what is the function of satellite in a chromosome?
There are at least 2 SAT chromosomes in each diploid nucleus. They
  play a vital role in the formation of the nucleolus after cell
  division is completed.
  
  In humans, chromosomes number 13, 14, 15, 21 and 22 are examples of
  SAT chromosomes.


cuted from http://en.wikipedia.org/wiki/Satellite_chromosome