A balloon-borne sun-tracking multichannel photometer for atmospheric aerosol measurements

A balloon borne multichannel photometer for measurement of atmospheric scattering in the near ultraviolet and the visible wavelength regions has been developed at the Physical Research Laboratory, Ahmedabad for study of the size distribution and number density of aerosols at tropospheric and lower stratospheric altitudes. The instrumentation involves tracking the sun in elevation and scanning in azimuth. The payload was recently flown on a 100 kg. balloon from the Hyderabad Balloon Facility on 18 April 1984. The balloon reached a float altitude of 35 km and good quality data has been obtained from an altitude of 6 km upto float altitude. Data analysis is still in progress. The present paper details the instrument design and presents a few illustrations of the instrument performance from this flight.     

Long extension reeling in the stratosphere — A progress report

A balloon-borne winching system providing an improved in-situ observational method for stratospheric photochemistry research was first reported to COSPAR two years ago. Sice that time a second flight has been successfully conducted in which a more complex detection package (98 kg) was twice lowered from a float altitude of 39 km for a distance of 8 km, and each time reeled back up to the winch. Controlled velocities of 4 to 7 meters/sec were implemented for both scans, and the package was brought to a brief stop during the first to evaluate the dynamic effects. Instrumentation aboard both the winch and the detection package again did not identify any threatening dynamic perturbations during any phase of the flight, thus indicating that long extension reeling in the stratosphere can now be conducted on an operational basis. The remaining minor problem areas in the payload are summarized, as are some directions planned for future utilization.     

Development of balloon-borne reel-down and -up winch system

Balloon-borne winches, which can reel down and up scientific instruments repeatedly, have been developed since 1981 in order to observe stratospheric vertical microstuctures. The instrument is suspended by a kevler wire through a traverse-cum ropeguide, and its depth is accurately measured by counting numbers of spool rotations and ropeguide turns. Battery consumption is minimized by utilizing an efficient deccelerator and a hysteresis brake. In 1983 we have successfully performed to reel up and down a 12 kg payload through 1 km for three cycles at 24 km altitude. We are improving the capability of the winch, and have succeeded (May 1984) to reel down a 22 kg payload up to 3 km from a balloon.     

The POKER experiment: A 10,800 cm2 MWPC's array payload for hard X-Ray Astronomy

In this paper the POKER-HXR81M hard X-Ray payload is described. The instrument, designed and built at the Istituto di Astrofisica Spaziale of Frascati, is a very large array of MultiWire Proportional Counters (MWPC) devoted to stratospheric observations of cosmic sources in the field of hard X-Ray Astronomy. The payload basically consists of four passively collimated MWPC's having a geometric sensitive area of 2,700 cm² each with an efficiency higher than 10% in the operative range 15–200 KeV (80% at 60 KeV) with a square field of view of 5° × 5° FWHM. The overall spectral resolution is 13% at 60 KeV. The four MWPC's are filled with a very pure gas mixture of Xenon-Argon-Isobuthane at high pressure (3 bars).This experiment has been successfully flown during summer 1981 from the Milo balloon facility (Sicily, Italy). The performances of the payload and the preliminary results obtained during the 17 hours flight are discussed.     

The high altitude student platform (HASP) for student-built payloads

An outstanding issue with aerospace workforce development is what should be done at the university level to attract and prepare undergraduates for an aerospace career. One approach adopted by many institutions is to lead students through the design and development of small payloads (less than about 500 grams) that can be carried up to high altitude (around 30 km) by a latex sounding balloon. This approach has been very successful in helping students to integrate their content knowledge with practical skills and to understand the end-to-end process of aerospace project development. Sounding balloons, however, are usually constrained in flight duration (∼30 min above 24 km) and payload weight, limiting the kinds investigations that are possible. Student built picosatellites, such as CubeSats, can be placed in low Earth orbit removing the flight duration constraint, but the delays between satellite development and launch can be years. Here, we present the inexpensive high altitude student platform (HASP) that is designed to carry at least eight student payloads at a time to an altitude of about 36 km with flight durations of 15–20 h using a small zero-pressure polyethylene film balloon. This platform provides a flight capability greater than sounding balloons and can be used to flight-test compact satellites, prototypes and other small payloads designed and built by students. The HASP includes a standard mechanical, power and communication interface for the student payload to simplify integration and allows the payloads to be fully exercised. HASP is lightweight, has simple mission requirements providing flexibility in the launch schedule, will provide a flight test opportunity at the end of each academic year.     

平流层飞艇总体设计的基础问题

平流层飞艇是一种新型的长航时临近空间飞行器，具有驻空高度高、驻空时间长、承载能力大、使用效费比高等特点，在对地观测及通信中继等领域具有广泛应用前景。但是该飞行器系统十分复杂，技术与设计实现难度大，总体设计需要考虑的基础问题及解决方案尚不完全明晰。根据平流层大气风场、温度和压力的基础特征，考虑平流层环境对平流层飞艇总体设计的影响，根据空气动力学与热力学基本理论，分析平流层飞艇的显著特征及与常规低空飞艇的区别，研究这些基础问题对平流层飞艇总体设计的影响，为平流层飞艇技术发展提供建议和参考。      

The Mars Environment Analogue Platform long duration balloon flight

The MEAP (Mars Environment Analogue Platform) mission was to fly a stratospheric balloon on a semicircular trajectory around the North Pole in summer 2008. The balloon platform carried the high-resolution neutral gas mass spectrometer P-BACE (Polar Balloon Atmospheric Composition Experiment) as scientific payload. MEAP/P-BACE is a joint project between the Esrange Space Center, Sweden, the University of Bern, Switzerland and the Swedish Institute of Space Physics (IRF), Kiruna, Sweden. Mission objectives were to validate the platform for future long duration flights around the North pole, to validate the P-BACE instrument design for planetary mission applications (conditions in the Earth stratosphere are similar to the conditions at the Mars surface), to study variation of the stratospheric composition during the flight and to gain experience in balloon based mass spectrometry. All objectives were fulfilled.     

空间小鼠实验有效载荷研究进展

啮齿动物是空间研究中常见的模型对象,已开展的空间生物实验中,小鼠表现出对飞行条件的有效适应.通过空间培养,研究者可对失重环境下小鼠的生理行为、骨骼和神经系统变化做进一步研究分析.本文对空间小鼠实验有效载荷的研究进展及其空间飞行实验进行了概述,为中国空间站上的小鼠培养箱设计提供参考.概述了地面小鼠培养技术和装置,为空间小...     

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.     

Remote data communications and command system

Scientific ballooning missions in the continental United States have traditionally been limited in flight time due to the loss of local telemetry capability as the payload drifts beyond the horizon. A Remote Data Communications & Command System has been developed by the NSBF which allows both the recovery and display of limited real-time data and complete command control of a balloon payload that is within the telemetry horizon of a remote station. The general capabilities of this system are discussed here from the standpoint of two virtual systems which can be used independently or together as a single system.     

The radiation controlled balloon (RACOON)

The RACOON concept permits the flight of large, low-cost polyethylene balloons for several weeks at stratospheric altitudes without ballast. The theory of operations is described. The RACOON balloon ascends each morning and descends at night. This movement of 15 to 20 km in altitude provides an ideal platform for vertical soundings and sampling measurements in the stratosphere. Results of a number of globe-circling flights are presented.     

Development of the High Altitude Student Platform

The High Altitude Student Platform (HASP) was originally conceived to provide student groups with access to the near-space environment for flight durations and experiment capabilities intermediate between what is possible with small sounding balloons and low Earth orbit rocket launches. HASP is designed to carry up to twelve student payloads to an altitude of about 36 km with flight durations of 15–20 h using a small zero-pressure polyethylene film balloon. This provides a flight capability that can be used to flight-test compact satellites, prototypes and other small payloads designed and built by students. HASP includes a standard mechanical, power and communication interface for the student payload to simplify integration and allows the payloads to be fully exercised. Over the last two years a partnership between the NASA Balloon Program Office (BPO), Columbia Scientific Balloon Facility (CSBF), Louisiana State University (LSU), the Louisiana Board of Regents (BoR), and the Louisiana Space Consortium (LaSPACE) has led to the development, construction and, finally, the first flight of HASP with a complement of eight student payloads on September 4, 2006. Here we discuss the primary as-built HASP systems and features, the student payload interface, HASP performance during the first flight and plans for continuing HASP flights. The HASP project maintains a website at http://laspace.lsu.edu/hasp/ where flight application, interface documentation and status information can be obtained.     

Properties of tandem balloons connected by extendable suspension wires

The tandem balloon system has been known as a candidate system for long duration flight balloons. In this paper, the properties of the system are analytically studied in a new way by introducing an extendable suspension wire in the Sky Anchor configuration, which consists of a zero-pressure main balloon suspending a payload and a super-pressure balloon suspended below the payload. It was found that extension of the suspension wire between the payload and the super-pressure balloon can extend the capability of the tandem system; the altitude of the zero-pressure balloon can be changed without any consumables except some energy, and the day–night oscillation of the balloon altitude can be suppressed. This property is useful as the vehicle for long duration flights. It is also pointed out that the method to control the altitude of a balloon using an additional suspended super-pressure balloon can also be applied for super-pressure balloons.     

Effect of vapor condensation on ascending performance of stratospheric airship

This paper reports a numerical investigation on the effects of water vapor condensing inside the air bag of a stratospheric airship on its ascending performance. The kinetic and thermal model considering vapor condensation was established, based on which a computer program was written in Fortran. The simulation results show that the vapor condensation remarkably affects the kinetic and thermal characteristics of the stratospheric airship in the ascent process. During the ascent process below 11 km, a large amount of latent heat is released when the water vapor in the air inside the air bag of the stratospheric airship condenses, which results in the increase of the temperature and the reduction of the weight of the air in the air bag, causing the airship to speed up, the accelerated expansion of the helium, and the decrease of the helium temperature in the helium bag. When the flight altitude is higher than 11 km, the effect of vapor condensation on the kinetic and thermal characteristics of the stratospheric airship is negligible because vapor is virtually nonexistent in the air.     

First results of a stratospheric experiment using a montgolfiere infra-rouge (MIR)

An original stratospheric experiment in the tropics has been performed on board the new long duration balloon system developped by the Centre National d'Etudes Spatiales in France. The experiment together with the performances reached in flight are presented.     

基于嵌套饱和的四旋翼无人机吊挂负载控制器设计

针对四旋翼无人机吊挂负载系统飞行中的摆角抑制问题,考虑过快位置机动容易引起吊挂大幅度摆动,提出了一种基于嵌套饱和的四旋翼无人机吊挂负载控制器。首先,利用扩张状态观测器估计干扰,设计具有强抗扰能力的垂直位置控制器;其次,基于简化模型通过构建李雅普诺夫函数,设计控制摆角收敛的抑摆控制器;最后,基于一种嵌套饱和控制方法,设计了限制机动速度的水平位置控制器。与已有控制方法的仿真对比表明,该控制器不但能保证四旋翼无人机吊挂负载系统稳定飞行,还能在大幅度位置机动指令下有效减小最大摆幅。     

一次暴雨激发平流层重力波的卫星观测与数值模拟

针对卫星Aqua/AIRS观测到的与2011年7月25日山东省乳山市特大暴雨相伴的一次平流层重力波过程,利用中尺度数值模式WRF进行暴雨诱发平流层重力波的数值模拟.对模式输出的垂直速度场和温度扰动场的分析表明,暴雨在平流层内的弧状波结构主要集中在降水云系东侧,水平影响范围大于1000km,且随着高度的增加,圆弧状结构趋于闭合,波动能量显著增强.此外,对垂直速度剖面结构分析表明,受高空东风和风切变的影响,重力波在上传过程中逆着背景风场向东传输,不同高度波动形态各异.基于快速傅里叶变换（FFT）的功率谱分析结果表明,此次暴雨激发的平流层重力波在35km高度的周期为7~20h,水平波长约为1000km,垂直波长为5~10km.通过分析动量通量的垂直输送,定量反映出重力波上传过程中的动力学变化特征.      

Measurements of electrical breakdown in the vicinity of a sounding rocket differentially charged to 10 kV

During the initial period of high voltage biasing of the SPEAR-3 sounding rocket payload, it was observed that electrical breakdown occurred in the gas surrounding the rocket. The breakdown occurred almost all the way to apogee of 289 km on the upleg, but did not recur on the downleg until the payload reached an altitude of 100 km. It is suggested that this behavior can be attributed to payload outgassing on the upleg leading to abnormally high gas pressure near the payload skin. Consideration of a modified Paschen discharge process with varying pressure along the discharge path was found to be consistent with the results.     

CREAM: 70 days of flight from 2 launches in Antarctica

The Cosmic-Ray Energetics And Mass balloon-borne experiment has been launched twice in Antarctica, first in December 2004 and again in December 2005. It circumnavigated the South Pole three times during the first flight, which set a flight duration record of 42 days. A cumulative duration of 70 days within 13 months was achieved when the second flight completed 28 days during two circumnavigations of the Pole on 13 January 2006. Both the science instrument and support systems functioned extremely well, and a total 117 GB of data including 67 million science events were collected during these two flights. Preliminary analysis indicates that the data extend well above 100 TeV and follow reasonable power laws. The payload recovered from the first flight has been refurbished for the third flight in 2007, whereas the payload from the second flight is being refurbished to be ready for the fourth flight in 2008. Each flight will extend the reach of precise cosmic-ray composition measurements to energies not previously possible.     

Analysis of long-endurance station-keeping flight scenarios for stratospheric airships in the presence of thermal effects

The ability to achieve long-endurance station-keeping flights makes stratospheric airships desirable platforms for the provision of communication and surveillance services. To maintain long-endurance flights, it is necessary to consider the problem of energy consumption. In this paper, we discuss long-endurance flight scenarios of stratospheric airships in the presence of thermal effects. The balance between buoyancy and gravity is influenced by thermal effects during the diurnal cycle. We perform a theoretical analysis based on the helium’s mass, pressure differential, and altitude as the main factors. To verify the effectiveness of the control over the pressure differential and the altitude, three long-endurance flight scenarios are proposed and compared. Then, the corresponding optimization problems are constructed to determine the energy-minimum flight. Finally, further efforts are made to reduce energy consumption. The realization and limitations of two strategies for improvement are analyzed. A comparison with other scenarios shows the effectiveness of energy conservation. The study in this paper thus provides a reference for station-keeping applications of stratospheric airships.