Glenbrook South track and field coach Kurt Hasenstein is no stranger to challenges. In his 30-plus years of coaching at Glenbrook South High School, he has taken on many of them. But now he might be taking on his toughest one of all. As part of the Titan Track Invite on Friday, May 6, he will attempt to assemble as many alumni, athletes and coaches as possible from the past 50 years of GBS track for a big reunion. Degree of difficulty: about 9.5.