For your perusal today, it’s a backup SOLRAD / GRAB satellite, on display at the Smithsonian National Air & Space Museum on the mall in Washington, D.C.:
This may not be the most sophisticated-looking spacecraft, but it has quite a prominent place in the history of the Cold War. While being publicized at the time of their launches (in the early 1960s) as scientific craft — SOLRAD was short for Solar Radiation — their prime purpose was as electronic intelligence gatherers, making them the world’s first reconnaissance satellites.
But how did they come to be? After a painful and very public failed launch on 6 December, 1957, the Vanguard I satellite was successfully launched into earth orbit in 17 March, 1958. This spurred discussion in multiple quarters as to just what military purposes could be accomplished in space, particularly since Vanguard provided a solid starting point for satellite design. The Naval Research Lab (NRL), which had done much of the Vanguard design work, responded with a proposal for a satellite that could intercept signals from Soviet air defense radars and relay them to friendly (to the U.S.) ground stations for analysis. With presidential approval of this scheme, Project Tattletale and the GRAB satellites (officially standing for Galactic Radiation And Background) were born.
The Soviet downing of a U-2 spy plane carrying Francis Gary Powers in 1960 only added extra impetus to the program, and the first GRAB satellite (carrying the SOLRAD solar radiation “cover” experiment) was launched less than two months later on 22 June. Launching “piggy-back” on a U.S. Navy “Transit” navigation satellite, the SOLRAD / GRAB drew very little press aside from its new way of getting to orbit.
Five SOLRAD / GRAB satellites were launched between 1960 and 1962 — of these, two were successful while the other three fell victim to launch failures of one kind or another. The program was terminated in 1977, and declassified in 1998. The satellite currently on display at the National Air and Space Museum would have been the sixth SOLRAD / GRAB satellite, and was donated to the museum in 2002.
From the placard:
Two out of five SOLRAD / GRAB satellites were successfully launched from 1960 to 1962. They not only measured solar radiation in an open scientific experiment, but also intercepted Soviet air defense radar — a highly classified mission. Their electronic intelligence mission and equipment were declassified in 1998.