Rhéa (14 August 1971 ) |
The 1971 nuclear testing campaign continued the developments in the previous year, as well as began a series of tests of new weapons concepts. 1971 also saw the beginning of France’s testing program for SLBM warheads, this period of SLBM proof testing would last until 1975. Consequently, almost all of the 1971 campaign’s objectives related to SLBM development.[1]
Work was also conducted on smaller, tactical nuclear weapons during this time period. These smaller weapons would eventually become the AN 51 and AN 52 warheads, each having a yield of 10 kilotons and 25 kilotons respectively. The French Army would use these warheads for the Pluton missile; the Tactical Air Force would deploy these warheads on the Jaguar A and Mirage III aircraft; and the Naval Air Force would also deploy these warheads as gravity bombs for the Super Etendard.[1]
The 1971 campaign featured 5 nuclear tests and possibly a single safety test, presumably related to TN-60 warhead development. The last test of the campgin, Rhea, was France’s third largest nuclear test at 955 kilotons. This would be the last French nuclear test to approach the megaton range yield mark. All the tests were conducted at Mururoa atoll; 3 at the Denise sector and 2 at the Dindon sector. All shots were fired from balloons.
A major objective of the 1971 campaign was to proof test and deploy the MR-41 warhead. The initial development of the MR-41 began in 1963, and later continued from 1966 to 1971. The MR-41 was the first boosted fission weapon France stockpiled; it used deuterium and tritium to boost the highly enriched uranium. It entered service shortly after being proof tested in 1971 and remained in the stockpile until 1979. This warhead armed the MSBS M1 and M2 SLBMs. The bomb weighed 700 kilograms, a relatively light weight for similar designs.
Another objective of the 1971 campaign was a crucial formula for the TN-60 thermonuclear warhead, primarily developing “hardening” and “miniaturization” of the design, as well as solving all security problems. This warhead was set to enter service five years after the campaign to arm the M20 SLBM. The last test of the campaign, Rhea, was most likely a full scale test of a prototype TN-60 device, and two smaller shots (Japet and Phoebe) were probably related to testing configurations for the primary trigger.
The third major objective for the series was to test a low-yield tactical warhead for the Pluton missile. This warhead would become the AN-51 and would enter service three years after being tested in the 1971 series.
