During school vacation week (February 16-21), the MIT Museum will celebrate National Engineers Week with Feb Fest — a week of engineering-specific activities, workshops, and afternoon demonstrations led by MIT students.  Some programs are free with Museum admission ($10 for adults, $5 for youth, students, and seniors).  Others cost $10 per student and require pre-registration by February 6.  Tickets for other programs are available to the first 25 people, 30 minutes before the event.  All programs take place at the MIT Museum, 265 Massachusetts Ave., Cambridge.