SPACE PLATFORMS -- Introduction

1. INTRODUCTION

1.1 Definition/Scope

The Space Platforms technology area includes efforts devoted to satellite systems and launch vehicles. Here, satellite refers only to the support platform as opposed to the mission payload, and the launch vehicles subarea includes ballistic missile technologies. There are two major subareas, as shown in Figure VIII.1: (1) Space Vehicles, focused on thermal management, structures, survivability, GN&C, power, and astronics (those aspects of electronics, sensors, communications, and satellite control technology required by the space environment) and; (2) Space Propulsion, which includes booster, orbit transfer and satellite propulsion. Space sensors, electronics, and communications payload technologies, unique to space, are part of the Sensors and Electronics panel and the Information Systems and Technology panel but are included here for completeness of space demonstrations.

Figure VIII.1. Planning Structure Space Platforms Technology Area

The Space Vehicles subarea includes all of the technology efforts contained in the Space Vehicles section of the 1995 Air and Space Vehicles DTAP along with space power from the 1995 Aerospace Power and Propulsion DTAP. However, the flight experiments technology effort has been incorporated into the technology demonstrations section of the 1996 DTAP. The Space Propulsion subarea is the corresponding portion of the 1995 Aerospace Power and Propulsion DTAP. See Resource Appendix for funding of this Defense Technology Area. The set of DoD S&T technology efforts included in this panel area encompasses the following:

Space Vehicles:

Thermal Management: focused on heat transfer/dissipation and cryocooler technologies for all satellite applications.
Structures: focused on the development of structures and structural control technology for DoD spacecraft and launch vehicles. Work on tankage for launch vehicles and inflatable structures for antennae or optics is now being included in this technology effort. Work on nozzles and cases for rocket systems is not included here but is included later in the Space Propulsion Subarea. Structures for hypersonic vehicles are not included in Space Platforms, but are covered under Air Platforms. In the same vein, work on Ground Based Anti-Ballistic Missile Missiles is not covered here, but is covered in the Weapons area.
Survivability: focused on surviving natural and hostile space environments using multiple strategies and active and passive techniques that may be employed in space vehicle design to improve on-orbit survivability.
Guidance, Navigation and Control (GN&C): focused on advanced GN&C science and technologies for launch from Earth, Earth orbit and free space. GN&C encompasses both launcher/missile guidance and spacecraft guidance in the unique gravity free/gravity controlled space environment. GN&C also involves the precise timing and time transfer technologies enabling the Global Positioning System (GPS), and advancing the technologies in GPS applications.
Spacecraft Power: focused on the generation, storage, and distribution of electrical power onboard spacecraft. This technology subarea covers the particularly stressing spacecraft problem of radiation hardened solar cells and power systems and long life energy storage systems.
Astronics: focused on adapting space unique technology including sensors, electronics, communications and satellite control technologies.

Space Propulsion:

The Integrated High Payoff Rocket Propulsion Technology Program (IHPRPT) is a tri-service/NASA/industry program designed to develop and demonstrate innovative and revolutionary technologies that will dramatically advance state-of-the-art propulsion technology. IHPRPT has been established to strengthen the propulsion technology base for application in U.S. military, civil, and commercial programs and 1995 marked the first year of this program. Participants in the IHPRPT program include the US Army, US Navy, US Air Force, NASA and industry. All participants are working together to achieve a common set of national propulsion goals.

Boost Propulsion: focused on large thrust producing engines and motors for first and second stage launch vehicle environments. Boost propulsion programs address both space boost and strategic (ballistic missile) boost technology development.
Orbit Transfer: focused on efficient chemical and non-chemical orbit transfer propulsion systems which move payloads from low-Earth orbit (LEO) to operational orbit altitudes.
Satellite Propulsion: focused on spacecraft propulsion for maneuver and station keeping that includes both chemical and non-chemical propulsion, e.g., solar electric and solar thermal.

1.2 Strategic Goals

The strategic goal is to exploit space platforms to provide warfighters with critical information and global communications. Space allows a whole range of critical military functions without the usual limitations associated with denied areas or geographical remoteness. Information provided U.S. military personnel by space-based systems includes: weather, forces location/movement, environmental monitoring, transportation routes, and advanced warning on weapons deployment. The essence of the DoD's use of space is as a domain in which huge quantities of information can be both gathered and delivered directly to the warfighter.

The goal for Space Vehicles is to construct spacecraft which are lighter, smaller, autonomous, require less power and have a longer functional lifetime with lower lifecycle costs while maintaining and improving overall system performance and operation. Achievement of this goal is grounded in the basic technologies of structures, power, electronics, etc. and will only be accomplished as these technologies are strongly supported and demonstrated for space vehicle application.

Space Propulsion is a critical supporting technology that has a large impact on the lower cost goal by providing for cheaper access to space. Both boost and orbit transfer propulsion technology developments are directed to this effort. Operations are also dependent on space propulsion technologies including timely access and on-orbit maneuvers. Figure VIII.2 identifies key technology transition/transfer opportunities in the Space Platforms area that will continue to enhance and enable the U.S. military dominance of the high ground. Included are commercial systems whose more frequent new starts and shorter development cycle time enable the rapid evolution of satellite technology. A list of acronyms can be found at the end of this chapter.

1.3 Aquisition/Warfighting Needs

U.S. space assets support five of the twelve Joint Warfighting Operational Needs/Capabilities. These five are (1) Dominant Battlespace Knowledge, (2) Information Warfare, (3) Counterproliferation, (4) Precision Force, and (5) Joint Theater Missile Defense. Dominant Battlespace Knowledge is supported by the following space missions: surveillance; intelligence; communications; mapping, geodesy, and charting; environmental monitoring; and command and control. Information Warfare is supported by the satellite control and space control missions, Counterproliferation by surveillance and intelligence missions, Precision Force by the navigation mission and Joint Theater Missile Defense is supported by the surveillance, intelligence, communications, and command and control missions. All of these space missions are in turn supported by the space launch and space system control missions, and the space unique aspects of system integration and acquisition. Space-related acquisition amounted to $13.5 billion in FY95.

	Years
	2000	2005	2010
Space Vehicles	SBIRS High 32 bit Rad Hard Processors MWIR Focal Planes NPOESS MAGIC Solar Cells Batteries PCS/Cellular Systems Sat Comm	SBIRS Low Cryocoolers LWIR Focal Planes Rad Hard Processors GPS IIF GN&C MAGIC Advanced EHF MILSATCOM 32 bit Processors RF & Laser X-Links Space Based JSTARS Sensors Electronics 2nd Generation PCS Sat Comm	Space Based AWACS HEXSAT Space Based Laser Systems Precision Platforms Space Power
Space Propulsion	RS-27 Upgrade EELV Tech Insertion Titan SRMU Solar Electric Propulsion	Environmentally Clean Motors Russian Engine Tech Reusable Cryo Engine Shuttle Replacement	Rapid Response ELV Improved Russian Engine Technology Trans Atmospheric Vehicle

Figure VIII.2. Space Platforms Technology Transition Opportunities

The Space Platforms technology area provides new and improved technologies which support, expand, and/or enable all of the above warfighter needs and space mission areas. The development of affordable, expendable boost and strategic propulsion systems will enhance the strategic agility of the United States space forces. The operational improvements for boost and orbit transfer systems by the years 2000, 2005, and 2010 include 9%, 16%, and 22% increases in payload capability or launch cost reductions of 19%, 31%, and 42%. Long-life, responsive spacecraft/satellite propulsion systems (solar electric, solar thermal, chemical) support the warfighter by enhancing strategic maneuverability and reliability of reconnaissance/surveillance and communication capabilities. Satellites in geosynchronous orbit will be able to extend their on-orbit life up to 45%, increase repositioning capabilities by a factor of 2-5 depending on the size of the satellite, or increase useful mission payload mass by 10-30%. In addition, this technology area supports acquisition by providing advanced electronic components which are lighter, faster, require less power, survive solar maximum conditions, etc. Advanced components being considered for MILSTAR for example, will produce a lighter satellite that allows use of a smaller launch vehicle resulting in a savings of $150M per launch. Individual improvements presented in this document are measured against current technology as opposed to planned improvements or future developments.