When NASA astronaut Kjell Lindgren traveled to the International Space Station (ISS) in 2015, he was expecting the air to smell a little like a locker room, he says in a new video posted by NASA. After all, the space station is essentially an airtight metal box where, most of the time, six or more crewmembers are constantly working, exercising and sweating.

Lindgren was in for a surprise, however, thanks to impressive technology in the space station's life support system. "The air in the space station actually smelled great," he says in the video. "The filters in the life support system do a great job cleaning the air. There were no issues at all."

The space station's life support system maintains the atmosphere aboard the station, providing the right amount of oxygen, stripping carbon dioxide from the air, keeping the temperature in a comfortable range and providing fresh water and light, according to NASA. [Will Smith Has a Few Quirky Questions for a Space Station Astronaut (Video)]

The technology is important, not only for keeping the air aboard the station fresh and the astronauts alive, but also for potential long-distance journeys in the future, like the journey to Mars. Aboard the station, Lindgren said he felt like a bridge builder, paving a pathway to the red planet.

"Hundreds of millions of miles from Earth, no one will be able to bring us fresh water or replace malfunctioning systems," Lindgren says. "We will be on our own — just us and the life support system."

The life support system aboard the space station acts as a test run for future long-distance explorations of the solar system, and technology is evolving based on lessons learned from the station.

"We want to increase the level of recycling wastes beyond what we do on the station now. Our ISS water system can recycle about 93 percent of the wastewater back to clean water," Molly Anderson, a principal technologist at NASA, says in the video. NASA scientists plan to fly a demonstration technology to the station soon that should be able to recover most of the other 7 percent, which is referred to as "brine." NASA scientists are also trying to improve the percentage of carbon dioxide that gets recycled back into oxygen. Right now, the life support system converts a little less than 50 percent, but they hope that future technology will be able to recycle at least 75 percent, if not all of the carbon dioxide on board.

The space station still depends on cargo missions to bring the astronauts fresh supplies, but future missions that leave Earth's orbit may not be able to rely on supply missions for support, so improvements to these life support systems will be vital for those journeys.

Follow Kasandra Brabaw on Twitter @KassieBrabaw. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.