Chanhassen resident Tom Vande Hei has an app on his phone that alerts him when the International Space Station is about to float across the sky above him.

For 168 days — from fall 2017 through February 2018 — Vande Hei and his wife, Mary, would go gaze at the sky whenever the space station crested the horizon.

It was only visible for one minute, three minutes, maybe seven minutes. But that was enough time to feel close to their son, Mark.

"He's only 240 miles away," Tom Vande Hei said.

Mark Vande Hei completed his first spaceflight in 2018 as an Expedition 53/54 crew member, during which he conducted four spacewalks, researched microgravity and measured the sun's energy input to Earth.

The Benilde-St. Margaret's and 1989 St. John's University graduate is slated to launch his second mission to the space station April 9. He'll participate in a live news conference at 10 a.m. Monday from the Gagarin Cosmonaut Training Center in Star City, Russia. It will air at

Vande Hei will join two Russian cosmonauts on the Expedition 64/65 crew, which is tasked with conducting hundreds of experiments to learn more about living in space.

"The space station is a critical test bed for NASA to understand and overcome the challenges of long-duration spaceflight and those insights gained will help send humans to the moon and eventually to Mars," states a NASA news release.

Two of Vande Hei's former physics professors said Wednesday that his accomplishments reflect his work ethic.

"He looked for the hardest things to do and that's what he would do," said Dean Langley, who still teaches at St. John's. "He wasn't just another college kid. He was impressive right from the get-go."

Vande Hei attended St. John's on an ROTC scholarship and was commissioned into the Army in 1989. He attained the rank of colonel and served as a combat engineer. He also earned a master of applied physics from Stanford and became an assistant professor of physics at the U.S. Military Academy in West Point before being selected as an astronaut in 2009.

Thomas Kirkman also teaches physics at St. John's. He's seen hundreds of physics majors since he came to the university nearly four decades ago — and many have gone on to accomplish great things, he said. But there's something special about becoming an astronaut.

"He's flown the highest," Kirkman said of Mark.

When Vande Hei was a child, he always liked to have a challenge, according to his parents.

"He was curious about everything. He had an insatiable curiosity," Mary Vande Hei said.

The couple traveled halfway across the world to watch their son during his first launch.

"We were screaming and crying. It was emotional," Mary Vande Hei said. "We were standing on the lawn a distance from the launchpad in Kazakhstan and there was a screen where we could see Mark inside the capsule. And then they did the countdown, but of course, it was all in Russian."

Because of the COVID-19 pandemic, Mark won't have any family there to say goodbye at his upcoming launch.

"The tough part right now is, because of COVID, we haven't touched Mark for a year and he's been in Russia since January," Mary Vande Hei said. "When we heard he was going up again — you know, we're very proud but we were also saddened because it could be six months to a year until we get a chance to touch him again."

During Vande Hei's time in space, his parents will be able to talk with him occasionally via videoconference, phone or e-mail.

And, of course, there's always the chance to look up at the sky.

"You can see that space station go over. It goes quickly," Mary Vande Hei said. "But when [the] app showed that it was coming over, we would run outside. Sometimes the neighbors would come out with us and we would toast."

Jenny Berg • 612-673-7299