objected, and then to Antler. At the AWTSC meeting on 7 December 1956, Martin suggested that the committee be reconstituted. A three-person Maralinga Safety Committee chaired by Titterton, with Dwyer and D. J. Stevens from the Commonwealth X-ray and Radium Laboratory as its other members, would be responsible for the safety of nuclear weapons tests, while a National Radiation Advisory Committee (NRAC) consider public health more generally. This reflected growing disquiet among the scientific community and the public at large over the effects of all atmospheric nuclear weapons testing, not just those in Australia, and growing calls for a test ban. Nonetheless, Operation Buffalo had attracted little international attention. The British Government rejected calls for a moratorium on testing, and announced at the US-UK talks in Bermuda in March 1957 that it would press on with the Operation Grapple hydrogen bomb tests. Martin's proposal was accepted, and the composition of the new NRAC was announced on 7 July 1957. John Moroney was appointed secretary of both committees. The AWTSC continued to report to the Minister of Supply, while the NRAC reported directly to the Prime Minister. The first round of Operation Grapple tests was unsuccessful in demonstrating a working hydrogen bomb design. This left plans for Operation Antler in disarray. By mid-June 1957, proposals for Antler included up to seven tests: of a surface-to-air warhead called Blue Fox, a small warhead called Pixie, four different versions of Red Beard, and a round designed to test the principle of radiation implosion. Initially it was planned to test Blue Fox (later renamed Indigo Hammer) in both boosted and unboosted form, but the disappointing results of boosting thus far meant that the benefit of boosting would be too small to warrant it, and this version was discarded. Pixie was an even smaller, lightweight () warhead with a plutonium core under consideration for use with the Royal Navy's Seaslug missile. Its drawback was that it required enough plutonium to build two Red Beards, and plutonium was scarce and expensive. In February 1957, the Australian authorities were notified of plans for six tests, including three using balloons, with maximum yields of up to . The UK had considerable experience with barrage balloons during the Second World War but the proposed use of balloons to carry warheads to a higher altitude than achievable with a tower was an innovation for Operation Antler. Use of balloons did