Mercury-Scout 1, or MS-1, was a United States spacecraft intended to test tracking stations for Project Mercury flights.

[1][2] It grew out of a May 5, 1961 NASA proposal to use Scout rockets to launch small satellites to evaluate the worldwide Mercury Tracking Network in preparation for crewed orbital missions.

When the spacecraft came within several hundred miles of a ground station, it could have line-of-sight voice and telemetry communications by HF (shortwave), VHF or UHF radio and C-band and S-band radar.

The ground stations were linked back to NASA's Mercury Control in Florida through land lines, undersea cables and in some cases HF radio.

On June 13 the NASA Space Task Group issued requirements for a modified Scout rocket and small communications satellite that became known as Mercury-Scout.

This article incorporates public domain material from websites or documents of the National Aeronautics and Space Administration.