Astronaut Kalpana Chawla became a hero to students at Colorado School of Mines when she went beyond NASA protocol to spend five hours Monday salvaging their broken space experiment. But more than that, Chawla and her six crewmates made the students feel like their best friends and equals in space science as they worked closely together during the past week. "They were real people. They didn't put themselves above anyone else. They made us feel important," said Ned Riedel, who helped design the Mines experiment, a system designed to fight fire in space and on Earth. He worked directly with the astronauts from Johnson Space Center in Houston until he returned to Colorado on Friday. Chawla worked tirelessly to fix a pesky leak on the Mines firefighting experiment as five students and professors watched, riveted, from payload control at the space center. When she was finished with the fixes, the experiment worked like a charm and data flowed to the students on the ground for a week, saving the future of the project. Students couldn't believe the time Chawla and the other astronauts devoted to their experiment. It was only one of 80 aboard the 16-day flight, including one by international high school students coordinated by the University of Colorado. And they couldn't believe how unassuming the astronauts were since meeting them 21/2 years ago and training them on the experiment. "They were incredibly nice people. Easy-going and down-to-earth people," said Riedel. "Working the mission with them, they were just fantastic. The timeline in space didn't allow the time we needed to get it online, and they gave it to us anyway," he said. "We learned things we never expected. We celebrated all the way to the end. We were ecstatic, which makes this even more horrible," Riedel said. "When I heard, I cried. I thought of their families. Now I'm just shocked. I can't get over it." "They sacrificed time from their meals and other things to give us time not scheduled for our experiment," said David Petrick, a Mines graduate who also returned Friday from Johnson Space Center, where he worked with the astronauts. The school's new-generation firefighting system produces a fine-water mist in spacecraft and has commercial applications on Earth, including in office towers. A 1996 international ban on ozone-depleting Halon 1301 as a chemical fire suppressant has created an urgent need for other environmentally friendly fire suppressants. The ban went into effect in 2000. Using water droplets one-tenth the size of a human air, the Mines mister creates a fog that sucks the heat out of fire, preventing its spread and saving lives. It's preferable to conventional water sprinklers because it causes less damage to expensive equipment such as computers. It's also an attractive alternative for planes and ships traveling with weight limits, said Frank Schowengerdt, director of Mines' Center for Commercial Application of Combustion in Space, one of 17 NASA-funded commercial space research centers in the country. The experiment on board Columbia was a tightly sealed 11/2-foot cannister with a tiny propane flame that ignited a gas mixture so researchers could examine how the mist worked in space. Thanks to the astronauts' devotion, the students were able to download 90 percent of the data they had hoped for through a satellite link last week. "This experiment that the shuttle crew worked so hard to repair a few days ago will move forward in their honor, and we will use the data they gleaned in space to build a firefighting system they would be proud of," Schowengerdt said. "And we will think of a way to name it after them. They made all the difference." The students were stunned at how humble the shuttle crew was as they worked together over the months. "What makes them extra special is you could walk up to them and they would remember your name and have a beer with you," Riedel said. That happened to Riedel and Petrick in December during final simulation exercises, when the students bumped into the shuttle crew at Petey's, an astronaut after hours hangout near Johnson Space Center. "I knew Ilan Ramon because he's an astronaut, but it floored me that he remembered my name and started introducing me around like I was his best friend," Riedel said. "That's just the kind of people they all were." The students were grieving on Saturday, feeling the loss of their science partners - astronauts they had come to call friends. "We were walking on sunshine Friday," Petrick said. "The Mission Control folks were smiling at us because we were dancing and singing, we were so happy. Then on Saturday we woke to this happening." "I thought on Monday it was going to be a tragedy because we wouldn't be able to get any data for our experiment," Riedel said. "Now I know the real definition of tragedy," he said, breaking into tears.