By Tracy Vogel/Johns Hopkins University
A heat shield you can scorch with a blowtorch until it glows red on one side and still comfortably touch on the other will protect a NASA probe flying to within 4 million miles (6.4 million km) of the sun’s surface.
The shield is the culmination of years of work by engineers to solve what they call the “thermal problem” of the soon-to-launch Parker Solar Probe.
“Thermal problem” is a shorthand way of referring to the extraordinary complications of a record-breaking dive directly into our star’s outer atmosphere, or corona.
While the probe orbits the sun and records data with onboard instruments, its thermal protection system will shield the spacecraft from heat more intense than any spacecraft has ever experienced. Combined with a water-powered cooling system, the thermal protection system will keep the majority of the probe’s instruments at about 85 degrees Fahrenheit (29.4 degrees C) – the equivalent of a nice summer day – while the TPS itself endures a temperature of 2,500 degrees Fahrenheit (1,371 degrees C).
Without the thermal protection system, there’s no probe.
Elisabeth Abel is TPS thermal lead at the Johns Hopkins University Applied Physics Laboratory. She said:
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