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ISS Materials Science Research

48:49 recording · AUTO · 3 speakers

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Brief overview

Exposing materials outside the space station is the only way to prove they survive low Earth orbit.

  1. Ground tests cannot replace flight dataGround facilities simulate single exposures, but space combines radiation, thermal cycling, debris and atomic oxygen at once, so spaceflight data are needed to validate a material.
  2. Orientation decides the exposureRam surfaces take a high flux of atomic oxygen, wake surfaces essentially none, zenith gets the most sunlight and nadir the least, so the same material responds differently.
  3. Fungal melanin protected the PLA biocompositesPost-flight comparison with Earth controls suggested combining PLA with fungal melanin enhanced its stability and protection in the low Earth orbit environment.
Executive Summary AI
  • Host Dane Turner opens Episode 430 of Houston We Have a Podcast on ISS materials science, with retired senior materials research engineer Kim DeGro and materials engineer Sylvie Crowell from NASA Glenn's Environmental Effects and Coatings Branch.0:00
  • Kim describes 36 years of research into the durability of spacecraft materials in low Earth orbit, covering atomic oxygen erosion, radiation embrittlement and discoloration, plus work on Hubble insulation blankets and materials retrieved from Mir after 10 years in space.10:09
  • Since 2001 she has been principal investigator for 18 MISSE experiments with 700 samples flown on the station, including five experiments with 367 samples on the MISSE Flight Facility, and her first MISSE experiment, PEACE Polymers, exposed 40 types of polymer to ram atomic oxygen for four years with help from 32 high school girls from Hathaway Brown School over 24 years.25:04
  • The MISSE-13 PCE-4 experiment was a passive experiment with 98 samples in the wake and zenith directions, and the melanin work found that PLA biocomposites infused with fungal melanin held up better in low Earth orbit, judged against a PVC backing layer that darkens under solar radiation.33:56
  • Sylvie is principal investigator for MISSE-23, Durability of Coatings, Polymers, and Ceramics for Space Applications, 40 samples launching in December 2026 and including lunar dust mitigation coatings her team is developing.44:42
Key Quote
“But a really memorable time for us was when our family watched Neil Armstrong take the first step on the moon back on July 21st, 1969.”
— Kim DeGro2:37
Key Quote
“But in low Earth orbit, the pressure is low, we're in the vacuum of space. So the O atoms, they don't really hit each other, they hit materials.”
— Sylvie Crowell16:46
Key Quote
“The zenith direction or the zenith surface is facing out to space and it gets the most sunlight.”
— Kim DeGro19:48