Project FIRE

Schematic drawing of Project FIRE Velocity Package. This was the design of a package used for flight tests with the Atlas rockets.

Project FIRE (Flight Investigation Reentry Environment) was a United States NASA effort to determine the effects of atmospheric entry on spacecraft materials.[1][2]

Project FIRE used both ground testing in wind tunnels and flight tests to test the effects of reentry heating on spacecraft materials, using a subscale model of the Apollo Command Module.[2]

Wind tunnel tests

Wind tunnel testing occurred at the 4-foot Unitary Plan Wind Tunnel, the High-Temperature Tunnel, and the Thermal Structures Tunnel at the Langley Research Center located in Hampton, Virginia.

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  Researcher checks model of Project FIRE Reentry package to be tested in Unitary Plan Wind Tunnel.
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  Test of Project FIRE model in Unitary Plan Wind Tunnel
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  Project FIRE model for wind tunnel tests
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  Project FIRE technicians preparing materials to be subjected to high temperatures that will simulate the effects of re-entry heating.

Flight tests

Project FIRE - Configuration of the upper stage and probe; flight trajectory

Recoverable reentry packages were flight tested using Atlas-D rockets with Antares-2 solid fuel upperstages (also used on the Scout rocket family),[3][4] launched from LC 12 at Cape Canaveral Air Force Station in Florida, United States.[5][2]

FIRE 1

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]

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  Gantry pull back at LC-12 for an Atlas 263D launch with Project FIRE 1
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  Atlas 263D rocket with Antares upper stage carrying Fire 1 re-entry capsule

FIRE 2

During the second trial, a propelled instrumented probe, referred to as a "flying thermometer", was launched into a ballistic 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]

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  Project FIRE 2 reentry package
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  Personnel of Langley Research Center at Cape Canaveral during preliminary checkout of Project FIRE velocity package before launch
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  Project FIRE 2 lifts off from launch complex 12 aboard an Atlas 264D, 22 May 1965
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  Project FIRE 2 reentry vehicle as photographed from Ascension Island
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  Project FIRE 2 reentry vehicle photograph notes by photographer Robert Collie

References

1. Morse, Mary Louise; Bays, Jean Kernahan (1973). The Apollo Spacecraft - A Chronology (PDF). Vol. 2. NASA.
2. Wade, Mark. "FIRE". Encyclopedia Astronautica. Retrieved 2023-11-17.
3. Krebs, Gunter D. "Atlas-D Antares-2". Gunter's Space Page. Retrieved 2023-11-17.
4. "Antares 2". astronautix.com. Retrieved 2024-05-09.
5. "Image of the Day Gallery". NASA. Retrieved 29 May 2013.
6. Krebs, Gunter D. "Fire 1, 2". Gunter's Space Page.