Browse Topic: Balloons
Ludwig Rudolf Rüb, a passionate inventor, lived in poverty most of his life and is virtually unknown in the rotorcraft community. His inventions covered combustion engines and motorcycles first. Around 1900 he built a paddle-wheel plane under contract by Count Zeppelin, next he designed and built a first version of a coaxial rotor helicopter in Munich, and then he moved to Augsburg for building a large fixed-wing aircraft. None of these were ever finished. At the begin of WW I, with support of the German army, he took up a refined version of his coaxial rotor helicopter concept as a highly agile and maneuverable replacement of the observation balloons used in those times, which also was intended to take an active part in warfare by installing a machine gun or dropping bombs. It included some astonishing advanced features and with the help of his sons the construction was finished; ground testing started in June 1918. The end of the war immediately stopped all works; the contract of Versailles demanded the destruction of that vehicle and thus formed the end of the Rüb aeronautical work. Ludwig Rüb died 1918, after months of illness, without having seen the rotors turning.
Flight power and energy requirement models were developed for Titan Aerial Daughtercraft (TAD) mission concepts, in which a small-scale (e.g. ≤ 10 kg) VTOL aircraft would conduct multiple sorties on Titan from a mothership (lander or balloon), recharging batteries from a radioisotope power source (RPS) on the mothership between sorties. The current study considers two design configurations for the TAD, a quadcopter and a tailsitter, and examines potential flight duration and range for lander-based scenarios, as well as allowable payload mass fraction and surface exploration range for balloon-based scenarios. To quantitatively compare the performance of these different configurations, a conceptual design analysis was developed. In a lander-based scenario, assuming a payload mass fraction of 25 percent and a conservative battery model, the estimated flight endurance at Titan's surface for a 10 kg quadcopter and tailsitter was estimated to be 7.6 hours and 11.7 hours respectively. Maximum flight radius from a lander across Titan's surface was found to be 82 km and 108 km, respectively. Modeling of balloon-based scenarios estimated allowable payload mass as a function of the total TAD mass and the float altitude of the balloon. For a balloon floating at 10 km altitude and a 10 kg TAD, the model estimated available payload mass of about 2.8 kg for a quadcopter and 3.5 kg for a tailsitter. The possible exploration range for the same balloon altitude and TAD system mass was computed to be 42 km for a quadcopter and 65 km for a tailsitter. The information estimated in the current mission analysis would yield initial insight for the entire mission architecture design; for example, selection of a landing point or balloon altitude that enables efficient and effective scientific activities over diverse surface features on the biggest moon of Saturn.
ABSTRACT A new method is demonstrated for measuring the noise radiated by a helicopter using a hot air balloon as the measurement platform to support one or more microphones below the hot air balloon basket. Similar to studies with stationary ground microphones, the vehicle is flown past the microphone to gather forward flight external noise data. Because the helicopter and the hot air balloon are both moving in the same air mass when the acoustic measurements are acquired, the new method has many advantages that can be exploited to better investigate helicopter noise sources. One particular advantage is that acoustic data can be taken above the tip-path plane of the rotor without introducing reflections from the ground. Results are presented for a Bell 206B-3 helicopter for several flight conditions demonstrating the advantages and disadvantages of this new acoustic flight testing method.
The goal of the High Energy Replicated Optics to Explore the Sun (HEROES) mission was to adapt an existing balloon payload, known as High Energy Replicated Optics (HERO), for solar observation. HERO used an on-axis star camera for fine aspect sensing, but this camera was too sensitive to be used when pointed near or toward the Sun. The pitch and yaw aspect system (PYAS) replaced the star camera during solar pointing. The PYAS used a computer vision algorithm to generate aspect solutions based on observations of a carefully constructed scene.
Existing scientific research balloons such as those launched from Wallops Flight Facility could be placed in near- Earth space where they would perform as solar sails, providing relatively inexpensive propulsion systems for interplanetary missions. The balloons would accelerate at rates comparable with the ion drive performance of the NASA Dawn spacecraft, so they would enable unprecedented low-cost access to interplanetary space.
Large axial load forces and extreme temperature ranges are typical for scientific balloon missions. Therefore, a durable, flexible, and thermally stable sensor material is needed. In this innovation, sensors have been designed to be integrated onto the load-bearing seams and/or outer balloon mesh polyethylene surface of the pressurized balloon system to measure accurately and continually axial loads under extreme environmental conditions for extended intervals (i.e. more than 100 days).
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