Section 59.09. Admission fees

In  order that the educational influence of
  the planetarium shall reach as many persons as possible, the board shall
  not fix admission fees, at rates higher than are necessary  to  pay  the
  cost   of   construction,  operation,  maintenance  and  repair  of  the
  planetarium  and  instruction  in  connection  therewith,  and  reserves
  therefor,  and  to pay the principal of and interest on any bonds issued
  hereunder, and to meet the reserves and sinking funds  provided  for  in
  any  resolution  authorizing such bonds. Classes from the public schools
  and colleges  of  the  city  of  New  York  shall  be  admitted  to  the
  planetarium  at such times and upon such days of the week and under such
  reasonable rules and regulations as the board shall prescribe.