M3Challenge: Moody's Mega Math Challenge is an Internet-based, applied math competition for high school juniors and seniors. The competition is free to register and participate and is open to high schools in 29 states.
Zero Robotics: Zero Robotics is an exciting International Space Station (ISS) national laboratory robotics programming competition which uses the Synchronized Position Hold and Reorient Experimental Satellites (SPHERES) facility, which is aboard the ISS. (A middle school competition is planned for the summer of 2013.) There is NO CHARGE for joining the competition!