SAFFIRE could provide valuable information for missions to Mars
On Feb. 24, 1997, a fire broke out on the Russian space station Mir. Although the trio of station members, Russian cosmonauts Valery Korzun and Aleksandr Kaleri, and NASA astronaut Jerry Linenger, were able to get it under control, the incident could have seen the loss of the station, as well as the crew. To prevent that from happening on future deep-space missions, NASA recently conducted the Saffire experiment to gain a better understanding of the dynamics of flame in space.
Spacecraft Fire Experiment-I, also called Safe Fire or “Saffire“, consists of three primary parts, each being carried out on flights of Orbital ATK’s Cygnus cargo freighters at a safe distance from the International Space Station (ISS). It is being flown to study large-scale flame spread and material flammability limits for extended periods of time in microgravity.
“On Earth, all inhabited structures—be it a building, an airplane a ship or a car—we’ve done full-scale testing of a fire and how it grows,” said David Urban, the principle investigator for Saffire. “We have an understanding of how to build vehicles and structures and how to defend against fires.”
In the past, research as to how flame behaves in space took place in smaller confines, whether it was on the Space Shuttle or ISS, with material the size of an index card. Saffire-I provided a far larger area to study in.
“We really don’t know what the fate of a fire [in space] is,” Urban said. “So our building of future spacecraft is based on one-g understanding and extrapolation from very small short duration experiments.”
Better fire research, such as those conducted with Saffire, could prove invaluable when NASA sends crews to deep space locations such as the planet Mars. By understanding how fires move in microgravity, it could allow engineers to design spacecraft that will discourage any potential fire spread.
Saffire-I launched on March 22, 2016, inside the S.S. Rick Husband Cygnus cargo ship atop a United Launch Alliance (ULA) Atlas V 401 rocket from Cape Canaveral Air Force Station’s Space Launch Complex 41 in Florida. However, scientists working on the experiment had to wait until the OA-6 ISS resupply mission was over before their studies could begin.
After the uncrewed Cygnus was unberthed and moved to a safe distance from the orbiting outpost, the experiment was conducted. It took place on the afternoon of Tuesday, June 14, with engineers at Orbital ATK’s facilities in Dulles, Virginia, assisting in the experiment’s supervision. The fire itself was activated by a hot wire.
The space in which the Saffire-I experiment was conducted measures about 1.6 feet (0.5 meters) wide by 3.2 feet (1 meter) deep by 4.3 feet (1.3 meters) long. Composed of an avionics bay as well as a flow duct, the cotton-fiberglass material that was burned in the experiment measured 1.3 feet (0.4 meters) wide by 3.2 feet (1 meter) long.
Over the course of about eight minutes, the material burned. Cameras and sensors observed the flame’s growth rate and the final size of the fire. Afterward, the data was downloaded over the course of the next eight days.
Cygnus remained in orbit until Wednesday, June 22, when it was commanded to deorbit over the Pacific Ocean. All of the Saffire-I data had since been downlinked back to Earth.
The next Cygnus to launch, the S.S. Alan Poindexter in August, will also have a Saffire experiment on board.
This second experiment will a have the same primary dimensions. The big difference will be in the number of samples. Instead of one big sample, there will be nine smaller samples, each being a different material.
Additionally, a third Saffire will fly on the OA-7 Cygnus, sometime later in 2016. It will once again be one large piece of material.
Video courtesy of NASA Johnson
Jason Rhian spent several years honing his skills with internships at NASA, the National Space Society and other organizations. He has provided content for outlets such as: Aviation Week & Space Technology, Space.com, The Mars Society and Universe Today.