RAPID: FireStation--Understanding Earth's Most Powerful Natural Particle Accelerator

研究人员将开发、建造、测试和交付一套名为FireStation的微型探测器，用于对国际空间站(ISS)上飞行的闪电进行光学、无线电和能量辐射测量。该仪器套件以美国国家科学基金会资助的立方体萤火虫为基础，将被包括在国际空间站上的国防部空间测试计划平台中，作为美国宇航局戈达德太空飞行中心建造的SpaceCube 2.0实验的一部分，计划于2013年交付给国际空间站。FireStation的硬件严重依赖于Firefly CubeSat现有的飞行备件，需要一些修改才能与Space Cube接口，而不是Firefly CubeSat总线。该仪器套件包括：一个灵敏的小型化无线电接收器，一个基于超快无机闪烁体的新型所谓的光能辐射探测器，以及一个多通道光度计系统，包括多波长滤光片和高速读数，提供闪电的准确定位，以及高分辨率的准确计时和多波长观测。Firefly和FireStation的共同主要目标是明确地确定地面伽马射线闪电(TGFs)是否由闪电产生，并确定产生在高海拔观测到的伽马射线通量的闪电的特征。这一信息将强烈限制将电子加速到雷暴上方~35 MeV的过程，因为这些电子被认为是TGFs的来源。TGFs本身就很有趣，因为它们是地球上最强大的自然粒子加速过程的结果，在这个过程中，热电子在不到1毫秒的时间内被激发到数千万电子伏特。这些被激发的电子产生大量的布里致辐射伽马射线和X射线，可以从轨道平台上观察到，电子本身可能逃逸到磁层高度并填充内部电子辐射带。锡耶纳学院的本科生将参与该项目的所有方面，从设计和开发，到制造和测试，到任务操作和数据分析。这些学生不仅将有非常难得的机会亲身体验现实生活中的太空项目，他们还将有机会参加全国性的会议，谈论他们在FireStation上的工作，并向其他科学家和工程师学习。锡耶纳学院和玻利维亚私立大学的学生还将合作部署一个能够提供闪电事件位置信息的甚低频地面站。

The investigators will develop, build, test, and deliver a suite of miniaturized detectors, called Firestation, for optical, radio, and energetic radiation measurements of lightning to be flown on the International Space Station (ISS). The instrument suite is based on the NSF-funded Cubesat Firefly and will be included in a DOD Space Test Program platform on the ISS as part of an experiment, the SpaceCube 2.0, built at NASA Goddard Space Flight Center, which is scheduled for delivery to the ISS in 2013. The hardware for FireStation relies heavily on existing flight spares from the Firefly CubeSat, with some modifications needed to interface with Space Cube, rather than the Firefly CubeSat bus. The instrument suite consists of: a sensitive miniaturized radio receiver, a novel so-called phoswich energetic radiation detector, based on an ultrafast inorganic scintillator, and a multi-channel photometer system, including multi-wavelength filters and high speed readouts, providing accurate localization of lightning flashes, as well as accurate timing at high resolution, and multi-wavelength observation. The shared main goal of Firefly and FireStation is to unambiguously determine if Terrestrial Gamma Ray Flashes (TGFs) are produced by lightning, and to determine the characteristics of lightning that produce the fluxes of gamma rays observed at high altitude. This information will strongly constrain the processes that accelerate electrons to ~35 MeV above thunderstorms, since these electrons are thought to be the source of TGFs. TGFs are of inherent interest, as they result from the most powerful natural particle acceleration process on Earth, in which thermal electrons are energized to tens of million electron volts in less than 1 millisecond. These energized electrons create copious bremstrahlung gamma and X-rays, which can be observed from orbiting platforms and the electrons themselves may escape to magnetospheric altitudes and populate the inner electron radiation belt. Undergraduate students at Siena College will be involved in all aspects of the project, from design and development, through fabrication and test, to mission operations and data analysis. Not only will these students get a very rare opportunity for hands-on, end-to-end experience on a real-life space project, they will also get a chance to travel to national meetings to talk about their work on FireStation, and to learn from other scientists and engineers. Students at Siena College and the Universidad Privada Boliviana (Private University of Bolivia) will also work together on deploying a VLF ground station capable of providing location information on lightning events.