As astronauts spend more and more time long-term in space, tending plants, running virtual London marathons, and living there for a year as Scott Kelly recently did, it becomes more and more important for us to know how certain things function in a microgravity environment.

For instance, we need to know how fire spreads in such an environment. With that in mind, NASA is conducting studies on the space shuttle and the International Space Station. But it's been important to keep these experiments within certain size and scope constraints, in order to protect the crew.

The newest experiment among those is bigger in scale. It's called the Spacecraft Fire Experiment, or Saffire for short. It will take place on three separate flights starting in March.

"A spacecraft fire is one of the greatest crew safety concerns for NASA and the international space exploration community," Gary Ruff, project manager for Saffire, said.

Up next under Saffire will be much larger flames. The experiments will look at how fire works its way across many types of combustible materials. But, fortunately, the studies will take place away from the space station -- so that astronauts there will not be in danger.

Those experiments will be remotely conducted within a 3 x 5 foot module. It will be sectioned into two compartments. On one side of it will be an avionics bay with sensors, video cameras that use high-definition, and equipment that processes signals. On the other side is hardware that will be used to start up a large flame and burn materials and fabrics inside.

The first and third parts of Saffire will involve burning a large 16 x 37-inch piece of SIBAL cloth -- a blend of cotton and fiberglass. There have been previous studies of this material's performance in microgravity combustion, but at a diminished size. In this case, the point will be to burn the SIBAL cloth from its bottom to learn how the flame will spread. If the flame putters out, the researchers will light it at the top again and find out what proceeds as the fire moves in an opposite direction to the airflow.

"Saffire seeks to answer two questions," David Urban, main investigator, said. "Will an upward spreading flame continue to grow or will microgravity limit the size? Secondly, what fabrics and materials will catch fire and how will they burn?"

The first of the experiments will take place on the Orbital ATK Cygnus cargo vehicle after it reaches ISS, resupplies the space station, and pulls away.

Follow Catherine Arnold on Twitter at @TreesWhales.