Space environment effects on equipment and structures—current and future technologies

The space environment is extremely hostile to the spacecraft but also to the equipment it carries. The materials which are used to the external side of the spacecraft, the solar panels, the sensors, and the electronics circuits, suffer greatly from their exposure to it. Extreme temperatures, ultraviolet radiation, ionizing radiation from solar proton events and cosmic rays, atomic oxygen in LEO, as well as collisions with micrometeoroids and space debris are factors that degrade the stuff, multiply the mission cost, and increase the risk. Therefore, the state-of-art of material technology is needed. In this study, a set of materials and technologies are presented, which reduce the above-mentioned risks. Extreme temperatures, ultra-vacuum, atomic oxygen, and high-energy radiation including particles as well as energy sources (X- and gamma rays) are potential extreme exposure conditions. Testing and qualification of materials exposed to these extreme conditions is a difficult task, to enable the design and manufacturing of high-endurance reliable components to be used in the world’s most sophisticated satellite and spacecraft components, as well as in future endeavors into the vicinity of the Solar System.

Tree rings reveal two strong solar proton events in 7176 and 5259 BCE

The Sun sporadically produces eruptive events leading to intense fluxes of solar energetic particles (SEPs) that dramatically disrupt the near-Earth radiation environment. Such events are directly studied for the last decades but little is known about the occurrence and magnitude of rare, extreme SEP events. Presently, a few events that produced measurable signals in cosmogenic radionuclides such as 14C, 10Be and 36Cl have been found. Analyzing annual 14C concentrations in tree-rings from Switzerland, Germany, Ireland, Russia, and the USA we discovered two spikes in atmospheric 14C corresponding to 7176 and 5259 BCE. The ~ 2% increases of atmospheric 14C recorded for both events exceed all previously known 14C peaks but after correction for the geomagnetic field, they are comparable to the largest event of this type discovered so far at 775 CE. These strong events serve as accurate time markers for the synchronization with floating tree-ring and ice core records and provide critical information on the previous occurrence of extreme solar events which threaten modern infrastructure.