Editing Project Pluto (section)

== Termination==
Despite the successful tests, the [[United States Department of Defense|Department of Defense]], the sponsor of the Pluto project, had second thoughts. ICBM technology had developed more quickly than expected, reducing the need for such highly capable cruise missiles. There were concerns about whether something so noisy, hot and radioactive could go undetected, and it would be dangerous to anyone and anything in its path. <!-- The ICBM had several advantages over the SLAM: it required less ground support and maintenance, and could be launched in minutes instead of several hours, and so was less vulnerable to a nuclear [[first strike (nuclear strategy)|first strike]].--> An ICBM traveled to its target faster and was less vulnerable to interception by Soviet air defenses.{{sfn|Herken|1990|pp=28–34}} The main advantage of the SLAM was its ability to carry a larger payload, but the value of this was diminished by improvements in nuclear weapon design that made them smaller and lighter, and the subsequent development of multiple warhead capability in ICBMs.<ref>{{cite web |title=Speed and the Cold War  |publisher= National Air and Space Museum |url=https://airandspace.si.edu/stories/editorial/speed-and-cold-war |access-date=3 February 2025}}</ref>
[[File:Building 2201 in 2007.jpg|thumb|right|Building 2201 in 2007]]
The other major problem with the SLAM concept was the environmental damage caused by radioactive emissions during flight, and the disposal of the reactor at the end of the mission.{{sfn|Layton|2020|p=9}} Merkle estimated that about 100 grams of [[fission products]] would be produced, of which he expected a few grams to be released and dispersed over a wide area.{{sfn|Merkle|1959|pp=10–11}} Atmospheric nuclear testing was still ongoing in the early 1960s, so the radioactive emissions were not considered to be a major problem by comparison. Although small compared to that produced by a nuclear explosion, it was a problem for testing.<ref>{{cite web |first=John |last=Krzyzaniak |date=20 August 2019 |title=Project Pluto and the trouble with Russia's nuclear-powered cruise missile |publisher=Bulletin of the Atomic Scientists |url=https://thebulletin.org/2019/08/project-pluto-and-trouble-with-the-russian-nuclear-powered-cruise-missile/ |access-date=25 May 2022 }}</ref> The noise level was estimated to be a deafening 150 [[decibels]].{{sfn|Layton|2020|p=9}} There was also the possibility of the missile going out of control.{{sfn|Herken|1990|pp=28–34}}

The idea of testing it over Nevada was quickly discarded. It was proposed to conduct test flights in the vicinity of [[Wake Island]], flying a figure-eight course. The reactor would then be dumped into the Pacific Ocean where it was {{convert|20000|ft|order=flip|sp=us|sigfig=1}} deep. By the early 1960s there was increasing public awareness of the undesirable environmental impacts of radioactive contamination of the atmosphere and the ocean, and the radioactive emissions from the missile were considered unacceptable wherever the tests were conducted.{{sfn|Herken|1990|pp=28–34}}

The AEC requested $8&nbsp;million (equivalent to ${{inflation|US-GDP|8|1964}} million in {{Inflation/year|US-GDP}}) in [[fiscal year]] 1965 for continued tests of Tory II-C and the development of Tory III, an improved version. In April 1964, the [[Joint Committee on Atomic Energy]] recommended that $1.5&nbsp;million be cut from this request. This provided continued funding for Tory II-C, but not for the development of Tory III. The Department of Defense's [[Under Secretary of Defense for Research and Engineering|Director of Research and Engineering]], [[Harold Brown (Secretary of Defense)|Harold Brown]], favored the continuation of Project Pluto at a low level of funding to progress the technology.{{sfn|Butz|1964|pp=30–33}} This was rejected by the [[House Appropriations Committee]]; the technology had been demonstrated by the successful Tory II-C tests, and if there was no longer a military requirement for it, there was no reason to continue funding. It therefore cut another $5.5&nbsp;million from the funding request, leaving only $1&nbsp;million for "mothballing" the project.{{sfn|Butz|1964|pp=30–33}}

On 1 July 1964, seven years and six months after it was started, Project Pluto was canceled.<ref name="fact sheet" /> Merkle hosted a celebratory dinner at a nearby country club for project participants where SLAM tie tacks and bottles of "Pluto" mineral water were given away as souvenirs. At its peak, Project Pluto had employed around 350 people at Livermore and 100 at Site 401, and the total amount spent had been about $260&nbsp;million (equivalent to ${{inflation|US-GDP|0.260|1964}} billion in {{Inflation/year|US-GDP}}).{{sfn|Herken|1990|pp=28–34}}