Interconnect Technology for Manned Space Flight

Impacts of Space Radiation on Interconnect Wire Harnessing

Low Earth Orbits are increasingly being utilized by satellite networks geared for principal delivery of internet content on a

worldwide basis. Low Earth Orbit, or LEO, happens to be relatively free from charged solar particles as it sits below the inner and outer Van Allen belts. Ionizing radiation remains an important factor however, and polar LEO orbits do cross charged particle areas at every pass. One of the questions we get asked quite frequently at Glenair is whether or not a particular interconnect technology is resistant to space

radiation. The answer to this question of course depends on the particulars and specifications of each individual application, as the physics of radiation in space— for example as it pertains to satellites in low earth orbit versus those subject to radiation effects in deep interplanetary space—are significantly different. In general, radiation that hits a spacecraft comes from either of two sources. The first is the sun, and if we understand its direct and indirect effects we will have mastered 99% of the subject at hand. However there is a small percentage of space missions that cannot rely solely on the sun as its source of energy. Such satellites often carry a small nuclear reactor called a radioisotope thermoelectric generator (RTG) which converts heat from a nuclear decay process into electricity. Generators of this type do emit some radiation, but that’s not the focus of the vast majority of the applications we see, which are almost exclusively focused on solar radiation.

The sun is a major source of electromagnetic radiation impacting satellites in low earth orbit. Direct impacts from solar flares and solar wind dominate the radiation environment experienced by LEO satellites.

Alpha (α) radiation consists of a fast-moving helium-4 nucleus, and is stopped by a sheet of paper. Beta (β) radiation, consisting of electrons, is halted by an aluminum plate. Gamma (γ) radiation, consisting of energetic photons, is gradually absorbed as it penetrates dense material. Neutron (n) radiation consists of free neutrons, blocked by light elements such as hydrogen, which slow and/or capture them. Galactic cosmic rays (not shown) consist of energetic charged nuclei such as protons, helium nuclei, and high-charged nuclei called HZE ions.

RADIATION TYPES