During 1960, the aerospace activities of English Electric merged with those of multiple other firms in the formation of the British Aircraft Corporation (BAC). The new entity continued its sponsored research into these concepts. According to author Nigel Henbest, one of BAC's research teams, headed by engineer Tom Smith, Chief of the Aerospace Department at BAC, that was initially investigating supersonic and hypersonic flight problems, became interested in the application of such a vehicle for space-related activities. The team compared their performance estimates of a winged reusable launch vehicle against conventional multistage rockets, determining that the approach was not cost-effective, largely due to it requiring different rockets to power each stage. Instead, by simplifying the launcher to use near-identical winged vehicles, considerable cost savings would then be achievable both in terms of its development and manufacture. Associated costs would have been further reduced by all of the elements being reusable and without any need for post-mission refurbishment, only requiring refuelling. Furthermore, the scale of the vehicles could be increased or decreased to produce launch vehicles to suit virtually any weight and thrust requirements. It has been claimed that from an early stage, BAC's space-related research was being influenced by foreign space programmes, most significant of these being the United States; reportedly, the company engaged in detailed studies of various transatlantic projects and proposals. One particular proposed vehicle, the Douglas Astro, is said to have impressed British researchers; around the beginning of 1964, the Astro was adopted as a conceptual starting point for BAC's own clustered design, which the company came to refer to as the Multi-Unit Space Transport And Recovery Device or MUSTARD; however, in common parlance, this moniker was usually written simply as Mustard. In the most intensely-studied design, Mustard was to have weighed roughly 420 tonnes prior to launch, and be capable of delivering a payload of three tonnes into a geostationary earth orbit (GEO). Stall and termination During 1964, the design of Mustard had reached the point where it was effectively complete. However, Smith acknowledges that in order to have continued the project through to the manufacturing stage, several billion pounds of investment would have been required, the financing of which was neither budgeted nor planned for by any entity. Writing for the scientific periodical New Scientist, author Nigel Henbest commented that it was unlikely that Britain could pursue the development of Mustard alone, but also suggested