The Charles River Museum of Industry & Innovation is launching FutureFixers Invention Adventure, a new after-school program for students aged 12-15.  It’s designed to engage middle-school boys and girls, drawing on STEM skills and focusing on cases to crack, riddles to unravel, stuff to take apart, and things to build.   The program will run March 31 through the end of the school year (except for school vacations), at a cost of $200.  One group will meet on Tuesdays and another group on Fridays, both 3:30-5:00 at the museum in Waltham (directions).  Register online or by phone (Katherine Davis: 781-893-5410) for either group.