Understanding how fire spreads in a microgravity environment is critical to the safety of astronauts who live and work in space. And while NASA has conducted studies aboard the space shuttle and International Space Station, risks to the crew have forced these experiments to be limited in size and scope. Fire safety will be a critical element as NASA progresses on the journey to Mars and begins to investigate deep space habitats for long duration missions.
The first Spacecraft Fire Experiment (Saffire-I) was the beginning of a three-part experiment to be conducted over the course of three flights of Orbital ATK’s Cygnus vehicle to investigate large-scale flame spread and material flammability limits in long duration microgravity.
The Saffire-I experiment enclosure was approximately half a meter wide by 1 meter deep by 1.3 meter long and consisted of a flow duct and avionics bay. Inside the flow duct, the cotton-fiberglass blend burn sample measured 0.4 m wide by 1 meter long. When commanded by Orbital ATK and Saffire ground controllers operating from Dulles, Virginia, it was ignited by a hot wire. Previous to this experiment, the largest fire experiment that had been conducted in space is about the size of an index card.
After the experiment was ignited, the Cygnus continued to orbit Earth for six days as it transmitted high-resolution imagery and data from the Saffire experiment. Following complete data transmission, the Cygnus spacecraft completed its mission with a destructive entry into the Earth’s atmosphere.
Saffire-I launched inside the Cygnus spacecraft atop the United Launch Alliance (ULA) Atlas V launch vehicle on March 22, 2016. Space Station Crew members successfully grappled Cygnus to the space station on March 26. The Saffire experiments were developed at NASA Glenn Research Center by the Spacecraft Fire Safety Demonstration Project and sponsored by the Advanced Exploration Systems (AES) Division of NASA’s Human Exploration and Operations Mission Directorate. AES pioneers new approaches for rapidly developing prototype systems, demonstrating key capabilities, and validating operational concepts for future human missions beyond low-Earth orbit. AES activities are uniquely related to crew safety and mission operations in deep space, with a strong focus on future vehicle development.