This is a full-scale mock-up of the articulated and folded collecting surfaces (the "wing assembly") from the second of three Pegasus satellites that were used to study the density of meteoroids and micrometeoroids in near-earth orbit. It lacks the instrument section and the payload adaptor. The spacecraft was built by Fairchild-Hiller under the management of NASA's Marshall Space Flight Center, and was launched on a Saturn IVB in May 1965 folded into an Apollo service module. It was transferred to NASM by the Kennedy Space Flight Center in June 1975, and shipped directly from there to the Michigan Space Center at the Jackson Community College, where it is still on loan.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.