( 12 ) United States Patent Beaux , II et al . ( 45 ) Date of Patent : References Cited ( 54 ) AIR - BUOYANT STRUCTURES AND U.S. PATENT DOCUMENTS ( 71 ) Applicant : Triad National Security , LLC , Los Alamos , NM ( US ) 9/1921 Armstrong 8/1985 Bliamptis 7/2002 Zollinger ( 72 ) Inventors : Miles Frank Beaux , II , Los Alamos , NM ( US ) ; Igor Olegovich Usov , Los Alamos , NM ( US ) ; Brian M. Patterson , Los Alamos , NM ( US ) ( 73 ) Assignee : Triad National Security , LLC , Los Alamos , NM ( US ) 1/2007 Akhmeteli B64B 1/06 ( Continued ) Subject to any disclaimer , the term of this patent is extended or adjusted under 35 OTHER PUBLICATIONS Aerogel.org website available at http://www.aerogel.org/?p=3 ( last accessed May 3 , 2018 ) . ( Continued ) Primary Examiner Valentina Xavier ( 74 ) Attorney , Agent , or Firm LeonardPatel PC ; Michael A. Leonard , II ; Sheetal S. Patel Related U.S. Application Data ( 60 ) Provisional application No. 62 / 515,469 , filed on Jun . ( 58 ) Field of Classification Search See application file for complete search history . Air - buoyant structures , and vehicles incorporating air - buoy ant structures , are provided . Hollow , air - buoyant structures may include a shell of ultra - low density aerogel material , foam material , or vapor - expanded material that is strong and stiff enough to withstand atmospheric pressure and light weight enough to achieve buoyancy in air under evacuation . The shell may be reinforced with a suitable reinforcing material , such as helical nanofibers . The air - buoyant struc tures may also include vacuum pumps and valves operably connected to or integrated with the hollow shell . The vacuum pumps and valves may be configured to pump air out of the hollow shell and allow air back into the hollow shell to control buoyancy . 19 Claims , 13 Drawing Sheets References Cited U.S. PATENT DOCUMENTS 5/2013 Heppe 9/2014 Duong OTHER PUBLICATIONS Expancel Microspheres Brochure available at https : // expancel . akzonobel.com/siteassets/20170606-download-expancel-expancel worlds - favorite - secret - ingredient.pdf ( last accessed May 4 , 2018 ) . Huihui Wu et al . , Studies of Interfacial Interaction between Poly mer Components on Helical Nanofiber Formation via Co Electrospinning , Polymers 10 , 119 ( 2018 ) . New Atlas DARPA Roughing Pump Article available at https : // newatlas.com/darpa-mems-smallest-vacuum-pumps/27883/ ( last accessed May 3 , 2018 ) . Silica Nanosprings Product Sheet available at https : //www.strem . com / uploads / technical_notes / 14-6052tech.pdf ( last accessed May Wikipedia Aerogel Page available at https://en.wikipedia.org/wiki/ Aerogel ( last accessed May 3 , 2018 ) . Wikipedia Roughing Pump Article available at https : //en.wikipedia . org / wiki / Roughing_pump ( last accessed May 3 , 2018 ) . * cited by examiner U.S. Patent Sheet 1 of 13 U.S. Patent Sheet 2 of 13 U.S. Patent Sheet 3 of 13 U.S. Patent Sheet 4 of 13 U.S. Patent Sheet 5 of 13 U.S. Patent Sheet 6 of 13 U.S. Patent Sheet 7 of 13 U.S. Patent Sheet 8 of 13 U.S. Patent Sheet 9 of 13 U.S. Patent Sheet 10 of 13 Resorcinol Formaldehyde - 70mg / cm Pyrolized Carbon - 30mg / cm Stress [ psi ] Strain [ % ] U.S. Patent SO , 90mg / cm Resorcinol Formaldehyde - 70mg / cm Stress [ psi ] Strain [ % ] U.S. Patent Sheet 12 of 13 Pressure ( Tor ] #Swagelok Cap Time [ min ] U.S. Patent Sheet 13 of 13 Communication Processor ( s ) Vehicle Control Other Functional Memory 715 AIR - BUOYANT STRUCTURES AND The plurality of vacuum pumps and valves are configured to pump air out of and allow air into the cavity to control buoyancy of the shell . CROSS - REFERENCE TO RELATED In yet another embodiment , an air - buoyant platform APPLICATION 5 includes a platform and a plurality of air - buoyant structures operably connected to the platform . The air - buoyant struc This application claims the benefit of U.S. Provisional tures , when evacuated , are configured to lift the air - buoyant Patent Application No. 62 / 515,469 filed Jun . 5 , 2017. The platform into the air . subject matter of this earlier filed application is hereby incorporated by reference in its entirety . BRIEF DESCRIPTION OF THE DRAWINGS STATEMENT OF FEDERAL RIGHTS In order that the advantages of certain embodiments of the invention will be readily understood , a more particular The United States government has rights in this invention description of the invention briefly described above will be pursuant to Contract No. DE - AC52-06NA25396 between rendered by reference to specific embodiments that are the United States Department of Energy and Los Alamos illustrated in the appended drawings . While it should be National Security , LLC for the operation of Los Alamos understood that these drawings depict only typical embodi National Laboratory . ments of the invention and are not therefore to be considered to be limiting of its scope , the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings , in which : The present invention generally relates to air - buoyant FIG . 1A is a perspective partially cutaway view illustrat technologies , and more particularly , to air - buoyant struc- ing a torus - shaped air - buoyant structure , according to an tures and vehicles incorporating such air - buoyant structures . 25 embodiment of the present invention . FIG . 1B is a side view illustrating a spherical air - buoyant BACKGROUND structure , according to an embodiment of the present inven Conventional air - buoyant systems , such as balloons , FIG . 1C is a side view illustrating a cylindrical air blimps , and the like , have become more expensive to utilize 30 buoyant structure , according to an embodiment of the pres due to the ever - increasing expense of helium gas , which is ent invention . becoming increasingly scarce . Also , in the case of balloons , FIG . ID is a side view illustrating a pill - shaped air rupture at maximum altitude often occurs , resulting in buoyant structure , according to an embodiment of the pres payloads falling in an uncontrolled manner , and possibly ent invention . into undesirable or dangerous locations ( e.g. , populated 35 FIG . 1E is a perspective view illustrating a connected , areas , remote locations , private property , etc. ) . Furthermore , sealed pipe that is bent along a plane , according to an partially filled balloons eventually lose buoyancy and also embodiment of the present invention . land in uncontrolled locations . Furthermore , the longest FIG . 2A is a top view illustrating a torus - shaped air operational duration that has been achieved for helium buoyant vehicle , according to an embodiment of the present 40 invention . balloons is approximately two years . Potential industrial FIG . 2B is a magnified top view illustrating a scientific ballooning applications also are not practical using conven payload of the torus - shaped air - buoyant vehicle of FIG . 2A , tional technologies since they generally require more per according to an embodiment of the present invention . manent deployment of balloon payloads . Accordingly , an FIG . 2C is a perspective view illustrating the payload , improved approach to air - buoyant systems may be benefi 45 according to an embodiment of the present invention . FIG . 2D is a side view illustrating the payload , according to an embodiment of the present invention . FIG . 3A is a bottom view illustrating a floating platform , according to an embodiment of the present invention . Certain embodiments of the present invention may pro- 50 FIG . 3B is a side view illustrating the floating platform of vide solutions to the problems and needs in the art that have FIG . 3A , according to an embodiment of the present inven not yet been fully identified , appreciated , or solved by tion . conventional air - buoyant technologies . For example , some FIG . 4 is a side view illustrating an air - buoyant vehicle embodiments pertain to air - buoyant structures and vehicles with a suspended payload , according to an embodiment of incorporating such air - buoyant structures . 55 the present invention . In an embodiment , an air - buoyant structure includes a FIG . 5 illustrates a spherical air - buoyant structure before shell that includes an aerogel material , a foam material , a and after evacuation , according to an embodiment of the vapor - expanded material , or any combination thereof . The present invention . air - buoyant structure also includes a cavity defined by the FIG . 6A is a graph illustrating stress versus strain for shell and located within the shell that is under reduced 60 certain aerogel materials at lower pressures , according to an pressure conditions as compared to atmospheric pressure at embodiment of the present invention . a specific altitude . FIG . 6B is a graph illustrating stress versus strain for the In another embodiment , an air - buoyant vehicle includes a aerogel materials of FIG . 6A at higher pressures , according shell . The air - buoyant vehicle also includes a cavity defined to an embodiment of the present invention . by the shell and located within the shell . The air - buoyant 65 FIG . 6C is a graph illustrating pressure versus time for vehicle further includes a plurality of vacuum pumps and aerogel materials of various densities , according to an valves operably connected to or integrated with the shell . embodiment of the present invention . FIG . 7 is a block diagram illustrating a computing system For onboard pumps , some embodiments may employ one configured to control an air - buoyant vehicle , according to an or more roughing pumps to remove air from the structure . A embodiment of the present invention . roughing pump , as its name implies , is a vacuum pump used to evacuate a sufficient amount of air to achieve a rough DETAILED DESCRIPTION OF THE 5 vacuum ( typically above 1x10-3 torr ( 0.1 Pascals ) . These EMBODIMENTS roughing pumps may be miniature roughing pumps in embodiments . Such miniature roughing pumps may be Some embodiments of the present invention pertain to similar to penny - sized roughing pumps developed for air - buoyant structures and vehicles incorporating such air DARPA , for instance . Some embodiments may employ buoyant structures . For instance , hollow structures may be turbo pumps or other vacuum pump technologies to achieve constructed that include a shell of ultra - low density aerogel a higher vacuum ( e.g. , high vacuum , ultra - high vacuum , or material , a foam material , or a vapor - expanded material extremely high vacuum ) . However , the benefits to buoyancy ( e.g. , silica - based , resorcinol formaldehyde - based , or car- of achieving vacuum conditions beyond rough vacuum are bon - based aerogels ) that is strong and stiff enough to with- typically minimal , at best . stand atmospheric pressure and light weight enough to The vacuum , rough vacuum , or reduced pressure envi achieve buoyancy in air under evacuation ( i.e. , a vacuum ronment within the structure eliminates the need for filling balloon ) . In some embodiments , ultralight aerogel materials the structure with lighter gases to achieve buoyancy . This such as those provided by AirloyTM ( e.g. , ultralight ceramics , also has the further benefit of making the structure cheaper , polymers , carbon , or metals and carbides ) may be used . In and if an explosive gas like hydrogen is used , potentially certain embodiments , ultra - low density foam materials may safer . Indeed , no gas is cheaper than nothing at all . Also , be used . However , any suitably strong material , such as light long - term or permanent operation may be realized . The metals or alloys , carbon fiber composites , etc. , may be used many practical applications of various embodiments without deviating from the scope of the invention . For include , but are not limited to , balloon - suspended Wi - Fi hot instance , some embodiments may utilize helical nanofiber 25 spots ( such as those needed for Project LoonTM ) , a helium reinforced composite structures ( e.g. , Silica NanospringsTM free alternative for floating warehouses ( e.g. , those envi by STREM ) . sioned by Amazon ) , air - buoyant delivery vehicles , air - buoy In certain embodiments , vapor - expanded materials , such ant servicing vehicles , cargo transport vehicles , blimps , high as Expancel MicrospheresTM , may be used . These materials altitude algae - based biodiesel production platforms are filled with a liquid that vaporizes when exposed to heat , 30 enhanced by ultraviolet light intensive environment , agri causing microspheres containing the material to expand . cultural surveillance vehicles , scientific and industrial bal Such structures operate via the opposite principle of a loons , a high altitude platform for launching space vehicles gas - filled balloon . More specifically , rather than the balloon and delivering rockets to the platform , potentially reducing containing gas internally and keeping gas from escaping in launch costs , etc. substantial quantities ( at least for a time ) , embodiments of 35 When developing an air - buoyant structure , some embodi the present invention utilize hollow structures with internal ments use hollow geometries that minimize the surface cavities under lower pressure or vacuum conditions that area - to - volume ratio of the structure . However , any desired keep air from the atmosphere from entering the structure in hollow structure that achieves a lower overall density than substantial quantities . Some embodiments also are capable air may be used without deviating from the scope of the of pumping air out of the structures and allowing air back 40 invention . At sea level and a temperature of 15 C. , air has into the structures , controlling buoyancy . It should be noted a density Ppair of approximately 1.225 kg / m ( i.e. , 1225.0 that multiple air - buoyant structures may be tethered together or otherwise incorporated into one application in order to The density of the structure depends on the material and increase overall buoyancy . This may be particularly useful shape that is used . The densities of some high strength for large applications or those requiring significant lifting 45 materials are provided below . capabilities , where manufacturing a monolithic air - buoyant structure to achieve this purpose may be difficult , cost prohibitive , or impossible with current technologies . The structures may be torus - shaped , pill - shaped , spheri cal , cylindrical , a more complex structure ( or structures ) 50 formed from interconnected tubes of the same or variable Density ( g / cm ) width , a lattice support matrix , or any suitable structure or Carbon Fiber ( Unidirectional ) structures that are air - buoyant when at least some air is Epoxy ( Standard Modulus ) pumped out of the inside of the structure ( s ) without devi Carbon Fiber ( Unidirectional ) / ating from the scope of the invention . For instance , some 55 Epoxy ( Intermediate Modulus ) Carbon Fiber ( Unidirectional ) non - limiting examples of geometries that may be used in Epoxy ( Intermediate Modulus ) some embodiments can be found in U.S. Pat . Nos . 1,390,745 Carbon Nanotubes ( CNTs ) and 4,534,525 and U.S. Patent Application Publication No. Aluminum ( 6061 - T6 ) 2007/0001053 . Removal of internal gases ( i.e. , evacuation ) Titanium ( 6M - 4V ) may be achieved with the use of an onboard pump . While 60 some embodiments may be produced with the air already Airloy TM Series X50 pumped out of the structure and sealed , using onboard Airloy TM Series X60 pumps provides more control and utility , and may allow for Airloy TM Series X100 Airloy TM Series X110 more complex structures , or combinations of structures , to Airloy TM Series X400 be built and deployed . Indeed , structures or combinations of 65 Air ( at sea level and 15 C. ) structures may be produced that conform to a payload , a vehicle body , etc. DENSITIES OF EXAMPLE HIGH STRENGTH MATERIALS Material : Aerogels are synthetic , porous , solid materials that have See cylinder structure 120 of FIG . 1C , where R extends extremely low densities . Densities in aerogel materials vary from , and perpendicular to , the concentric center of structure based on the material that is used and the porosity of the 120 to the outside of shell 122 and L extends parallel to the aerogel . Volumetrically , aerogels are typically 95-99 % air , concentric center of structure 120 from the outside of shell with one produced aerogel being 99.98 % air in volume . The 5 122 at one end of cylinder structure 120 to the outside of air is trapped in pores within the aerogel , and the pores may