Laboratory Investigation of Lightweight Heater Tape for Shuttle Propellant Tank

Experimental measurements under simulated typical operating conditions have established that the addition of surface (or near-surface) lightweight mylar electrical heater tape to external tank (ET) sprayed-on-foam-insulation (SOFI) panels results in an efficient approximately 67 F (approx. 36 C) surface temperature rise for a 10-W/sq ft applied power per unit area of SOFI surface. Consideration was given to the application of the lightweight mylar heater tape used in these measurements to the ice critical areas of the ET. A cryogenically cooled power distribution system capable of providing a 10-w/sq ft heating rate was investigated for a configuration covering 8545/sq ft of ET area. Total onboard system weight was estimated to be approximately 33 lb with a total mylar heater tape weight of approximately 6 lb. Keywords: Space shuttle, Ice formation prevention, Ice prevention, Heater tape, VAFB launch site.