fusion energy foundation

Space Science& TechnologyThe Solar Polar Mission:A New Window on FusionEditor's Note: The U.S. House AppropriationsCommittee voted May 9 toterminate the Solar Polar Mission bycutting all its funding in the 1980 supplementalbudget. NASA had alreadypostponed the two-satellite launchdate from 1983 to 1985 in an attemptto meet the committee's budget-cuttingrequirements. The committee'sdecision now goes before the fullHouse vote. Your letters can help turnthe situation around. Write your congressmanand senator and write Rep.)amie Whitten (D-Miss.), chairman,House Appropriations Committee,and Rep. Edward Boland (D-Mass.),chairman. Subcommittee on IndependentAgencies, House AppropriationsCommittee, both at 2426 Rayburn,Washington, D. C. 20515.The Solar Polar Mission, an internationalproject for study of the nearestworking fusion reactor to theEarth—the Sun—promises to provideessential new information for nuclearfusion power development. The missionis jointly sponsored by the NationalAeronautics and Space Administration(NASA) and the EuropeanSpace Agency (ESA) under a"memorandum of understanding"signed in 1979.By launching two spacecraft to examinethe Sun from opposite polessimultaneously, scientists will obtainthe first three-dimensional view ofthe Sun and its atmosphere, or heliosphere.The probability that theSun's polar regions have much lessactivity than other solar regions willallow scientists to observe and measureprocesses underneath the Sun'ssurface corona—processes revealingmore about the thermonuclear processeswithin the star.Moreover, since the Sun's spots,70 FUSION September 1980magnetic Storms, and other activitiesaffect the Weather, climate, and radiocommunications on Earth, closermeasurements and better understandingof the fundamental scientificprocesses of the Sun will eventuallyallow scientists to predict the changesin communications possibilities necessaryfor improving navigation andradio transmission.The mission will be the first to senda craft outside the plane of the ecliptic(the plane' in which the Earth orbitsthe Sun), which no spacecraft has hadsufficient energy to do before.The two Solar Polar spacecraft, onebuilt by NASA and the other by ESA,will include stationary instrumentswith their sights fixed on specific objects,and instruments mounted on aspinning platform to see in many directions.NASA's Space Shuttle is assigned tolaunch the two spacecraft in a necessaryfirst step to reach Jupiter. Jupiter'simmense gravity will thenboost them free of the plane of theecliptic, and as the craft fly by thegiant planet, they will also make X-raymeasurements.On their mission, the Solar Polarspacecraft are set to explore and addto information on:Corona: In 1962, Mariner II verifiedearlier theories that a solar wind continuouslyblows outward from theSun's corona, or outer halolike layer.Since then, scientists have learnedthat high-speed streams in the solarwind cause periodic magnetic stormson Earth. Scientists suspect that thesestreams originate from holes in thecorona. Spacecraft observations ofthese coronal holes could allow themto predict geomagnetic and auroralactivity as far as 10 days in advance, tohelp shortwave radio communications,navigation, and geological explorationsystems that use magnetometers.Two of the Solar Polar Mission'sinstruments, the white-light coronagraphand an X-ray (ultraviolet)telescope, will give scientists a threedimensionalview of the Sun's corona.Convection layer: Underneath thecorona, closer to the thermonuclearreactions taking place in the core ofthe Sun, is a layer from which it appearsthe Sun's magnetic fields originate.Heat from the fusion reactionscannot escape to space as fast as it isAfter NASA's Space Shuttle launches the two Solar Polar spacecraft,Jupiter's huge gravitational force will boost the spacecraft free of theplane of the ecliptic allowing them to travel to the Sun's poles. An artist'sdepiction of the Shuttle launching appears on page 35.