Toda a evolução do conhecimento cientifico sobre os Raios-Cósmicos ocorrida no século XX nos levou a seguinte constatação: raios cósmicos constituem um fluxo variável no tempo e no espaço de partículas atômicas e sub- atômicas energéticas totalmente ionizadas (com energias e abundâncias características) que permeia continuamente o sistema solar produzindo ionização e reações nucleares na atmosfera terrestre. Por serem eletricamente carregadas, o espectro de energia dessas partículas varia quando o fluxo atravessa irregularidades magnéticas e/ou turbulências. Medidas (diretas ou indiretas) deste fluxo feitas na superfície da Terra permitem o estudo dos processos físicos que ocorreram durante a jornada dos raios-cósmicos desde sua origem até o momento de sua medida, incluindo aqueles envolvidos em seu processo inicial de aceleração e em seu processo de transporte pela Heliosfera, magnetosfera e atmosfera terrestre. Desta forma, podemos considerar uma partícula de raio-cósmico como um mensageiro celeste. Por isso, muitos trabalhos têm usado as pegadas deixadas pelos raios-cósmicos na superfície da Terra (através de medidas de superfície dos traçadores cosmogênicos) como ferramenta para estudos da Física Espacial, Solar e Atmosférica. Este artigo discute como o conhecimento cientifico sobre os Raios-Cósmicos evoluiu e apresenta uma breve revisão sobre os conceitos físicos que envolvem esses mensageiros celestes.

All the evolution of the scientific knowledge about Cosmic Rays (CRs) in the 20 t h century leads to the following statement: Cosmic Rays constitutes a time and spatial variable flux of fully ionized energetic atoms and sub-atomic particles with specific abundances and energies that continuously permeates the solar system, reaching the Earth and producing ionization and nuclear reactions in our atmosphere. Since the primary CR flux is composed of charged particles, it is expected that any magnetic irregularity and/or turbulence affects their large scale transport and consequently its energy spectrum. Moreover, since the interaction of the CR particles with the terrestrial atmosphere produces not only atmospheric ionization, but also nuclear reactions (creating a cascade of secondary particles), it is easy to understand that near ground CR measurements (direct or indirect) may allow us to study the physical processes involved in the journey of CR particles (including the birth conditions of the lower energetic ones and the propagation of the higher energetic ones through the heliosphere) before reaching the terrestrial environment, and also along the transport of the secondary particles into the Earth's atmosphere. In this sense, considering a cosmic ray particle as a ”celestial messenger” is reasonable. Therefore, several works have been using the CR footprints found in the terrestrial surface (through the ground-based measurement of cosmogenic tracers) as a tool for solar and atmospheric studies. It is present here a discussion concerning the time evolution of the CR scientific knowledge and a brief review of the physical concepts of those celestial messengers.

ABSTRACT: This work presents the design and characteristics of a new compact ultraviolet (UV) irradiator used in a biological onboard space flight experiment. The experiment, called DRM, took place in the International Space Station research facility (ISS-13 expedition), during the Centenary Mission (Russian-Brazil) in March-April 2006. The DRM main objective was to correlate the DNA repair mechanism and mutagenesis with microgravity. A compact irradiator apparatus was designed for DRM to allow in situ induced radiation in space. This apparatus, called CIM, uses UV-A Light-emitting diodes (LEDs) with 375 nm wavelength as molecular lesions inducers on four bacterial E. coli strains. The manned space mission restrictions were focused on during the CIM main parts design. The ultraviolet dosimetry is also described in this document as DRM experiment results and the CIM operational data are reported to certify the CIM design and DRM protocol compatibility in space application.