 The planetarium remained at normal levels of service during this renovation period , but attendance dropped significantly , particularly when the adjacent museum was closed for a period of two years during the most intensive phase of its second major expansion . In all , the construction phase lasted for four years , from 1978 to 1982 . In particular , some school groups that could justify the expense of seeing the museum and a planetarium show in a single day 's outing had difficulty justifying a visit solely to the planetarium . 
