High-altitude Scientific Balloon Research Articles

Application of NASA core Flight System to Telescope Control Software for 2017 Total Solar Eclipse Observation

The core Flight System (cFS), developed by NASA, is a reusable software framework and a set of pluggable software applications that take advantage of the rich heritage of NASA’s successful space missions. We applied the cFS to the development of telescope control software for the observation of the 2017 total solar eclipse. Four main modules were developed: imaging control, mechanism control, data handling, and automated observation. Other modules, such as communication and scheduler, were reused from the cFS. Using an integrated observation system, we successfully observed the total solar eclipse, in which the linearly polarized brightness of the solar corona and sky background were measured at four different wavelengths. In this study, we demonstrated the usefulness of the cFS to develop telescope control software through an eclipse observation system, the so-called DICE (DIagnostic Coronagraph Experiment) mission. Our experience and knowledge of the cFS were expanded to a flight software BITSE (Balloon-borne Investigation of Temperature and Speed of Electrons in the corona), the high-altitude scientific balloon mission in 2019. We plan to apply this approach to future solar coronagraph observations, such as CODEX (COronal Diagnostic EXperiment), on the International Space Station. We expect that the cFS can also be applied in telescope control software for ground-and space-based observations.

Solar Array Power Prediction for Near-Space Vehicles Based on a Hybrid Method

Compared with other energy sources in near-space, solar energy is more renewable, stable and accessible, which makes solar cells the main source of energy for long-endurance near-space vehicles. However, due to the limited solar cells laying area and complex flight conditions, near-space vehicles are facing tense energy supply situation during flight. Therefore, fast and accurately online power prediction of the solar array, which has important significance for power management, efficient use and reliable operation of the energy system, is the key point to solving the situation at present. In this paper, a hybrid online power prediction method combined particle filter and power calculation model is proposed. Firstly, a comprehensive solar cell array power calculation model for the near-space vehicle is established. Then, the particle filter algorithm is used to estimate optimally the important parameters in the power calculation model with the flight data, to realize the dynamic, rapid and accurate prediction of the power generation of the vehicle during flight. Finally, the data obtained from flight tests of the stratospheric aerostat and high-altitude scientific balloon are verified and compared with the other four models. The results demonstrate that the generation power prediction method proposed in this paper has higher prediction accuracy, which will be a good guiding significance for the actual flight of different types of near-space vehicles.

Aerodynamic Tethered Sails for Scientific Balloon Trajectory Control: Small-Scale Experimental Demonstration

High-altitude scientific balloons are often prohibited from flying due to the risk associated with flying over populated areas. One solution to this problem is the use of a trajectory control system to control the ground track of the balloon. To assess the performance of one such trajectory control system in a real wind field, a small-scale sail was designed and built to fly beneath a moored balloon. Three test phases of rudder deflection were used to demonstrate the effect of the sail guiding force on the balloon, and the sail demonstrated the ability to move the balloon laterally due to a change in rudder deflection. A theoretical model of the system was found to qualitatively agree with the experimental values of sail displacement and mooring tether tension. At a high level, these results demonstrate that a tether-and-sail system shows promise as a trajectory control system for scientific balloons.

Survival of desert algae Chlorella exposed to Mars-like near space environment

Desert was considered terrestrial analogues of Mars. In this study, dried cells of desert green algae Chlorella were exposed to Mars-like near-space environment using high-altitude scientific balloons. We found that while a majority of Chlorella cells survived, they exhibited considerable damage, such as low photosynthetic activity, reduced cell growth, increased cell mortality rate, and altered chloroplast and mitochondrial ultrastructure. Additionally, transcriptome analysis of near space-exposed Chlorella cells revealed 3292 differentially expressed genes compared to cells in the control ground group, including heat shock proteins, antioxidant enzymes, DNA repair systems, as well as proteins related to the PSII apparatus and ribosomes. These data shed light on the possible survival strategy of desert algae to near space environments. Our results indicated that Mars-like near space conditions represent an extreme environment for desert algae in terms of temperature, pressure, and radiations. The survival strategy of Chlorella in response to near space will help gain insights into the possibility of extremophile colonization on the surface of Mars and in similar extraterrestrial habitats.

Advances in Chinese polar scientific exploration using high-altitude balloons

Polar Regions, which generally refer to Antarctica and the Arctic, play a key role in global change and are optimal locations for space observation. The expansion of polar exploration and research regarding global climate issues and development of future environmental policies has become important and debated worldwide. China has been conducting research in Polar Regions since 1980 and has accomplished a series of scientific achievements. However, China’s polar investigations began somewhat later that those of Europe and the United States, with insufficient observational data and limited diversity of detection platforms. To solve the problem, high-altitude scientific balloons have been used as an important means to help China rapidly to advance exploration in Polar Regions. High-altitude balloons offer many advantages, such as stable flight for several months, strong carrying capacity, flexibility with experiments, low cost, and fast recovery. For many years, the United States, Japan, Europe, and other developed countries have used high-altitude scientific balloons to conduct polar scientific experiments. Polar Regions are ideal for long-term scientific exploration using high-altitude balloons due to polar vortices (atmospheric circulation), continuous solar radiation (summer polar days), and especially because there are no airspace restrictions in Antarctica. The Chinese Academy of Sciences has carried out multiple space exploration projects using high-altitude balloons at Xianghe Station since 1978 and has conducted a series of experiments using high-altitude balloons at the ice-laden “Third Pole” in the Qinghai-Tibet Plateau in collaboration with the Aerospace Information Research Institute. Sixteen high-altitude balloon flight tests were successfully deployed in 2019. Within the field of high-altitude balloons for near-space exploration, China has an excellent scientific research team and technical foundation that is at par with those of other countries. However, scientific exploration based on high-altitude balloon platforms in Polar Regions remains challenging. To serve the relevant national strategies, it is needed to define major scientific questions in polar exploration and conduct research in a timely manner. Owing to the unique advantages of polar regions, China can carry out polar exploration using high-altitude balloon platforms for a variety of tasks (e.g., in-situ measurement, dropsonde sounding, astronomical observation, and remote sensing) from different scientific disciplines, such as environmental science, atmospheric science, space weather, planetary observation, solar physics, and biological research). Based on China’s current balloon exploration capabilities, relevant work will be carried out step by step from earth observation, sky monitoring to near-space detection, aiming at an integrated capability. The specific research subjects include: (1) Polar ice sheet change; (2) polar geological environment studies; (3) polar habitat monitoring; (4) polar space environment monitoring; (5) polar atmosphere detection; (6) polar near-space biological research; (7) planetary science; and (8) astronomical observation. High-altitude balloons will also play an important role in future studies involving in-situ measurement and dropsonde sounding, astronomical observation, and remote sensing, which will further enhance China’s scientific research in the Polar Regions. This will enhance China’s status and legitimacy in the peaceful use and development of Polar Regions and would give China more clout internationally in polar affairs.

비용효율적인 고고도 과학기구 개발 및 비행시험

비용효율적인 고고도 과학기구 개발 및 비행시험

Numerical research on the thermal performance of high altitude scientific balloons

Internal infrared (IR) radiation is an important factor that affects the thermal performance of high altitude balloons. The internal IR radiation is commonly neglected or treated as the IR radiation between opaque gray bodies. In this paper, a mathematical model which considers the IR transmissivity of the film is proposed to estimate the internal IR radiation. Comprehensive ascent and thermal models for high altitude scientific balloons are established. Based on the models, thermal characteristics of a NASA super pressure balloon are simulated. The effects of film IR property on the thermal behaviors of the balloon are discussed in detail. The results are helpful for the design and operation of high altitude scientific balloons.

Performance simulation of high altitude scientific balloons

The design and operation of a high altitude scientific balloon requires adequate knowledge of the thermal characteristics of the balloon to make it safe and reliable. The thermal models and dynamic models of altitude scientific balloons are established in this paper. Based on the models, a simulation program is developed. The thermal performances of a super pressure balloon are simulated. The influence of film radiation property and clouds on balloon thermal behaviors is discussed in detail. The results are helpful for the design and operate of safe and reliable high altitude scientific balloons.

Study of seasonal variation of winds in upper stratosphere over Hyderabad

A predictability of the stratospheric zonal winds above 38 km during the turnaround is an essential parameter for planning of the high-altitude scientific balloon flights. This information is more relevant in the case of Hyderabad balloon facility which is closer to equator and has much more unstable wind reversal patterns which appears to have changed enormously during the last decade probably in correlation with the global warming. With a majority of our flights reaching the altitudes of 38–42 km and the requirement of long float durations, a prior knowledge of wind pattern during the summer and winter turnaround seasons is highly desirable. Furthermore, the flight operation corridor for balloon flights from Hyderabad is limited to 400 km and though in the west direction there are flat lands, in all other three directions, the landscape is dotted by water bodies, reserve forests and hilly terrain, and therefore need of such a data is essential. In order to establish the climatology of the stratospheric winds and study their inter-annual variability over Hyderabad for the turnaround periods, we have made a detailed analysis of the United Kingdom Meteorological office data between 2000 and 2007, to derive average wind parameters (magnitude, direction) at different ceiling altitudes above 38 km. These results can be used only as general trend of stratospheric wind and should not be the limitation of the UKMO Data.

Observations of Cygnus X‐1 with the EXITE2 Hard X‐Ray Balloon Payload

We present results from the second-generation Energetic X-ray Imaging Telescope (EXITE2) observations of the black hole X-ray binary Cyg X-1 during the experiment's 1997 and 2001 flights. The EXITE2 phoswich [NaI(Tl)/CsI(Na)] detector is designed to image cosmic X-ray sources in the hard X-ray band by using the coded-aperture imaging technique from a high-altitude scientific balloon. The sky image reconstruction methodology used for EXITE2 is also discussed in detail. Background reduction (PSD rejection), subtractive flat-fielding, pixel shuffling, and image functions are introduced. During the observations from the EXITE2 1997 and 2001 flights, Cyg X-1 is easily detected in the 37-237 keV energy range. During the 1997 observations, the spectrum is well fitted by a Comptonization model. The spectral signatures and the observed 100 keV flux, together with the RXTE ASM light curve, indicate that the source was in the typical low state during this observation. Evidence is seen for hard X-ray variability on timescales on the order of 10 minutes. During the 2001 flight the spectrum is best fit by an extended power law with no observable cutoff. This is possible evidence of a transition to the high state, which is indeed seen in the RXTE ASM light curve shortly after our observation.

Nylon-6 and Montmorillonite-Layered Silicate (MLS) Nanocomposites

Reducing the high gas permeability of plastic packaging is of serious concern for a variety of applications in food packaging and microelectronics arena. In the development of high altitude scientific balloons, the potential for unmanned mission success is critically related to the improvement in helium barrier capability. Separately, the introduction of expandable smectite clays, such as montmorillonites, into polymers has resulted in improved barrier properties. Here we investigate the mechanical properties and helium permeability of dispersed montmorillonite-layered silicates (MLS) in nylon-6 nanocomposite films. A 20 wt% MLS in nylon-6 master batch was prepared in a twin-screw extruder and then mixed with nylon to produce nylon MLS nanocomposites with MLS content ranging from 1 to 5% for testing. The nylon nanocomposites were extruded into films. A highly exfoliated dispersion in different films was determined using X-ray diffraction. Nylon-6 nanocomposites showed formation of -crystalline form, which was absent in neat nylon-6. Differential Scanning Calorimetry (DSC) confirmed the crystallinity change and the role of MLS as an additional nucleation contributor. The glass transition and mechanical properties were related to the nucleation capabilities of MLS. Increase in the degree and type of crystallinity together with tortuous path development due to exfoliated dispersion were the primary reasons behind the improvement in gas barrier properties of exfoliated nylon-6 nanocomposites.

Gore/Seam Architectures for Gossamer Structures

Gossamer spacecraft are ultra-low-mass (areal densities <1 kg/m 2 ) structures with applications in communications, imaging, and propulsion. Often large, for example, diameters greater than 10 m, aperture architectures canbe either filled (monolithic) or sparse (segmented). Although filled apertures provide the greatest performance, manufacture of large monolithic, that is, seamless, apertures is extremely challenging, Gore/seam architectures provide a compromise for fabrication of gossamer spacecraft. Segments (gores) are manufactured and then assembled into a continuous aperture by seaming together the gores. A similar process was chosen for the Inflatable Antenna Experiment and has been used for decades in the fabrication of large high-altitude scientific balloons. The architecture options for design and fabrication of gossamer spacecraft are reviewed, with particular emphasis on precision applications in communications and imaging. The near-term inevitability of seaming as a fabrication method is emphasized, and the point of view is taken of using to advantage. The possibility of seams to mitigate some of the aforementioned issues is discussed and extended to go further to find other uses for the active seams. Lessons learned from NASA's high-altitude balloon program are reviewed in improving structural integrity through use of novel gore/seam design.

Gamma-ray Large-Area Space Telescope (GLAST) balloon flight engineering model: overview

The Gamma Ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) is a pair-production high-energy (>20 MeV) gamma-ray telescope being built by an international partnership of astrophysicists and particle physicists for a satellite launch in 2006, designed to study a wide variety of high-energy astrophysical phenomena. As part of the development effort, the collaboration has built a Balloon Flight Engineering Model (BFEM) for flight on a high-altitude scientific balloon. The BFEM is approximately the size of one of the 16 GLAST-LAT towers and contains all the components of the full instrument: plastic scintillator anticoincidence system (ACD), high-Z foil/Si strip pair-conversion tracker (TKR), CsI hodoscopic calorimeter (CAL), triggering and data acquisition electronics (DAQ), commanding system, power distribution, telemetry, real-time data display, and ground data processing system. The principal goal of the balloon flight was to demonstrate the performance of this instrument configuration under conditions similar to those expected in orbit. Results from a balloon flight from Palestine, Texas, on August 4, 2001, show that the BFEM successfully obtained gamma-ray data in this high-background environment.

Development of an xspec-based spectral analysis system for the coded-aperture hard X-ray balloon payload EXITE2

We present the spectral analysis system for the second-generation energetic X-ray imaging telescope experiment (EXITE2) balloon payload. EXITE2 is an imaging hard X-ray telescope using a coded-aperture mask and a NaI/CsI phoswich detector operating in the energy range 20–600 keV. The instrument was flown on a high-altitude scientific balloon from Ft. Sumner, NM on 7–8 May, 1997. We describe the details of the EXITE2 spectral analysis system, with emphasis on those aspects peculiar to coded-aperture instruments. In particular, we have made our analysis compatible with the standard X-ray spectral fitting package xspec by generating a response matrix in the appropriate format including all the effects of a coded-aperture system. The use of xspec, which may be a first for coded-aperture data, permits great flexibility in the fitting of spectral models. The additional effects of our phoswich system, or any other detector-specific considerations, may be easily included as well. We test our spectral analysis using observations of the Crab Nebula, and find that the EXITE2 Crab spectrum is consistent with those recorded by previous instruments operating in this energy range.

Predictions of nonlinear viscoelastic behavior using a hybrid approach

An approach for nonlinear viscoelastic characterization is presented which uses the combined measurements from creep and dynamic mechanical tests. Although the methodology should extend to several materials and geometries, this research concentrates on thin film polymers used in the manufacture of high altitude scientific balloons. Typically, the constitutive behavior of these materials is characterized through the use of linear viscoelastic techniques. Although this linear approach provides an accurate model for small strains or loads, these materials have been shown to be highly stress dependent and, consequently, it is necessary to identify this nonlinear behavior. Traditional creep measurements require extensive laboratory test times, yet the results obtained from dynamic mechanical analysis provide the capability to predict long term material performance without a lengthy experimentation program. However, dynamic mechanical methods are currently limited to linear response; thus, an approach is presented in which the stress-dependent behavior is derived from short-term creep measurements in a manner analogous to time-temperature superposition. Predictions of material response using linear and nonlinear approaches are compared with experimental results obtained from traditional long-term creep tests. Although linear pre-dictions deteriorate for large stresses, excellent agreement is shown for the nonlinear model.

Characterization of nonlinear viscoelastic behavior using a dynamic mechanical approach

The authors present a method to characterize nonlinear viscoelastic behavior using measurements from dynamic (oscillatory) mechanical tests. Frequency-derived measurements are transformed into time-domain properties providing the capability to predict long-term material performance without a lengthy experimentation program. Results are presented for thin-film high-performance polymer materials used in the fabrication of high-altitude scientific balloons. Predictions based on a linear test and analysis approach are shown to deteriorate for moderate to high stress levels expected for long-duration balloon systems. Tests verify that nonlinear viscoelastic response is induced by large stresses. Thus, an approach is developed in which the stress-dependent behavior is examined in a manner analogous to modeling temperature-dependent behavior with time-temperature correspondence and superposition principles. The development leads to time-stress correspondence and superposition of measurements obtained through dynamic mechanical tests. Predictions of material behavior using measurements based on linear and nonlinear approaches are compared with experimental results obtained from traditional creep tests. Excellent agreement is shown for the nonlinear model

A preliminary study on dust grains in the stratosphere

Collected by means of a high-altitude scientific balloon and a self-made automatic sample collector, a total of 276 dust grains were selected for the study of shape, grain size and optical property. Some of the grains were examined by X-ray diffraction and electron microprobe techniques. The stratospheric dust grains can be classified as 6 types: cosmic dusts, cosmic dusts (?), microtektite, natural pollutants, artificial pollutants and the unknown substances. The different types of dust grains have different characters and distinguishing symbols. Widespread in the space of the solar system, cosmic dusts are the initial substances of the solar system and, to some degree, have recorded a great wealth of information on the early history of the solar system. So they have become one of the important objects in the field of cosmochemistry at present time. Since the 1960’s, scholars of many countries have collected cosmic dusts both in the space near the earth (using rockets, space probes and space shuttles)and in the stratosphere (using high-altitude balloons or U-2airplanes). According to the shape (the scanning electron microimage), element composition (the energy-dispersive X-ray spectrum) and optical properties of dust grains, the substances in the stratosphere can be classified as 5 types:cosmic dusts, alumina spheroids, terrestrial artificial pollutants, terrestrial natural pollutants and unknown substances (CDPET, 1982).

Data Acquisition, Reduction, And Transmission of Atmospheric Electricity Data on High-Altitude Scientific Balloons

The second generation of a microprocessor system used on high-altitude scientific balloons is described. The system performs a variety of functions as a controller, a signal processor, and a scientific processor. Two flights of the system demonstrated its reliability although balloon failures prevented the system being fully tested.

Microprocessor Implementation of an FFT for Ionospheric VLF Observations

A fast fourier transform algorithm is implemented on a CMOS microprocessor for application to very low-frequency electric fields (<10 kHz) sensed on high-altitude scientific balloons. Two FFT's are calculated simultaneously by associating them with conjugate symmetric and conjugate antisymmetric results. One goal of the system was to detect spectral signatures associated with fast time variations present in natural signals such as whistlers and chorus. Although a full evaluation of the system was not possible for operational reasons, a measure of the system's success has been defined and evaluated.