Flagship Program. The Flagship Program is a series of NASA missions to explore the Solar System. It is the largest and most expensive of three classes of NASA Solar System Programs, the other two being the medium-cost New Frontiers Program and the lowest-cost Discovery Program. According to NASA, the cost of a Flagship-class mission is over $1 billion. These missions will be crucial in allowing humans to reach and explore high-priority targets. These critically important targets could help establish the limits of
not flammable; not combustible or easily set on fire. Origin of nonflammable. 1960-1965. First recorded in 1960-65; non- + flammable.
To avoid confusion, choose flammable when you are referring to something that catches fire and burns easily, and use the relatively recent nonflammable when referring to something that doesn't catch fire and burn easily.