AAS 97-666

MAXIMIZING THE LAUNCH WINDOW OF THE GLOBAL POSITIONING REPLENISHMENT SATELLITES

D. Cave and P.E. Jasper - Lockheed Martin Corporation

Abstract

The existing 24-satellite Global Positioning System constellation will be replenished by GPS Block IIR satellites. Replenishment vehicles are required to achieve any given constellation plane within a tolerance of several degrees of right ascension on any given date.

Lockheed Martin Missiles and Space, under the direction of the Air Force, conducted a study to plan the launch window to achieve GPS IIR requirements within system error budgets. This paper presents the method developed in the study to maximize the launch window duration within operational constraints.