Smith David J, Sowa Marianne B
National Aeronautics and Space Administration, Space Biosciences Division, NASA Ames Research Center, Moffett Field, California 94035.
Gravit Space Res. 2017 Jul;5(1):52-73.
Despite centuries of scientific balloon flights, only a handful of experiments have produced biologically-relevant results. Yet unlike orbital spaceflight, it is much faster and cheaper to conduct biology research with balloons, sending specimens to the near space environment of Earth's stratosphere. Samples can be loaded the morning of a launch and sometimes returned to the laboratory within one day after flying. The National Aeronautics and Space Administration (NASA) flies large, unmanned scientific balloons from all over the globe, with missions ranging from hours to weeks in duration. A payload in the middle portion of the stratosphere (~35 km above sea level) will be exposed to an environment similar to the surface of Mars: temperatures generally around -36 °C, atmospheric pressure at a thin 1 kPa, relative humidity levels < 1%, and a harsh illumination of ultraviolet (UV) and cosmic radiation levels (about 100 W/m and 0.1 mGy/d, respectively) that can be obtained nowhere else on the surface of the Earth, including environmental chambers and particle accelerator facilities attempting to simulate space radiation effects. Considering the operational advantages of ballooning and the fidelity of space-like stressors in the stratosphere, researchers in aerobiology, astrobiology, and space biology can benefit from balloon flight experiments as an intermediary step on the extraterrestrial continuum (ground, low Earth orbit, and deep space studies). Our review targets biologists with no background or experience in scientific ballooning. We will provide an overview of large balloon operations, biology topics that can be uniquely addressed in the stratosphere, and a roadmap for developing payloads to fly with NASA.
尽管进行了数百年的科学气球飞行，但只有少数实验产生了与生物学相关的结果。然而，与轨道太空飞行不同的是，用气球进行生物学研究要快得多且成本更低，可以将标本送到地球平流层的近太空环境中。样品可以在发射当天早上装载，有时在飞行后一天内就能返回实验室。美国国家航空航天局（NASA）从全球各地放飞大型无人科学气球，任务持续时间从数小时到数周不等。位于平流层中部（海拔约35公里）的有效载荷将暴露在与火星表面类似的环境中：温度通常在-36°C左右，大气压力稀薄至1千帕，相对湿度<1%，以及强烈的紫外线（UV）和宇宙辐射（分别约为100瓦/平方米和0.1毫戈瑞/天），这种环境在地球表面的其他任何地方都无法获得，包括试图模拟太空辐射效应的环境舱和粒子加速器设施。考虑到气球飞行的操作优势以及平流层中类似太空应激源的逼真度，航空生物学、天体生物学和空间生物学领域的研究人员可以从气球飞行实验中受益，将其作为外星连续体（地面、近地轨道和深空研究）中的一个中间步骤。我们的综述针对的是没有科学气球飞行背景或经验的生物学家。我们将概述大型气球操作、平流层中可以独特解决的生物学主题，以及开发与NASA一起飞行的有效载荷的路线图。
