This is a full-scale reconstructed model of the Explorer 10 satellite. Explorer 10 was designed to map the interplanetary magnetic field using three different magnetometers, as well as a plasma probe. The most sensitive of those was mounted in a very prominent sphere mounted atop a fiberglass support boom. The magnetometers were produced by Goddard Space Flight Center, and the Massachusetts Institute of Technology provided the plasma probe. It launched in March 1961 aboard a Thor-Delta with the intention of inserting it into a highly elliptical orbit to reach the region of space between the Earth and Moon. The data stream lasted only for 52 hours when the craft was estimated to be over 40 earth-radii distant, 2/3rds the distance to the lunar orbit. Explorer 10 made the first measurements of magnetic fields and solar plasmas outside the Earth's magnetosphere. The data gathered gave support to the theory that the magnetic field surrounding the Earth is closely tied to that of the Sun.
The replica was refurbished by technicians at the Goddard Space Flight Center prior to its transfer to NASM from NASA in March 1975. All the major internal scientific instruments are represented, but many of the internal elements are dummies.
This object is on display in Space Science at the Steven F. Udvar-Hazy Center in Chantilly, VA.