The radio transmission crackled for a second, paused, and crackled again before a voice broke through: “This is NA1SS reading you loud and clear.”

Jerico Dzicek’s jaw dropped as she turned to her fellow members of the Vail Vaqueros 4-H Club’s Ham Radio Project and smiled in amazement. The voice on the other end of the radio connection belonged to NASA astronaut Kjell Lindgren, who chatted with the students as he worked aboard the International Space Station 240 miles above the Earth’s surface.

With only a 10-minute window to speak with Lindgren before the space station passed out of range, Jerico, 14, quickly took the ham radio microphone and asked her first question: “What would you do if you damaged your space suit when you were out in the field? Over.”

Amid crackles of static as volunteer ham radio technician Larry Brown fine-tuned the connection, Lindgren, a native of Taiwan who grew up in England and studied in the United States, explained the procedure, with the gist being: “We would begin going to the airlock and get back inside the vehicle.”

As Mason Fosdick, 8, held a second microphone so the 75 people gathered at the Vail Theatre of the Arts at Empire High School could hear, Zane Walker, 12, asked Lindgren whether it was hard to work without gravity.

“Zane, well, the absence of gravity up here is probably one of the most pleasant things about being in space,” Lindgren said. “But it’s definitely different.”

“It makes it very easy to get around. You can almost pretend like you’re flying around, but it does make it hard to work sometimes,” he said, explaining tools float away while he is working and the contents of bags spill upward as soon as they open.

Ham radio allows two-way communication without the use of cellphone or Internet connections and has been used around the world for more than a century.

The “ham” comes from a pejorative term used by professional operators upset that early amateurs were bogging down the radio system, says the American Radio Relay League. Amateur operators started using the term and the original meaning has largely disappeared.

In all, the seven Vail Vaqueros members asked more than a dozen questions of the astronaut, who boarded the space station in July.

Jacob Komper, 14, asked how astronauts dispose of human waste. Lindgren explained that urine is recycled into drinking water, while solid waste is securely stored.

Sitka Mitkiff, 10, wanted to know which academic subjects a future astronaut should study. Lindgren, who is a physician, recommended biology and medicine, but also added that math, engineering, and technology “are all very important subjects and they prepare you well.”

Max Walker, 12, asked how fire starts in a spacecraft.

“Max, that’s a great question and it’s certainly something we prepare for,” Lindgren said, explaining astronauts minimize sparks about the space station to avoid starting a fire.

“We also try to minimize the fuel, so most of the things in the cabin are plastic and nonflammable,” Lindgren said.

Matt Fosdick, 13, asked about Lindgren’s favorite nonessential comfort item.

“I think it would probably be the pictures of my family, my wife and my children,” Lindgren said, calling separation from his family “one of the biggest challenges” of living aboard the space station.

After the space station passed out of range, Jake Weller, 16, described the call as “truly a chance of a lifetime.”

“Being able to talk to an astronaut who is at the time up in space, using this equipment, was great,” he said.

“That was probably the coolest thing I’ve ever done, ever,” Jerico Dzicek said.

With Saturday’s call, the group became one of 24 schools and youth organizations that will speak with an astronaut aboard the space station this year, said Lani Dzicek, project leader for the Vail Vaqueros and mother of Jerico.

The call came about after the group visited the “ham shack,” as the University of Arizona’s amateur radio club’s headquarters is known, in November and the members asked Dzicek to see if they could speak with an astronaut.

“They’re all so excited right now. I think this has got everybody really excited about science and space,” she said.

Contact Curt Prendergast a 573-4224 or cprendergast@tucson.com. On Twitter @CurtTucsonStar.