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At least 73 records · Page 4

A Spreadsheet Simulation Tool for Terrestrial and Planetary Balloon Design

During the early stages of new balloon design and development, it is necessary to conduct many trade studies. These trade studies are required to determine the design space, and aid significantly in determining overall feasibility. Numerous point designs then need to be generated as details of payloads, materials, mission, and manufacturing are determined. To accomplish these numerous designs, transient models are both unnecessary and time intensive. A steady state model that uses appropriate design inputs to generate system-level descriptive parameters can be very flexible and fast. Just such a steady state model has been developed and has been used during both the MABS 2001 Mars balloon study and the Ultra Long Duration Balloon Project. Using Microsoft Excel's built-in iteration routine, a model was built. Separate sheets were used for performance, structural design, materials, and thermal analysis as well as input and output sheets. As can be seen from figure 1, the model takes basic performance requirements, weight estimates, design parameters, and environmental conditions and generates a system level balloon design. Figure 2 shows a sample output of the model. By changing the inputs and a few of the equations in the model, balloons on earth or other planets can be modeled. There are currently several variations of the model for terrestrial and Mars balloons, as well there are versions of the model that perform crude material design based on strength and weight requirements. To perform trade studies, the Visual Basic language built into Excel was used to create an automated matrix of designs. This trade study module allows a three dimensional trade surface to be generated by using a series of values for any two design variables. Once the fixed and variable inputs are defined, the model automatically steps through the input matrix and fills a spreadsheet with the resulting point designs. The proposed paper will describe the model in detail, including current variations. The assumptions, governing equations, and capabilities will be addressed. Detailed examples of the model in practice will also be used.

Raquea, Steven M.

Recent Progress in Materials Selection and Characterizations for Ultra Long Duration Balloon (ULDB) Missions

The development and characterization of materials suitable for ultra long duration balloon flights has recently been the focus of the materials R&D efforts for the NASA balloon program. Although basic materials selection criteria is similar to those used for conventional balloon missions, additional considerations related to balloon design, fabrication, durability, environmental effects, and cost must also be considered. Among these, the highest impact on material selection is, related to the design shape of the balloon. Work done by independent researchers indicate that for pumpkin type balloons, the load-carrying member is the tendon rather than the structural envelope. This in turn lowers the strength requirements on the envelope material to a large extent. Several materials and material combinations were explored for both design systems. This paper will present the progress made to date in the selection and characterization of these materials and the technical challenges remaining to be overcome,

Said, Magdi A.

TMBM: Tethered Micro-Balloons on Mars

The use of balloons/aerobots on Mars has been under consideration for many years. Concepts include deployment during entry into the atmosphere from a carrier spacecraft, deployment from a lander, use of super-pressurized systems for long duration flights, 'hot-air' systems, etc. Principal advantages include the ability to obtain high-resolution data of the surface because balloons provide a low-altitude platform which moves relatively slowly. Work conducted within the last few years has removed many of the technical difficulties encountered in deployment and operation of balloons/aerobots on Mars. The concept proposed here (a tethered balloon released from a lander) uses a relatively simple approach which would enable aspects of Martian balloons to be tested while providing useful and potentially unique science results. Tethered Micro-Balloons on Mars (TMBM) would be carried to Mars on board a future lander as a stand-alone experiment having a total mass of one to two kilograms. It would consist of a helium balloon of up to 50 cubic meters that is inflated after landing and initially tethered to the lander. Its primary instrumentation would be a camera that would be carried to an altitude of up to tens of meters above the surface. Imaging data would be transmitted to the lander for inclusion in the mission data stream. The tether would be released in stages allowing different resolutions and coverage. In addition during this staged release a lander camera system may observe the motion of the balloon at various heights above he lander. Under some scenarios upon completion of the primary phase of TMBM operations, the tether would be cut, allowing TMBM to drift away from the landing site, during which images would be taken along the ground.

Sims, M. H.

Sampling of Trace Atmospheric Constituents Above the Surface of Mars from a Montgolfiere Balloon

We suggest that use of an aerially deployed, solar-heated balloon, or Montgolfiere, during a Martian polar summer could provide an optimal platform for atmospheric measurements near the surface. Solar Montgolfieres are empty balloons with a hole in the bottom that fill with ambient atmosphere while failing and are rapidly heated in by the sun, thus providing buoyancy. Such a balloon would be driven by the Martian winds in the constant sunlight of a high latitude entry and could provide a traverse of thousands of kilometers. It would encircle the Martian north polar region over a period,likely lasting over one earth month, and its altitude could be controlled as low as 100 meters to as high as 4000 meters above the surface. The significant payload of tens of kilograms allowed by this technology could readily accommodate the mass of instrumentation and the power source needed for a sensitive search for disequilibrium species that might provide the atmospheric signature of localized subsurface biological or geological activity. A mass spectrometer used in combination with gas enrichment techniques can provide sensitivities to sub parts per billion for several species of interest. Additional highly specific and sensitive detectors can search for other species or measurements of their mixing ratio variation along the path of the balloon. It would be useful to combine these atmospheric measurements with electromagnetic sounding to search for variations in subsurface conductivity that might indicate the presence of subsurface water. After a month of operation, the balloon could also soft land the DBMS to provide additional data on soil samples from a 1-2 meter subsurface drill. In order to float a 30-kg payload at altitudes between 100 m and 4000 m above the Martian north polar surface, an aluminized polyethylene Montgolfiere would be approximately 29 meters in diameter and have a mass of 27 kg. Altitude variations could be accomplished by means of an upper vent to release hot gas, as has been tested at JPL, or be means of a simple, internal winch mechanism to decrease the volume of the balloon. JPL has successfully deployed three polyethylene Montgolfieres at 4-6 mbar pressure in the Earth's stratosphere and will be deploying a 20-m diameter polyethylene Montgolfiere later in 2001.

Jones, Jack A.

2023 Updates from the NASA Balloon Program Office

This presentation offers an overview of NASA's Balloon Program Office, which is responsible for the design, development, and execution of scientific balloon missions for a variety of scientific disciplines. The paper discusses the history of the program, its current capabilities, and future plans for expanding the scope of its scientific investigations. The paper also provides details on the various types of balloons used by the program, as well as the unique challenges involved in launching and recovering these balloons from remote locations around the world. In addition, the paper highlights some of the significant scientific achievements made possible by the program, including the study of cosmic rays, the search for dark matter, and the exploration of the Earth's atmosphere. Finally, the paper outlines the potential future directions of the program, including the development of larger, longer-duration balloons and the integration of new technologies such as optical communication and autonomous systems. Overall, this paper provides a comprehensive overview of NASA's Balloon Program Office and its ongoing efforts to advance scientific understanding of our world and the universe beyond.

Sarah A Roth

A study of resistive peeling–ballooning modes across spherical tokamaks

We investigate how non-ideal-magnetohydrodynamics (MHD) effects, in particular plasma resistivity, impact the peeling–ballooning stability thresholds in spherical tokamaks. This analysis follows the discovery of resistive kink-peeling modes in ELMing National Spherical Torus Experiment (NSTX) discharges. In the present study we extend this modeling to ELMing pulses in the Mega Ampere Spherical Tokamak (MAST) and MAST—Upgrade (MAST-U), where we find a clear resistive scaling for peeling–ballooning modes. While in NSTX ideal-MHD predicts stability for ELMing discharges, in MAST-U we find that the plasma is slightly unstable to peeling–ballooning modes, but is fully stabilized once diamagnetic effects are considered in terms of a growth rate normalization. A resistive power law scaling is calculated for these modes on MAST-U, which lies in between that of tearing modes and resistive interchange modes. A comparison between M3D-C1 and NIMROD shows reasonable agreement for this scaling. Resistivity destabilizes the modes and the peeling–ballooning unstable domain is considerably expanded in both, MAST and MAST-U. In addition to the MAST/-U pulses we also analyze resistive PB stability in a NSTX-similarity discharge on DIII-D. While having a different aspect ratio from NSTX, this discharge uses NSTX-like shaping parameters, toroidal field and plasma current. By considering these discharges alongside NSTX cases, we identify conditions influencing the onset of resistive peeling–ballooning modes. Furthermore, our findings indicate that magnetic shear in the pedestal region is closely linked to the emergence of resistive edge modes.

MAST-U

A Comparison of Two Non-Contact Strain Measurement Techniques with Applications to Scientific Balloons

Strain measurements of scientific balloon films are necessary for evaluating the film’s material properties, validating material models, and structural evaluations of scale model balloons. This paper presents a comparison of the strain measurement techniques used by the Balloon Program Office’s Balloon Research and Development Lab at NASA Wallops Flight Facility. Two non-contact strain measurement techniques are presented for comparison, along with an assessment of measurement accuracy for both methods. The case study of a vertically oriented cylindrical balloon is presented to illustrate both systems’ performance and draw nominal conclusions of strain as a function of pressure and axial load.

Non-Contact

A Comparison of Two Non-Contact Strain Measurement Techniques with Applications to Scientific Balloons

Strain measurements of scientific balloon films are necessary for evaluating the film’s material properties, validating material models, and structural evaluations of scale model balloons. This paper presents a comparison of the strain measurement techniques used by the Balloon Program Office’s Balloon Research and Development Lab at NASA Wallops Flight Facility. Two non-contact strain measurement techniques are presented for comparison, along with an assessment of measurement accuracy for both methods. The case study of a vertically oriented cylindrical balloon is presented to illustrate both systems’ performance and draw nominal conclusions of strain as a function of pressure and axial load.

Non-Contact

On the response of superpressure balloons to displacements from equilibrium density level

The response of a superpressure balloon to an initial displacement from its constant-density floating level is examined. An approximate solution is obtained to the governing vertical equation of motion for constant-density superpressure balloons. This solution is used to filter out neutrally buoyant oscillations in balloon records despite the nonlinear behavior of the balloon. The graph depicting the pressure data after deconvolution between the raw pressure data and the normalized balloon wavelet shows clearly the strong filtering-out of the neutral buoyancy oscillations.

Levanon, N.

Antarctic topography from balloons

A description is presented of an investigation involving the collection of Antarctic ice sheet surface topography data by means of balloons, floating at an altitude of about 12.5 km, which traversed the Antarctic during its 1975 summer. These balloons were part of 411 constant density balloons launched in the Southern Hemisphere during the Tropical Wind, Energy conversion and Reference Level Experiment. The three sensors carried by each balloon included a radio altimeter, a pressure sensor, and an ambient temperature sensor. Data transmitted by a balloon are received by a measuring system on board the Nimbus-6 satellite. A synoptic map is presented of the 150 mbar pressure surface at 1200 GMT, December 11, 1975.

Levanon, N.

The response of a constant-volume balloon to periodic three-dimensional flow

A theoretical treatment is presented of the motion of a constant-volume balloon immersed in a three-dimensional spatially nonhomogeneous periodic flow field with a mean translational flow velocity. The governing equations are the equations of conservation of momentum of the balloon, coupled with the equations of conservation of momentum of the fluid. In the mathematical model employed, the flow field is represented by a periodic function. The numerical results are in general agreement with observations. Noteworthy is that the balloon does not move with the same mean velocity as the wind and, thus, when Taylor's hypothesis for the fluid is satisfied, the balloon does not 'lock in' with the wind velocity. When Taylor's hypothesis for the parcel is satisfied, however, the balloon does match the mean wind direction (but not its speed).

Tatom, F. B.

Balloon concepts for scientific investigation of Mars and Jupiter

Opportunities for scientific investigation of the atmospheric planets using buoyant balloons have been explored. Mars and Jupiter were considered in this study because design requirements at those planets bracket nominally the requirements at Venus, and plans are already underway for a joint Russian-French balloon system at Venus. Viking data has provided quantitative information for definition of specific balloon systems at Mars. Free flying balloons appear capable of providing valuable scientific support for more sophisticated Martian surface probes, but tethered and powered aerostats are not attractive. The Jovian environment is so extreme, hot atmosphere balloons may be the only scientific platforms capable of extended operations there. However, the estimated system mass and thermal energy required are very large.

Ash, R. L.

Ozone profiles from tethered balloon measurements in an urban plume experiment

NASA Langley Research Center used two tethered balloon systems to measure ozone in the general area of Norfolk, Va. The large balloon system which has an altitude range of 1,500 meters was located at Wallops Island, Va., and the smaller balloon which has an altitude range of 900 meters was located at Chesapeake, Va. Each balloon system measured ozone, temperature, humidity, wind speed, and wind direction from ground to its maximum altitude. From these measurements and from the location of the balloon sites, areas of ozone generation and ozone transport may be inferred. The measurements which were taken during August 1979 are discussed as well as the measurement techniques.

Youngbluth, O., Jr.

THERMTRAJ: A FORTRAN program to compute the trajectory and gas film temperatures of zero pressure balloons

A FORTRAN computer program called THERMTRAJ is presented which can be used to compute the trajectory of high altitude scientific zero pressure balloons from launch through all subsequent phases of the balloon flight. In addition, balloon gas and film temperatures can be computed at every point of the flight. The program has the ability to account for ballasting, changes in cloud cover, variable atmospheric temperature profiles, and both unconditional valving and scheduled valving of the balloon gas. The program was verified for an extensive range of balloon sizes (from 0.5 to 41.47 million cubic feet). Instructions on program usage, listing of the program source deck, input data and printed and plotted output for a verification case are included.

Horn, W. J.

The Vega balloon experiments

The goals of the Vega-1 and -2 experiments were to trace the large- and small-scale motions, measure the turbulent heat and momentum flow in the cloud layer, and determine the physical parameters of the Venus atmosphere. The arrangement of the balloon-probe payload, the balloon-deployment sequence, and the balloon flight paths are described. The balloons drifted latitudinally in the Venus atmosphere about one-third the way around the planet at a height of 53-54 km and speeds close to 67 m/sec. The balloon-probe signals, recorded on earth by radio telescopes of ten countries, are being processed.

Sagdeev, R. Z.

Implications of the Vega balloon results for Venus atmospheric dynamics

During the Vega Venus balloon mission, data on the thermodynamic state of the atmosphere were obtained as well as wind and cloud information. Explanations are provided for the following: (1) the large amplitude atmospheric vertical winds encountered by the Vega balloons, (2) the observed 6.5 K temperature difference consistently measured between the two Vega balloons, and (3) the apparent influence of surface topography on atmospheric motions seen by the Vega-2 balloon as it flew over mountainous terrain (known as Aphrodite). It is believed that vertical winds of the magnitude encountered by the Vega-2 balloon over Aphrodite may be the result of surface-induced gravity waves.

Young, R.

Mobile, high-wind, balloon-launching apparatus

In order to place instruments for measuring meteorological and electrical parameters into thunderstorms, an inexpensive apparatus has been developed which makes it possible to inflate, transport, and launch balloons in high winds. The launching apparatus is a cylinder of bubble plastic that is made by joining the sides of the cylinder together with a velcro rip strip. A balloon is launched by pulling the rip strip rapidly. This allows the balloon to pop upward into the ambient low-level wind and carry its instrumentation aloft. Different-sized launch tubes are constructed to accommodate particular sizes of balloons. Balloons have been launched in winds of about 20 m/s.

Rust, W. David

Balloon-borne characterization of the Martian surface and lower atmosphere

A recent NASA-sponsored design course at Utah State University (USU) has focused upon a Mars Lander/Rover system designed to descend from a Martian orbit and deploy both surface and balloon-borne instruments to examine the Martian surface and lower atmosphere. The latter stages of the USU design effort placed major emphasis on the design of the balloon rover. This paper presents the results of that emphasis by discussing the payload requirements, identification of the design parameters, surface vs. descent deployment, design tradeoff studies, site-influenced departures from the baseline design, the final design concept, and the resulting balloon performance. A single hydrogen superpressure balloon is selected for use in the design mission. The paper concludes that characterization of the Martian surface and lower atmosphere by a descent-deployed, balloon-borne rover is a viable concept that should be actively pursued.

Redd, F. J.