Ballistic-missile research with athena

Abstract

Athena was conceived to reduce the cost of ballistic-missile experimentation and employs comparatively inexpensive solid-propellant rockets to simulate the flight dynamics of intercontinental ballistic missiles. It is a four-stage, partially guided vehicle that has been launched from a point near Green River in south-eastern Utah and impacted at the White Sands Missile Range (WSMR) 420 naut miles away. The vehicle propels a variety of payloads into the atmosphere at various velocities and re-entry angles from altitudes < 400,000 ft. The nominal performance requirements are 1) 50-lb pay load delivered at 250,000 ft, 2) separation distances (fourth stage from pay load) of at least 5000 ft at test altitudes, 3) velocity at test altitudes of 22,000 fps, 4) re-entry angles of 18° to 46°, and 5) payload angle of attack as close to zero as possible. Nomenclature a.c. = aerodynamic center CD = drag coefficient CNCX = normal-force slope coefficient F A = pitch frequency h = altitude M = Mach number P = spin rate R = range $ref = reference area t = time VE = re-entry velocity ex. = angle of attack 7 = flight path angle