Batteries and Fuel Cells in Space by Gerald Halpert, Harvey Frank, and Subbarao Surampudi

he year 2000 will mark the 44th sions. The Ni-Cd battery became the lasted five months. It also utilized a anniversary of the space program major energy storage device over the much larger Ag-Zn battery. Silver-zinc that began with the launch of the next 20 years because of its long cycle batteries have been used in several U.S. first Sputnik on October 4, 1956. life. The Ni-H2 battery started to play a spacecraft. Ranger 3 (1961 launch), uti- Tremendous progress has been role in the 80s. Recently, there has been lized two, 14 cell 50 Ah, Ag-Zn batteries made in the exploration of space considerable interest in the use of for its main power, and two, 50 Ah, 22 Tsince the late 50s. Thanks to the flexi- lithium-ion batteries because of their cell batteries for its TV camera power. bility and capability of batteries and high specific energy and energy den- Ranger 3 was placed into solar orbit fuel cells, NASA and the U.S. Air Force sity. A chronological history of battery and took moon photos. Mariner 2, con- (USAF) have been able to accomplish a firsts in space appears in Table I. taining one battery of 18, 40 Ah, Ag-Zn wide range of challenging space mis- Silver-Zinc Batteries—The earliest use cells, was launched August 27, 1962, sions. Batteries and fuel cells are used in of a battery in an orbital spacecraft was and was the first successful interplane- a wide variety of space applications the primary Ag-Zn battery used in the tary mission to Venus. such as launch vehicles, earth-orbiting Russian spacecraft, Sputnik, launched Nickel-Cadmium Batteries—The first spacecraft, space shuttle, crew return October 4, 1956. This primary battery use of Ni-Cd batteries for primary vehicles, astronaut equipment, plane- was used to provide power for commu- power was on Explorer 6, which sur- tary spacecraft, landers, rovers, and pen- nication and spacecraft operation. vived for only three months. In April etrators. In these missions, batteries and There were no solar cells available for 1960, NASA launched the first suc- fuel cells are used as a primary source of charging, and thus when the energy cessful long-term low earth orbit (LEO) electrical power or as an electrical was depleted, communication was ter- weather satellite, TIROS I. Eight TIROS energy storage device. minated. The Ag-Zn primary was spacecraft were subsequently launched. Space missions impose several crit- intended to provide power to the 84 kG The TIROS system contained three ical performance requirements on bat- spacecraft for three weeks. The space- strings of 21 Ni-Cd cylindrical F-5 cells teries and fuel cells. Batteries required craft actually remained in orbit for containing glass-metal seals to insulate for space applications must be capable three months. The second Sputnik, the positive terminal from the metal of operating in a hard vacuum and launched a month later, carried the dog case. Capacity was selected so that withstand severe launch environments known as Laika. The second Sputnik depth of discharge (DOD) was very low, (vibration, shock, and acceleration). was six times larger than first one and only 3%, so as to extend battery life. Space applications also require batteries that can provide maximum electrical energy in minimum weight and volume. Long cycle life (> 30,000 cycles) is the critical driver for orbiting spacecraft, and long active shelf life is the driver for planetary probes (> 7-10 years). Radiation resistance and operation at temperatures as low as -80°C is essential for some planetary missions. No single battery system can meet all these complex requirements. A number of different battery systems, such as silver-zinc, nickel-cadmium, nickel- hydrogen, and lithium, have been used to meet the complex requirements of various missions. In general, the specific energy of batteries in space has grown (see Fig. 1). Generally, batteries for space applications are custom designed and fabricated to meet the mission requirements. Some of the important space applications for batteries and fuel cells are discussed below.

A History of Space Batteries

The Ag-Zn battery was the first choice in the early days of space mis- FIG. 1. The evolution of flight batteries. (Photo courtesy of Jet Propulsion Lab.)

The Electrochemical Society Interface • Fall 1999 25 The long life capability was achieved at The OAO power system utilized a tem- were assembled into a standard battery the expense of increased battery size perature-compensated voltage (VT) and installed with the remainder of and cost. charge control system that applied a power electronics into the modular In November 1964, the first pris- constant voltage to batteries during power subsystem by McDonnell-Dou- matic Ni-Cd cells, produced by Gulton charge. This method resulted in appli- glas. The first lot of standard 20 Ah cells Industries, were flown on Explorer 23. cation of a high current from the solar in standard 20 Ah batteries were flown These were configured in a close knit arrays until the battery reached a preset successfully on the Solar Max mission battery pack held together with end limit. At the preset voltage, the charge for more than eight years. When the plates and metallic rods. As such, they current tapered until the end of the mission was terminated, the battery provided a more efficient battery design sunlight period, thus reducing the over- capacity was found to be an amazing than cylindrical cells. General Electric charge and reducing the I2R heat that is 16 Ah. Subsequently, the technology of Gainesville, Florida, and Eagle-Picher a cause of cell degradation. The selected was extended to 50Ah cells, which were Company of Joplin, Missouri, devel- voltage limit was based on a parallel set used on several NASA spacecraft, such oped prismatic batteries that operated of temperature compensated voltage as Landsat, TOPEX, UARS, and GRO. successfully in space for many years. curves (VT curves). The VT curve selec- The “super” Ni-Cd cells, developed In 1966, the Orbiting Astronomical tion used to limit the charge voltage by Eagle-Picher, were the next step to Observatory (OAO) series of spacecraft provided flexibility to account for enhance the Ni-Cd energy density and developed by the prime contractor, unexpected high depths of discharge life. These cells utilized electrochemi- Grumman Aerospace, utilized three and/or imbalance between cells and/or cally deposited plates of the technology batteries of 20 Ah prismatic Gulton batteries. developed for Ni-H2 cells. The non- cells uniquely assembled into two bat- In the mid-70s, NASA undertook a woven nylon separator was replaced tery frames. Pairs of cells were inter- program to develop “standard” flight with an inorganic PbO-impregnated spersed within the two assemblies to hardware. To this end, Goddard Space “Zircar” to minimize separator degrada- minimize temperature variation. Until Flight Center was responsible for devel- tion. NASA utilized these in the late 80s this time there was little application of oping the “standard” Ni-Cd cell and on small satellites, such as the small charge control and charge was carried battery. The cells, manufactured by Explorer series. out in the sun at the 10-20 hour rate. General Electric and later the Gates Co.,

TABLE I. Chronological List of First Use of Batteries in Space

Launch Date Spacecraft Life in Space Battery/Fuel Cell Type

12/6/56 ...... Vanguard...... Failed ...... Zn/HgO ...... First U.S. Launch 2/1/58 ...... Explorer 1 ...... 3.8 Months ...... Zn/HgO ...... Van Allen Radiation Belt 8/6/59 ...... Explorer 6 ...... 2 Years ...... Cylindrical Ni/Cd ...... First Earth Photos 3/13/61 ...... IMP 1 ...... 3.5 Years ...... Ag/Cd...... Non-Magnetic 1/26/62 ...... Ranger 3 ...... Solar Orbit ...... Ag/Zn...... Moon Photos 4/26/62 ...... Ariel I...... 14 Years ...... Prismatic Ni/Cd...... 1st in LEO 8/21/62 ...... Gemini ...... 7 Days ...... PEM Fuel Cell ...... PEM Fuel Cell 8/27/62 ...... Mariner 2...... Venus...... Ag/Zn...... 1st Planetary 6/23/63 ...... Syncom-2 ...... N/A ...... Cylindrical Ni/Cd ...... 1st in GEO 5/20/65 ...... Apollo Command Module...... Short Life...... Ag/Zn...... Limited Cycle Life 6/23/66 ...... NTS-2...... 5 Years ...... Ni/H2 ...... 12 Hour Polar 9/23/66 ...... USAF ...... Classified ...... Ni/H2 ...... LEO 9/7/67 ...... Biosatellite 2 ...... 3 Months...... PEM Fuel Cell ...... 1st Use of Nafion 10/11/68 ...... Apollo 7...... 11 Days ...... Alkaline Fuel Cell ...... 1st Manned Apollo 2/14/80 ...... Solar Max ...... 8 Years ...... Ni/Cd ...... “Standard Battery” 4/12/81 ...... Shuttle (STS-1)...... 2 Days ...... Alkaline Fuel Cell ...... 1st Shuttle 5/19/83 ...... Intelsat V ...... 14 Years ...... Ni/H2 ...... GEO 4/4/83 ...... STS-3 ...... Days...... Li-BCX ...... Astronaut Use 4/6/84 ...... LDEF ...... 6 Years ...... Li Cells ...... Exposure to Space 10/18/89 ...... Galileo ...... Hours ...... Li-SO2 ...... Jupiter Probe 4/25/90 ...... Hubble Space Telescope ...... In Orbit ...... Ni/H2 ...... NASA LEO 6/10/90 ...... Leasat...... Orbiting...... “Super” Ni/Cd ...... GEO 1/25/94 ...... Clementine ...... 5 Months...... SPV Ni/H2 ...... Lunar Mapping 1/25/94 ...... Tubsat-B ...... 4 Years ...... 2 Cell CPV ...... Store Messages 5/1995...... Centaur ...... 1st Mission ...... Li-SOCl2...... 28v, 250 Ah Battery 5/5/96 ...... Iridium-1 ...... Commercial...... 50 Ah SPV ...... 88 S/C to Date-LEO 11/19/97 ...... Flight Experiment ...... USAF Experiment ...... Na/S ...... 7 Day Experiment

26 The Electrochemical Society Interface • Fall 1999 Nickel-Hydrogen Batteries—The nickel- used in the commercial iridium satel- the membrane of choice for all PEM hydrogen (Ni-H2) battery was developed lites developed by Motorola. More than fuel cells including JPL’s newly discov- in the 60s. It made use of the NiOOH 60 iridium spacecraft have been ered direct methanol fuel cell. While electrode from the Ni-Cd cell and the H2 launched. the PEM fuel cell served well in this ini- electrode from a fuel cell. These cells Lithium Primary Batteries—Primary tial application, it did not have the employed an individual pressure vessel lithium batteries, including Li-SO2, Li- power density capabilities of the alka- to contain hydrogen at a pressure of SOCl2, LI-BCX, Li-(CF)x, and Li-MnO2 line type of fuel cell that was concur- 400-600 psi. The replacement of the systems, have been used for a number rently under development. Subsequent cadmium electrode with a hydrogen of applications in astronaut equip- Apollo manned flights (1968-72) uti- electrode reduced weight and increased ment, planetary probes, and rovers. Li- lized the alkaline electrolyte fuel cell energy, thus almost doubling the spe- (CF)x batteries were used as the containing potassium hydroxide elec- cific energy over the Ni-Cd cell. How- emergency destruct battery in launch trolyte held in an asbestos type sepa- ever, because of the cylindrical vehicles. Li-SO2 batteries were used in rator. The shuttle orbiter fuel cell configuration of the pressure vessel and the Long Duration Exposure Facility power plant, developed by United the wider spacing of the cells on the and in the Galileo, Cassini, and Star- Technologies Corp. and produced baseplate, the specific energy of the dust Probes. Li-BCX cells, a spin-off today by International Fuel Cells, con- battery was similar to that of the Ni-Cd from biomedical applications, and tains three H2/O2 alkaline fuel cell battery on a gravimetric basis. On a manufactured by Wilson Greatbatch, power plants supplying 12 kW at peak volumetric basis, the energy was signif- have been in use since 1983 aboard the and 6 W average power in perfor- icantly less than that of the Ni-Cd bat- shuttles in astronaut equipment. Li- mance. The operating temperature is tery. However, this system offered the SOCl2 batteries were used in the 83-105°C. The current density is 66-450 capability of extended cycle life at Sojourner Rover and in the DS-2 Mars mA/cm2. The system is capable of higher DOD and calendar life than the Penetrator. 2,000 hours of operation. The shuttle Ni-Cd battery. The first launch of Ni-H2 Lithium-ion Rechargeable Batteries— orbiter fuel cell power plant is 23 kg battery was in the Navy’s NTS-2 space- Li-ion rechargeable batteries are com- lighter and delivered eight times the craft where it was used as a back up to pact, lightweight, and have already power of the Apollo fuel cell system. the main Ni-Cd battery. Comsat was appeared in many consumer products. PEM fuel cells based on Nafion are the first to develop this battery and use These are indeed attractive but have presently being considered for the it in the Intelsat V spacecraft in a geo- not yet been used in space. For this shuttle orbiter. stationary (GEO) mission. The Ni-H2 reason, NASA and the USAF have estab- battery was first flown on Intelsat V, a lished a joint interagency program to Space Applications GEO spacecraft in 1983. Almost all develop these for aerospace and aircraft GEO spacecraft now use Ni-H2 bat- applications. NASA is planning to use The following sections describe the teries. Hughes Aircraft Corp. also these batteries for a number of future requirements of batteries and fuel cells played a major role in the development space missions such as Mars 2001 for various space applications. The of Ni-H2 cells and batteries for space. Lander, Mars 2003 Rover, Europa, New major government agencies involved The first NASA LEO spacecraft to use Millennium ST4, and Solar Probe. Plans in the development of batteries and Ni-H2 batteries was the Hubble Space are also being made to replace the fuel cells for space include: NASA Cen- Telescope launched in 1990. The Inter- existing hydraulic auxiliary propulsion ters (Goddard Space Flight Center, national Space Station is also planning unit of the shuttle with an electrically Glenn-Lewis Research Center, Johnson to use Ni-H2 batteries. controlled system using 100-150 kWh Space Center, Marshall Space Flight In 1983, Eagle-Picher was successful Li-ion batteries. The USAF is consid- Center, and Jet Propulsion Laboratory); in housing two Ni-H2 cells in the same ering these cells for use in aircraft, the USAF (Wright Laboratory, Phillips cylinder, and this design has been des- unmanned aircraft vehicles, and GEO Laboratory, and Aerospace Corp.); and ignated as the common pressure vessel and LEO spacecraft. the U.S. Navy (Naval Research Labora- (CPV) configuration. The first signifi- Fuel Cells—The first use of a fuel cell tory and Naval Surface Warfare cant NASA application of a CPV bat- system in space was in the Gemini pro- Center/Crane). Much of the U.S. tery, was in the Jet Propulsion gram on August 21, 1962. At that time, Department of Defense (DoD) informa- Laboratory (JPL) Mars Global Surveyor the first of seven Gemini earth-ori- tion on DoD applications is not readily mission in 1994. This battery con- ented, manned spacecraft was available, therefore the information tained 3 1/2˝ diameter cells and was launched with a proton exchange below is primarily that of NASA. rated at 20 Ah. A smaller (16 Ah) bat- membrane (PEM) electrolyte fuel cell, Rockets and Launch Vehicles—In tery containing 2 1/2˝ diameter CPV known at that time as the solid rockets and launch vehicles, batteries cells was also used in the Mars 98 and polymer electrolyte ion exchange are primarily used for ignition of the Stardust spacecraft. These spacecraft membrane fuel cell. Six more Gemini solid rocket motors, and powering the were designed and assembled by Lock- spacecraft were successfully flown with pyro systems, guidance and control heed-Martin Aerospace Corp. In par- this fuel cell through 1966. The electronics, and communication sys- allel with these developments, Johnson Biosatellite 2, launched September 7, tems. Batteries required for these appli- Controls developed a single pressure 1967, utilized a PEM fuel cell system cations must possess high specific vessel Ni-H2 battery in which 22 cells with an important change involving energy and specific power. In addition, were mounted in the same structure. the use of an improved membrane they must have long storage life. Cycle This assembly was used for the first material known as Nafion (perfluo- life requirements of these missions are time in 1994 in Clementine, a Navy roalkanesulfonic acid polymer), a regis- minimal. Both primary and recharge- satellite. Currently, these are being tered trademark of the DuPont able Ag-Zn batteries have been used in manufactured by Eagle-Picher and are Company. Since then, Nafion has been sounding rockets and launch vehicles.

The Electrochemical Society Interface • Fall 1999 27 Reserve Ag-Zn and thermal batteries are craft in GEO orbit. During the 135 and SAFT are the primary source of Ni- the choice for use in missiles. Ag-Zn days of full sun, power for the space- Cd and Ni-H2 cells. Li-ion batteries are batteries have been developed and pro- craft loads and battery charging is sup- presently being developed for these duced by Yardney, Eagle-Picher and plied by the solar arrays. The full sun applications. BST. Li-SOCl2 (7 kWh, 250 Ah, 28V) period is followed by an eclipse season Space Shuttle—The space shuttle batteries were developed by Yardney characterized as follows: 23 earth days requires a power source that can pro- and SAFT for Centaur launch vehicles of increasing daily eclipse periods from vide 6-12 kW for 2,000 hours. Batteries to replace the Ag-Zn batteries, in order 1 up to 70 minutes (remainder of each cannot satisfy this application, as the to extend operating time in placing day in full sun), followed by 23 days of required battery weight would be pro- payloads in orbit. decreasing daily eclipse periods from hibitive. The application can and has, LEO and GEO Spacecraft—Circling 70 minutes down to 1 minute however, been met with an alkaline the earth every 100 minutes, the LEO (remainder of each day in full sun). fuel cell operating on hydrogen and spacecraft, located approximately 100 During the varying eclipse periods, oxygen stored separately in cryogenic miles above the earth, is in the sun power for the spacecraft loads is sup- tanks. International Fuel Cells is pro- approximately 65 minutes and plied by the batteries. During the viding alkaline fuel cells for the shuttle eclipsed for 35 minutes. During the remainder of each earth day, when the orbiter applications. This system has sun exposure, solar arrays convert the spacecraft is in full sun, e.g., from a been in use for the past 18 years. Plans sun’s energy to electrical power, which max of 23:59 minutes to a min of are underway to replace the alkaline operates the spacecraft and charges the 22:10, the solar arrays provide power fuel cell system with an advanced battery. Thus, because of the contin- for battery charging and spacecraft PEM-based system. The replacement of uous 100-minute sun/eclipse periods, power. The maximum discharge the hydrazine-powered auxiliary LEO spacecraft require batteries that period occurs only twice a year at the power unit (APU) with an electric APU experience 5,000 charge/discharge 23rd day midpoint of each eclipse powered by 100-150 kWh Li-ion bat- cycles per year. Generally, LEO space- season. At the midpoint day, the batteries is also underway. craft require batteries capable of oper- teries are subjected to the greatest Astronaut Equipment—Astronauts ating for a period of five years and depth of discharge, which can range have a number of applications needing delivering more than 30,0000 cycles. from 40 to 70% DOD. Thus the 23rd batteries to power portable equipment Ni-Cd and Ni-H2 batteries have this day serves as the design point for the such as cameras, tools, laptop com- required cycle life capability and are GEO battery in that it must provide puters, and lights. Key requirements of presently being used in several LEO this maximum power for tens of years. these batteries are that they be safe as spacecraft (see Figs. 2 and 3). Lighter As in the LEO spacecraft, it is during well as compact and lightweight so weight Li-ion batteries are available the eclipse period when the spacecraft that they do not adversely impact but these require improved cycle life requires stored energy from the battery astronaut mobility. Silver-zinc batteries capabilities before they can be consid- to provide power for the instrument met these requirements in the early ered for LEO applications. loads as well as spacecraft communica- stages of the manned flight program. GEO spacecraft are located approxi- tions, attitude control, and power con- Primary lithium batteries can reduce mately 22,000 miles above the earth in ditioning. size and weight to an even greater a fixed location relative to the earth. Ni-Cd batteries were originally used extent than Ag-Zn batteries, but could The GEO spacecraft are in full sun for for GEO spacecraft applications. not be used until their safety had been 135 earth days followed by an eclipse Presently Ni-H2 batteries are being demonstrated. With the application of season of 46 earth days. This process used in most of the GEO spacecraft adequate safeguards, and after exten- occurs twice each year and is repeated due to their long calendar life and sive testing, NASA/Johnson Space continuously for the life of the space- availability in large sizes. Eagle-Picher Center (NASA/JSC) approved the use of

FIG. 2. (left) Ni-Cd Battery. (Photo courtesy of Jet Propulsion Lab.)

FIG. 3. (above) Mars Global Surveyor. 2 cell CPV Ni-H2 Battery. (Photo courtesy of Jet Propulsion Lab.)

28 The Electrochemical Society Interface • Fall 1999 selected primary lithium batteries for with the Mars Pathfinder) employed exist elsewhere than on planet Earth; specified astronaut equipment. primary Li-SOCl2 batteries manufac- (3) to identify the existence of Earth- NASA/JSC has subsequently developed tured by SAFT (see Fig. 5). Low temper- like planets beyond our solar system; safety requirements for all batteries ature rechargeable Li-ion batteries are (4) to utilize the knowledge of the Sun, considered for use in astronaut equip- being developed for future Mars Earth, and other planetary bodies to ment. Several specific cells of the fol- Rovers. develop predictive environmental, cli- lowing types have been approved for Planetary probes require primary mate, natural disaster, and natural use in astronaut equipment: alkaline, batteries that can provide high specific resource models, to help ensure sus- Ag-Zn, Ni-Cd, Ni-MH, and Li-BCX (Li- energy and energy density and possess tainable development and improve the SOCl2 cells with bromine chloride). long active shelf life (six to eight quality of life on Earth; and (5) to The Li-BCX system is specifically being years). In addition, some of the mis- determine the feasibility of estab- used in the helmet lights and TV cam- sions require batteries to operate at lishing a permanent human presence eras. Plans are being developed to temperatures as low as -80°C and within space. These programs and missions replace the limited cycle life of the stand 80,000 G shock/acceleration. Li- require revolutionary technology Ag/Zn battery in the manned maneu- SO2 batteries were used for the probe advances in several areas including vering unit with a Li-ion battery. on the Galileo mission to Jupiter. The new power sources and energy storage Planetary Landers, Rovers, and probe of the Stardust mission has also devices. Existing batteries (Ni-Cd, Ni- Probes—Planetary landers require employed Li-SO2 batteries. Li-SOCl2 H2 and Ag-Zn) may satisfy a limited rechargeable batteries that can provide batteries, capable of operating at -80°C, number but cannot be expected to sat- high specific energy (> 100 Wh/kg) were used on the two penetrators that isfy all of these new and challenging and long active shelf life (> 10 were launched along with Mars 98 mission requirements. months). In addition, these batteries spacecraft. Some of the planetary exploration must be capable of operating at tem- missions require batteries that can peratures as low as -40°C. Cycle life The Future of Batteries and operate at ultra low temperatures in requirements of these missions are Fuel Cells in Space the range of -20 to -100°C (probes, lan- modest, less than 300 cycles, at mod- ders, rovers, and penetrators); with- erate depth of discharges. Ag-Zn bat- In the next millennium, NASA is stand ultra high G forces to 80,000 G teries manufactured by BST were used planning a number of exciting and (penetrators); and provide exception- in the Mars Pathfinder mission (see challenging space programs and mis- ally long cycle life capability (orbiters). Fig. 4). Li-ion batteries are being con- sions to explore our universe. The In addition, the requirements demand sidered for future Mars Landers. major goals of the NASA space pro- that these batteries be very lightweight Battery requirements for planetary gram are: (1) to obtain an improved and compact. The majority of the far rovers are similar to those of the lan- understanding of the evolution and term solar system exploratory missions ders. Silver-zinc batteries were used on formation of universe, galaxies, stars, are projected to use very small space- the Moon Rover vehicle. The and planets; (2) to determine the exis- craft of the “shoe box size.” Also being Sojourner (Mars Rover launched along tence of life, in any form, that may considered are robotic devices like

FIG. 4. (above) Mars Pathfinder. Silver-Zinc Battery. (Photo courtesy of Jet Propulsion Lab.)

FIG. 5. (right) Sojourner Rover. Li-SOCl2 Batteries. (Photo courtesy of Jet Propulsion Lab.)

The Electrochemical Society Interface • Fall 1999 29 micro- and nano-rovers. These micro- by utilization of local resources. Acknowledgments spacecraft will, in turn, require micro- Advanced fuel cells are presently being batteries, batteries on a chip, considered for surface power genera- The work described in this paper micro-capacitors, and mW fuel cells. tion. High specific energy batteries, was performed by the Jet Propulsion Future earth-orbiting missions capable of operating at low tempera- Laboratory, California Institute of require large size batteries with long- ture, may also be required for manned Technology, under a contract with the cycle, and calendar-life capabilities. rover applications. ■ National Aeronautics and Space Future LEO missions will require bat- Administration. teries that can provide a cycle life in excess of 50,000 cycles at 50% or greater DOD. Future GEO missions will require large size batteries capable of About the Authors operating over 15-20 years. NASA also plans to develop revolu- Gerald Halpert, past Chairman of the Battery Division, has more than 40 years tionary new advanced transportation experience in batteries and fuel cells for Aerospace and Defense applications. He systems that can accommodate recently retired as Program Manager from the Jet Propulsion Laboratory. humans during travel to distant desti- nations. Among these are crewed mis- Harvey Frank has more than 40 years experience in fuel cell and battery develop- sions to explore planetary and other ment and recently retired as Senior Member of the Technical Staff from Jet Propulsion bodies in the solar system. NASA will Laboratory. fully integrate and utilize the Interna- tional Space Station, the space shuttle, Subbarao Surampudi, Chairman of the Battery Division, has 25 years of experi- and other international contributions ence in electrochemical technologies. He is currently Supervisor of the Electrochemical to achieve these goals. These missions Technologies Group at the Jet Propulsion Laboratory. require power sources that can operate

30 The Electrochemical Society Interface • Fall 1999