Iowa-born astronaut Peggy Whitson says she’s confident NASA will find out what caused the space shuttle Columbia to break up Saturday — and that the shuttle flights will resume. Dr. Whitson returned in December from a six-month mission aboard the International Space Station, and in her first interview since the disaster, she says she was not watching tv when the Columbia broke apart on reentry.She says she was on her way to watch her nephew play basketball when a friend called her and told her the news, and she turned around and went back home to watch news reports. Whitson was at her childhood home in Mount Ayr preparing for a series of visits to southern Iowa schools to talk with students about her experience in space. Whitson canceled those appearances after learning of the disaster, and five days later, says it’s still tough to talk about the loss. She says it’s all very difficult, and the easy part is to try and stay busy. Whitson knew the Columbia crew well and says they were probably closer than other shuttle crews.She says crews are typically in training for a year or less to build up camaraderie, but this crew had been together closer to two-and-a-half years. While there’s never been an accident before during reentry, Whitson says it’s one of the toughest parts of the mission.She says you have to do a de-orbit burn halfway around the world and there’s only one chance to get it right to land at the proper place on earth. Much of the talk of Columbia’s fate has centered on the tiles that protect the shuttle from the heat of reentry. Whitson says losing tiles is something that happens.She says many of the shuttle missions have had tiles come off the ship and landed safely, but she says it is something they try to avoid. While the circumstances of the disaster forced Whitson to cancel her school visits, she says she will return as it means a lot to her to come home.Whitson, was Iowa’s first woman in space, and was the first science officer aboard the International Space Station. A member of Columbia’s crew Laurel Salton was born in Ames and later moved to Wisconsin when she was two.