Browse Topic: Balloons
Implants that steadily release the right dose of a drug directly to the target part of the body have been a major advance in drug delivery. However, they still face some key challenges, such as ensuring that the drug is released at a constant rate from the moment it is implanted and ensuring that the implant is soft and flexible enough to avoid tissue damage but tough enough not to rupture. One particular challenge is to avoid triggering the foreign body response, which is when the patient’s body encloses the implant in a tight capsule of tough connective tissue which can slow the drug’s release or prevent it from diffusing out.
Stratospheric balloons are routinely used for Earth imaging and environmental monitoring in the upper atmosphere. The balloons are often enormous in size — several hundred feet —and when inflated could engulf an entire football stadium. Urban Sky, a Denver-based stratospheric technology and remote sensing startup, has miniaturized the technology for collecting images and data of the Earth by developing small stratospheric balloons.
Researchers have designed materials that can control and mold a balloon into pre-programmed shapes. The system uses kirigami sheets — thin sheets of material with periodic cuts — embedded into an inflatable device. As the balloon expands, the cuts in the kirigami sheet guide the growth, permitting expansion in some places and constricting it in others. The researchers were able to control the expansion not only globally to make large-scale shapes but locally to generate small features. The team also developed an inverse design strategy, an algorithm that finds the optimum design for the kirigami inflatable device that will mimic a target shape upon inflation.
This study investigates the physical phenomena that affect a high-altitude airship in the presence of lifting gas losses from the hull. General atmospheric thermodynamics and basic physical principles are adopted to describe the behavior of an airship with envelope failures that generate buoyant gas dispersion or depressurisation phenomena. Overpressure that could grant to maintain some controllability during a large part of the descent is assessed by mean of the thermodynamic model of the envelope in the presence of gas losses. Optimisation of the inflation parameters is provided and the conditions for avoiding dangerous crashes on the ground and the potential recovery of a damaged vehicle, people and its payload. In particular, the requirements for a slow depressurisation is computed by the equilibrium with the atmosphere and then how can it be possible to sustain controlled navigation are determined. A key factor for security relates directly to the capability of preserving some
Experiments in space can be expensive and infrequent, but Earth’s upper atmosphere is accessible via large scientific balloons, and can be used to address many of the same fundamental questions. Scientific balloons are made of a thin polyethylene film inflated with helium, and can carry atmospheric sampling instruments on a gondola suspended underneath the balloon that eventually is returned to the surface on a parachute. For stratospheric flights between 30 and 40 km above sea level, balloons typically reach the float altitude 2-3 hours after launch, and travel in the direction of the prevailing winds.
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.
NASA relies on the Natural Environments (NE) Branch located at Marshall Space Flight Center (MSFC) to provide databases that represent the wind magnitudes and wind changes expected on day-of-launch (DOL) for vehicle programs that MSFC NE supports. MSFC NE has traditionally utilized weather balloon measurements to generate the wind profiles used in DOL loads and trajectory simulations. However, balloon measurement archives have three limitations in that (1) they do not contain a large enough sample to adequately represent the wind environment at extreme percentiles, (2) balloons could misrepresent the aloft wind environment due to their rise rate and drift characteristics, and (3) the Space Shuttle Program’s operational requirements significantly drove the atmosphere databases’ development. To help mitigate these limitations, MSFC NE used the 50-MHz Doppler Radar Wind Profiler (DRWP) at Kennedy Space Center (KSC) to validate balloon measurements on DOL during the SSP.
The maturity reached in the development of Unmanned Air Vehicles (UAVs) systems is making them more and more attractive for a vast number of civil missions. Clearly, the introduction of UAVs in the civil airspace requiring practical and effective regulation is one of the most critical issues being currently discussed. As several civil air authorities report in their regulations “Sense and Avoid” or “Detect and Avoid” capabilities are critical to the successful integration of UAV into the civil airspace. One possible approach to achieve this capability, specifically for operations beyond the Line-of-Sight, would be to equip air vehicles with a vision-based system using cameras to monitor the surrounding air space and to classify other air vehicles flying in close proximity. This paper presents an image-based application for the supervised classification of air vehicles. First, several vehicle images, taken from different points of view, are transformed using a descriptor of salient
The flight simulation of airships and hot air balloons usually considers the envelope geometry as a fixed shape, whose volume is eventually reduced by ballonets. However, the dynamic pressure or helium leaks in airships, and the release of air to allow descent in hot air balloons can significantly change the shape of the envelope leading to potential dangerous situations. In fact, in case of semi-rigid and non-rigid airships a reduction in envelope internal pressure can reduce the envelope bending stiffness leading to the loss of the typical axial-symmetric shape. For hot air balloons thing goes even worse since the lost of internal pressure can lead to the collapsing of the balloon shape to a sort of vertically stretched geometry (similar to a torch) which is not able to sustain the attached basket and its payload. These effect should be considered in simulations, however to compute in real time the envelope shape with Finite Element Methods is a complex and demanding task due to the
In early 2015, a field campaign was conducted at the NASA Glenn Research Center in Cleveland, Ohio, USA. The purpose of the campaign is to test several prototype algorithms meant to detect the location and severity of in-flight icing (or icing aloft, as opposed to ground icing) within the terminal airspace. Terminal airspace for this project is currently defined as within 25 kilometers horizontal distance of the terminal, which in this instance is Hopkins International Airport in Cleveland. Two new and improved algorithms that utilize ground-based remote sensing instrumentation have been developed and were operated during the field campaign. The first is the ‘NASA Icing Remote Sensing System’, or NIRSS. The second algorithm is the ‘Radar Icing Algorithm’, or RadIA. In addition to these algorithms, which were derived from ground-based remote sensors, in-situ icing measurements of the profiles of supercooled liquid water (SLW) collected with vibrating wire sondes attached to weather
The Earth’s magnetosphere offers a wealth of information on particle dynamics, acceleration, and trapping. Fast neutrons, produced in the Earth’s atmosphere by the impact of galactic cosmic rays (GCRs) and solar energetic particles (SEPs), are an important but poorly measured component of the radiation environment in the inner magnetosphere. Cosmic ray albedo neutron decay (CRAND), whereby atmospheric neutrons beta-decay into protons and electrons, is a significant source of energetic protons in the inner radiation belt. Current models of the inner proton belt rely heavily on Monte Carlo simulations for the CRAND component, validated primarily by a handful of single-point balloon measurements from the 1970s.
Sample return missions have the ability to vastly increase scientific understanding of the origin, history, current status, and resource potential of solar system objects including asteroids, comets, Mars, and the Moon. However, to make further progress in understanding such bodies, detailed analyses of samples are needed from as many bodies as possible. A standoff sample collection system concept has been developed that would quickly obtain a sample from environments as varied as comets, asteroids, and permanently shadowed craters on the Moon, using vehicles ranging from traditional planetary spacecraft to platforms such as hovering rotorcraft or balloons on Mars, Venus, or Titan. The depth of penetration for this harpoon- based hollow collector was experimentally determined to be proportional to the momentum of the penetrator in agreement with earlier work on the penetration of solid projectiles. A release mechanism for the internal, removable sample cartridge was tested, as was an
This paper presents a structural analysis of an engine chassis for a disc-shaped airship demonstrator. The objective was to verify such design solutions for application in the European Union's MAAT (Multibody Advanced Airship for Transport) project. In many airship designs, the engines are attached to the airship frame, located inside the balloon, in order to allow for thrust vector control. These airships have aerodynamic control surfaces to improve maneuverability. For the demonstrator, three engines are considered, with a non-rigid internal structure for their attachment. The engines are located on a horizontal plane (the symmetry plane of the balloon), with two lateral engines and one in front of the balloon. The chassis installation allows the engines to be attached either directly to the exterior envelope by using Kevlar connections, or to the central structural pipe. This chassis design has a simple construction, compared to typical structures addressed in the literature. The
A standoff sample collection system would be capable of quickly obtaining a sample from environments as varied as comets, asteroids, and permanently shadowed craters on the Moon from vehicles ranging from traditional planetary spacecraft to platforms such as hovering rotorcraft or balloons at Mars, Venus, or Titan. The depth of penetration for this harpoon-based hollow collector design was experimentally determined to be proportional to the momentum of the penetrator, in agreement with earlier work on the penetration of solid projectiles. A release mechanism for the internal, removable sample cartridge was tested, as was an automatic closure system for the sample canister and tether recovery approaches.
Typical lighter-than-air vehicles utilizing a superpressure design such as balloons, aerostats, or blimps, have one or more fittings attached to the gas containment skin that can serve as load attachment points or inflation/vent ports. These fittings are often sealed to the skin with a silicone gasket and a room temperature vulcanizing (RTV) adhesive. This type of seal works very well over the temperature range encountered in the Earth’s atmosphere (–60 to +40 °C). However, balloons designed to operate at Titan or Mars would encounter temperatures much colder than those found on Earth, making this type of seal inadequate.
This paper presents a mathematical model of the vertical forces acting on an airship during vertical motion. The main effort is the definition of an airship model, which move only vertically by ballast, and buoyancy effects, with a much reduced energy consumption for take-off and landing operations. It has been considered a disc-shaped airship, which can operate using the open balloon airship architecture defined to operate safely with hydrogen. This architecture does not require internal ballonets, because of the connected increased fire dangers that they create even if vented. Several models of airship based on vertical forces have been presented in literature. They often consider only the US or International Standard Atmosphere models and they neglect effects of weather conditions. The latter are connected with the location and with the season. These environmental and climatic factors have a large influence on behaviors of the airship system, because it is well known that the
Medical device manufacturers are being challenged by strong market demand for tubing that delivers increased functionality, lower profiles, and lower costs—pushing the limits of material behavior and manufacturing science. Next-generation balloon catheters are expected to deliver significantly higher burst pressures and better puncture resistance. They are also being designed to transport target-specific drug-polymer payloads or flexible microelectronic packages to various parts of the human body. These enhanced miniaturization and functionality requirements of medical devices are also creating substantial design and manufacturability challenges. For example, how can an R&D team combine a 35-atm balloon with a robust weld and corresponding shaft tube, within a folded balloon profile that is compatible with a 0.065 inch sheath?
Controlling the forming of large thermoplastic parts from a simulation requires very precise predictions of the pressure and volume profile evolution. Present pressure profile based simulations adequately predict the thickness distribution of a part, but the forming pressure and volume profile development lack the precision required for process control. However new simulations based on the amount of power required to form the material can accurately predict these pressure and volume profiles. In addition online monitoring of the forming power on existing machines can be easily implemented by installing a flow rate and pressure meter at the gas entrance, and if necessary, exits of the part. An important additional benefit is that a machine thus equipped can function as an online rheometer that can characterize the viscosity of the material at the operating point by tuning the simulation to the online measurements. This method can characterize materials at the actual, very high strain
Among Americans over 80, who represent the fastest growing segment of the U.S. population, half are debilitated with a neurodegenerative disorder. Of this group, 5.4 million now have Alzheimer’s Disease, and according to recent data released by the Alzheimer’s Association, by the year 2050 that number is expected to balloon to 16 million. As prevalence numbers steadily climb, the key to combatting the Alzheimer’s epidemic is to focus on diagnosing the disease long before it ravages the brain. And the best place to start is the heart, says Jack C. de la Torre, adjunct professor of psychology at The University of Texas at Austin.
A document describes a next-generation tumbleweed rover that involves a split balloon system that is made up of two half-spherical air bladders with a disc between them. This disc contains all the electronics and instruments. By deflating only the bottom balloon, the rover can sit, bringing the surface probe into contact with the ground. The bottom balloon has a channel passing through it, allowing the surface probe to reach the surface through the balloon. Once the sample has been gathered and analyzed, the rover can re-inflate the lower air bladder and continue rolling.
This paper presents the new Hydrogen Fire-safe Airship system that overcomes the limitations present in previous airships designs of that kind, when considering their functioning at advanced operative position. Hydrogen is considered to be more effective than helium because of its low-cost production by hydrolysis, which process is nicely driven only by the photovoltaic energy. This paper presents a novel architectural concept of the buoyant balloon designed to increase the fire related safety, when applying hydrogen as the buoyant gas. The proposed buoyant volume is designed as a multi-balloon structure with a naturally ventilated shape, to ensure that hydrogen cannot reach the dangerous concentration level in the central airship balloon. This concept is expected to be the start of a novel hydrogen airship type, to be much safer than preceding ones. It permits to reduce the traditional economic costs, when compared with helium inflated airships, due to the helium scarcity in the world
An affordable technology designed to facilitate extensive global atmospheric aerosol measurements has been developed. This lightweight instrument is compatible with newly developed platforms such as tethered balloons, blimps, kites, and even disposable instruments such as dropsondes.
A winch system provides a method for launch and recovery capabilities for kites and tethered blimps or balloons. Low power consumption is a key objective, as well as low weight for portability. This is accomplished by decoupling the tether-line storage and winding/ unwinding functions, and providing tailored and efficient mechanisms for each. The components of this system include rotational power input devices such as electric motors or other apparatus, line winding/unwinding reel(s), line storage reel(s), and independent drive trains.
A lift-gas cracker (LGC) is an apparatus that generates a low-molecular-weight gas (mostly hydrogen with smaller amounts of carbon monoxide and/or carbon dioxide) at low gauge pressure by methanol reforming. LGCs are undergoing development for use as sources of buoyant gases for filling zero-gauge-pressure meteorological and scientific balloons in remote locations where heavy, high-pressure helium cylinders are not readily available. LGCs could also be used aboard large, zero-gauge-pressure, stratospheric research balloons to extend the duration of flight.
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