Jekyll2023-02-07T22:16:52-06:00https://headfullofair.com/Head Full of Airheadfullofair.com collects Mathew Lippincott's DIY aerospace projects and research on kites, balloons, and low power flight. Read about developments in tethered balloons, free flight balloons, and novel strategies for navigating the atmosphere. Favorite topics include: Aerostats, kite-balloons, solar hot air balloons, kite anemometersMathew Lippincottheadfullofair@gmail.comA New Sputnik Moment2023-02-07T00:00:00-06:002023-02-07T00:00:00-06:00https://headfullofair.com/post/new-sputnik<p>When an F-22 fighter jet destroyed a Chinese high altitude balloon last week, many saw the latest high tech aircraft deflating an old-fashioned novelty. The balloon, however, represents the newest aerial navigation technology, and a category of aircraft that will only grow in importance.</p>
<p>The F-22 arrived in the upper stratosphere by brute force, its turbofan running at full tilt, <a href="https://www.youtube.com/watch?v=n068fel-W9I">vectoring thrust to maintain altitude</a> with an all-consuming roar audible over a dozen miles away. The balloon, meanwhile, had silently and elegantly pinpointed an overflight of US missile silos after a transcontinental journey, navigating there on wind currents selected by precise weather measurements and accessed with a little bit of solar power.</p>
<p><img src="/assets/images/aerocene/spy-balloon/loon-312-days.png" alt="Loon's record breaking 312 day flight path" /></p>
<p><em>Loon’s record-breaking flight. Loon, LLC, 2020</em></p>
<p>Both aircraft were built upon technologies and flight concepts of previous centuries. Wind current-based balloon navigation was proposed at the outset of human flight in the late 1700s, and the first jets emerged 80 years ago. However, it has been a long time since jets added genuinely new capabilities. Modern jets emerge from a series of design compromises in a well-defined domain. The <a href="https://en.wikipedia.org/wiki/Lockheed_F-104_Starfighter">F-104</a>, designed in the 1950s, was better equipped to meet a balloon at high altitude than the F-22. The F-22 is more efficient and maneuverable, stealthier, and less likely to kill its pilots; different capabilities chosen through trade-offs.</p>
<p><img src="/assets/images/aerocene/spy-balloon/F_104A.jpg" alt="Sure, the F-104 was designed to kill people and was so dangerous to pilots that Boeing had to pay claims to families who lost loved ones to crashes, but damn is it a cool airplane" /></p>
<p><em>This is what the past looks like: 1958 USAF illustration of the F-104 Starfighter, one-time airplane altitude and time-to-climb record holder</em></p>
<p>The future of flight is not brute-forcing our way through the atmosphere in fuel-intensive sprints; it is data-driven, efficient, and persistent. Although precision wind current navigation of balloons may have been first proposed nearly two and a half centuries ago, it has only been demonstrated in the past half decade: first by <a href="https://en.m.wikipedia.org/wiki/Loon_LLC">Loon</a>, and then by a variety of teams at <a href="https://www.thedrive.com/the-war-zone/40638/what-we-know-about-the-high-tech-balloons-lingering-off-the-coasts-of-the-u-s-recently">Raven Aerostar</a> and <a href="https://www.ball.com/aerospace/programs/earth-science-weather/oawl-wind-lidar">Ball Aerospace</a>, <a href="https://www.urbansky.com">Urban Sky</a>, and now the People’s Liberation Army Air Force. Precision wind current navigation by balloon is the latest cutting edge of flight technology, and US teams are leading with demonstrations of far more complex flight logistics than the recent Chinese balloon.</p>
<p><em>Raven Aerostar, selling military surveillance balloons in 2020:</em></p>
<iframe width="560" height="315" src="https://www.youtube-nocookie.com/embed/C0xXKrLCDd8" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen=""></iframe>
<p>Whether floating on a balloon or gliding on wings (see my post <em><a href="/post/sailing-the-sky/">sailing the sky</a></em>), future aircraft will leverage weather data to use the energy of the atmosphere itself for controlled flight. They will be able to stay aloft for weeks, months, or <a href="https://www.headfullofair.com/post/stars/">even years at a time</a>. In the near term, these data-driven flight systems will compete with satellites, offering similar or better capabilities at lower cost and with far fewer environmental impacts. Already, space luminaries such as Anousheh Ansari are investing in solar powered stratospheric platforms like <a href="http://sceye.com">Sceye</a>. These companies will present serious competition for the space launch industry.</p>
<p>Over the longer term, data-driven, solar and wind-powered flight systems will, I hope, define a new era in human flight. These flight systems will lower the cost of air freight and air travel to within reach of everyone, and promise new sources of energy through <a href="https://airbornewindeurope.org/about-airborne-wind-energy/">airborne wind power</a>. Data-driven flight offers a vision of an exciting transportation future that doesn’t demand ever more energy per passenger. An <a href="https://aerocene.org/about_2020/">Aerocene</a> era, as Tomas Saraceno has coined it, where we inhabit the atmosphere rather than merely visiting it.</p>
<p><img src="/assets/images/aerocene/spy-balloon/aerocene-mx-2016.JPG" alt="Aerocene project flight in Mexico, 2016. CC BY" /></p>
<p><em>The Aerocene Project in Mexico, 2016. CC BY Aerocene Project.</em></p>
<p>In the wake of this balloon overflight, there are increasing calls for asserting military dominance over near space, locking down our common sky behind fictitious borders. Yet the balloon, a captivating, diaphanous, and ethereal aircraft, only ever posed a hazard if shot down. Had the balloon popped on its own, a parachute would surely have carried it to a gentle landing.</p>
<p>Resist the violent posturing. This moment calls for diplomatic opening and the creation of shared rights of way, just as the International Geophysical Year laid the groundwork for the launch of Sputnik and the creation of the Outer Space Treaty. Don’t let fear foreclose the future of flight.</p>
<p>This post is a part of my <a href="/tags/aerocene">Aerocene series on the future of flight</a>.</p>
<p><em>Header Image: Evan Fisher CC-BY</em></p>MathewWhen an F-22 fighter jet destroyed a Chinese high altitude balloon last week, many saw the latest high tech aircraft deflating an old-fashioned novelty. The balloon, however, represents the newest aerial navigation technology, and a category of aircraft that will only grow in importance.Solar Thermal Atmospheric Research Station (STARS) Proposals, 1978-19822022-11-27T00:00:00-06:002022-11-27T00:00:00-06:00https://headfullofair.com/post/stars<p>In the early 1960s, Buckminster Fuller did back-of-the-envelope calculations for a giant, solar-heated balloon that he called Cloud Nine. This 1-mile (1.6km) diameter rigid geodesic sphere could, he claimed, house thousands.</p>
<p><img src="/assets/images/aerocene/stars/buckminster-fuller-shoji-sadao-cloud-9.jpg" alt="Project for Floating Cloud Structures (Cloud Nine). R. Buckminster Fuller and Soji Sadao" /></p>
<p><em>Project for Floating Cloud Structures (Cloud Nine). R. Buckminster Fuller and Soji Sadao</em></p>
<p>In the late 1970s, electrical engineer and physicist Ernest C. Okress picked up on the Cloud Nine idea for a concept he called the Solar Thermal Atmospheric Research Station (STARS). Fuller loaned him a 36-inch-wide tensegrity sphere<sup>[2]</sup>, and assistance came from Okress’s Franklin Research Institute colleagues Robert K. Soberman and C.C. Von Statten. They performed concept-level studies demonstrating the feasibility of a mile-wide, rigid platform floating in the stratosphere, as well as outlining possible construction methods. In May of 1982, Science Digest reported that Okress and Soberman were developing a 650-foot-diameter STARS prototype called the Solar Powered Stratospheric Platform (SPSP), but this is the last press report I can find on STARS, and no more papers were published.</p>
<p><img src="/assets/images/aerocene/stars/solar-thermal-atmospheric-research-station-2081-oneill-edit.jpg" alt="Franklin Research Institute Concept Art for STARS. From Gerard K. O'Neill's 1981 book 2081" /></p>
<p><em>Franklin Research Institute Concept Art for STARS. From Gerard K. O’Neill’s 1981 book 2081</em></p>
<p>I discovered STARS while flipping through <em>2081</em>, a tome of Gerard K. O’Neill’s predictions of the future, and this post collects the information and concept art I’ve uncovered since then. STARS also inspired the 1983 Poul Anderson novel <em>Orion Shall Rise</em>.</p>
<p><img src="/assets/images/aerocene/stars/orionshallrise.jpg" alt="Peter Elson's Cover for the 1987 edition of Poul Anderson's Orion Shall Rise" /></p>
<p><em>Peter Elson’s Cover for the 1987 edition of Poul Anderson’s Orion Shall Rise</em></p>
<h1 id="the-stars-concept">the STARS concept</h1>
<p>STARS is proposed as a double envelope balloon whose envelopes have an infrared reflective coating on their interior, similar to a double-layered greenhouse. Half of STARS is metallized and reflective to direct more sunlight to the solar energy absorption system. Various solar energy absorption systems are proposed, including photovoltaics, a solar-concentrating heat engine, suspended black carbon dust, and darkened water vapor.</p>
<p>In some scenarios, flipping the balloon upside down at night to minimize radiative heat loss is considered, although Okress and Soberman note that flipping the structure introduces substantial complexity.</p>
<p><img src="/assets/images/aerocene/stars/alt-energy-spsp-geometry.png" alt="Diagram of STARS and its day and night orientation, from Alternative Energy 3 Conference presentation" /></p>
<p><em>Diagram of STARS and its day and night orientation</em></p>
<p>A modular, rigid, tensegrity structure gives the balloon a stiff surface necessary to resist wind gusts, as STARS is large enough to cross atmospheric layers and experience substantial wind shear. Modularity also allows the balloon to be repaired in flight and remain aloft indefinitely.</p>
<p><img src="/assets/images/aerocene/stars/alt-energy-3-tensegrity.png" alt="36-inch tensegrity geodesic loaned to the STARS team by Buckminster Fuller's company, Geometrics, Inc." /></p>
<p><em>36-inch tensegrity geodesic loaned to the STARS team by Buckminster Fuller’s company, Geometrics, Inc.</em></p>
<p>Hexagonal tensegrity modules are interchangeable and collapsable, allowing them to be serviced, replaced, and assembled piecemeal. The envelope film is held in place along the perimeter cables of each module, so that it can be replaced. 1 mil (25.4 µm) thick polyester film is assumed in most configurations, with polyvinyl fluoride (Tedlar) for smaller, higher-temperature prototypes.</p>
<p><img src="/assets/images/aerocene/stars/alt-energy-3-support-structure.png" alt="Proposed STARS modules and connection schema from Alternative Energy 3 Conference presentation" /></p>
<p><em>Proposed STARS modules and connection schema</em></p>
<p>Each module’s rigid members are made from hollow double cones of thin (1 mil, 25.4 µm) steel or aluminum that are pressurized for rigidity.</p>
<p><img src="/assets/images/aerocene/stars/sawe1376-pg39.png" alt="Proposed STARS module detail from SAWE 1376" /></p>
<p><em>Proposed STARS module detail</em></p>
<p>In order to avoid jet-dominated airspace, STARS flies above approximately 20 kilometers (about 65,000 feet) in air that is assumed to be -55 degrees Celsius. The interior of STARS is assumed to be 26.7 degrees, for a super temperature of 81.7 degrees Celsius. Plenty of excess energy is available to maintain this temperature from day to night.</p>
<p><img src="/assets/images/aerocene/stars/sawe1376-pg35.png" alt="Calculated excess energy from SAWE 1376" /></p>
<p><em>Calculated excess energy</em></p>
<p>STARS’ rigid structure precludes changing size, and so STARS is a zero pressure design; interior pressure is the same as exterior pressure. Pumped air ballast is used to adjust to small changes in temperature. However, maintaining a constant interior temperature from day to night requires removing excess energy from the balloon during the day and adding energy at night to make up for losses.</p>
<p>The most extensively explored system for balancing day to night energy needs is an onboard solar thermal power plant generating hydrogen. hydrogen is used for powered thrusters and to maintain interior temperature. Interestingly, hydrogen is not proposed as a lifting gas.</p>
<p><img src="/assets/images/aerocene/stars/alt-energy-3-diagram.png" alt="Diagram of solar-thermal power plant inside STARS from Alternative Energy 3 presentation" /></p>
<p><em>Diagram of solar-thermal power plant inside STARS</em></p>
<p>As an electrical engineer, Okress is interested in STARS functioning similarly to a space-based solar power station, transmitting excess energy to the ground using a microwave array. He also proposes replacing power storage by sending power to STARS at night to maintain altitude, either from the ground or from a space-based solar power station. This power station design for STARS receives the most effort in illustration.</p>
<p><img src="/assets/images/aerocene/stars/sawe1376-pg41.png" alt="Illustration of solar-thermal power plant inside STARS from SAWE 1376" /></p>
<p><em>Cutaway diagram of STARS as a solar-thermal power station. The dish in the middle is a parabolic reflector made from thin film, directing sunlight upwards towards another sphere representing the concentrator/heat engine. below the dish is a spherical balloon for pumped air ballast. structures around the balloon’s hemisphere represent thrusters to maintain position. The open bottom shows an airship shuttle leaving.</em></p>
<p>Although many components of this power station are speculative, STARS certainly has the excess lift to carry such a system.</p>
<p><img src="/assets/images/aerocene/stars/ieee-lift.png" alt="STARS free lift calculated for various sizes and component designs, from IEEE 0018-935 1200-0041-00.75" /></p>
<p><img src="/assets/images/aerocene/stars/sawe1376-pg40.png" alt="Excess lift from SAWE 1376" /></p>
<p>Three assembly methods are proposed: on the ground, over water, or in the upper atmosphere. Ground assembly requires a deep valley protected from the wind, and is based on elevating a mast structure in the center.</p>
<p><img src="/assets/images/aerocene/stars/sawe1376-pg43.png" alt="Ground assembly concept for STARS" /></p>
<p>Assembly on the water would result in a submerged STARS that would then be floated and inflated, requiring an extremely deep bay or lake.</p>
<p><img src="/assets/images/aerocene/stars/sawe1376-pg44.png" alt="Ground assembly concept for STARS" /></p>
<p>Okress proposes that STARS is best assembled in the upper atmosphere, although he does not explain how all those tons of material will stay aloft before fully enclosing a large volume of air. Okress’s reasoning for atmospheric assembly is that a super temperature necessary for take off will subject the balloon’s envelope to absolute temperatures that are too high. The polyester film specified for the balloon cannot handle such heat, and the alternatives suggested (PTFE, Tedlar) are problematic for cost and environmental reasons. However, polypropylene film is commercially available as greenhouse plastic and is structurally sound past the 108 degrees Celsius Okress imagines necessary <sup>[2]</sup>.</p>
<h1 id="my-thoughts">my thoughts</h1>
<p>Aircraft prototypes often fail catastrophically, and rigid lighter-than-air craft tend to have very large prototypes. Development is risky and high stakes. The smallest viable STARS prototype is an 80-ton, 200-meter-diameter structure made out of pressurized metal spikes<sup>[3]</sup>. If airborne megastructures ever come into existence, they will have to start from smaller, lower-stakes prototypes.</p>
<p>Smaller prototypes require an envelope with an order of magnitude lower mass per unit area than the 2 ounces per square foot of STARS <sup>[3]</sup>. An order of magnitude improvement seems feasible with contemporary composites. I’ve made rigid kites from Dyneema fabric and carbon fiber that come out around 0.05oz per square foot.</p>
<p>Several other technologies required for STARS are far more mature than they were in the early 1980s. Photovoltaics can replace the bulky solar thermal system. Shifting a balloon’s altitude to navigate precisely over long distances has recently been demonstrated by Loon, StratOAWL, and others, and could replace most of the thruster-based maneuvering STARS proposes.</p>
<p>The fossil fuel intensity and unknown environmental impacts of large-scale rocket launches make a STARS-like platform a desirable replacement for satellite systems. New technology makes STARS more possible, and floating in the upper atmosphere rather than circling the earth should reduce costs per kilogram by at least three orders of magnitude<sup>[6]</sup>.</p>
<p>However, there remain no high-altitude airships to reach, resupply, and maintain a giant upper-atmospheric structure. The last attempt at constructing such a craft, Lockheed-Martin’s HALE-D, was canceled. Like STARS, each of those airship prototypes will be big, high stakes, and risky.</p>
<p>Rockets and jets are mature, incumbent technologies supported by a large number of professionals, educational programs, established infrastructure, supply networks, and a huge installed base of equipment, creating path dependency. Until the aerospace industry is forced to reckon with the intense environmental impacts of burning massive amounts of fuel in the upper atmosphere, new lighter-than-air craft will remain on the industry’s fringes.</p>
<h1 id="situating-stars-within-solar-ballooning">situating STARS within solar ballooning</h1>
<p>Research into STARS began after the first solar hot air balloon flights of Tracey Barnes (1973) and Dominic Michaelis, who flew over the English Channel in 1984. STARS also ran concurrently with beginning of the CNES Montgolfière Infrarouge project that flew balloons heated by the infrared flux of earth. These balloons were half-silvered and made from mylar, like the STARS concept.</p>
<p>Since at least 2010, Aerocene artist and solar aeronaut Tomás Saraceno has been using half-reflective spherical balloons as representations of floating habitat concepts.</p>
<h1 id="misguided-concept-art">misguided concept art</h1>
<p>Someone at <em>Science Digest</em> commissioned this realistic illustration of a STARS diagram. It’s kind of ridiculous:</p>
<p><img src="/assets/images/aerocene/stars/ian-worpole-science-digest-1982-solar-powered-stratospheric-platform-a.jpg" alt="Ian Worpole's realistic illustration of a diagram" /></p>
<h1 id="bibliography">bibliography</h1>
<h3 id="art">art:</h3>
<p>I’m pretty sure there is more concept art out there. Unfortunately, the Franklin Research Institute was dissolved in the mid-1980s, and the Franklin Institute does not have records from the Franklin Research Institute. What records remain are at the University of Delaware and Swarthmore College. Librarians at both institutions were unable to identify further info on this project.</p>
<p>Fuller, R. Buckminster and Shoji Sadao. 1960. <em>Project for Floating Cloud Structures (Cloud Nine)</em>. Stanford: Stanford University Libraries Department of Special Collections, Estate of R. Buckminster Fuller.</p>
<p>Elson, Peter. 1987 edition. <em>Orion Shall Rise</em>. Cover for book of the same name by Poul Anderson, originally published 1983. New York: Simon & Schuster.</p>
<p>Worpole. Ian. 1982. <em>Dirigible at the Edge of Space</em>. Science Digest, Volume 90, May 23, 1982. Des Moines: Hearst Corporation.</p>
<p>O’Neill, Gerard K. 1981. <em>2081: A Hopeful View of the Human Future</em>. New York: Simon & Schuster.</p>
<h3 id="papers-referenced">papers referenced:</h3>
<p>The core information about STARS is contained in the 1980 presentation to the Society of Allied Weight Engineers.</p>
<p>[1] Okress, Ernest C. 1978. <em>The Franklin Institute has High Hopes for Its Big Balloon</em>. IEEE Spectrum 0018-935/1200-0041$00.75, December, 1978. New York: Institute of Electrical & Electronics Engineers.</p>
<p>[2] Okress, Ernest C. and Robert K. Soberman. 1980. <em>Solar Thermal Research Station (STARS)</em>. Presentation at the 39th Annual Conference of the Society of Allied Weight Engineers. SAWE Paper No. 1376. Los Angeles: Society of Allied Weight Engineers, Inc.</p>
<p>[3] Okress, Ernest C. and Robert K. Soberman. 1980. <em>Solar Powered Stratospheric Platform (SPSP).</em> Proceedings of the Third Miami International Conference on Alternative Energy Sources, December 15-17, 1980. Volume 3, Solar Energy 3. ed. Veziroğlu, Nejat T. Washington (DC): Hemisphere Publishing Corporation.</p>
<p>[4] Okress, Ernest C. and Robert K. Soberman. 1981. <em>A Stratospheric Platform - Substantial Advances of the STARS Project</em>. Presentation at the 40th Annual Conference of the Society of Allied Weight Engineers. SAWE Paper No. 1436. Los Angeles: Society of Allied Weight Engineers, Inc.</p>
<p>[5] Okress, Ernest C. and Robert K. Soberman. 1981. <em>Solar Powered Stratospheric Platform</em> Space Manufacturing IV : Proceedings of the fifth Princeton/American Institute of Aeronautics and Astronautics Conference, May 18-21, 1981. Washington (DC): American Institute of Aeronautics & Astronautics.</p>
<p>[6] Yajima, Nobuyuki, Naoki Izutsu, Takeshi Imamura, and Toyoo Abe. 2004. <em>Scientific Ballooning: Technology and Applications of Exploration Balloons Floating in the Stratosphere and the Atmospheres of Other Planets</em>. New York: Springer.</p>
<h3 id="further-references-not-found">further references not found:</h3>
<p>Okress, Ernest C. and Robert K. Soberman. 1980. Paper IAF 79-F-35, Proceedings of the XXXth International Astronautic Federation Congress, September 21, 1979. Munich: Pergamon Press.</p>
<p>Okress, Ernest C., Robert K. Soberman, and Von Stretten. 1980. The Construction Specifier, Vol. 3 No. 1. January, 1980. Alexandria (VA): Construction Specifications Institute.</p>MathewIn the early 1960s, Buckminster Fuller did back-of-the-envelope calculations for a giant, solar-heated balloon that he called Cloud Nine. This 1-mile (1.6km) diameter rigid geodesic sphere could, he claimed, house thousands.Milwaukee Harbor, Komatsu North America2022-10-21T00:00:00-05:002022-10-21T00:00:00-05:00https://headfullofair.com/post/Milwaukee%20Harbor%20Komatsu<p>My current <a href="/tags/rigs">kite aerial photography rigs</a> and a <a href="/tags/flat-winder">flat winder</a> of string, fits in a small shoulder bag and weighs a little over 2 pounds. My rig’s portability let me do a quick flight at the new Komatsu headquarters, across from the school of Freshwater Sciences on Milwaukee Harbor.</p>
<p><img src="/assets/images/aerials/komatsu/DJI_0752.jpg" alt="Komatsu headquarters" /></p>
<p><img src="/assets/images/aerials/komatsu/DJI_0737.jpg" alt="Komatsu headquarters" /></p>
<h1 id="inside-my-bag">Inside my bag:</h1>
<ul>
<li><a href="/tags/flat-winder">flat winder</a> with 500 feet of 110-pound test dacron line</li>
<li>kevlar-lined goatskin gloves</li>
<li>Into the Wind Levitation Light kite</li>
<li>Phone holder for jogging (worn on wrist for camera control)</li>
<li>DJI Pocket 2 with qifi adapter</li>
<li><a href="http://kaptery.com/">KAPtery</a> 3D Printed <a href="https://www.thingiverse.com/thing:281677">Picavet</a></li>
<li>Picavet rod replaced with a <a href="https://www.mcmaster.com/98831A570/">1/4-20 nylon threaded rod</a>, wingnuts, and washers.</li>
</ul>MathewMy current kite aerial photography rigs and a flat winder of string, fits in a small shoulder bag and weighs a little over 2 pounds. My rig’s portability let me do a quick flight at the new Komatsu headquarters, across from the school of Freshwater Sciences on Milwaukee Harbor.Kite photos from the Frank Mots International Kite Festival, Milwaukee2022-10-20T00:00:00-05:002022-10-20T00:00:00-05:00https://headfullofair.com/post/frank-mots-intl-kite-fest-mke<p>At the 2022 <a href="https://city.milwaukee.gov/County-Events/Frank-Mots-International-Kite-Festival-at-Veterans-Park">Frank Mots International Kite Festival</a> in Milwaukee, We flew kites and <a href="/post/tulle-kite-banners/">kite banners</a>, and also captured aerial photos (this post) and <a href="/post/frank-mots-intl-kite-fest-gallery/">ground shots</a>. I flew my DJI Pocket 2, mounted to a <a href="https://www.thingiverse.com/thing:281677">3D printed picavet rig</a> from the <a href="http://kaptery.com/">KAPtery</a>, and lifted by my (now discontinued) Into the Wind <a href="https://intothewind.com/Item--i-3610">Levitation</a> Light. Colleen Donaldson controlled the camera from an iPhone on the ground while I maneuvered the kite.</p>
<p>We were out at the point in veterans park, which became the major public flying field during the festival.</p>
<p><img src="/assets/images/aerials/fmikfmke/vetsparkosm.png" alt="our location in veterans park, from Open Street Map" /></p>
<p>We spotted a wide variety of excellent commercial and homemade kites. We also flew two text banners, and this was the first time they’ve been captured from kites.
The silver kite seen on the ground is by <a href="https://www.haiwenlin.com/about">Hai-Wen Lin</a>. This kite’s hand-dyed tails look great in these photos.</p>
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</figure>MathewAt the 2022 Frank Mots International Kite Festival in Milwaukee, We flew kites and kite banners, and also captured aerial photos (this post) and ground shots. I flew my DJI Pocket 2, mounted to a 3D printed picavet rig from the KAPtery, and lifted by my (now discontinued) Into the Wind Levitation Light. Colleen Donaldson controlled the camera from an iPhone on the ground while I maneuvered the kite.Ground photos from the Frank Mots International Kite Festival, Milwaukee2022-10-20T00:00:00-05:002022-10-20T00:00:00-05:00https://headfullofair.com/post/frank-mots-intl-kite-fest-gallery<p>At the 2022 <a href="https://city.milwaukee.gov/County-Events/Frank-Mots-International-Kite-Festival-at-Veterans-Park">Frank Mots International Kite Festival</a> in Milwaukee, we flew kites and <a href="/post/tulle-kite-banners/">kite banners</a>, and Colleen Donaldson and I (mostly Colleen) took photos of the kites from the ground (this post) and also from the <a href="/post/frank-mots-intl-kite-fest-mke/">air</a>.</p>
<p>We were out at the point in veterans park, which became the major public flying field during the festival.</p>
<p><img src="/assets/images/aerials/fmikfmke/vetsparkosm.png" alt="our location in veterans park, from Open Street Map" /></p>
<p>We spotted a wide variety of excellent commercial and homemade kites. The silver kite deconstructing itself while remaining flying is by <a href="https://www.haiwenlin.com/about">Hai-Wen Lin</a>, and was a favorite.</p>
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</figure>MathewAt the 2022 Frank Mots International Kite Festival in Milwaukee, we flew kites and kite banners, and Colleen Donaldson and I (mostly Colleen) took photos of the kites from the ground (this post) and also from the air.sailing the sky: endless gliding takes shape2022-06-19T00:00:00-05:002022-06-19T00:00:00-05:00https://headfullofair.com/post/sailing-the-sky<p>While sailing the sky is often used as a flight metaphor, sailing physics may be directly applicable to continuous flight. Can two wings, one functioning as a “keel” and the other as “sail,” generate continuous lift? The question is being actively researched, and I’ve collected the core technologies in this post.</p>
<h1 id="boats-get-new-wings">boats get new wings</h1>
<p>Ocean sailing has experienced a recent infusion of soaring technology, as parawings developed for soaring have been adapted to kiteboats and kite foiling. Experimental sailcraft and aircraft suggest that soaring may benefit from ocean sailing strategies.</p>
<p>A sailing vessel generates its motion through the difference in speed between two fluids — air and water.</p>
<p><img src="/assets/images/aerocene/sailing/Voilier-width-800.jpg" alt="sailboat illustrated by the Syroco project" />
<em>Image: <a href="https://syro.co/en/news/laile-deau-and-the-weightless-yacht-concept/">Syroco</a></em></p>
<p>A traditional sailboat uses its mass to stabilize itself, but more recent techniques, such as kite foiling, reduce the sailing system to two wings, one in the air and the other in water.</p>
<p><img src="/assets/images/aerocene/sailing/Kitefoil.jpg" alt="kitefoil" />
<em>Image: <a href="https://commons.wikimedia.org/wiki/File:Kitefoil.jpg">Wikimedia Commons</a></em></p>
<p>Parawing designer Luc Armant’s <em>l’aile d’eau</em> (water-wing) concept (<a href="http://www.augredelair.fr/wp-content/uploads/2015/01/luc_armant_ailedeau.pdf">PDF link in French</a>) aligns the forces of the wings in the water (hydrofoil) and air (aerofoil) to garner even greater efficiency. <sup>[1]</sup></p>
<p><img src="/assets/images/aerocene/sailing/Speedcraft-width-800.jpg" alt="l'aile d'eau concept illustrated by the Syroco project" />
<em>Image: <a href="https://syro.co/en/news/laile-deau-and-the-weightless-yacht-concept/">Syroco</a></em></p>
<p>Armant’s ambitions are now reaching full-size through the <a href="https://syro.co/en/">Syroco</a> project, which aims to break 150kph in a sailing vessel by implementing the <em>l’aile d’eau</em> concept. Armant is an advisor to Syroco.</p>
<iframe width="560" height="315" src="https://www.youtube-nocookie.com/embed/Blb2S6Ytngg" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe>
<h1 id="sailing-between-winds">sailing between winds</h1>
<p><img src="/assets/images/aerocene/sailing/engblom_sail_board.jpg" alt="Engblom's DAP vehicle concept from NIAC" />
<em>Engblom’s Dual Aircraft Platform concept from <a href="https://www.nasa.gov/feature/virtual-flight-demonstration-of-stratospheric-dual-aircraft-platform/">NIAC</a></em></p>
<p>What if, instead of the airfoil and hydrofoil of the <em>l’aile d’eau</em> concept, two airfoils were used? The idea of sailing the sky with two airfoils connected by a cable long enough to bridge two different wind currents precedes the <em>l’aile d’eau</em> in concept, if not in execution. Richard Miller, editor of <em>Soaring</em> Magazine in the 1960s and a popularizer of hangliding, spread the concept and claimed to have experimented with it.<sup>[2]</sup></p>
<p>Regardless of the idea’s provenance, the dual airfoil concept has become the subject of serious inquiry by William Engblom and his team at Embry-Riddle through a series of NASA Innovative Advanced Concepts (NAIC) grants.<sup>[3]</sup> Engblom’s Dual Aircraft Platform (DAP) is intended as an
“<a href="https://en.wikipedia.org/wiki/Atmospheric_satellite">atmospheric satellite</a>,” a long-duration flying craft that can replace the functions of an orbital satellite.</p>
<iframe width="560" height="315" src="https://www.youtube-nocookie.com/embed/fidiDPaLWWw" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe>
<p>DAP can derive positive lift from any two winds with 10% or greater shear, a condition that should be common enough to enable DAP to circle an area indefinitely (station-keeping).<sup>[4]</sup> The DAP system, however, does not rely entirely on soaring — it uses wind shear, when available, to spin its propellers and charge on-board batteries. When wind shear is not available, the propellers are used to sustain flight.</p>
<p><img src="/assets/images/aerocene/sailing/niac_engblom_phii.png" alt="Engblom's DAP vehicle concept from NIAC, detail" />
<em>detail of DAP concept from <a href="https://www.nasa.gov/feature/virtual-flight-demonstration-of-stratospheric-dual-aircraft-platform/">NIAC</a></em></p>
<p>The DAP system hinges on its ability to calculate a flight path based on sensor data about air currents. I can’t find any reference to a specific sensor system in the DAP literature, but the use case appears similar to the <a href="https://www.ball.com/aerospace/programs/earth-science-weather/oawl-wind-lidar">Ball Aerospace Optical Autocovariance Wind Lidar (OAWL)</a>. OAWL uses green (532nm) and/or UV (355nm) lasers to track the movement of water vapor and particles to infer wind speed. These sensors <a href="https://www.technologyreview.com/2018/11/14/139092/darpa-is-testing-stratospheric-balloons-that-ride-the-wind-so-they-never-have-to-come-down/">appear to be deployed</a> for navigation on a series of <a href="https://www.thedrive.com/the-war-zone/40638/what-we-know-about-the-high-tech-balloons-lingering-off-the-coasts-of-the-u-s-recently">experimental US military balloon flights</a>.</p>
<p>DAP captures wind energy using kiting on a tether, giving it more in common with tethered <a href="https://airbornewindeurope.org/about-airborne-wind-energy/">airborne wind energy</a> concepts than other aircraft. Indeed, Engblom states that the traditional glider shape of DAP was chosen to jumpstart prototyping, and a different platform was initially intended for study.<sup>[5]</sup> Given the vast array of airborne wind energy concepts, the ideal DAP-style craft appears as-yet unknown.</p>
<p><img src="/assets/images/aerocene/sailing/DOE-AWE.jpg" alt="Figure 2. DOE. 2021. Challenges and Opportunities for Airborne Wind Energy in the United States. Report to Congress. Washington (DC): US Department of Energy." />
<em>different airborne wind energy concepts (DOE 2021)<sup>[6]</sup> <a href="https://airbornewindeurope.org/wp-content/uploads/2021/12/report-to-congress-challenges-opportunities-airborne-wind-energy-united-states.pdf">PDF link</a></em></p>
<h1 id="future-developments">future developments</h1>
<p>As I hinted in the header image of this post, I am most interested in whether this flight strategy can be applied to personal aircraft, especially foot-launched aircraft (hangliders and paragliders).</p>
<p><img src="/assets/images/aerocene/sailing/sail-glider.jpg" alt="Concept for paraglider sailing" /></p>
<p>Could a robotic kite on a tether be deployed while paragliding for long-distance sailing/soaring? The possibility is tantilizing, and much of the hardware appears near term: robotic kites are established technology (at least at the research level of airborne wind energy), and the sensors and computing hardware necessary to calculate the flight path can’t be far off, given that my phone has lidar and high-powered 532nm and 355nm laser diodes are commercially available at fairly low cost. Still, several crucial questions remain:</p>
<ul>
<li>Does the flight space of ultralight aircraft (below 19,000 feet) include enough shear winds?</li>
<li>What sort of tether markings are required (flags, strobes, etc.), and is their drag acceptable?</li>
<li>Are the simple wings of paragliders and hangliders efficient enough to exploit wind shear?
<ul>
<li>Akimov and Polivanov<sup>[4]</sup> claimed sustained flight was possible with 10% shear but assumed a glide ratio of 40. A paraglider has a glide ratio of about 10 and the best hangliders have glide ratios of about 20.</li>
</ul>
</li>
</ul>
<p>What other issues do you see? <a href="/contact">Get in touch</a>. I’ll add your comments to this post.</p>
<h1 id="notes">notes</h1>
<p>[1] Luc Armant <a href="https://www.flyozone.com/paragliders/team/luc-armant">is responsible for many refinements of modern parafoils</a>. Armant has a <a href="https://youtu.be/1tEw_mlUh7g">charming video</a> compiling his late 1990s <em>l’aile d’eau</em> experments with small, unguided models that he chased across the water in a motorboat (it makes me wish I understood French).</p>
<p>[2] Richard Miller wrote about the dual airfoil concept in his influential 1967 book on glider experimentation, <em><a href="https://www.worldcat.org/title/without-visible-means-of-support/oclc/430247">Without Visible Means of Support</a>.</em> Miller claimed that <a href="https://en.wikipedia.org/wiki/Alois_Wolfm%C3%BCller">Alois Wolfmüller</a> experimented with a free-flying system of two kites in 1909, and that Miller himself replicated such tests (Miller 115). He also implies that Soviet experimenters used a similar system to slingshot a rigid-wing glider to record-breaking altitude in 1937, with a Fyodorov at the controls (Miller 43). I can find no confirmation for any of Miller’s claims.</p>
<p>[3] William Engblom’s team conducted a <a href="https://www.nasa.gov/feature/virtual-flight-demonstration-of-stratospheric-dual-aircraft-platform/">virtual flight simulation</a>, <a href="https://ntrs.nasa.gov/citations/20190001176">tested of a single scaled model on a tether</a> from the ground, and <a href="https://arc.aiaa.org/doi/abs/10.2514/6.2018-3887">designed a sailing path optimization algorithm</a>. Engblom describes the system in-depth in <a href="https://livestream.com/accounts/7167144/events/4425551/videos/103083420">his talk at the 2015 NASA Innovative Advanced Concepts (NIAC) Conference</a>.</p>
<p>[4] <a href="https://iopscience.iop.org/article/10.1088/1742-6596/1404/1/012075/meta">A.M. Akimov and P.A. Polivanov. 2019. <em>Study of the Possibility of Steady Horizontal Flight of the Dual Aircraft Platform with the Wind Shear.</em> Journal of Physics: Conference Series 1404 012075. Bristol: IOP Publishing Ltd.</a></p>
<p>[5] The initial proposal for the DAP platform involved a tandem-wing aircraft that looks like a canard glider with extremely exaggerated canards. It is the subject of a graduate thesis:
<a href="https://commons.erau.edu/edt/104/">McKee, Michael E. 2012. <em>Novel Airframe Design for the Dual-Aircraft Atmospheric Platform Flight Concept.</em> Masters Thesis. Daytona Beach: Embry Riddle Aeronautical University.</a></p>
<p>[6] DOE. 2021. <em>Challenges and Opportunities for Airborne Wind Energy in the United States.</em> Report to Congress. Washington (DC): US Department of Energy. <a href="https://airbornewindeurope.org/wp-content/uploads/2021/12/report-to-congress-challenges-opportunities-airborne-wind-energy-united-states.pdf"><em>PDF link</em></a></p>MathewWhile sailing the sky is often used as a flight metaphor, sailing physics may be directly applicable to continuous flight. Can two wings, one functioning as a “keel” and the other as “sail,” generate continuous lift? The question is being actively researched, and I’ve collected the core technologies in this post. boats get new wings Ocean sailing has experienced a recent infusion of soaring technology, as parawings developed for soaring have been adapted to kiteboats and kite foiling. Experimental sailcraft and aircraft suggest that soaring may benefit from ocean sailing strategies.bigger kite banners2021-05-07T00:00:00-05:002021-05-07T00:00:00-05:00https://headfullofair.com/post/tulle-kite-banners<p>This tutorial details a fairly quick and inexpensive method for creating big banners to fly from a kite.</p>
<p><em>Header photo by Mike Hastie</em></p>
<p>Previously, I attempted paper banners, detailed in an earlier <a href="/post/kite-banners">post</a> and <a href="/post/making-a-paper-banner">tutorial</a>. While functional, the paper banners are fragile and can’t scale. This tutorial is based on the easily-available 54-inch-wide tulle; however, I am planning to try greater widths.</p>
<p><strong>This tutorial assumes kite flying expertise.</strong> Please do not go flying kite banners without first learning to fly big kites, familiarizing yourself with the flying area and weather, and planning for an emergency. If you’re just getting started, see the American Kitefliers Association’s <a href="https://www.kite.org/about-kites/how-to-fly-a-kite/">How to Fly a Kite</a>.</p>
<h2 id="banner-basics">banner basics</h2>
<p>The banner’s structure is simple: a long rectangle with an edge reinforced by twine, held taught by rigid battens (sticks) and the tension of carabiners clipped into the kite line.</p>
<p>In the diagram below, the battens are blue, the twine is red, material edges are black, and reinforcement strips are dotted lines. The tulle is folded over the twine along the edges and additional strips of tulle hold the battens in place.</p>
<p><img src="/assets/images/banner/bannerdiagram2.jpg" alt="sign loop diagram " /></p>
<p>Carabiners clip to the loops of twine and are wrapped into the line.</p>
<p><img src="/assets/images/banner/carabiner.png" alt="carabiner attachment" /></p>
<p>Ideally, a sign will be made all at once on a flat surface and left to dry over night. To accomplish this, the message should be planned ahead of time, scaled to the length of the banner, and the locations of battens (sticks that keep the sign from flapping in the wind) picked out. The size of the banner should also fit within the available space.</p>
<p><img src="/assets/images/banner/2020/20200702_213629.jpg" alt="Image of No Estas Solo sign on floor" /></p>
<p>Although slightly trickier, the sign can also be made in multiple pieces and assembled.</p>
<p>The “paint” is dilute, water-based PVA glue (white glue, i.e. Elmers) mixed with fabric dye which fills in the tulle’s mesh to create a vibrant, translucent film that glows in the sky.</p>
<h2 id="supplies">supplies:</h2>
<h3 id="materials">materials</h3>
<ul>
<li>white polyester tulle
<ul>
<li>54 inches wide and long enough for your message</li>
</ul>
</li>
<li>Rit fabric dye (or similar)
<ul>
<li>to color glue for lettering/painting</li>
<li>I suggest red for sky lettering. It glows and is more visible than black.</li>
</ul>
</li>
<li>gallon of PVA glue
<ul>
<li>white glue, i.e. Elmers</li>
<li>a sign will use about 1/3 of a gallon of glue</li>
</ul>
</li>
<li>polyethylene tarp
<ul>
<li>i.e. painter’s plastic</li>
<li>long enough to lay under your message</li>
</ul>
</li>
<li>masking tape or painter’s tape
<ul>
<li>used to hold tarp in place</li>
</ul>
</li>
<li>two buckets for mixing glue</li>
<li>natural fiber twine, 50 pound test or stronger
<ul>
<li>i.e. hemp, sisal, etc.</li>
<li>synthetic will not work; rough, absorbent natural fibers hold glue</li>
</ul>
</li>
<li>bamboo strips, wood lathe, dowels, or other lightweight stick for battens
<ul>
<li>must be as long as the tulle’s width</li>
</ul>
</li>
<li>2 large aluminum carabiners, 50 pound rating or more</li>
<li>4-6 smaller carabiners</li>
</ul>
<h3 id="tools">tools</h3>
<ul>
<li>6-inch paint roller handle
<ul>
<li>a half-width roller is a good width for letters</li>
<li>a handle extender is helpful</li>
</ul>
</li>
<li>3-inch roller or paint brush
<ul>
<li>for gluing the edges to the twine</li>
</ul>
</li>
<li>roller tray</li>
<li>sharp fabric cutting tool for tulle</li>
<li>weights for holding tulle in place (paint cans, rocks, etc.)</li>
</ul>
<h2 id="planning-the-banner">planning the banner</h2>
<h3 id="pick-a-message">pick a message</h3>
<p>Since the message determines the length of the banner and the material needed, start by picking a short message and drawing the letters to scale. Estimate the width of your standard letter to quickly estimate the length. I’ve used a 2-foot wide, 4-foot high standard letter on 54-inch-wide tulle. After finalizing the message, I’ll then refine my estimated length by making allowances for narrow letters like a lower-case “l” and adding the two triangles to the sides.</p>
<p>I think 35 feet is about the maximum length for a sign that a one-person kite can lift. For instance, my 54-inch-high “Defund Police” banner is 27 feet long.</p>
<p><img src="/assets/images/banner/2020/IMG_20200718_203352.jpg" alt="Defund the police, photo Phil Sano" /></p>
<p>To my eye, a mix of lowercase and capital letters creates the most compact and legible sign at a distance, although these letters are somewhat trickier to paint and plan. Evenly-spaced capital letters are simpler to paint and plan. However, They can be harder to read, especially if narrow. Symbols are hard to read.</p>
<p><img src="/assets/images/banner/2020/DSC_2330.jpg" alt="No Big Oil Bailout banner with people launching, photo Mike Hastie" /></p>
<p><img src="/assets/images/banner/2020/pest-2020-07-25-233126.jpg" alt=" I helped rig this banner but it was painted by Veterans for Peace. Stop the war machine banner, photo Mike Hastie." /></p>
<p>Most people will read this message from a long distance away or in tiny letters of a cellphone photo. No matter how big the message is, the sky is much, much bigger.</p>
<p><img src="/assets/images/banner/2020/DSC_2397.jpg" alt="sign at an extreme distance, photo Mike Hastie" /></p>
<h3 id="plan-the-locations-of-battens-sticks">plan the locations of battens (sticks)</h3>
<p>Two fairly stiff battens should be at the vertical sides of the banner’s two triangles. The battens minimize flapping, since flapping lowers legibility and also stresses the kite line attachment points.</p>
<p>The other battens are optional. I find a few extra battens keep the sign from sagging in the middle. They can be very thin, and their placement doesn’t need to be regular. They are only needed every 6 to 10 feet.
<img src="/assets/images/banner/bannerdiagram2.jpg" alt="sign loop diagram " /></p>
<p>Hide the battens behind the vertical sections of letters or place them clearly in the space between letters. Don’t place them at the edges of letters, as that can disrupt the silhouette.</p>
<p>For instance, in the banner below, there is a batten hiding behind the “f,” “n,” “P,” and “l.”</p>
<p><img src="/assets/images/banner/2020/P2410557.jpg" alt="Defund police, photo Colleen Donaldson" /></p>
<p><img src="/assets/images/banner/2020/jayne-2020-07-25-123110.jpg" alt="Breonna Taylor sign in process, photo and banner Jayne Meacham" /></p>
<p>In the above example of Breonna Taylor sign, Jayne Meacham painted the letters backwards (face down) in order to glue the battens to the back side of the banner, giving it a clean look and also attaching the battens at the same time as the letter painting.</p>
<p>I do not suggest building the banner without any battens; however, kite tails strategically attached to the bottom edge of the banner can pull it fairly taught.</p>
<h2 id="prepairing-the-area-and-supplies">prepairing the area and supplies</h2>
<h3 id="mixing-glue--paint">mixing glue & paint</h3>
<p>PVA glue should be thinned, 1 part glue to 2 parts water, and mixed thoroughly. About a gallon of this thinned glue is needed for a sign– a quart of glue for the edges and the rest for the letters. One packet of fabric dye can color up to a gallon of this thinned mixture into paint for the letters.</p>
<p><img src="/assets/images/banner/2020/jayne-2020-07-24-133501.jpg" alt="image of mixed glue dripping, photo Jayne Meacham" /></p>
<p>The paint mixture’s color will intensify as it dries. The pinkish glue/paint above made the intense color in the Breona Taylor sign above.</p>
<p>I’ve tried some other colorants, including house paint, alcohol ink, and poster paint, but Jayne’s suggestion of fabric dye not only gives the most vibrant color, its the cheapest (by far!) and easiest to find.</p>
<h3 id="surface-prep-and-letter-layout">surface prep and letter layout</h3>
<p>Lay the polyethelyne tarp down, stretch flat, and tape in place. The flatter the surface, the more consistent the film of paint will be when dried and peeled from the tarp.</p>
<p>Get some weights ready to hold the banner and twine in place.</p>
<p>Lay out the tulle and mark the locations of the battens. Mark the locations of the letters and sketch a level of detail you need to paint them. You can mark letters on the tulle with a thick sharpie. The tulle’s mesh doesn’t show marks from even 10 feet away.</p>
<p><img src="/assets/images/banner/2020/jayne-2020-07-23-205607.jpg" alt="show marked letters, photo Jayne Meacham" /></p>
<h3 id="edging-the-banner">edging the banner</h3>
<p>Pull twine taught across the top of the banner and tie loops, starting at one corner and working across to the locations of each batten until the far corner is reached. Do not cut the twine, as you will work it around the outside edge in one big loop.</p>
<p>Stretch the twine taught 3 inches down from the top of the sign and pin in place using weights on the two end loops.</p>
<p><img src="/assets/images/banner/bannerdiagram1.jpg" alt="sign loop diagram" /></p>
<p>Continue stretching twine around the side triangles and bottom of the tulle, 3 inches in. Use weights to hold it in place on the bottom triangles. Lay the twine down before cutting the side triangles, and, using the edge of the twine as a rough guide, cut the tulle off 3 inches out from the twine.</p>
<p>Trim the triangle cut-offs of tulle into roughly 5-inch-wide strips for use holding the battens in place.</p>
<h2 id="gluing-and-painting">gluing and painting</h2>
<p>Multiple people can work on the banner at the same time, and edging the banner with glue and painting letters can happen simultaneously.</p>
<p>Edging does not have to be neat. Just use a brush or small roller to soak the edges with glue, directly on top of the folded-over tulle. The glue will soak through.</p>
<p><img src="/assets/images/banner/2020/20200702_211450.jpg" alt="rough edging" /></p>
<p>Letters should be somewhat neat but they will be seen from at least 50 feet away (probably farther) and no one will notice some rough edges and wrinkles.</p>
<p><img src="/assets/images/banner/2020/20200702_191903.jpg" alt="painting with the roller" /></p>
<p><img src="/assets/images/banner/2020/20200725_165321.jpg" alt="messy" /></p>
<p><img src="/assets/images/banner/2020/NoEstas-Solo.jpg" alt="No Estas Solo, photo La Resistencia" /></p>
<h3 id="applying-the-battens">applying the battens</h3>
<p>The reinforcement battens can be applied after the glue dries, which takes at least 8-16 hours, or, if you painted the letters backwards, the battens can be applied directly after painting the letters.</p>
<p><img src="/assets/images/banner/2020/20200702_211507.jpg" alt="No Estas Solo batten application" /></p>
<p>Lay down the battens and put 4-5-inch-wide tulle strips over top. Soak with glue. If the batten won’t lay flat, use weights to push it down.</p>
<p><img src="/assets/images/banner/2020/20200702_213638.jpg" alt="No Estas Solo batten application" /></p>
<h2 id="go-fly">go fly</h2>
<p>roll the banner up, put it on your bicycle, and go fly with a friend!</p>
<p><img src="/assets/images/banner/2020/20200425_135720.jpg" alt="banner on a bike" /></p>
<h2 id="thanks">thanks</h2>
<p>These instructions were refined with the help of Jayne Meacham, following them from a distance. Banner making required a lot of hands– special thanks to PEST and Colleen Donaldson. Most of the flight photos here are from photographer Mike Hastie, many thanks for his diligent work capturing these banner lifts.</p>MathewThis tutorial details a fairly quick and inexpensive method for creating big banners to fly from a kite.Airpup on Innovation Nation2021-04-30T00:00:00-05:002021-04-30T00:00:00-05:00https://headfullofair.com/post/airpup-on-cbs<p>Airpup was recently featured on CBS’s <a href="https://www.thehenryford.org/explore/innovation-nation/episodes/creative-circuits/">Innovation Nation with Mo Rocca</a>.</p>
<iframe width="560" height="315" src="https://www.youtube-nocookie.com/embed/CDJGiPt_ids" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe>
<p>Thanks to Karly Placek, John Murphy, and the <a href="https://www.litton.tv/">Litton Entertainment</a> team for making a film shoot work in the midst of the pandemic and for flying me to California so we could have better weather. Also thanks to <a href="https://www.imdb.com/name/nm4184546/">Albert Lawrence</a>, who picked out the perfect orange outfit to go with Aipup.</p>
<p><img src="/assets/images/airpup/airpup-innov-nation-2.jpg" alt="John and Albert with Airpup" /></p>MathewAirpup was recently featured on CBS’s Innovation Nation with Mo Rocca.DJI Pocket 2 for Kite Aerial Photography2021-04-29T00:00:00-05:002021-04-29T00:00:00-05:00https://headfullofair.com/post/DJI-pocket-kap<p>I’ve recently taken three flights using the DJI Pocket 2 with WiFi dongle for aerial photography, conducting two short flights on Airpup and another brief flight as a kite aerial photography (KAP) rig.</p>
<p>With the WiFi dongle, the Pocket 2 is a small (~140g), 3-axis gimbal-stabilized camera capable of sending a remote video feed to DJI’s Mimo app and being remotely controled by the app. The original DJI Pocket didn’t offer a video feed, so when I saw they added this feature to the Pocket 2, I picked one up, just in time for <a href="/post/airpup-on-cbs/">Airpup’s debut on CBS</a>.</p>
<h2 id="attachment-for-flight">Attachment for flight</h2>
<p>Attachment to Airpup was simple– I used the Pocket 2’s included hard case to provide a horizontal 1/4-20 mounting point, and a velcro strap and small foam block to keep the camera from twisting.</p>
<p><img src="/assets/images/airpup/pocket2airpup.jpg" alt="DJI Pocket 2 mounted on Airpup" /></p>
<p>For KAP, I coupled the Pocket 2 with a Chris Fastie’s <a href="https://www.thingiverse.com/thing:281677">3D printed Picavet</a> from the <a href="http://kaptery.com/product/picavet-kit">Kaptery</a>, replacing the picavet’s main mounting shaft with three inches of nylon 1/4-20 screw stock.</p>
<p><img src="/assets/images/rigs/pocketpicavet.jpg" alt="DJI Pocket 2 on a picavet kite aerial photography rig" /></p>
<h2 id="features-and-usability">Features and usability</h2>
<p>Remote control and video feed functions work quite well on the Pocket 2. Although the video feed to my Android phone can begin to stutter above about 100 feet, it has been consistenlty usable up to about 250 feet and doesn’t lose connection until about 400+ feet. That said, my (admittedly old) phone battery is drained completely in about a half-hour of useage. On future flights I will use a spare battery.</p>
<p>Stability in flight is an issue with the Pocket 2. Unfortunately, DJI doesn’t offer the ability to lock in a camera heading and only a tilt lock is available. While the Mimo software offers an object/person tracking function, if the camera’s motion is too severe, it can be difficult to lock in object tracking. The tracking is also imperfect and hard to lock on.</p>
<p>The panorama features also didn’t work in flight. The Pocket 2, for some reason, switched direction 180 degrees when asked to perform a panorama. It then complained about the handle moving and failed to generate a complete panorama.</p>
<p>Overall, The Pocket 2 can make a great rig for casual aerial photography. Without a heading lock, however, it isn’t a good option for orthophotography and is only mediocre at aerial video.</p>
<h2 id="flight-photos">Flight photos</h2>
<p>I mostly have fooled around with the device, and don’t have any great footage or photos to share yet– the battery life of my phone being a major limiting factor here.</p>
<p>The old Milwaukee water tower and view south, Milwaukee, WI. Video Still.</p>
<p><img src="/assets/images/aerials/pocket/DJI_0009 194.jpg" alt="The old Milwaukee water tower and view south, Milwaukee, WI. Video Still." /></p>
<p>Prepping a picavet using my bicycle as the frame.
<img src="/assets/images/aerials/pocket/20210425_135300-sm.jpg" alt="prepping a picavet using my bicycle as the frame." /></p>MathewI’ve recently taken three flights using the DJI Pocket 2 with WiFi dongle for aerial photography, conducting two short flights on Airpup and another brief flight as a kite aerial photography (KAP) rig.Airpup production patterns2021-04-07T00:00:00-05:002021-04-07T00:00:00-05:00https://headfullofair.com/post/airpup-production-plans<p>Final plans for the production Airpup design are now <a href="https://github.com/mathewlippincott/airpup-balloon/">available on Github</a>, released as open hardware under the <a href="https://cern-ohl.web.cern.ch/home">CERN Open Hardware Licence</a>.</p>
<p>While assembly instructions are included in the Github repository, I’ve also repeated them here. The header image shows how to seal the envelope as a three-part flat pattern. Sewing instructions are below:</p>
<h2 id="sewing-airpup">Sewing Airpup</h2>
<h3 id="components">Components:</h3>
<ul>
<li>Ripstop Polyester Panels (0.6oz)
<ul>
<li><strong>2x</strong> Wing Panels</li>
<li><strong>2x</strong> Winglets</li>
<li><strong>2x</strong> Keels</li>
</ul>
</li>
<li>1-inch Ripstop Nylon Ribbon components(1.75oz)
<ul>
<li><strong>2x</strong> Winglet Pockets</li>
<li><strong>2x</strong> Keel Pockets</li>
<li>All edge binding</li>
</ul>
</li>
<li>2-inch Ripstop Nylon Ribbon (1.75oz)
<ul>
<li><strong>2x</strong> Wing Pocket (has Gluing Patch sewn in center)</li>
<li><strong>2x</strong> Winglet Reinforcements</li>
<li><strong>4x</strong> Keel Reinforcements</li>
</ul>
</li>
<li>Fiberglass Reinforced PVC
<ul>
<li><strong>6x</strong> Gluing Patches for attachment to the ballon envelope
Grosgrain Ribbon</li>
<li><strong>2x</strong> Bridle Loops</li>
</ul>
</li>
</ul>
<p><img src="/assets/images/airpup/assembly/components.png" alt="components" /></p>
<h3 id="assembly">Assembly</h3>
<p><img src="/assets/images/airpup/assembly/whole.png" alt="the whole sewn component" /></p>
<p>The fin structure of Airpup is assembled as individual panels which are then joined by edge binding along the length of the Keel Pockets.</p>
<p>Most stitches are a 3mmx3mm zigzag stitch, unless specified.</p>
<h4 id="keels">Keels</h4>
<p><img src="/assets/images/airpup/assembly/keel.png" alt="keels" /></p>
<ol>
<li>Tack Keel Reinforcements to both sides of Keel tips.</li>
<li>Edge bind two exposed sides of Keel and Winglet.</li>
<li>Sew Bridle Loops to Keels.</li>
<li>Tack Keel Pockets to Keels, wrapping folded ends of Keel Pockets around to the inside of the Keels.</li>
<li>Sew Keel Pocket Closed with a vertical straight stitch, curving to a horizontal hold stitch. Reverse to double stitch.</li>
<li>Sew bottom of Keel pocket to Keel, leaving 1/8” margin and 1 1/4” gap for Pocket entry.</li>
</ol>
<h4 id="winglets">Winglets</h4>
<p><img src="/assets/images/airpup/assembly/winglet.png" alt="winglet" /></p>
<ol>
<li>Tack Winglet Pockets and Reinforcements to one side of Winglet’s tips.</li>
<li>Edge bind two exposed sides of Keel and Winglet.</li>
<li>Sew sides of Winglet Pockets in place.</li>
<li>Sew Winglet Reinforcements in place.</li>
</ol>
<h4 id="wing">Wing</h4>
<p><img src="/assets/images/airpup/assembly/wing.png" alt="wing" /></p>
<ol>
<li>Tack Wing panels together with seam tape and stitch.</li>
<li>Tape Wing Pocket in place, folded in half over the front edge of Wing. Tape in place with masking tape, then stitch, leaving a 1/2” wide pocket.</li>
<li>edge bind the back edge of the Wing.</li>
</ol>
<h4 id="combining-panels-and-finishing">Combining Panels and Finishing</h4>
<p><img src="/assets/images/airpup/assembly/half-edgebind.png" alt="half-edgebind" /></p>
<ol>
<li>Align Wing, Keel, and Winglet, to the back corner of the ripstop polyester panels. Tack together. Edge bind together.</li>
<li>Align other Keel and Winglet with Wing, aligning to back corner.</li>
<li>Mark locations of Gluing Patches with alignment tool and tape in place with masking tape. Check symmetry of the two sides and adjust Gluing Patches if necessary.</li>
<li>Sew Gluing Patches along 2” marked center, sewing to the edge-bound section and along the bottom of the pocket.</li>
</ol>
<p><img src="/assets/images/airpup/assembly/half-edgebind-patch.png" alt="half-edgebind" /></p>
<h4 id="grouping-assembly-tasks">Grouping Assembly Tasks</h4>
<p>The assembly is easier to perform if edge binding and other tasks are grouped. This is my suggested order.</p>
<ol>
<li>
<p>Tack Winglet Pockets and Winglet Reinforcements to one side of Winglets tips.</p>
</li>
<li>
<p>Tack Keel Reinforcements to both sides of Keel tips.</p>
</li>
<li>
<p>Edge bind two exposed sides of Keel and Winglet.</p>
</li>
<li>
<p>Edge bind back edge of Wing.</p>
</li>
<li>
<p>Sew Keel Reinforcements to Keels.</p>
</li>
<li>
<p>Sew Bridle Loops to Keels.</p>
</li>
<li>
<p>Tack and sew Keel Pocket to Keel.</p>
</li>
<li>
<p>Sew Wing Pocket onto front edge of Wing.</p>
</li>
<li>
<p>Align one edge of Keel, Winglet, and Wing to the back corner of polyester panels.</p>
</li>
<li>
<p>Tack together Keel, Winglet, Wing, and Keel Pocket.</p>
</li>
<li>
<p>Edge bind.</p>
</li>
<li>
<p>Align other side of Keel, Winglet, Wing and Keel Pocket, aligning to back corner.</p>
</li>
<li>
<p>Edge Bind.</p>
</li>
<li>
<p>Use alignment tool to identify Gluing Patch locations.</p>
</li>
<li>
<p>Tape Gluing Patches in place, sew into location.</p>
</li>
</ol>MathewFinal plans for the production Airpup design are now available on Github, released as open hardware under the CERN Open Hardware Licence.