The Athena launch system for small payloads

Abstract

An overview is presented of the Athena (formerly LMLV) family of vehicles that was developed to support the current trend toward smaller, rapidly developed, cheaper spacecraft programs. Athena is the system to be fully developed without any government funding, and follows Lockheed Martin's commitment to mission success that has been the hallmark of over thirty years of Atlas and Titan services. An overview of the basic Athena design is provided, along with a summary of payload fairing, payload adapter, and separation system options. Athena's use of Thiokol's Star motors as injection stages is presented for mission requirements other than Low Earth Orbit (LEO). Finally, results of the successful Athena I/Lewis and Athena Il/Lunar Prospector launches are provided, along with a summary of the current manifest. Program Overview Lockheed Martin has made operational a new family of small vehicles that address the growing government and commercial market for smaller, rapidly developed, cheaper satellite programs. The Lockheed Martin Athena family of configurations makes maximum use of existing stage components, subsystems, and facilities in order to minimize development cost, schedule, and programmatic risk. The two currently-available configurations exhibit a high degree of commonality in stage hardware, subsystems, and flight software. The Athena III variant will use a majority of common hardware with Athena I and II, and be sized to attain 8000-10000 Ibs of payload capability to LEO. The Athena I and II configurations and one of several candidate Athena III concepts are illustrated in Figure 1. The Athena team priorities are three-fold: establish a highly reliable system, maintain an affordable services price that is flexible to customer needs, and maintain an aggressive development schedule that does not compromise the previous two priorities. The Athena Program is a part of Lockheed Martin Astronautics' Commercial Launch Services group, which also provides Atlas and Proton services, and is based in Denver, Colorado. Athena represents a strategic commercial partnership between Lockheed Martin, Thiokol, Pratt & Whitney, and Primex Aerospace; each of whom invested in the development of their respective subsystems. Lockheed Martin assumes responsibility for the overall system, its integration and operation, and all services provided to a contracting customer. The program is designed to provide a capacity of 12 flights per year, launching from both Launch Complex-46 (LC-46) at Cape Canaveral Air Station (CCAS) and Space Launch Complex-6 (SLC-6) at Vandenberg Air Force Base (VAFB). After two successive first launch successes, the Athena I for the SSTI-Lewis mission and the Athena II for the Lunar Prospector mission, the Athena Program currently has five contracted missions through 1999. The Athena configurations consist of flightproven solid rocket motor main stages and a flightproven storable liquid propulsion system for injection orbit trim and attitude control, thus achieving the high injection accuracy of typical liquid propulsion vehicles without the associated high costs. Thiokol's family of Star SRMs are available for use as f Copyright © 1998 by Lockheed Martin Corporation. Published by the American Institute of Aeronautics and Astronautics, Inc. with permission. * Senior Member 120 American Institute of Aeronautics and Astronautics Copyright© 1998, American Institute of Aeronautics and Astronautics, Inc. injection stages for planetary, middle-Earth-orbit, and geosynchro-nous transfer orbits. The Athena I configuration provides 794 kg of injected payload to low Earth orbit (LEO), where LEO is optimally defined to be a 185 km circular orbit inclined 28.5 degrees. The Athena II configuration can provide over 1,973 kg of injected payload to LEO. The Athena III configuration is currently baselined as an in-line configuration (no strap-on motors), having up to 4,300 kg of payload capability to (LEO). The current baseline utilizes a derivative of the most successful large solid rocket motor ever flown: the Space Shuttle's Redesigned Solid Rocket Motor (RSRM). Figures 2, and 3 provide approximate performance capabilities of the operational Athena I and Athena II configurations, respectively, as a function of injection orbit. The elliptical orbits utilize a 185 km perigee altitude. Figure 4 summarizes approximate Athena performance capabilities to geosynchronous transfer orbit (GTO), recognizing that the perigee kick motor would be chosen based upon specific mission performance requirements. Figures 5 and 6 summarize approximate performance to Earth escape orbits for Athena I and Athena II, respectively. UP TO 9,500 Ib (4,308 kg) UP TO 4,350 Ib _____ 11 <J73 \ca ORBIT (1,973kg) ADJUST, MODULE (0AM)