Multi-Layer Films and Tapes Provide Thermal Protection for NASA Spacecraft
- Tuesday, 27 September 2011
The final flight of the Space Shuttle Atlantis carried Multi- Layer Insulation (MLI) materials from Dunmore Corp. The MLI materials replace heavier materials such as metals and composites used to shield sensitive space-based systems from cold, debris, and radiation. The cargo bays on Atlantis, as well as the Endeavor and Discovery shuttles, are lined with insulation blankets covered by Dunmore’s thermal protection systems (TPS). The insulation blankets protect the inside of the shuttle from extreme temperature fluctuations when the cargo bay doors are open.
Atlantis Carried Multi-Layer Insulation (MLI) Materials." class="caption" align="right">The outer layer of the MLI blanket is made up of a lightweight, tightly woven fabric coated with a fine layer of aluminum that protects the MLI system from tearing or being punctured by micro-debris. It also provides protection from solar radiation. The protective materials also are used on the current generation of GPS satellites, and will be supplying to the next-generation GPS III program that will encompass a minimum of 30 new satellites. The materials can also be found on the Hubble Space Telescope and the recently launched NASA/JPL Aquarius spacecraft.
Layers of the MLI materials also will protect NASA’s Juno probe from extreme temperatures and radiation on its fiveyear journey to Jupiter to perform the first detailed mapping of that planet’s massive magnetic field.
The films comprise the external insulation blankets that will shield Juno’s electronic systems from heat, cold, and radiation. Dunmore also provided the adhesive tape that insulates the probe’s internal wiring. The 2,300 feet of pure, gold-coated insulation tape neutralizes the magnetic field from Juno’s electrical wiring and prevents it from interfering with instruments that will map Jupiter’s magnetic field in high definition. In addition to its instruments, Juno is also carrying three large solar array panels that required insulated wiring.
NASA expects Juno’s 400-million-mile journey across the solar system to yield detailed new data on Jupiter’s origin, evolution, and its massive magnetic field, the largest in our solar system. Twin magnetometers mounted on a 13-foot boom wrapped in insulation blankets made of MLI material will render the magnetic field in high-resolution images.
Polyimide and/or polyester layers that are vapor-deposited with 99.99% aluminum, on one or both sides, assist in the MLI material’s heat management. As it is very difficult to design an MLI blanket that reflects 100% of incident radiation, an MLI design can range from a few simple layers, to a complex array of blankets that completely surrounds the spacecraft and many of its external components. The designs of these layers typically reflect 95% of radiation back away from the spacecraft. The total effect by the time the radiation energy makes its way to the innermost layers is effectively a 100% reflective barrier.
TPS materials, with engineered absorptance and emittance properties, are used for passive thermal control systems. These materials are used for many applications on the spacecraft, such as structural members, instrumentation, antennas, radiators, wiring harnesses, and sunshield covers. The TPS materials have been part of nearly all space programs worldwide since the mid-80s, and are widely used in the International Space Station, as well as all U.S. and European launch vehicles.