This presentation was part of the session : Short CoursesSixth International Planetary Probe WorkshopLow temperature mechanisms: No universally accepted definition, but: environmental temperature < Earth ambient (which can be as low as -50 C). Typical cases: Mars surface missions (operation down to -90 C environmental temperature typically required). Outer planet moons surface missions (operation down to -200 C environmental temperature typically required). Special, cryogenic applications: mechanisms in front ends of cryogenically cooled space telescopes (operation down to -250 C environmental temperature typically required). Mechanisms in free space at large solar distances: e.g. pointing mechanisms. Issues: proper choice of tribological elements & treatments; temperature gradients (temporal & spatial); use of local heaters to condition elements
