Louisville-resident Gerold Willing sat in his recliner in early December and stared at the laptop screen, which was transmitting the launch of a NASA supply rocket from Cape Canaveral, Fla., to the International Space Station.
The associate professor of chemical engineering at the University of Louisville was plagued by a mixture of anxiety and anticipation, as he literally had something riding on the rocket: an experiment through which he and several UofL colleagues hoped to gain insights into some fundamentals of physics.
He had good reason for concern: The experiment, for which the researchers had received a NASA grant and on which they had worked for months, initially was to have been launched into space six months earlier, in June 2015, with a SpaceX craft — which exploded. And that delayed the subsequent SpaceX flight, which had been scheduled for August.
NASA finally agreed to take the UofL experiment to the ISS on its Dec. 5 launch. Willing traveled to Florida to tour Kennedy Space Center, connect with NASA officials and witness the launch. With the help from NASA, he picked a good vantage point from which to view the takeoff. However, NASA postponed the launch because of rain. The next day would not work either, and it was only a 50/50 chance for Saturday. Disappointed, Willing traveled back to Louisville.
So a couple of days later, he found himself viewing the launch on his laptop.
This time, the rocket took off without a problem.
“It was definitely a relief to finally see it go,” Willing told IL last week.
Thousands of photographs
A few days ago, in a laboratory on UofL’s campus, a team led by Stuart Williams, assistant professor of mechanical engineering, gathered around a computer screen to analyze some of the 20,000 photographs that cameras shot during the experiment on the ISS.
The researchers are trying to figure out why and how certain particles suspended in a substance — say blood cells in plasma — interact and clump.
Knowing why and how fast the particles, called colloids, clump or form chains gives the researchers insight into the fundamentals of physics. The applications of the knowledge range from the prevention of the clumping of laundry detergent to critical medications that do not spoil as quickly to more efficient solar panels.
The colloids are so tiny that researchers have trouble, even with powerful microscopes, observing the particles’ behavior. Red blood cells, for example, measure five micrometers, or 5/100th of a millimeter.
To be able to watch the colloids’ interaction, the researchers made use of UofL’s state-of-the-art Micro/Nano Technology Center to create — ironically — slightly larger particles. But size also adds weight, which means the colloids’ interaction is affected by gravity. To get around the gravitational effects, the colloids are rocketed to the microgravity of the International Space Station.
On the ISS, an astronaut inserted a cartridge with the colloidal solution into a special microscope. He stirred the solution, and then the researchers, who could watch the interaction live, waited to see what happened. Cameras captured the images that the researchers back on earth are now analyzing.
Williams said that once scientists understand why the colloids aggregate, for example, they can figure out how to prevent — or encourage — the aggregation, or even how to accelerate it with external stimuli, such as temperature, pressure or magnetic fields.
With that kind of knowledge, researchers could manipulate colloids to assemble in certain patterns. The UofL team used a glass derivative, silsesquioxane, in the experiment, and Williams said he hopes researchers eventually will be able to manipulate the particles so that they line up in a more structured way on solar panels, for example, to improve their efficiency.
Willing, the chemical engineering professor, said current solar panels have some inefficiencies because during production it’s difficult to control where particles land because they’re essentially painted on a surface and controlled by the force of the brush strokes and by gravity. That can lead to clumping and short circuits. If researchers learn how to coax particles to line up in an ordered structure, they can significantly increase the panels’ output.
The research is funded by a $750,000 grant from NASA, which the UofL team received together with professors from the University of Kentucky and Western Kentucky University. The teams also are collaborating with the Advanced Colloid Experiments team at NASA, the Glenn Research Center.
The local team expects to release a paper on its findings by the end of the summer and give presentations at conferences in November. At the end of this summer, Willing will travel to the Los Alamos National Laboratory in New Mexico to try to repeat some aspects of the experiment. It’s all part of a series of more testing and planning to prepare to launch more experiments into space in 2018 or 2019.