Pall filters and the mixing process in the collection bag. 
NASA/TM—2011-217033 22

6.1 Hydrodynamic Characterization

The characterization of the flow loop is quantified via the flow meter and the pressure losses across 

the Pall filters and the DI resin cartridge. A time trace of the flow rate through the system and 

corresponding pressure drops are shown in Figure 14 and Figure 15. The flow and pressure spike at the 

start of this purification cycle was due to the initial opening of valves that resulted in an inrush of fluid. 

Flow and pressure oscillations at the end of this cycle were due to air bubbles that entered the system 

from the accumulator. The Coriolis flow meter has the capability to measure the density of the fluid 

passing through it and registered significant fluctuations. These fluctuations were also recorded in the 

inlet conductivity sensor and confirm the presence of air bubbles prior to the Pall 1.2-μm Supor filters.

Figure 14.—Time trace of flow rate through IVGEN system.

Figure 15.—Time traces of pressure losses through IVGEN system.
NASA/TM—2011-217033 23

The method of characterizing flow through a packed bed is the Darcy equation:

L

kA P Q ∆

μ = − (1)

where

Q volumetric flow rate

k Darcy constant

A cross-sectional area

ΔP pressure difference

L length of the packed bed

This equation may be applied to flow through the Pall filters; however, given that the parameters of 

the cross-sectional area and the length, or thickness, of the hydrophilic membrane are fixed quantities, this 

is combined with the Darcy constant to yield the following:

μ

∆ = − P Q C (2)

with C being defined as 

L

kA C = (3)

Due to the costs and constraints of the spaceflight experiment, the IVGEN system was tested for only 

one set of Pall filters and DI resin cartridge at nominally the same flow rate. This set of data can be 

compared to normal gravity data obtained over a wider range of flow rates and system temperatures and 

tabulated.

The results of the spaceflight tests are shown in Table 3. The NS–1 and NS–2 collection samples 

were generated on the first day of test operations. WFI–3 and WFI–4 collection samples were generated 

on the second day of operations and WFI–5 and WFI–6 were generated on the third and final day of 

operations. Overall, while the liquid flow rate was slightly faster than desired, it was acceptable, because 

the conductivity data suggested that the DI cartridge was providing acceptable purification. The total 

pressure loss through the system showed a 7 percent increase from the first sample to the last samples 

produced. The pressure loss within the DI cartridge increased by 30 percent through the course of the 

experiment. While it is plausible that the DI cartridge may have captured additional particulate matter that 

contributed to the gradual increase, the Inlet Pall filters should have captured this matter. Other 

possibilities remain: Swelling of the resin beads due to continued exposure to the water or a shifting,

settling of the resin beads over time due to vibrations encountered either during flow or exposure to low 

gravity, or crushing and crumbling of the particles and subsequent plugging of interstitial flow paths 

within the cartridge.

The maximum pressure drop is encountered when the flow valve between the accumulator and the 

purifier is opened. The first sample had the lowest maximum pressure drop among all of the samples 

generated. This may be because the system was relatively dry at this point and the pressure required to 

pass single-phase air through the system is much lower than single-phase liquid or a two-phase gas and 

liquid mixture. Minor differences in the timing of opening the valves on the purifier unit may also 

contribute to the differences in the maximum pressure loss encountered.

After the first day of operations, the components with the most significant contribution to the 

maximum pressure drop were the exit Pall filters. While there may be slight differences in the purity of 

the potable water supply, it is more likely that the exit Palls were becoming plugged with particulate 

matter. These filters have a life of 96 hr which fell within the operational parameters of the experiment. 
NASA/TM—2011-217033 24

TABLE 3.—HYDRODYNAMIC TEST RESULTS FROM SPACEFLIGHT EXPERIMENT

Collection bag

Parameter NS 1 NS–2 WFI–3 WFI–4 WFI–5 WFI–6

Average flow rate, mL/min 28.6 28.8 28.0 28.6 26.8 27.5 Average pressure drop

Inlet Palls, psi 0.25 0.27 0.28 0.27 0.26 0.26

DI cartridge, psi 0.14 0.15 0.14 0.14 0.19 0.18

Exit Palls, psi 1.08 1.09 1.10 1.09 1.11 1.10

Total, psi 1.47 1.50 1.51 1.50 1.55 1.55

Maximum 

pressure 

drop

Total, psi 2.09 3.61 3.48 3.62 4.13 2.45

Major contributor Inlet 

Palls

Inlet 

Palls

Exit 

Palls

Exit 

Palls

Exit 

Palls

Exit 

Palls

TABLE 4.—FLOW CONSTANTS FOR 

CRITICAL COMPONENTS OF IVGEN

Component –C,

cm3

/s2

Inlet Palls 0.00256

DI cartridge 0.00433

Exit Palls 0.00062

Referring back to Equations (2) and (3), the values of the constant –C are shown in Table 4. It should 

be noted that these values can easily be adjusted for a number of reasons. First, there are additional flow 

system components, namely the isolation valves and the conductivity sensors, which were lumped into 

these calculations and add flow resistance or pressure loss. In addition, both sets of Pall filters were 

plumbed into the system in parallel, the net effect being to reduce the pressure loss. Nevertheless, these 

values may be used as an approximation for an operational system.

From a hydrodynamic standpoint, the IVGEN system did not exceed the maximum pressure drop 

within the system, which was 10 psi. The average pressure drop was 1.5 psi and the peak value 

encountered was less than 5 psia. The average flow rate for the IVGEN system was 28 mL/min which 

was very close to meeting the target flow rate range of 17 to 25 mL/min. This range was selected to meet 

the minimum production rate required for the system (approximately 1 l/hr) and to provide sufficient 

residence time, or exposure, for the liquid within the DI cartridge. Even with the slightly faster flow rate, 

the IVGEN system was able to meet the purification requirements.

6.2 Conductivity

As was noted earlier, conductivity sensors were positioned within the purifier to measure the 

effectiveness of the DI cartridge in purifying the water and to determine the mixing effectiveness. All six 

samples were evaluated for the purification effectiveness, but only two samples, NS–1 and NS–2, were 

evaluated for the uniformity of solution concentration after the mixing was completed.

6.2.1 Purification 

The time trace for NS–1 sample is shown in Figure 16. Both the potable water input and the purified 

water output are shown. It should be noted that there is an initial spike in both the input and output 

streams that is partially attributable to a temperature effect on conductivity (Figure 17) and to bed 

“rinsing.” As liquid stagnates within the bed, the DI resin leaches some of its contents into the water. Bed 

rinsing flushes this solution from the bed. Towards the end of the time trace, there are several points 

where the conductivity for the potable water drops below the average value. These values are most likely 
NASA/TM—2011-217033 25

attributable to bubble passage through the conductivity sensor. Similar drops in the density measurement 

and widely fluctuating flow rate measurements from the Coriolis flow meter were recorded during this 

time period. Further analysis included calculating the mass flow rate based on the volumetric flow rate 

and density and integrating the mass flow rate over the experiment duration to obtain a total mass 

collected. The total mass was in agreement with the post-flight weight of the NS–1 collection bag. These 

results revealed that the IVGEN system processed an insufficient amount of liquid. 

Figure 16.—Time history trace for DI cartridge purification capability.

Figure 17.—Time history trace for water temperature in conductivity sensors.
NASA/TM—2011-217033 26

As was stated earlier, the conductivity sensors provided a limited verification that the purified water 

produced would meet USP standards for WFI. Solution sterility and other contaminants, such as 

endotoxins, oxidizable substances, and particulate matter, could not be measured in a timely and costeffective manner on orbit, but the contents of NS bags were tested by a Food and Drug Administration 

(FDA)-certified lab after these bags were returned from the ISS on STS–132. It should be noted that the 

USP does adjust the maximum acceptable conductivity levels for temperature as shown in Table 5

(Ref. 20). As can be seen from the table, the maximum acceptable conductivity for WFI is between 1.3 

and 1.4 μS/cm for the test conditions.

TABLE 5.—TEMPERATURE CORRECTED 

ACCEPTABLE CONDUCTIVITY 

VALUES FOR WFI

Temperature,

°C

Conductivity,

μS/cm

15 1.0

20 1.1

25 1.3

30 1.4

35 1.5

To provide additional margin, for this data analysis the maximum acceptable concentration was taken to 

be 1.0 μS/cm. While the initial spike in the potable water supplied to the IVGEN may be due to warming of 

the liquid within the MSG, ionic impurities leaching from the DI resin beads into the stagnant water are the 

probable culprit. This conductivity spike was noted each time flow through the DI cartridge was initiated. 

The DI resin manufacturer specifies that within seven “bed volumes,” the output water will have flushed 

these impurities away (Ref. 31). For the IVGEN experiment, a bed volume was approximately 30.1 mL.

Average purification was defined as the percentage change in the instantaneous conductivity between 

the input (potable water) and output (purified water) from the DI cartridge: 

Potable

Potable Purified 100%

C

C C P − = (4)

Table 6 presents a synopsis of the purification capability of the DI cartridge from the two 

conductivity probes in the purifier assembly. Overall, average purifications of about 98 percent were 

achieved for each bag of potable water that was processed. It should be noted that the WPA supplied a 

very clean water supply that had an average conductivity of about 4 μS/cm with no maximum value 

greater than 7 μS/cm. The minimum values for the instantaneous conductivity data for the potable water 

were most likely due to the passage of air bubbles from the accumulator into the purifier. The first set of 

Pall filters, which removed large particulate matter and air bubbles, were located downstream of both the 

flow meter and the inlet conductivity sensor. As was discussed earlier, the Coriolis flow meter is capable 

of measuring the fluid flow rate and the fluid density. Comparison of the sample volume and the sample 

mass appears consistent with the exception of NS–1. For this sample, there is approximately a 2:1 

discrepancy between the volume and mass measured. A closer examination of Figure 16 reveals at the 

end of the time trace, significant fluctuations in the conductivity for the potable water input. Again, this 

was most likely due to the presence of air within the source water. This discrepancy has repercussions 

later in the experiment, during the generation of the NS solution.

With regards to the purified water produced, with the exception of the startup spike for NS–1 and 

WFI–3, all samples fall well within the criteria for the maximum acceptable conductivity. For these two 

samples, the flushing of a single bed volume of liquid (30 mL) through the DI cartridge brings the volume 

averaged conductivity measurement to within specifications. The remaining samples also had startup 

spikes; however, the spikes did not exceed the USP threshold of 1.3 μS/cm, but as an academic exercise, a 

much lower threshold was chosen (0.2 μS/cm), and the rinse volumes for these samples were calculated.
NASA/TM—2011-217033 27

TABLE 6.—SYNOPSIS OF PURIFICATION CONDUCTIVITY DATA

Collection bag

Parameter NS–1 NS–2 WFI–3 WFI–4 WFI–5 WFI–6

Volume, mL 2621 1516 1520 1521 1501 1488

Volume, g 1392 1498 1500 1498 1482 1465 Potable water inputInstant

Average, μS/cm 4.02 3.87 3.57 3.57 3.32 3.36

Maximum, μS/cm 6.99 6.49 4.96 4.24 4.09 3.78

Minimum, μS/cm 3.80 0.48 2.06 2.20 2.72 2.94

Volume 

averagedAverage, μS/cm 4.20 3.98 3.65 3.63 3.28 3.37

Maximum, μS/cm 6.08 5.32 5.89 4.92 3.55 3.74

Minimum, μS/cm 4.03 3.02 3.59 3.59 2.77 3.35

Purified water output

Instant

Average, μS/cm 0.068 0.058 0.065 0.050 0.067 0.050

Maximum, μS/cm 1.636 1.013 1.107 0.436 0.967 0.040

Minimum, μS/cm 0.034 0.040 0.046 0.041 0.048 0.232

Volume 

averagedAverage, μS/cm 0.171 0.116 0.065 0.070 0.119 0.060

Maximum, μS/cm 1.440 0.769 0.084 0.390 0.660 0.052

Minimum, μS/cm 0.074 0.072 1.105 0.057 0.079 0.190

Averaged purification 98.4 98.5 97.8 98.4 98 98.3

Rinse 

volumes

Threshold conductivity, μS/cm 1.0 0.2 1.0 0.2 0.2 0.2

Instant, mL 10.4 42.5 9.8 22.2 32.8 13.3

Average, mL 21.7 181.1 16.7 58.0 171.6 0.0

It should be noted that a single DI cartridge easily produced about 9 L of purified water and showed 

no signs of exhausting the purification capability. However, ground-based testing using tap water that had 

an average conductivity ranging from 250 to 300 μS/cm would show cartridge exhaustion within 6 L of 

processed water. Again, this is due to the high purity of the WPA water used as a source for IVGEN. 

6.2.2 Mixing Uniformity

For samples NS–1 and NS–2, software activated the magnetic stirrer after the collection bag had 

received one-half of the total filtered liquid volume. After purification ceased and flow into the collection 

bag had stopped, a crewmember closed the valve between the collection bag and the purification 

assembly. Stirring continued for 20 min for sample NS–1 and only 5 min for NS–2.

Prior to the fill, all sample/collection bags had some residual air content. This was particularly true for 

the two bags containing the premeasured quantity of salt and stir bar. Consequently, as purified water 

entered the bag, a large air bubble was trapped inside the bag. When mixing was initiated, the large air 

bubble would periodically encounter the rotating stir bar and have a portion shear off into smaller bubbles 

(Figure 18).

Per the procedure, the collection bag was removed from the mixing assembly and placed in a blood 

pressure cuff that was inflated to pressurize the collection bag. The collection bag was connected to the 

purifier assembly that was connected to the sterile transfer bag assembly. This arrangement permitted the 

measurement of the solution conductivity as it flowed from the collection bag to the transfer bag.

As can be seen from Figure 19 and Figure 20, with the exception of the conductivity dropouts, due to 

the passage of air bubbles through the conductivity sensor, the upper bound of the conductivity is fairly 

flat with some minor variations that coincide with temperature fluctuations within the solution.

Referring to Figure 19, the time-averaged conductivity measurement is 18.5 ± 0.4 mS/cm from the 

time flow is initiated until after 43 min have elapsed. However, if conductivity readings associated with 

the passage of bubbles through the conductivity cell are discounted from the averaging routine, the 

average is 20.2 ± 0.4 mS/cm, which corresponds nicely with Figure 20.

Similarly, the same averaging methodology is applied to sample NS–2 in Figure 20. This time, 

however, the time average for the first 25 min of the fluid transfer is 16.3 ± 0.4 mS/cm while an average 
NASA/TM—2011-217033 28

over the entire transfer period that discounts the readings associated with bubble passage yielded a value 

of 16.5 ± 0.4 mS/cm. For this case, good agreement is obtained between both values.

It should be noted; however, that while both mixtures appear to be uniform, there is considerable 

difference in these baseline conductivity measurements even though the target salt concentration was 

0.9 g/L of water. This discrepancy will be discussed in more detail in the next section.

Figure 18.—Collection bag for NS–1 prior to (left) and during mixing (right).

Figure 19.—Mixing uniformity results for NS–1.
NASA/TM—2011-217033 29

Figure 20.—Mixing uniformity results for NS–2.

6.3 Post-Flight Analysis

Upon sample return, the NS–1 and NS–-2 sample bags were inspected, photographed, and weighed.

These bags were then shipped to Pace Analytical Services, Inc., an FDA-certified laboratory, to evaluate

the contents for compliance with USP standards for sterile sodium chloride solution for injection. The 

types of tests and results are shown in Table 7.

As was stated earlier, the experiment requirements called for 13.5 ± 0.67 g of sodium chloride to be 

measured and preloaded into each of the two collection bags. The requirements also called for flow rate 

measurements that were within ±1 percent of the full-scale measurement range to ensure that a tolerance 

of 25 ml in the total volume was collected.

Several potential causes for the failure were identified and evaluated. Among these causes are the 

following:

• Incorrect amount of water introduced into the collection bag

• Incorrect amount of salt introduced into the mixing bag

• Insufficient mixing that did not sufficiently dissolve salt crystals or homogenize solution

• Evaporation from the bag

TABLE 7.—USP TESTING RESULTS

Test Specification NS–1 

result

NS–2 

result

Sterile sodium chloride for injection 95.0 to 105.0% of target 117.0% Fail 93.8% Fail

Endotoxin concentration <0.0050 EU/mL Pass Pass

Heavy metals by USP <231> Not more than (NMT) 0.001% Pass Pass

Identification sodium by USP <191> Sample responds to tests for sodium Pass Pass

Identification chloride by USP <191> Sample responds to tests for chloride Pass Pass

Iron by USP <241> NMT 2 ppm Pass Pass

Particulate analysis by USP <788> ≤25 particles per mL larger than 10 μm

≤3 particles per mL larger than 25 μm

3.40 Pass

0.00 Pass

1.20 Pass

0.00 Pass

Sterility by USP <71> No growth Pass Pass

pH testing by USP <791> 4.5 to 7.0 5.4 Pass 5.4 Pass
NASA/TM—2011-217033 30

Reviewing the sensor data from the orbital operations, it was highly likely that an insufficient amount 

of water was purified and charged into collection bag NS–1. This was confirmed by post-flight weight 

NS–1 bag assembly of 1371 g, which is significantly less than the specified mass of water of 1500 g.

Nevertheless, additional analyses were conducted to decisively eliminate other potential causes. The 

water volume in the NS–2 bag was within acceptable margins, based on both sensor data and the post 

flight weight.

With regards to insufficient mixing time, per Barlow (Ref. 19), a time of 4 min for a smaller stir bar at 

900 rpm should have been sufficient to achieve the necessary homogeneity within the solution. Even at a

revolution rate of 50 percent of the target value, 10 min should have been sufficient. Actual mixing times 

ranged from 5 to 20 min after the collection bag had been filled and did not account for the 34 min of 

mixing time while NS–1 was filling. Furthermore, the conductivity sensor during the fill of the transfer 

bag indicated a relatively consistent level. There was still concern that residual salt crystals may have 

been trapped inside the fill port of collection bag and did not get immersed by the water and thus 

dissolved during the mixing process.

While it was not the original plan, the collection bags for NS–1 and NS–2 were returned from the 

ISS. A procedure was developed to take advantage of this opportunity by analyzing the residual contents 

of the bags to better determine the cause of the saline discrepancy. It was decided to use a technique 

called inductively coupled plasma optical emission spectrometry (ICP/OES). Sodium was chosen since 

ICP/OES has a sensitivity of 50 μg/L while ion chromatography is used for chloride content but has a 

detection limit of 50 mg/L. However, the sample needed to be diluted since the technique required at least 

100 mL of sample, and there was only an estimated 10 to 20 mL of residual solution within each bag. 

Details of this procedure and test results can be found in Appendix C, Investigation Results for Out-ofSpecification Saline Concentration.

Each bag was weighed and approximately 100 mL of ASTM Type I water (highly purified) was 

added to the bag and the bag was reweighed. The water was sloshed around the bag in various 

orientations to ensure that any undissolved salt crystals would contact the water. The contents were 

drained into clean sample containers and sent to Precision Analytical, Inc., for the ICP/OES analysis. The 

“empty” bag was weighed, dried with gaseous nitrogen, and reweighed.

The samples were analyzed and the results were 1.36 g/L of sodium for NS–1 and 0.568 g/L for 

NS–2. This concentration equates to 13.78 g for NS–1 and 12.59 g for NS–2. As stated earlier, each 

collection bag should have been filled with 13.5 ± 0.67 g of sodium chloride, thus NS–1 was filled with 

an acceptable amount of salt while NS–2 had an insufficient amount of salt. The completed test plan, the 

results from the chemical analysis performed by Precision Analytical, and an analysis that converts these 

findings into the salt mass loaded into each bag is in Appendix C.

Additional collection bags were prepared with stir bars and salt, but were placed in bonded storage 

and not used. During this anomaly investigation, the contents of three of these bags were evaluated. The 

bags had an “extracted” salt mass of 13.34, 13.23, and 12.76 g. This measurement was simply based on 

the salt that was removed from the bag. To negate the possibility of sample loss during this process, a 

second set of measurements were also made. The bags were weighed initially before the salt extraction. 

After the salt was extracted, the bags were rinsed to remove any residual salt and then reweighed. The 

difference between these weights yielded a calculated salt mass of 13.595, 13.449, and 12.773 g,

respectively. Thus, while two of the bags were within the specification, at least one additional bag did not 

meet the requirement. To summarize the findings:

• NS–1’s salt concentration was too high. The cause was that an insufficient amount of purified 

water was supplied to the collection bag because a significant amount of air had entered the 

accumulator during the filling process. Consequently, the estimate for the amount of residual air 

in this transfer line was larger than expected and the first filling of the accumulator did not have 

sufficient water. One potential resolution is to place a bubble separator at the accumulator inlet.

• NS–2’s salt concentration was too low. The cause was that an insufficient amount of salt was 

placed into the collection bag during the bag assembly process. While certificates of conformance 
NASA/TM—2011-217033 31

received with the salt-filled bags indicated that the salt quantity met the tighter manufacturing 

specification of 13.5 ± 0.5 g. Each individual bag was not tested directly for salt quantity. 

However, initial lot testing―conducted prior to the full-up flight system configuration tests—was 

performed in which several bags were filled with a known quantity of water (1500 mL) and 

analyzed for salt concentration. The salt concentration was found to be within an acceptable range 

for all tested bags. Performing a pre-salt and post-salt mass analysis on all bag assemblies should 

be done rather than lot testing, but this would have significantly affected the flight hardware 

delivery schedule for IVGEN.

7.0 Plans

Although the spaceflight experiment was conducted and test results evaluated, there is still a 

significant amount of work that should be completed, both with regards to testing and the design of an 

operational system.

7.1 Testing

Two types of testing and the subsequent data analysis are in the process of being performed. Data 

have been obtained but need additional analysis to assess the effect of temperature on the system. In the 

event that an IVGEN operational system is needed to address a spaceflight medical emergency, the 

chances are that the environmental control and life support system may not be functioning optimally. One 

result of this may be that the cabin and or potable water supply temperature may be either very warm or 

very cold. A series of tests were performed to assess the DI cartridge’s performance with input water at 

temperatures of 4, 15, 25, and 35 °C. The performance with regards to the cartridge purification ability 

and the pressure loss as a function of the flow rate through the cartridge is being evaluated. In addition, 

given that some DRMs have durations of at least 2 or 3 years, the packaging technique and the effect of 

shelf life on the DI resin are also being evaluated. As received from the manufacturer, the resin has a 

moisture content of about 60 percent and the storage container prevents direct contact with the 

atmosphere. The storage technique is important because the resin is degraded by both desiccation and 

exposure to carbon dioxide, which it absorbs. Exposure to the atmosphere produces both of these negative 

outcomes and, therefore, must be avoided by proper packaging.

To validate the IVGEN storage technique, two sets of cartridges have been prepared and are 

undergoing shelf life testing. The first set of cartridges contains ResinTech’s MBD–10–NG resin within a 

polycarbonate tube that is capped with stainless steel fittings at each end. The second set of cartridges 

contains ResinTech’s MBD–10–ULTRA resin also within a polycarbonate tube that is capped with 

stainless steel fittings at each end, but in a hermetically sealed bag. It was learned early in the program 

that vacuum sealing these bags was detrimental to the DI resin purification performance as it dried the 

resin. Once every 6 months, one cartridge from each set will be removed from storage and tested. Pending 

the results of these tests, it may be necessary to reevaluate the storage technique and restart testing.

7.2 Operational System Design

The operational IVGEN system will not be identical to the experimental system. The experiment 

included conductivity sensors and temperature sensors to verify purity of water. However, with the use of 

either a color-indicating DI resin to indicate capacity or by certifying that a DI cartridge cannot produce 

more than a given quantity of purified water, it is not necessary to use these sensors. A flow meter was 

used to identify flow-induced causes for anomalies, such as the air bubble. The Pall filters performed as 

advertised; however, an additional set of filters should be placed on the inlet of the accumulator. If that 

step were to be taken, the user could be confident of an appropriate saline concentration. Pressure 

transducers were used to determine the scalability of the system in terms of cartridge length versus

quantity of purified water produced.
NASA/TM—2011-217033 32

Based on the experiment results, though, the following should be addressed:

• Shelf life and storage techniques: Testing is ongoing and needs to be continued to verify that the 

components of the system can be stored for up to 5 years and maintain desired capability.

• Accurate metering of water volume: Based on the results from NS–1 testing, the amount of water 

that is introduced into the salt bag is critical to producing an NS solution of acceptable 

concentration. There are several technologies that may be used to address this concern including 

the use of more bubble separators or traps in strategic locations within an operational system or 

the use of a microgravity-rated, liquid-only, volumetric flask.

• Testing of purification “challenges”: In determining the final spaceflight experiment hardware, 

the IVGEN team worked closely with a pharmaceutical consultant to develop a pharmaceutical 

process validation plan. Execution of this test plan with the final system should be performed to 

document the maximum capacity of the system for each known contaminant. These challenges 

should include preparing and testing samples of purified water with known concentrations of 

particulate matter, endotoxins, sucrose, ammonia, and representative water meeting the NASA’s 

SWEG, 41000 and CxP 20024 guidelines by flowing it through the system.

• Depletion of purification capability: The ISS already provides highly purified water courtesy of 

the WPA. Future exploration systems may not provide potable water of such quality.

Consequently, either the cartridges will have to be rated for the potable water supply of each 

spacecraft system or some method, such as either conductivity probes or color-indicating, puritysensitive DI resin will need to be used to ensure a quality product.

8.0 Conclusion

Intravenous Fluid Generation (IVGEN) experiment was operated onboard the International Space 

Station (ISS) during May 2010. This hardware demonstrated the capability to generate intravenous (IV)

fluid from ISS Water Processing Assembly (WPA) potable water using a water purification technique and 

pharmaceutical mixing system. Six 1.5-L bags of purified water were produced. Two of these bags were 

mixed with sodium chloride to make 0.9 percent normal saline (NS) solution. These two bags were 

returned to Earth to test for compliance with USP requirements.

On-orbit results indicated that all of the experimental success criteria were met with the exception of 

the salt concentration. Problems with a large air bubble in the first bag of purified water resulted in a 

slightly concentrated saline solution of 117 percent of the target value of 0.9 g/L. This problem can be 

resolved by placement of a gas-liquid separator filter immediately upstream of the liquid inlet to the 

accumulator. The second bag had an inadequate amount of salt premeasured into the mixing bag resulting 

in a slightly deficient salt concentration of 93.8 percent of the target value. The United States 

Pharmacopeia (USP) permits a range from 95 to 105 percent of the target value. 

The testing plans for improvements for an operational system were also presented and included shelf 

life testing of the storage technique for the DI resin cartridge and challenging the purification ability of 

the DI resin cartridges.

References

1. “The Vision for Space Exploration,” NASA, 

http://www.nasa.gov/pdf/55583main_vision_space_exploration2.pdf, February 2004.

2. “Exploration Systems Architecture Study Final Report,” NASA/TM—2005-214062,

http://www.nasa.gov/pdf/140649main_ESAS_full.pdf

3. Miller, F.J., Niederhaus, C., Barlow, K., Griffin, D., “Intravenous Solutions for Exploration Missions, 

“45th AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV, AIAA–2007–544, 2007.

4. Watkins, S.D. “Space Medicine Exploration: Full Medical Condition List,” NASA/TP—2010-

216118, 2010.
NASA/TM—2011-217033 33

5. Crew Health Care System (CHeCS) – International Medical Hardware Catalog, Ver 5.1, April 2005.

6. Bagdigian, R., Cloud, Dale, and Bedard, J., “Oxygen Generation Systems Status of the Regenerative 

ECLSS Water Recovery,” SAE 2006–01–2057, 2006

7. United States Pharmacopeia National Formulary (2007).

8. James, J.T., and Torin McCoy, J., “Spacecraft Water Exposure Guidelines (SWEGs),” JSC–63414, 

November 2008.

9. “System Specification for the International Space Station,” NASA SSP 41000 Rev E, May 1997.

10. “Constellation Program Human-Systems Integration Requirements,” CxP70024, December 2006.

11. “Pressurized Payload Accommodation Handbook: International Space Station Program,” SSP 57020, 

2004.

12. Carter, D.L., “Status of the Regenerative ECLSS Water Recovery System,” SAE 2009–01–2352, 

International Conference on Environmental Systems, Savannah, GA, 2009.

13. Creager, G., “An Evaluation of IV Fluids Requirements for the Space Station Freedom Health 

Maintenance Facility Assuming a 10-Day Therapeutic Stay,” Krug Life Sciences, 1991.

14. “Space Station LVP Mixing System: Interim Report #2,” J. Ogle, M. Finley, and J. Kipp, Baxter 

Healthcare, June 1989.

15. Niederhaus, C.E, and Miller, F.J., “Intravenous Fluid Mixing in Normal, Partial, and MicroGravity: 

Down-selection of Mixing Methods,” NASA/TM—2008-21500, 2006.

16. Lloyd, C., Creager, G., Guess, T., Giglio, D., “Post Mission Summary—Two Week Report, Spacelab 

J (STS 47): Inflight Demonstration of the Space Station Freedom Health Maintenance Facility Fluid 

Therapy System,” October 1992.

17. Koenig, D.W., Bruce, R.J., and Stowe, R P., “Analyses of Spacelab-J Fluid Therapy System 

Samples,” Test Report #M078/92, October 1992.

18. Schultz, J.R., Memo on “Chemical Analysis Results from the Fluid Therapy System Flight Test on 

STS-47,” to Richard L. Sauer, November 12, 1992.

19. Barlow, K.L., “Intravenous fluid mixing times quantified using planar laser-induced fluorescence,”

Master’s Thesis, Case Western Reserve University, 2007.

20. United States Pharmacopeia – National Formulary Fifth Supplement, Physical Tests/Water 

Conductivity (645) 3465–3467.

21. Niederhaus, C.E., Barlow, K.L., Griffin, D.W., Miller, F.J., “Medical Grade Water Generation for 

Intravenous Fluid Production on Exploration Missions,” NASA/TM—2008-214999, 2008.

22. King, C.J., Separation Processes, Second Edition, McGraw-Hill Book Company, pg 45–48, 1980.

23. Wykes, V., Fong, K., Gilmore, S., Scarpa, P., Woodward, D., “Onboard System for Production of 

Intravenous Fluids,” Aviation, Space, and Environmental Medicine, Vol. 76, No. 3, p. 220, March 

2005.

24. Wykes, V., Jayakumar, P., Scheuer, W., Guess, T., Scarpa, P., Fong, K., “A Portable Intravenous

Fluid Production System Using Reverse Osmosis Technology for Medical Emergency in Space,”

Aviation, Space, and Environmental Medicine, Vol .77, No. 3, p. 333, March 2006.

25. Taylor, M.A., Alambra, E.F., Anes, J., Behnke, J., Enachescu, B., Fitzgerald, C.L., Fortado, M., 

Sizelove, M.L., “Remote Site Production of Sterile Purified Water from Available Surface Water,” 

Prehospital and Disaster Medicine, Vol. 19, No. 3, pp. 266–277, 2004.

26. Akse, J.R.; Dahl, R.W.; Wheeler, R.R., “Continuous-Flow System Produces Medical-Grade Water,” 

NASA Tech Briefs, LEW–18159–1, pp. 25–26, March 2009.

27. The Society of U.S. Naval Flight Surgeons, The United States Naval Flight Surgeon Handbook, 2nd 

edition, 1998.

28. Motil, B.J., Balakotaiah, V., and Kamotani, Y., “Effects of Gravity on Cocurrent Two-Phase GasLiquid Flows through Packed Columns,” AIAA–2001–0767 and NASA/TM—2001-210705, 2001.

29. Holder, D.W. and Parker, D.S. “Volatile Removal Assembly Flight Experiment and KC–135 Packed 

Bed Experiment: Results and Lessons Learned,” SAE 2000–01–2251, 30th International Conference 

on Environmental Systems, Toulouse, France, 2000.
NASA/TM—2011-217033 34

30. Spivey, R., Sheredy, W., and Flores, G., “An Overview of the Microgravity Science Glovebox (MSG) 

Facility, and the Gravity-Dependent Phenomena Research Performed in the MSG on the International 

Space Station (ISS),” AIAA–2008–812, 46th AIAA Aerospace Sciences Meeting and Exhibit, Reno, 

NV, 2008.

31. ResinTech, Inc. “Specification Sheet for MDB–10, Mixed Bed Resins,” 

http://www.resintech.com/products/frm_ProductInfo.aspx?qProductId=78, 2011.
NASA/TM—2011-217033 35

Appendix A.—Acronyms and Abbreviations

ALSP Advanced Life Support Pack 

ASTM American Society for Testing and Materials

CEV Crew Exploration Vehicle

CHeCS Crew Health Care System

CWC Contingency Water Container

DACU Data Acquisition and Control Unit

DC direct current

DI deionization

DRM Design Reference Mission 

ECLSS Environmental Control and Life Support Systems 

EPA Environmental Protection Agency

EVA Extravehicular Activity

FDA Food and Drug Administration

FTS Fluid Therapy System

GRC Glenn Research Center

ICP/OES inductively coupled plasma optical emission spectrometry

ISS International Space Station

IV intravenous

IVGEN Intravenous Generation

JSC Johnson Space Center

KSC Kennedy Space Center

MCL maximum contaminant level

MDL Shuttle Middeck Locker 

MSG Microgravity Science Glovebox

NASA National Aeronautics and Space Administration

NMT not more than

NPDWR National Primary Drinking Water Regulations 

NS normal saline

OGS Oxygen Generation System

PCDB Patient Condition Database

PE polyethylene
NASA/TM—2011-217033 36

PLIF Planar Laser-Induced Fluorescence

PWD Potable Water Dispenser

PWR Potable Water Reservoirs

RO reverse osmosis

SAL Sterility Assurance Level

SBIR Small Business Innovative Research

SM Service Module

SMEMCL Space Medicine Exploration Medical Condition List

SSP Space Station Program

STS Space Transportation System (Space Shuttle)

SWEG Spacecraft Water Exposure Guideline

SWFI Sterile Water for Irrigation 

SWI Sterile Water for Injection

SWIS Sterile Water for Injection System

TFC thin-film composite

TOC Total Organic Carbon

UPA Urine Processing Assembly

USP United States Pharmacopeia

WFI water for irrigation

WPA Water Processing Assembly
NASA/TM—2011-217033 37

Appendix B.—Test Results

B.1 Bag 1, Normal Saline

Figure B.1.—Bag 1, time trace of volumetric flow rate.

Figure B.2.—Bag 1, time trace of fluid density.
NASA/TM—2011-217033 38

Figure B.3.—Bag 1, time trace for mass flow rate.

Figure B.4.—Bag 1, time trace of pressure drop.
NASA/TM—2011-217033 39

Figure B.5.—Bag 1, time trace on conductivity for potable water input and purified water output from 

DI Cartridge.

Figure B.6.—Bag 1, time trace of conductivity and temperature during transfer of saline solution to sterile bag.
NASA/TM—2011-217033 40

Figure B.7.—Bag 1, time trace for purification efficiency.

Figure B.8.—Bag 1, time trace for instantaneous and average conductivity for the purified water output 

from DI Cartridge.
NASA/TM—2011-217033 41

B.2 Bag 2, Normal Saline

Figure B.9.—Bag 2, time trace of volumetric flow rate.

Figure B.10.—Bag 2, time trace of pressure drop.
NASA/TM—2011-217033 42

Figure B.11.—Bag 2, time trace on conductivity for potable water input and purified water output 

from DI Cartridge.

Figure B.12.—Bag 2, time trace for purification efficiency.
NASA/TM—2011-217033 43

Figure B.13.—Bag 2, time trace for instantaneous and average conductivity for the purified water output 

from DI Cartridge.

Figure B.14.—Bag 2, time trace of conductivity and temperature during transfer of saline solution to sterile 

bag.
NASA/TM—2011-217033 44

B.3 Bag 3, Purified Water

Figure B.15.—Bag 3, time trace of volumetric flow rate.

Figure B.16.—Bag 3, Time Trace of Pressure Drop.
NASA/TM—2011-217033 45

Figure B.17.—Bag 3, time trace on conductivity for potable water input and purified water output 

from DI Cartridge.

Figure B.18.—Bag 3, time trace for purification efficiency.
NASA/TM—2011-217033 46

Figure B.19.—Bag 3, time trace for instantaneous and average conductivity for the purified water 

output from DI Cartridge.

B.4 Bag 4, Purified Water

Figure B.20.—Bag 4, time trace of volumetric flow rate.
NASA/TM—2011-217033 47

Figure B.21.—Bag 4, time trace of pressure drop.

Figure B.22.—Bag 4, time trace on conductivity for potable water input and purified water output 

from DI Cartridge.
NASA/TM—2011-217033 48

Figure B.23.—Bag 4, time trace for purification efficiency.

Figure B.24.—Bag 4, time trace for instantaneous and average conductivity for the purified 

water output from DI Cartridge.
NASA/TM—2011-217033 49

B.5 Bag 5, Purified Water

Figure B.25.—Bag 5, time trace of volumetric flow rate.

Figure B.26.—Bag 5, time trace of pressure drop.
NASA/TM—2011-217033 50

Figure B.27.—Bag 5, time trace on conductivity for potable water input and purified water output 

from DI Cartridge.

Figure B.28.—Bag 5, time trace for purification efficiency.
NASA/TM—2011-217033 51

Figure B.29.—Bag 5, time trace for instantaneous and average conductivity for the purified water 

output from DI Cartridge

B.6 Bag 6, Purified Water

Figure B.30.—Bag 6, time trace of volumetric flow rate.
NASA/TM—2011-217033 52

Figure B.31.—Bag 6, time trace of pressure drop.

Figure B.32.—Bag 6, time trace on conductivity for potable water input and purified water output 

from DI Cartridge.
NASA/TM—2011-217033 53

Figure B.33.—Bag 6, time trace for purification efficiency.

Figure B.34.—Bag 6, time trace for instantaneous and average conductivity for the purified water 

output from DI Cartridge.

NASA/TM—2011-217033 55

Appendix C.—Investigation Results for 

Out-of-Specification Saline Concentration

C.1 Completed Test Plan
NASA/TM—2011-217033 56
NASA/TM—2011-217033 57
NASA/TM—2011-217033 58
NASA/TM—2011-217033 59
NASA/TM—2011-217033 60
NASA/TM—2011-217033 61
NASA/TM—2011-217033 62
NASA/TM—2011-217033 63
NASA/TM—2011-217033 64
NASA/TM—2011-217033 65
NASA/TM—2011-217033 66

C.2 Chemical Analysis Results of Bag Contents (Performed by Precision Analytical)
NASA/TM—2011-217033 67
NASA/TM—2011-217033 68
NASA/TM—2011-217033 69
NASA/TM—2011-217033 70
NASA/TM—2011-217033 71
NASA/TM—2011-217033 72

C.3 Conversion Analysis
NASA/TM—2011-217033 73
NASA/TM—2011-217033 74
NASA/TM—2011-217033 75
NASA/TM—2011-217033 76
NASA/TM—2011-217033 77
REPORT DOCUMENTATION PAGE Form Approved 

OMB No. 0704-0188 

The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the 

data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this 

burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. 

Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB 

control number. 

PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 

1. REPORT DATE (DD-MM-YYYY)

01-07-2011 

2. REPORT TYPE

Technical Memorandum 

3. DATES COVERED (From - To)

4. TITLE AND SUBTITLE

Final Report for Intravenous Fluid Generation (IVGEN) Spaceflight Experiment 

5a. CONTRACT NUMBER

5b. GRANT NUMBER

5c. PROGRAM ELEMENT NUMBER

6. AUTHOR(S)

McQuillen, John, B.; McKay, Terri, L.; Griffin, DeVon, W.; Brown, Dan, F.; Zoldak, John, 

T. 

5d. PROJECT NUMBER

5e. TASK NUMBER

5f. WORK UNIT NUMBER

WBS 444543.01.02.01 

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

National Aeronautics and Space Administration 

John H. Glenn Research Center at Lewis Field 

Cleveland, Ohio 44135-3191 

8. PERFORMING ORGANIZATION

 REPORT NUMBER

E-17731 

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

National Aeronautics and Space Administration 

Washington, DC 20546-0001 

10. SPONSORING/MONITOR'S

 ACRONYM(S)

NASA 

11. SPONSORING/MONITORING

 REPORT NUMBER

NASA/TM-2011-217033 

12. DISTRIBUTION/AVAILABILITY STATEMENT

Unclassified-Unlimited 

Subject Categories: 34 and 52 

Available electronically at http://www.sti.nasa.gov 

This publication is available from the NASA Center for AeroSpace Information, 443-757-5802

13. SUPPLEMENTARY NOTES

14. ABSTRACT

NASA designed and operated the Intravenous Fluid Generation (IVGEN) experiment onboard the International Space Station (ISS), Increment 23/24, during May 2010. This 

hardware was a demonstration experiment to generate intravenous (IV) fluid from ISS Water Processing Assembly (WPA) potable water using a water purification technique 

and pharmaceutical mixing system. The IVGEN experiment utilizes a deionizing resin bed to remove contaminants from feedstock water to a purity level that meets the 

standards of the United States Pharmacopeia (USP), the governing body for pharmaceuticals in the United States. The water was then introduced into an IV bag where the fluid 

was mixed with USP-grade crystalline salt to produce USP normal saline (NS). Inline conductivity sensors quantified the feedstock water quality, output water purity, and NS 

mixing uniformity. Six 1.5-L bags of purified water were produced. Two of these bags were mixed with sodium chloride to make 0.9 percent NS solution. These two bags were 

returned to Earth to test for compliance with USP requirements. On-orbit results indicated that all of the experimental success criteria were met with the exception of the salt 

concentration. Problems with a large air bubble in the first bag of purified water resulted in a slightly concentrated saline solution of 117 percent of the target value of 0.9 g/L. 

The second bag had an inadequate amount of salt premeasured into the mixing bag resulting in a slightly deficient salt concentration of 93.8 percent of the target value. The 

USP permits a range from 95 to 105 percent of the target value. The testing plans for improvements for an operational system are also presented.

15. SUBJECT TERMS

Microgravity applications; Water treatment; Separation; Fluid flow; Medical equipment 

16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF

 ABSTRACT

UU 

18. NUMBER

 OF 

 PAGES

85 

19a. NAME OF RESPONSIBLE PERSON

STI Help Desk (email:help@sti.nasa.gov) 

a. REPORT

U 

b. ABSTRACT

U 

c. THIS 

PAGE

U 

19b. TELEPHONE NUMBER (include area code)

443-757-5802 

Standard Form 298 (Rev. 8-98)

Prescribed by ANSI Std. Z39-18