When NASA’s space shuttle Discovery is launched this Thursday after a three-month delay, it will send the work of Yale applied physics professors Marshall Long and Mitchell Smooke soaring to new heights.
Long and Smooke are endeavoring to improve safety in space stations as well as discover more efficient fuel combustion methods on Earth through an experiment they will conduct on the combustion process in zero gravity. The experiment, called SLICE, will investigate the changing nature of ignited gases in space and may be useful in reducing pollution emissions by improving the efficiency of the burning method, Long said.
“It is a very beautiful experiment, investigating a phenomenon that can only be observed in microgravity,” Princeton University professor Chung Law, who is not involved in the experiment, said.
While the shuttle launches on Thursday, the actual experiment will be conducted this fall at the International Space Station. Because the researchers themselves cannot go into space, they will train astronauts to conduct it for them as they oversee the experiment from the ground.
When the astronauts reach the space station, they will ignite a single tube containing a mix of methane, ethylene and propane. Once they have completed each analysis they will add increasing amounts of dilutants to the mixture.
When the gases are set alight, the flame will hover above the tube, Long explained. It will also be circular in shape instead of elongated as normally seen on Earth, he added.
Thursday’s launch has been years in the making.
Since the idea was formed several years ago, Smooke has been creating the computational model for the experiment, solving hundreds of equations to predict velocity, temperature and the concentration of elementary components of the combustion process.
“The calculations are put through a much more stringent test in space than on the ground,” Smooke explained. “[This] allows us to study where the mechanism works, where it breaks down and what causes certain substances to burn in space.”
Long, on the other hand, has been focusing on the experimental aspect of the project by working with laser technology to acquire as much quantitative data as possible from the fairly simple equipment approved by NASA for the experiment.
On Thursday, a Nikon camera will be strapped onboard the space shuttle to collect photographs of the flame. Long also said he hopes to obtain measurements of temperature and soot levels to aid his study of combustion in space.
Three experts interviewed said Smooke and Long’s research is extremely important for improving the combustion process.
“The experiment is essential to validate the model, as they can conduct experiments without buoyancy affecting the results, as it does on Earth,” NASA’s David Urban said. “It could potentially improve energy efficiency, reduce pollution and improve safety on the space station.”
The study is similar to one conducted by Dennis Stocker at NASA, but Stocker said it tests a wider range of conditions with improved measurements.
Smooke and Long are currently working on the next phase of their research, which will involve conducting the same experiments as SLICE, but will be completely automated.
The next experiment, ACME, is scheduled to be sent into space in 2014.