Tuesday, January 21, 2014

Combustion continues to draw researchers to International Space Station (ISS)

Astronaut Chris Cassidy installs the right glove on the Microgravity Science Glovebox just before starting a BASS investigation experiment run. 

Credit: NASA

The mesmerizing power of fire keeps researchers returning to the lab to understand the fundamental combustion science behind it.

Combustion has powered our world and consumed scientific attention for years, both on Earth and in space.

Fire continues as the focus with the Burning and Suppression of Solids-II (BASS-II) experiments, which recently launched to the International Space Station aboard the Orbital 1 cargo resupply mission.

Designed by researchers at NASA's Glenn Research Center in Cleveland, BASS-II is scheduled to operate through August 2014.

Through a series of experiments, scientists will investigate the combustion of a variety of solid materials, including plastic and fabric samples with different geometries.

Fabric sheets and plastic slabs, cylinders and spheres will be burned in the station's Microgravity Science Glovebox (MSG), provided by ESA.

This contained facility provides an environment that allows astronauts to burn open flames safely aboard station for scientific investigation.

An earlier BASS study, which used the MSG and ran on the space station in 2012, provided an initial look at burning materials with different shapes.

Researchers used that investigation to assess the effectiveness of nitrogen in suppressing microgravity fires.

BASS-II takes that research even further with five separate investigations overseen by five different research teams.

While each investigation has its own goal (flammability, flame spread, extinguishment, etc.), they share the same objective: a better understanding flame behaviour in space and on Earth.

"These are the thickest samples we've flown to date," said Sandra Olson, spacecraft fire safety researcher and BASS-II principal investigator at Glenn.

"We're looking to see how long it takes to reach a steady-state flame. How long it takes them to extinguish."

"We want to learn how to screen materials for future flights. A primary goal of BASS-II is improved spacecraft fire safety, improved understanding of combustion in space and how to avoid it."

"If you're on a mission far from Earth, a fire can be catastrophic. We want to select the safest materials."

These two candle flame images from BASS (side by side, left) show air flow from bottom to top, as compared with how a flame appears on Earth (right). Credit: NASA

The aim is to better understand the basic structure of flames and fires.

The results of BASS-II should help researchers refine computational models and theories about flame behaviour.

To produce better models, scientists need reliable data. Earth-based flame studies are greatly affected by gravity.

Buoyancy, which makes hot gasses rise, usually causes flame flickering even in a still environment.

If researchers can reduce buoyancy to near zero, they have the opportunity to study a range of flame behaviour that may be concealed by the influence of gravity.

Read the full article here

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