The email from NASA Commander Scott Kelly arrived two weeks ago bearing good news: The ping pong paddles were finally aboard the International Space Station.

Back on Earth, a 22-year-old Gresham man had to wait a fortnight to see the viral video evidence of his summer experiments.

"We knew it would work," said Karl Cardin, the Portland State University engineering student who designed four paddles made out of a hydrophobic polycarbonate material.

On Thursday, it was finally game on.

Kelly tweeted out a mesmerizing minute-long video showing the paddles' water-repelling power.

Try this, Mary Poppins! Super-hydrophobic polycarbonate ping pong paddles and a water ball in space! #YearInSpacehttps://t.co/BB0Z35jbVa — Scott Kelly (@StationCDRKelly) January 21, 2016

The video showed Kelly, bespectacled and bald, wearing a black shirt and holding two square-shaped paddle about a forearm's-length apart. A spherical drop of water floated between the two paddles, bouncing off one and toward the other.

At his parent's house, Cardin's family gathered around a computer screen to take in the video.

Cardin was excited his family could finally understand what he was doing with "those crazy ping pong paddles."

"It's one of those things that you don't really believe it until you see it," said Cardin, a Sam Barlow High School graduate who expects to finish his engineering degree this fall.

"It was really exciting."

Cardin, a senior, started working at PSU's Dryden Drop Tower lab at the Maseeh College of Engineering and Computer Science last summer.

A predecessor had designed similar paddles, destined for a separate outer space mission. But those paddles were aboard an ill-fated SpaceX Falcon 9 mission that exploded last summer.

Cardin picked up the pieces soon after, and said he started largely from scratch. He worked on the material and laser-cut design, and teamed with graduate and Ph.D. candidates in PSU's "micro-gravity" lab to test the product.

The Drop Tower is 102 feet tall, and includes aluminum framed shaft that is designed to eliminate drag and allow for engineering experiments in "micro-gravity" scenarios.

Cardin credited his professor, Mark Weislogel, who worked on a zero-gravity designed coffee cup that went into space in 2013 for his guidance and inspiration on the project.

PSU student designed ping pong paddles in viral NASA video 4 Gallery: PSU student designed ping pong paddles in viral NASA video

In August, NASA came calling, saying there was room for the paddles on a supply mission in August.

Cardin said Weislogel told him, "Space opened up." He worked nearly around the clock to finish the paddles in a week's time.

"It's kind of an opportunity that you can't miss," he added.

PSU's research could pay dividends for NASA. According to a press release, the hydrophobic material could be used to promote heat transfer in cooling systems aboard space craft.

Cardin said there are so many possibilities of experiments in outer space with fluids.

"Apply it in a way that everyone can recognize and enjoy, that's really powerful," Cardin said.

Cardin said he and others in the lab were biting their nails to see exactly what Kelly would do with the paddles once they arrived.

The possibilities are now endless, he said. "People are wanting televised ping pong tournaments."

-- Andrew Theen

atheen@oregonian.com

503-294-4026

@andrewtheen