Project FIRE (Flight Investigation Reentry Environment) was a United StatesNASA effort to determine the effects ofatmospheric entry on spacecraft materials.[1][2]
Project FIRE used both ground testing inwind tunnels andflight tests to test the effects of reentry heating on spacecraft materials, using a subscale model of theApollo Command Module.[2]
Wind tunnel testing occurred at the 4-footUnitary Plan Wind Tunnel, the High-Temperature Tunnel, and the Thermal Structures Tunnel at theLangley Research Center located inHampton, Virginia.
Recoverable reentry packages were flight tested usingAtlas-D rockets withAntares-2 solid fuel upperstages (also used on theScout rocket family),[3][4] launched fromLC 12 atCape Canaveral Air Force Station inFlorida, United States.[5][2]
The first Project FIRE reentry package was propelled to an altitude of 122 km (76 miles) by an Atlas-D Antares-2 launch vehicle (missile 263D) on 14 April 1964.[6]
Following a coasting phase that reached an apogee exceeding 800 km (500 miles) the velocity package initiated the reentry vehicle's trajectory, plunging it into a trajectory at a velocity of 11,300 m/s (25,000 mph) with a minus 15 degree trajectory.[6] As the spacecraft descended towards Earth, a solid-fuel Antares II rocket positioned behind the payload ignited for 30 seconds, elevating the descent speed to 40,501 km/h (25,166 mph).[6] Temperature data from the spacecraft's instruments were transmitted to the ground, indicating an estimated exterior temperature of 11,400 K (20,100 °F).[6]
Approximately 32 minutes post-launch, the spacecraft made impact into the Atlantic Ocean.[6]
During the second trial, a propelled instrumented probe, referred to as a "flying thermometer", was launched into aballistic trajectory over 805 km (500 miles) high by an Atlas-D Antares-2 booster (missile 264D) on 22 May 1965.[6]
As the spacecraft initiated its descent after 26 minutes of flight, the Antares II rocket accelerated its fall. The probe entered the atmosphere at a velocity of 40,877 km/h (25,400 mph), generating temperatures of approximately 11,206 K (19,711 °F).[6] Ground stations received data on heating throughout the descent.[6]
Thirty-two minutes post-launch, and a mere six minutes after the Antares ignition, the device impacted in the Atlantic Ocean approximately 8,256 km (5,130 miles) southeast of the Cape.[6]
