{Article} SciTechMed: Space Debris and the celebration of NASA’s Mariner II
- On 14th December 1962, NASA’s Mariner II passed within 35,000km of
Venus, becoming the first spacecraft to successfully fly by another
planet.
- From this historic voyage, we learned that Venus rotates in a
counter direction to most planets in our solar system, has a
high-pressure carbon dioxide atmosphere and continuous cool cloud cover.
- Whither Mariner II now? Endlessly circling the Sun, in a heliocentric
orbit. Space debris: a serious problem for our immediate galaxy.
- Space debris, also known as orbital debris, space junk, and space waste, is the collection of objects in orbit around Earth that were created by humans but no longer serve any useful purpose. These objects consist of everything from spent rocket stages and defunct satellites to erosion, explosion and collision fragments. As the orbits of these objects often overlap the trajectories of newer objects, debris is a potential collision risk to operational spacecraft. The vast majority of the estimated tens of millions of pieces of space debris are small particles, less than 1 centimetre (0.39 in). These include dust from solid rocket motors, surface degradation products such as paint flakes, and coolant released by RORSAT nuclear powered satellites. Impacts of these particles cause erosive damage, similar to sandblasting. This damage can be partly mitigated through the use of the "meteor bumper", which is widely used on spacecraft such as the International Space Station. However, not all parts of a spacecraft may be protected in this manner, e.g. solar panels and optical devices (such as telescopes, or star trackers), and these components are subject to constant wear by debris (and to a much lesser extent, micrometeoroids).
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