r-squared attenuation


Senior Member
Russia, Russian
Could you, please, explain me, what does the highlighted part mean:
The huge glowing radiators mounted to the engines dissipate their heat, and the enormously long central truss, with its own protective coolers and reflectors, protects the cargo and crew modules from the engines' heat and radiation using the simple rule of r-squared attenuation rather than heavy shielding.
(it is about a spaceship)
  • panjandrum

    Lapsed Moderator
    English-Ireland (top end)
    The intensity of radiation gets less the further away you are from the source.
    The intensity of radiation is inversely proportional to the square of the distance from the source.
    If you go twice as far away, the radiation reduces to a quarter.

    The point is that the crew are protected from the engines' heat and radiation because they are very far away from them.