NASA has placed samples of Zylon webbing used in its Hypersonic Inflatable Aerodynamic Decelerator (HIAD) on the United States Space Force’s X-37B Orbital Test Vehicle to study how the material ages during extended exposure to the space environment. The payload launched to low Earth orbit on Aug. 21 and will remain in space for long-duration testing before being returned for analysis by NASA’s Langley Research Center in Hampton, Virginia.
What NASA Is Testing
The Zylon straps are structural elements of the HIAD aeroshell, serving both as short tie straps that connect inflatable rings and as longer load-distribution members across the cone-shaped structure. Multiple Zylon samples are housed in small canisters aboard the X-37B, with two packing configurations designed to simulate how HIADs are stowed before deployment: tightly coiled and loosely packed. Some canisters include miniature temperature and humidity sensors that record environmental conditions at set intervals.
When the flight samples return, researchers will compare them with identical control samples stored on Earth. The team aims to characterize material changes due to the space environment, including vacuum, radiation, and thermal cycling, and to assess any impacts on strength retention and durability prior to atmospheric entry heating.
Why HIAD Matters for Planetary Entry
Inflatable decelerators are being developed to enable larger spacecraft to safely descend through the atmospheres of Mars, Venus, and Saturn’s moon Titan. Unlike rigid aeroshells constrained by launch vehicle diameters, HIADs can be tightly packed for launch and then deployed to much larger diameters.
- Increased diameter decelerators improve drag for entry, descent, and landing.
- Greater drag capacity supports higher-mass payloads and higher-elevation landing sites.
- Compact stowage allows efficient use of launch volume for spacecraft and cargo.
NASA has previously demonstrated the concept at Earth with the LOFTID (Low-Earth Orbit Flight Test of an Inflatable Decelerator) mission in November 2022, which validated inflatable aeroshell performance during reentry after a short period in space.
Focus on Long-Duration Aging
The X-37B experiment is designed to provide data on how Zylon webbing behaves after months in orbit, addressing a critical gap between short-term exposure and the longer durations expected for deep-space transits. The study also evaluates whether different packing approaches influence aging, informing stowage and handling practices for future missions.
What Comes Next
Post-flight, NASA Langley will conduct comparative testing of tensile strength, stiffness, and other material properties across the flight and ground control sets, along with inspections for microstructural changes. The results will guide protection strategies, packing configurations, and design margins for next-generation HIAD systems intended to deliver heavier payloads to planetary surfaces.
Source: NASA
