Development of the NASA Ultra-Long Duration Balloon
Development of the NASA Ultra-Long Duration Balloon
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NASA 超长持续时间气球的开发
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
Nasa Gsfc
中科院分区：
文献类型：
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作者：
H. Cathey;D. Pierce;Nasa Gsfc
美国国家航空航天局（NASA）的“超压气球”被设计成能够在恒定高度中纬度、长时间飞行，即使在昼夜转换期间也是如此。这是50多年来第一个全新的气球设计，通常被称为ULDB（超长持续时间气球）。本文主要介绍了美国宇航局戈达德航天飞行中心瓦勒普斯飞行设施气球项目办公室的超压气球研制情况。NASA ULDB开发项目的目标是试图延长大型科学气球有效载荷的潜在飞行时间。要展示的领域包括设计方法、遇到的部署问题和建议的解决方案、地面测试和分析概述。未来的地面测试和额外的试飞计划也将被提出。未来的试飞目标将以增加悬挂载荷和高度的方式进行。这将包括预计的气球体积、有效载荷能力和试飞地点。1. 介绍和背景在恒定的浮力高度上对重载荷进行更长时间的平流层飞行的愿望一直是美国国家航空航天局（NASA）超长持续时间气球（ULDB）努力发展的焦点（Cathey, 2000）。ULDB项目的目标是开发一种能够携带2721公斤有效载荷至33.5公里长达100天的气球飞行器。上一代平流层超压气球的重量限制约为90公斤。该项目成立于1998年，已经进行了多次试飞。每次飞行都为设计团队提供了宝贵的工程数据。ULDB的工作继续以增量的步骤进行开发。为了补充测试飞行，一些地面测试模型已经被用作开发工作的一部分。试飞和地面测试扩展了材料，制造方法和设计细节的知识。这些设计细节包括用于在气球中应用肌腱和单个gore的形状以保持稳定形状的方法。到目前为止，在项目中遇到的故障模式都是不允许延长飞行时间的类型。随着项目进展到将更重的有效载荷飞行到更高的高度，这些更大的气球有可能发现进一步的设计挑战。这些气球的设计是非常新的技术，应该这样看待。最近的努力集中在地面测试和分析上，以了解之前观察到的气球在浮子上部署的问题。南瓜气球设计的修订方法已经通过模型气球的地面测试、两次试飞和额外的模型测试进行了测试。该设计方法不需要缩短，并且在制造过程中可以显著减少球囊的处理，从而减少对信封造成损坏的机会。模型气球的成功地面试验导致了一个~176,000立方米（~6.2 MCF -百万立方英尺）气球的制造和试飞。飞行前分析预测预测，建议的飞行气球设计是稳定的，应该充分展开。修改后的超长持续时间气球设计的第一次试飞很短
The National Aeronautics and Space Administration’s (NASA) “Super-pressure Balloon” is designed to be capable of mid-latitude, long-duration flights at constant altitude even during day-night transitions. This first totally new balloon design in more than 50 years is commonly referred to as ULDB (Ultra Long Duration Balloon). This paper concentrates on the super-pressure balloon development by the NASA Balloon Program Office at Goddard Space Flight Center’s Wallops Flight Facility. The goal of the NASA ULDB development project is to attempt to extend the potential flight durations for large scientific balloon payloads. Areas to be presented include the design approach, deployment issues that have been encountered and the proposed solutions, ground testing, and an analysis overview. Future plans for both ground testing and additional test flights will also be presented. Goals of the future test flights, which are staged in increments of increasing suspended load and altitude, will be presented. This will include the projected balloon volumes, payload capabilities, and test flight locations. 1. Introduction and Background The desire for longer duration stratospheric flights at constant float altitudes for heavy payloads has been the focus of the development of the National Aeronautics and Space Administration’s (NASA) Ultra Long Duration Balloon (ULDB) effort (Cathey, 2000). The goal of the ULDB project is to develop a balloon vehicle capable of carrying a 2721 kg payload to 33.5 km for up to one hundred days. The weight limit for the previous generation of stratospheric super pressure balloons was approximately 90 kilograms. The project, established in 1998, has conducted a number of test flights. Each flight has provided valuable engineering data for the design team. The ULDB effort continues the development in incremental steps. To supplement the test flights, a number of ground test models have been used as part of this development effort. The test flights and ground testing have expanded the knowledge of the materials, fabrication methods, and design details. These design details include the method used for applying the tendons and shape of the individual gores in the balloon to maintain a stable shape. The failure modes encountered so far in the project have all been the types that would not allow for extended flight durations. As the program progresses to flying heavier payloads to higher altitudes, there is the potential to uncover further design challenges with these larger balloons. The design of these balloons is very new technology and should be viewed as such. Recent efforts have focused on ground testing and analysis to understand the previously observed issue of balloon deployment at float. A revised approach to the pumpkin balloon design has been tested through ground testing of model balloons, through two test flights, and additional model testing. The design approach does not require foreshortening, and will significantly reduce the balloon handling during manufacture reducing the chances of inducing damage to the envelope. Successful ground testing of model balloons lead to the fabrication and test flight of a ~176,000 m 3 (~6.2 MCF – Million Cubic Foot) balloon. Preflight analytical predictions predicted that the proposed flight balloon design to be stable and should fully deploy. The first test flight of the revised Ultra Long Duration Balloon design was a short