QTYUIOP THERMIONIC SPACE POWER THE EMERGING SOURCE OF SPACE POWER IN THE NEXT DECADE AUBURN UNIVERSITY AUGUST 17, 1999

QTYUIOP TRENDS IN SPACE l COMMICATION SATELLITES (COMSATS) WANT HIGHER POWER kW NOW, WANT 30+ kW IN FUTURE l MILITARY MOVING ASSETS TO SPACE –SPACE-BASED RADAR/LASER - 80 kW REQUIRED l SPACE EVOLVING INTO MILITARY “AREA OF RESPONSIBILITY” –SIGNIFICANT MILITARY/COMM’L ASSETS IN SPACE –LIKE LAND, SEA, AIR: SPACE MUST BE DEFENDED –SPACE SUPERIORITY VEHICLE (SSV) NECESSARY TO ACCOMPLISH THIS

QTYUIOP VOLUME OF GEO-SATELLITE LAUNCHES IS INCREASING

QTYUIOP DILEMMA OF GEO SATELLITES l EXPLOSIVE DEMAND FOR GEO COM SATS –DIRECT BROADCAST (e.g. TV) –DATA TRANSMISSION l ONLY 360 GEO SLOTS EXIST –SUPPLY OF GEO SLOTS LIMITED, DEMAND GROWING l HOW TO GENERATE MORE REVENUE? –INSTALL MORE TRANSPONDERS PER SATELLITE l WEIGHT OF SATELLITE REACHES LIMIT OF LAUNCH VEHICLE

QTYUIOP SOLAR TI IS AN ENABLING TECHNOLOGY l AT HIGH POWER, SOLAR-TI IS LIGHTER, CHEAPER THAN SOLAR PHOTOVOLTAICS l GEOCOM SATELLITES –THERE IS A LIMITED # OF SAT POSITIONS –DEMAND IS INCREASING FOR GLOBAL TELECOMMUNICATIONS –FOR REVENUE TO GROW, SATS MUST PUT ON MORE TRANSPONDERS  MORE POWER –  50 GEO SATS/YR WILL NEED REPLACEMENT

QTYUIOP BASIC THERMIONICS (TI) PRINCIPLES e-e- e-e- ~1800 K e-e- ~1000 K EXTERNAL LOAD e-e- e-e- HEAT IN HEAT OUT PLASMA “CLOUD”

QTYUIOP THERMIONIC CHARACTERISTICS l EMITTER IS HEATED 1600K K l ELECTRONS BOIL OFF EMITTER, CONDENSE ON 800 K K l ELECTRONS (e.g. ELECTRICAL POWER) DIRECTED THROUGH EXTERNAL LOAD l DESIREABLE FEATURES: –SIMPLE, NO MOVING PARTS –HIGH HEAT REJECTION TEMPERATURE

QTYUIOP THERMIONICS ORIGINALLY DEVELOPED FOR SPACE NUCLEAR POWER l SDI NEEDED kW FOR SPACE WEAPONS l THERMIONICS WAS ATTRACTIVE –SIMPLE, NO MOVING PARTS –HIGH HEAT REJECTION TEMPERATURE LEADS TO SMALL RADIATOR l RUSSIANS ORBITED TWO 5 kW TI REACTORS

QTYUIOP THERMIONICS (TI) USED ON BOEING SOLAR ORBITAL TRANSFER VEHICLE l THERMIONICS IS THE POWER TECHNOLOGY OF CHOICE ON BOEING SOTV PROGRAM –PRODUCES POWER AT LOW MASS l SOTV GENERATES POWER & PROPULSION –SOLAR FLUX REFLECTED AND CONCENTRATED BY MIRRORS –USED TO HEAT THERMIONIC CONVERTERS FOR ELECTRICAL POWER –ALSO USED TO HEAT HYDROGEN FOR THRUST

QTYUIOP SOLAR THERMIONICS CONCEPT LARGE INFLATABLE REFLECTOR THERMIONIC % EFFICIENCY TELECON BROADCAST Target on Earth HIGHLY REFLECTIVE SURFACE

QTYUIOP SOLAR THERMIONICS: MAJOR COMPONENTS INFLATABLE CONCENTRATOR HEAT RECEIVER THERMIONIC CONVERTERS SOLAR INPUT

QTYUIOP MASS OF GEO SATELLITE l THREE MAIN COMPONENTS OF SATELLITE MASS –(1) ELECTRICAL POWER SYSTEM –(2) PROPELLANT NEEDED TO GET FROM LEO TO GEO –(3) PAYLOAD (PRODUCES REVENUE) l GOAL IS TO MINIMIZE (1) + (2), MAXIMIZE (3)

QTYUIOP SOLAR TI MINIMIZES POWER SYSTEM + PROPELLANT MASSES l SOLAR TI POWER SYSTEM LIGHTER THAN SOLAR PANELS –AT 50 kW: l PV = 2820-lb. l TI = 1294-lb. –SAVINGS = 1526-lb. l HIGH ELECTRIC POWER PERMITS USE OF EFFICIENT ELECTRIC PROPULSION –ELECTRIC PROPULSION USES ONLY 20% OF PROPELLANT AS EXISTING CHEMICAL SYSTEMS

QTYUIOP SOLAR TI ALLOWS LARGER PAYLOADS ON GEO SATELLITES TITAN-IV LAUNCH OF 10,000-lb INTO GEO EXISTING SOLAR-PVFUTURE SOLAR-TI

QTYUIOP PRINCIPAL COMPONENTS: INFLATABLE CONCENTRATOR 50 ft DIA INFLATABLE ANTENNA, ON 100 ft BOOM, SUCCESSFULLY DEPLOYED FROM SHUTTLE

QTYUIOP PRINCIPAL COMPONENTS: THERMIONICS l THERMIONIC PERFORMANCE HAS IMPROVED –OXYGENATED ELECTRODES HAVE DEMONSTRATED 20% ELECTRODE EFFICIENCY

QTYUIOP CONCLUSIONS l USE OF SPACE SATELLITES IS INCREASING –POWER LEVELS NEEDED IN SATELLITES IS RISING l THERMIONICS IS EMERGING AS A CONTENDER TO PRODUCE POWER FOR THESE NEWER, MORE POWERFUL SATELLITES –CHEAPER AND LIGHTER THAN SOLAR PANELS

QTYUIOP QUESTIONS FOR BUSINESS TEAM TO ADDRESS l WHO ARE COMMERCIAL USERS OF SPACE POWER? –SATELLITE MANUFACTURERS l SPACE SYSTEMS LORAL l HUGHES l LOCKHEED l BOEING l WHAT POWER LEVELS DO USERS WANT AND WHEN –15 kW AVAILABLE TODAY –WHAT IS NEEDED IN 2005, 2010, & BEYOND

QTYUIOP QUESTIONS FOR BUSINESS TEAM TO ADDRESS (CONT) l BARRIERS TO MARKET ENTRY FOR NEW TECHNOLOGY –SATELLITE MFGS ALSO PRODUCE SOLAR PANELS –RELIABILITY/COST NOT DEFINED l HOW MANY AND WHAT TYPES OF SATS ARE LAUNCHED/YR: TODAY & FUTURE –LEO, MEO, GEO –POWER LEVELS

QTYUIOP QUESTIONS FOR BUSINESS TEAM TO ADDRESS (CONT) l IS OFFERING A COMBINATION OF POWER AND PROPULSION ATTRACTIVE? –AT PRESENT, POWER AND PROPULSION ARE TWO SEPARATE SETS OF HARDWARE l SOLAR PANELS FOR POWER l CHEMICAL PROPULSION = QUICK TRIP TIME –POWER & THERMAL PROPULSION l THERMAL PROPULSION = MEDIUM EFFICIENCY, MEDIUM TRIP TIME –POWER & ELECTRIC PROPULSION l ELECTRIC PROPULSION = HIGH EFFICIENCY, LONGER TRIP TIME