HUNTSVILLE, ALA. — Leidos Inc., a defense, aviation and biomedical research company, has signed a 61,358-square-foot lease at 915 Explorer Blvd. in Huntsville. The company occupies multiple locations in the city but plans to consolidate much of its operations to the single-story flex building. The property is located within Cummings Research Park, the second-largest research park in the United States, trailing only Research Triangle Park in Raleigh. Carter Burwell of JLL’s Birmingham office, and Doug Seale and Mateo Diachok of JLL’s Washington, D.C., office, represented Leidos in the transaction.