A C-17 Globemaster III assigned to Joint Base Charleston prepares to land at McEntire Joint National Guard Base, S.C., Nov. 16, 2020. Palmetto Challenge is a global mobilization exercise held at McEntire Joint National Guard Base, S.C., and Pope Army Airfield, N.C. The exercise is held in order to develop readiness and awareness in a simulated deployed environment for over 100 Airmen from Joint Base Charleston.