The Civil Air Patrol (US Air Force affiliate) has many STEM lessons and kits available to educators for a one-time fee. The kits include robotics, microcontrollers, telescoopes, flight simulators and others.
This is an annotated bibliography of over 70 elementary STEM resources including lessons, construction materials, robotics, and other integrative resources.
This website, maintained by elementary STEM consultant Bob Claymier, contains:
1) A list of over 40 STEM resources for grades K-6 ( construction materials, books, curriculum, websites) related to elementary STEM.
2) a list of over 40 robotics and coding resources for grades K-6
3) A free set of standards-based science lessons for grades K-6, all with an engineering component
4) A free monthly elementary STEM newsletter (current and archived editions) that contain information on resources, events, and articles pertaining to elementary STEM.