Students at zero gravity

Engineering students to take a ride on the vomit comet in the name of research

Mifi Purvis - 16 February 2017

(Edmonton) A water droplet, when it freezes, will form a little peak, making its profile resemble that of an upside-down peach. Scientist call it the "freezing drop tip singularity" and the interesting thing about it is the peak is always at the same mathematical angle. Faculty of Engineering assistant professor Prashant Waghmare's iSSELab demonstrated this effect in a recently published article in the journal Applied Physical Letters. This angle forms under all known conditions.


There are big unknowns

Right now, no one knows if a droplet will form that little peak when it freezes in outer space. But in the first week of August, a team of undergraduate and graduate students from the Faculty of Engineering with their faculty advisor, Prashant Waghmare at the Department of Mechanical Engineering, will find out. This project, along with three more from other Canadian universities, was selected by Students for the Exploration and Development of Space (SEDS-Canada) and its partners to conduct experiments aboard the National Research Council of Canada's Falcon 20 aircraft. Two members of Waghmare's group, called Team iSSELab, will experience the microgravity conditions astronauts deal with aboard the International Space Station.

Students in space! (Actually, space-like conditions, right down to the barfing)

"Our team lead is PhD student M. Farhad Ismail and we have three undergraduate students, one from electrical and two from mechanical engineering," Waghmare says. "Research scientist Aleksey Baldygin and I are the faculty advisors." Team members will travel aboard the Falcon 20 to conduct the experiments. In a little over an hour, the Falcon 20 will make 12 parabolic maneuvers simulating microgravity and allowing the students to conduct the experiment and to collect the data several times.

"Nausea is common," says Roxy Fournier, project manager at SEDS-Canada, "so if one student is especially sick, the other can finish the work." The team will report the data afterwards, hopefully submitting a resulting paper for publication. Very impressive, but it begs the question: why do we want to learn about the freezing dynamics of a droplet in near-zero gravity?

This will be important when you go to Mars

The way liquid crystalizes or solidifies is important when it comes to 3-D printing, which is revolutionizing the approach to keeping an inventory of parts-a major logistical challenge to space travel. On a trip to Mars, 3-D printing could help you make parts based on schematics and reverse-engineering, so if something breaks on your journey or during your time on the planet's surface, you could print a replacement part instead of relying on ingenuity and duct tape.

Sound farfetched? It's part of the Canadian Space Agency's 2016-2017 Report on Plans and Priorities. We have to be able to carry out rapid prototyping for repairing old components or creating new ones. For that reason, the project is attracting interest. KRÜSS, a German company that produces measuring instruments for surface and interfacial chemistry, is a major sponsor, as is Engineering Beyond, an Edmonton research and development company specializing in optical engineering.

These students aren't going to Mars

Sadly, no. But once the team has passed the preliminary design review in February and the critical design review in April (where they conduct the experiment on Earth), they'll be ready to send two lucky members up on the Falcon 20 in August.

"This is the first baby step towards the giant leap," says Waghmare. "We need to know, when liquid solidifies at micro-gravity, does it have the same properties as on Earth?" Water is a great test, because its solidification process, which produces that signature peak on a droplet, is so well understood.

After their return, iSSELab team will engage with students from a local high school in the community outreach portion of their project. Who knows? They might inspire the future generation of engineers in space.

"Space is the next frontier where a lot of students will direct their careers," Waghmare says. "We will need a trained workforce. This initiative started by SEDS-Canada will certainly help to achieve this goal." One day, astronauts printing a new lag bolt to replace one on their spacecraft will need to count on the process.