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.