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On June 11 and 15, 1985 two packages with balloons have been inserted in the atmosphere of Venus from the Soviet VEGA landing modules. This paper summarizes the pressure, temperature, wind illumination and backscattering data from the balloons.
NASA's high altitude balloon borne scientific payloads are typically suspended from a deployed flat circular parachute. At flight termination, the recovery train is pyrotechnically separated at the parachute apex and balloon nadir interface. The release of elastic energy stored in the parachute at zero initial vertical velocity in the rarefied atmosphere produces high canopy opening forces that subject the gondola to potentially damaging shock loads. Data from terminations occurring at altitudes to 40 km with payloads up to 2500 kg on parachutes up to 40 m in diameter are presented. Measured loads are markedly larger than encountered via packed parachute deployment for similar canopy loadings. Canopy inflation is significantly suppressed in the early stages and then accelerated during final blossoming. Data interpretation and behavioral phenomena are discussed along with proposed shock attenuation techniques.
Interstellar CII and OI forbidden lines were observed by the Balloon-Borne Infrared Telescope (BIRT) with a Fabry-Perot spectrometer. Two balloon flights were successfully made. With a method of 'frequency switching', diffuse CII forbidden-line emission was efficiently detected and mapped in extended regions around HII/molecular cloud complexes and in a wide area of the Galactic plane. It has been shown that the CII forbidden-line emission is very strong and ubiquitously distributed in interstellar space in the Galaxy.
Results of ongoing studies of high-resolution solar absorption spectra aimed at the identification and quantification of trace constituents of importance in the chemistry of the stratosphere and upper troposphere are presented. An analysis of balloon-borne and ground-based spectra obtained at 0.0025/cm covering the 700-2200/cm interval is presented. The 0.0025/cm spectra, along with corresponding laboratory spectra, improves the spectral line parameters, and thus the accuracy of quantifying trace constituents. Results for COF2, F22, SF6, and other species are presented. The retrieval methods used for total column density and altitude distribution for both ground-based and balloon-borne spectra are also discussed.
A new remote sensing instrument, the Submillimeterwave Limb Sounder, has been developed to simultaneously measure ClO, HCl, O3 and HO2 from high altitude balloon and aircraft platforms. The instrument is a double sideband heterodyne radiometer measuring atmospheric thermal emission spectra near 640 GHz from the Earth's limb. The instrument was flown in April and October, 1991 and in February, 1992 on high altitude balloon platforms over the southwestern United States.
In the generation, storage, and use of hydrogen for balloon purposes it is necessary to be able to determine, first, its lifting power, and, secondly, its purity. The lifting power may be determined directly from the specific gravity. Contamination by other gases may be determined by analysis for oxygen, carbon dioxide, etc., by the usual methods of gas analysis. The determination of oxygen is important, since the presence of oxygen in amounts beyond certain limits will make the compressing, handling, and use of the gas hazardous. If the specific gravity of the gas is known, however, it may not be necessary to analyze the gas for oxygen and other gases, because the specific gravity in itself is a delicate criterion of the purity of hydrogen. Report describes a simple, portable apparatus for testing hydrogen, with special reference to its use in balloons.
This project called Electrodynamics of the Middle Atmosphere (EMA): Superpressure Balloon Program was begun by the PI at the Aerospace Corporation in Los Angeles under joint NSF and NASA funding originally combined in one grant ATM80-17071 and has continued at the University of Washington under grants ATM8212283, ATM84-11326 and ATM86-15628 and NASA grants NAGW-724 and NAGS-635. In the EMA experiment a comprehensive set of electrical parameters was measured during eight long-duration balloon flights in the Southern Hemisphere stratosphere. These flights resulted in the largest vector electric field data set ever collected from the stratosphere which has been a treasure-trove of new phenomena. Since the stratosphere has never been electrodynamically sampled in this systematic manner before, it is perhaps not surprising that several new discoveries have been made and reported. Another way to measure the success of this first EMA project is to note that all together the total data rate was about 1 bit/sec/payload amounting to 12 MBytes (1/3 of 1 standard 1600 BPI magnetic tape) which nevertheless has resulted in 14 papers and 2 masters theses (so far! . Ten of these papers and one masters thesis specifically acknowledge the support by NASA grant NAGS-635 are discussed herein.
This video discusses how NASA uses large helium-filled balloons to take payloads up 25 miles to the edge of space to gather data. Balloons provide a cost effective approach to reach these heights.
We present preliminary results for the PPB (Polar Patrol Balloon) experiment. The balloon was launched at 07:55 UT on 23 September and dropped at 21 UT on 28 September 1991. During the period, ozone and aerosol concentrations were measured correspondingly along the track. During the Lagrangian type observation, drastic change of ozone concentration in 'same air mass' and positive correlation between ozone concentration and sulfate aerosol amount were obtained at the level within 80-78 hPa. During the descent motion at 80 deg S active PSC's (type-1 and -2) were observed from 200 hPa to 80 hPa.
A novel cryogenic Fourier transform spectrometer (FTS) has been developed for limb emission measurements in the mid IR-region from balloon-borne platforms. The FTS is a rapid scanning interferometer using a modified Michelson arrangement which allows a spectral resolution of 0.04 cm(exp -1) to be achieved. Solid carbon-dioxide cooling of the spectrometer and liquid-helium cooling of the detectors provide adequate sensitivity. The line of sight can be stabilized in terms of azimuth and elevation. A three-mirror off-axis telescope provides good vertical resolution and straylight rejection. Calibration is performed by high elevation and internal blackbody measurements. Four balloon flights were performed, two of them during spring turn-around 1989 and 1990 over mid-latitudes (Aire sur L'Adour, France, 44 deg N) and two near the northern polar circle in winter 1992 (Esrange, Sweden, 68 deg N). Limb emission spectra were collected from 32 km to 39 km floating altitudes covering tangent heights between the lower troposphere and the floating altitude. The trace gases CO2, H2O, O3, CH4, N2O, HNO3, N2O5, ClONO2, CF2Cl2, CFCl3, CHF2Cl, CCl4, and C2H6 have been identified in the measured spectra. The 1989 data have been analyzed to retrieve profiles of O3, HNO3, CFCl3 and CF2Cl2. The flights over Kiruna have provided the first ever reported profile measurements of the key reservoir species ClONO2 and N2O5 inside the polar vortex.
Angular resolution and structural information from the far-infrared mapping of astronomical sources (Galactic star forming regions, spiral galaxies, etc.) made using the TIFR 1 m balloon-borne telescope and the IRAS have been compared. The effective wavelengths of the TIFR two-band photometer are 58 and 150 microns. From IRAS, the survey COADD data, additional observations (AO's) made with the survey detectors with different Macros (DPS, DSD, DPM), as well as the chopped photometric channel (CPC) data have been considered here. The observed signals have been processed using different deconvolution strategies, either based on a maximum entropy method (MEM) developed at TIFR or the HiRes package developed at IPAC. Relative merits of each of these, under different conditions of signal to noise ratio, are highlighted. The following sources have been selected for illustration: Carina complex, W31 region, IRAS 10361-5830 (all Galactic), M101 and M81 (extragalactic). The main conclusions are: far-infrared maps from MEM deconvolution of balloon-borne data have the best angular resolution; MEM deconvolution of IRAS AO's gives resolution comparable to HiRes but with less amount of computation, though the dynamic range in MEM maps is less than in HiRes maps.
The MIXE detector developed at NASA/MSFC is designed for x-ray astronomy and consists of a multiwire proportional counter sensitive to photons less than 150 keV. The detector has been flown on several balloon flights with higher than expected background levels observed. Previous predictions of the detector background due to atmospheric gamma-ray and cosmic diffuse sources were much less (factor of 3) than flight background measurements. The work reported here was undertaken to determine if the additional contribution from gamma-rays generated by albedo and cosmic-ray induced neutrons in the detector and payload assembly could account for the background levels observed. Monte Carlo nuclear interaction and radiation transport simulations were made for the ambient cosmic-ray environment corresponding to a previous MEE balloon flight at 3 g/cm(exp 2) residual atmosphere and 42 N geomagnetic latitude. The omnidirectional albedo neutron spectrum and the GCR proton spectrum which were used as input to the calculations are shown. For the albedo angular distribution, the predicted up/down flux ratio of 2.5 was used together with the angular dependence measured by Preszler, et al.
This proposal funded 100 high altitude weather balloons costing $15,500 to support the deployment of a Rayleigh/Raman/Na lidar at the South Pole. One year of measurements have been completed and it is estimated that the balloons will provide another 1-2 years of data.
Funds from this grant were used to support the continuing development of BOOMERANG, a 1.3 m, balloon-borne, attitude-stabilized telescope designed to measure the anisotropy of the Cosmic Microwave Background (CMB) on angular scales of 12 min to 10 degrees. By the end of the funding period covered by this grant, the fabrication of most of the BOOMERANG sub-systems was completed, and integration and test of the payload at Caltech had begun. The project was continued under a new grant from NASA and continuing funding from the NSF. Payload integration and test was completed in April, 1997. A campaign to Palestine, Texas, resulted in two test flights during 1997. A flight on August 12, 1997 was terminated on ascent due to a leaky balloon. The payload was successfully recovered, refurbished, and flown again on August 29, 1997. The second flight was completely successful, and qualified the payload for an LDB flight from McMurdo Stn., Antarctica, in December 1998.
A balloon-borne instrument was constructed for observations of vertical profiles of cloud condensation nucleus (CCN) concentrations, active at 1% supersaturation. Droplet concentration in the static thermal-gradient diffusion chamber is deduced from the amount of scattered laser light detected by a photodetector. The photodetector is calibrated using a video camera and computer system to count the number of droplets produced from NaCl aerosol. Preliminary data are available from nine early morning profiles obtained at Laramie, Wyoming, between June 1995 and January 1997. To complement the CCN measurements, instruments that measure condensation nuclei (CN) and aerosols with diameter greater than 0.30 micrometers (D(sub 0.3) were also included on the balloon package. CCN concentrations exhibited a general decrease from the surface to the top of the boundary layers, were generally uniform through well-mixed layers, and show variability above well-mixed layers. In general, the structure of the CCN profile appears to be closely related to the structure in the CN and D(sub 0.3) profiles. Summer profiles generally have CCN concentration greater than 200/cu cm up to 500 mbar, whereas winter profiles are less than 200/cu cm at all levels.
Under the support of this grant a balloon-borne gondola containing a variety of aerosol instruments was developed and flown from Laramie, Wyoming, (41 deg N, 105 deg W) and from Lauder, New Zealand (45 deg S, 170 deg E). The gondola includes instruments to measure the concentrations of condensation nuclei (CN), cloud condensation nuclei (CCN), optically detectable aerosol (OA.) (r greater than or equal to 0.15 - 2.0 microns), and optical scattering properties using a nephelometer (lambda = 530 microns). All instruments sampled from a common inlet which was heated to 40 C on ascent and to 160 C on descent. Flights with the CN counter, OA counter, and nephelometer began in July 1994. The CCN counter was added in November 1994, and the engineering problems were solved by June 1995. Since then the flights have included all four instruments, and were completed in January 1998. Altogether there were 20 flights from Laramie, approximately 5 per year, and 2 from Lauder. Of these there were one or more engineering problems on 6 of the flights from Laramie, hence the data are somewhat limited on those 6 flights, while a complete data set was obtained from the other 14 flights. Good CCN data are available from 12 of the Laramie flights. The two flights from Lauder in January 1998 were successful for all measurements. The results from these flights, and the development of the balloon-bome CCN counter have formed the basis for five conference presentations. The heated and unheated CN and OA measurements have been used to estimate the mass fraction of the aerosol volatile, while comparisons of the nephelometer measurements were used to estimate the light scattering, associated with the volatile aerosol. These estimates were calculated for 0.5 km averages of the ascent and descent data between 2.5 km and the tropopause, near 11.5 km.
We are developing high-energy replicated optics for a balloon-borne hard-x-ray telescope. When completed, the telescope will have around 150 square cm of effective collecting area up to 65 keV, and an angular resolution of around 30 arc seconds, half power diameter. When used in conjunction with an array of focal plane imaging detectors, for which Gas Scintillation Proportional Counters are under development, the payload will provide unprecedented sensitivity for pointed observations in the hard-x-ray band. We will present an overview of the High Energy Replicated Optics (HERO) program together with test data from the first mirror units. The overall sensitivity of the full payload, when flown on long- and ultra-long-duration balloon flights, will be compared with past and planned satellite-borne hard-x-ray missions.
High altitude balloon (20 km) and low-density capture media were explored to return meteor-related dust during the November 1998 Leonids meteor storm. One 20-30 micron particle captured showed a characteristic signature of extraterrestrial origin, featuring high aluminum, magnesium and other non-volatile metals. The technique of balloon capture will be optimized for March and November 1999 reflights.