Integrated MLI

Integrated Multi-Layer Insulation (IMLI) is a next generation ultra-high performance thermal insulation. IMLI uses Discrete Spacer Technology™ to improve thermal performance and predictability and offers significant advantages over traditional MLI and Spray-On Foam Insulation (SOFI).

  • IMLI provides improved thermal performance from low conductivity discrete spacers with controlled inter-layer spacing and density, and results in reduced system power and improved cryogenic system life. IMLI measured results show up to 50% less heat leak per layer than traditional MLI.
  • Proprietary spacers create a robust, bonded structure that can support dynamic loads.
  • Test results show agreement within 10% of SINDA thermal models - with no correction factors.
  • IMLI can be fabricated using low cost, automated manufacturing processes.
  • Modular design enables rapid implementation, installation and easy repairs if damage occurs.
  • IMLI products are extensible to a broad range of mission environments and applications.

IMLI technology has been expanded into a family of products to address a broad range of thermal insulation needs, including traditional MLI uses, SOFI replacement, advanced thermal shield systems for cryogenic propellant storage, exposed surfaces of launch vehicles and micrometeoroid shielding.

Integrated Multi-Layer Insulation (“IMLI”), a next generation MLI that uses polymer spacers to maintain layer separation and reduce heat leak through the system, has been successfully demonstrated and proven to have advantages over conventional MLI. A NASA Phase II SBIR program successfully designed, built and tested IMLI, improving thermal performance from 1.96 W/m2 to 0.41 W/m2 (thermal conductivity of 0.07 mW/m-K for IMLI with 14 layers per inch, 20-layer blanket, 3.6cm thick, 77K to 295K). Numerous IMLI prototype build and test cycles have improved the technology, performance, fabrication processes, and moved the technology from TRL4 to TRL6.

IMLI is a robust insulation with layer spacing precisely controlled by proprietary Tripod Post low conductance micro-molded polymer spacers, and with layers bonded together into sub-blankets. IMLI offers 27% lower heat leak per layer than conventional MLI, and can be fabricated with lightweight mylar layers so that the overall blanket mass is less than conventional MLI.

IMLI Advantages include:

  • 27% better performance per layer than the best conventional MLI
  • 16 to 50% lower fabricated and installed cost than MLI
  • Fewer layers required for same heat leak as MLI
  • More robust bonded up structure with layer spacing precisely controlled
  • More predictable and repeatable performance
  • Seams are individual layer temperature matched
  • Ability to be installed onto a large cryotank in panels

Other advantages of IMLI over conventional MLI include robust bonded up structures that don’t change in density with presence or absence of gravity, clean inner surfaces with low outgassing that vent more rapidly than conventional MLI and reach thermal insulation performance seven to 16 times faster than MLI. IMLI has undergone vibration testing to the NASA GEVS standard without damage, and has been subjected to rapid depressurization in a launch profile rapid evacuation without any damage.

Future versions of IMLI could be used where very low particulates are needed, such as with optical systems. And a fully electrically conductive, grounded IMLI blanket could be designed such that grounding the blanket could be achieved without grounding posts and additional holes punched through the insulation blanket.

Integrated MLI is an innovative, next generation MLI offering higher performance and numerous other advantages over conventional netting MLI. It should be suitable for a number of aerospace cryogenic passive thermal insulation needs, and should be the insulation system of choice for some applications.