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

Siena University, Loudonville NY

Investigators

Abstract

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.