The Asp (Atmospheric Sounding Projectile) was created by Cooper Development for the US Navy for the purpose of probing the mushroom clouds of nuclear explosions. The rocket was propelled by a polysulfide or polyurethaneperchlorate solid propellant. Fin and payload dimensions and materials varied from project to project.
Flares trailed from the fin tips to aid in tracking, and spin tabs along the trailing edges of the fins reduced trajectory variations from thrust misalignment.