How the ISS dodges debris
Orbiting 400 kilometres above us in low-earth orbit, the ISS is particularly vulnerable to damage from space debris. Manned modules and other vulnerable areas have been fitted with protective aluminium shields – both during and since construction. The ISS also carries out debris avoidance manoeuvres to dodge space junk or micrometeorites. After being warned of such dangers, the ISS is sent a few kilometres higher or lower using a short engine thrust from a docked Automated Transfer Vehicle (ATV) or Progress spacecraft. The ATV is fitted with an automatic system that will abort the docking procedure if it detects any danger from debris. If any debris comes within 0.75 kilometres above or below the space station, or within 25 kilometres around it that cannot be avoided, the ISS is put into unmanned mode and the astronauts have to seek protection in a spacecraft docked with the station. In 2008 and 2009 astronauts had to seek refuge in a Soyuz craft due to such warnings.