Emily Corwin / NHPR

When celebrated Concord resident and high school teacher Christa McAuliffe died in the Challenger explosion in 1986, an out-ofโ€“ state donor offered $500,000 to build a monument in downtown Concord. As then-mayor Jim MacKay remembers, the city declined. Instead, the state built a planetarium. Today โ€“ 26 years after the state opened the McAuliffe Planetarium โ€” the facility is on its way to becoming a private, nonprofit institution.