This is a fantastic resource for authentic projects:
NASA Weekly Emails for Teachers
NASA is involved with anything and everything that has to do with flight and space exploration. They also are involved in many other areas of science and technology that have been offshoots from their research (biology, medicine, ecology, geography…). When I visited the NASA Glenn Research Center as part of an educator program, I was honestly stunned by the wide and varied research they were doing! So even if you aren’t planning an authentic project about flight or space, don’t overlook this valuable resource!