To test a key instrument of a spacecraft that will fly closer to the sun than any before, engineers at Oak Ridge National Laboratory and the University of California–Berkeley used ORNL’s powerful plasma-arc lamp as a solar heat flux simulator. They tested the Fields instrument, which will make direct measurements of electric and magnetic fields, radio emissions and shock waves that course through the Sun’s atmospheric plasma. Tests at ORNL showed the instrument can take the heat it will encounter during NASA’s Solar Probe Plus mission.
Johns Hopkins University’s Applied Physics Laboratory has designed and will build and operate the spacecraft for NASA. When the spacecraft launches in 2018, it will carry instruments for several experiments aimed at understanding how the solar corona heats and solar wind accelerates.1
Space’s extreme environment makes testing the Fields instrument under high heat flux a critical aspect of design. During the spacecraft’s closest passes around the Sun, a mere 3.7 million miles from the star’s surface, outside temperatures will near 1,200 degrees Celsius. During the ORNL tests, that temperature was attained with the plasma-arc lamp operating at 58 percent power.
1Johns Hopkins Applied Physics Laboratory (2015). NASA Gives GreenLight for Johns Hopkins APL to begin building solar probe plus spacecraft. Retrieved from: http://www.jhuapl.edu/newscenter/pressreleases/2015/150408.asp