SEP 2018


Issue link:

Contents of this Issue


Page 85 of 91

SEPTEMBER 2018 84 CompositesWorld FOCUS ON DESIGN Heatshield for Extreme Entry Environment Technology (HEEET): A broader mission 3D woven fabric enables scalable, tailorable heatshield that cuts cost, boosts performance for future spacecraft. » e heatshields that protect spacecraft structure and payload from the intense heat of entry into a planet's atmosphere are critical components and, historically, have been uniquely devel- oped, at great cost, for each mission. at's something the Heat- shield for Extreme Entry Environment Technology (HEEET) team at NASA is seeking to change. It has developed a family of constituent thermal protection system (TPS) materials that can be used on multiple spacecraft intended for multiple destinations, reducing the design time and cost per shield and mission. HEEET also aims to reduce heatshield weight, cutting mass by up to 50%, with a corresponding reduction in G loads (gravity forces) on the spacecraft. e key to HEEET's performance is a dual-layer, carbon fiber and phenolic fabric. Dual-layer TPS systems have been proposed before, with layers bonded, says Don Ellerby, research scientist at NASA Ames Research Center (Mountain View, CA, US). "But the challenge they faced was what to bond them with that will survive the high temperatures during entry. e HEEET system gets around this by integrally weaving and interlocking the two layers." Ethiraj Venkatapathy, NASA Ames' principal technologist for Entry Systems and team leader for Advanced TPS development, notes that the advantages of using 3D woven fabrics in composite structures was well known. "Applying them in thermal protection systems was new," he says. "We wanted a materials technology that can meet the require- ments of many different missions," he adds. at meant it must By Ginger Gardiner / Senior Editor Standardizing thermal protection for higher performance HEEET (top left) seeks to replace bespoke heatshields with a standardized system that can be adapted to protect many spacecraft — for missions to Venus, Mars (top right), Saturn and more — from extreme temperatures as they enter a planet's atmosphere. Using a two-layered, 3D woven carbon fiber/phenolic fabric (bottom right), it also lowers mass and improves performance. Source (clockwise)| NASA Ames / NASA/JPL-Caltech/Univ. of Arizona / Bally Ribbon Mills

Articles in this issue

Archives of this issue

view archives of CompositesWorld - SEP 2018