1. Carbon Dioxide and Moisture Removal System NASA ECLSS July 17, 2002

2. 07-17-02Coeus Engineering2 Team Organization Jessica BadgerJessica Badger –Project Coordinator –Honeycomb structures April SnowdenApril Snowden –Researcher –Carbon nanotubes Dennis ArnoldDennis Arnold –Team Leader –Aerogels Julia ThompsonJulia Thompson –Researcher –Honeycomb structures

3. 07-17-02Coeus Engineering3 Overview Space Launch Initiative ProgramSpace Launch Initiative Program Current RCRS DesignCurrent RCRS Design –Solid Amine Technology/Ion Resin Beads Carbon Dioxide/Moisture Removal System (CMRS) Design RequirementsCarbon Dioxide/Moisture Removal System (CMRS) Design Requirements Coeus Engineering’s Design ProcessCoeus Engineering’s Design Process Possible DesignsPossible Designs –Honeycomb structures –Carbon nanotubes –Aerogels Future WorkFuture Work

4. 07-17-02Coeus Engineering4 Space Launch Initiative Program Focuses on the future of exploration and development of spaceFocuses on the future of exploration and development of space Creation of 2 nd Generation Reusable Launch Vehicle (RLV)Creation of 2 nd Generation Reusable Launch Vehicle (RLV) –Reduce risk of crew loss to 1 in 10,000 missions –Lower payload cost to less than $1,000 per pound –Incorporate latest technology for CO 2 removal

5. 07-17-02Coeus Engineering5 Current RCRS Design 11 layered CO 2 adsorbent “beds”11 layered CO 2 adsorbent “beds” Alternating active and inactive bedsAlternating active and inactive beds –Active beds remove CO 2 –Inactive beds exposed to vacuum release CO 2 Dimensions: 3 ft x 1 ft x 1.5 ftDimensions: 3 ft x 1 ft x 1.5 ft –70% beds –30% controls/valving Removes ≈ 0.62 lbs CO 2 /hourRemoves ≈ 0.62 lbs CO 2 /hour –7 member crew –Requires 26 lbs of solid amine chemical –Requires flow rate of 40 cfm

6. 07-17-02Coeus Engineering6 Current RCRS Design Ion resin beadsIon resin beads –Copolymer of polystyrene and divinylbenzene –Sometimes made from Acrylic –≈ 3mm diameter –Extremely porous –Coated surface area: 250-350 m 2 /cm 3

7. 07-17-02Coeus Engineering7 Current RCRS Design Hamilton Standard produces solid amines used in RCRSHamilton Standard produces solid amines used in RCRS Solid amine chemicalsSolid amine chemicals –CO 2 and H 2 O “loosely” bond to solid amines –Reaction produces heat –Common alkanolamine CO 2 adsorbents: –monoethanolamine (MEA) –diethanolamine (DEA) –methyldiethanolamine (MDEA)

8. 07-17-02Coeus Engineering8 Current RCRS Design Active/Inactive beds inter- layeredActive/Inactive beds inter- layered –Active beds pressurized and heated –Inactive beds cold and exposed to vacuum –Large pressure and temperature gradients Aluminum Puffed Duocell FoamAluminum Puffed Duocell Foam –Houses ion-resin beds –Structural rigidity –Heat transfer properties

9. 07-17-02Coeus Engineering9 Current RCRS Design Channeled air flowChanneled air flow –Each bed contains 4 bead-filled foam chambers Retaining screensRetaining screens –Prevent beads from entering main air stream –8 screens per layer –Create large pressure drop

10. 07-17-02Coeus Engineering10 CMRS Design Requirements Maximize solid-amine surface areaMaximize solid-amine surface area Minimize pressure drop through each bedMinimize pressure drop through each bed Maximize structural rigidityMaximize structural rigidity Maximize heat transfer from active to inactive bedsMaximize heat transfer from active to inactive beds

11. 07-17-02Coeus Engineering11 Design Process

12. 07-17-02Coeus Engineering12 Honeycomb Structures

13. 07-17-02Coeus Engineering13 Honeycomb Structures Applied in directional air/fluid flow control and/or energy absorptionApplied in directional air/fluid flow control and/or energy absorption Available in 5052 and 5056 Aluminum alloysAvailable in 5052 and 5056 Aluminum alloys Varied cell sizesVaried cell sizes –1/16” - 3/8” Can be perforatedCan be perforated –Allows air flow –Improves heat removal

14. 07-17-02Coeus Engineering14 Honeycomb Structures Various grades can be exposed to temperatures up to 430 o FVarious grades can be exposed to temperatures up to 430 o F 5 lbs/ft 35 lbs/ft 3.0015 nominal thickness.0015 nominal thickness Provides for about 30.38 in 2 surface area per cubic inchProvides for about 30.38 in 2 surface area per cubic inch

15. 07-17-02Coeus Engineering15 Honeycomb Structures

16. 07-17-02Coeus Engineering16 Carbon Nanotubes Enter the World of

17. 07-17-02Coeus Engineering17 What is it? Discovered by Sumio Iijima in 1991Discovered by Sumio Iijima in 1991 High-resolution transmission electron microscopyHigh-resolution transmission electron microscopy

18. 07-17-02Coeus Engineering18 Types of Carbon Nanotubes Single-walled carbon nanotubeSingle-walled carbon nanotube –Single sheet of carbon atoms –1 < d < 3 nm. Multi-walled carbon nanotubeMulti-walled carbon nanotube –Multiple sheets of carbon atoms –d > 3 nm.

19. 07-17-02Coeus Engineering19 Attributes of Carbon Nanotubes DiameterDiameter –Size of nanometers –1/50,000 th of a human hair LengthLength –Several micrometers –Largest is ~ 2 mm Each nanotube is a single moleculeEach nanotube is a single molecule –Hexagonal network of covalently bonded carbon atoms

20. 07-17-02Coeus Engineering20 Mechanical Properties Extremely strongExtremely strong –10-100 times stronger than steel per unit weight High elastic moduliHigh elastic moduli –About 1 TPa FlexibleFlexible –Can be flattened, twisted, or bent around sharp bends without breaking Great performance under compressionGreat performance under compression High thermal conductivityHigh thermal conductivity

21. 07-17-02Coeus Engineering21 Possible Uses Transistors and diodesTransistors and diodes Field emitters for flat-panel displaysField emitters for flat-panel displays Cellular-phone signal amplifiersCellular-phone signal amplifiers Ion storage for batteriesIon storage for batteries Materials strengthenerMaterials strengthener –Polymer composites –Low-viscosity composite

22. 07-17-02Coeus Engineering22 Potential Use for CMRS Coat nanotubes with solid amineCoat nanotubes with solid amine –Maximize surface area Eliminate mesh retaining screenEliminate mesh retaining screen –Carbon nanotubes fixed to housing structure –No need for beads –Minimize pressure drop Nanotube structure to channel airNanotube structure to channel air –Replace aluminum Duocell foam with aluminum/carbon nanotube composite –Coat carbon nanotubes with solid amine and fit into honeycomb or Versacore structure

23. 07-17-02Coeus Engineering23 What is an Aerogel? Critically evaporated gelCritically evaporated gel Lightest solid knownLightest solid known Almost transparentAlmost transparentsolid Great insulatorGreat insulator

24. 07-17-02Coeus Engineering24 The History of Aerogels Samuel Stephens KistlerSamuel Stephens Kistler A friendly little wagerA friendly little wager First publication: Nature 1931First publication: Nature 1931 Little done until late 1970’sLittle done until late 1970’s

25. 07-17-02Coeus Engineering25 Aerogels as Support Structures Young’s modulus: 10 6 – 10 7 N/m 2Young’s modulus: 10 6 – 10 7 N/m 2 Tensile strength:16 KpaTensile strength:16 Kpa Density: ≥ 0.003 g/m 3Density: ≥ 0.003 g/m 3 Support 1500 timesSupport 1500 times their own weight

26. 07-17-02Coeus Engineering26 Aerogels as Insulation Examples of use:Examples of use: –Modern refrigerators –Mars rover 39 times better than best39 times better than best fiberglass insulation

27. 07-17-02Coeus Engineering27 Aerogels as High Surface Area Materials Up to 99% airUp to 99% air Pore sizePore size –Range from 3 nm to 50 nm –Average about 20 nm Effective surface area:Effective surface area: 300 – 400 m 2 /cm 3

28. 07-17-02Coeus Engineering28 Aerogels and Coeus Engineering RecapRecap –Strong –Lightweight –High surface area –Does not require a screen Can the aerogel be coated?Can the aerogel be coated? Different base materialsDifferent base materials Place inside honeycombPlace inside honeycomb

29. 07-17-02Coeus Engineering29 Carbon Nanotubes / Aerogels Properties Ion Resin Beads Carbon Nanotubes Aerogels Surface Area 250-350 m 2 /cm 3 300-800 m 2 /cm 3 300-400 m 2 /cm 3 Young's Modulus N/A 1 TPa 10 6 -10 7 Pa Tensile Strength N/A 30 GPa (max) 16 kPa Cost???

30. 07-17-02Coeus Engineering30 Future Plans Wrap-up researchWrap-up research –Nanotubes –Aerogels –Carbon nanofoam Prepare cost analysisPrepare cost analysis Compare and contrast research findingsCompare and contrast research findings –Confer with John Graf Decide on a final recommendationDecide on a final recommendation Final presentation and final reportFinal presentation and final report

31. 07-17-02Coeus Engineering31 Special Thanks!! Dr. John GrafDr. John Graf Dr. Ronald O. StearmanDr. Ronald O. Stearman Marcus KrugerMarcus Kruger

32. 07-17-02Coeus Engineering32 Questions? Preguntas?Preguntas? Questionne?Questionne? Bопрос?Bопрос? Kwestie?Kwestie? Ninau?Ninau? Swali?Swali? Spørsmål?Spørsmål? Förhöra?Förhöra?