Question: are there any other known "Manhattan projects" and if not, why not?

Yes, although not at that scale.

- Several products from the Lockheed Skunk Works, including the U-2 and SR-71 reconnaissance aircraft and the early stealth aircraft.

- Russian titanium submarines

- The original US spy satellites, the CORONA program.

- At the moment, China building aircraft carriers. They're built in shipyards that also build container ships, and it's hard to tell from the air which hulls are military.

▲

crazygringo 5 days ago | parent | prev | next [-]

Not sure what you mean. Atomic bomb projects in other countries? Of course. Other large-scale engineering-led national projects? Yes, like the moon landing.

	▲	dylan604 5 days ago \| parent \| next [-]
		Moon landing was done in full view of the public while the Manhattan project was a total secret. Based on that, I don't think they are the same. One could suggest the development of the B2 Stealth bomber would be closer than NASA. The design of satellites used by NRO are much more secret than NASA.
	▲	catigula 5 days ago \| parent \| prev [-]
		I mean very simply: a highly secretive project that explores new physics for some radical new, destructive technology. It's interesting that everyone here is talking about mundane technologies or technologies that stem from a project that is almost 100 years old. What happened to physics? We just found the one interesting thing and that was it?

▲

sib 5 days ago | parent | prev | next [-]

The Apollo project was also surprisingly large and complicated...

▲

bwanab 5 days ago | parent | prev | next [-]

Evidently the development of the B29 bomber (one of which carried the Hiroshima/Nagasaki bombs) cost more than the Manhattan project. https://en.wikipedia.org/wiki/Boeing_B-29_Superfortress

▲

aerostable_slug 5 days ago | parent | prev | next [-]

A similarly-scaled endeavor created and produced the B-29 bomber.

▲

ricksunny 5 days ago | parent | prev [-]

>Question: are there any other known "Manhattan projects" and if not, why not?

Answering this question is necessarily an exercise in tautology. If there were any other extant Manhattan Projects, we would not citably known about it because, being a ‘Manhattan Project’, it would be replete with secrecy, including disinformation to keep the public from giving leaks about it any credibility. (case example, the Alamogordo Trinity test was called an ammunition explosion accident, by way of an Army Air Forces colonel, for the benefit of the good people of nearby Albuquerque).

Many today suspect the UAP study subject as being an ongoing decades-long Manhattan Project, from the late 1940s onward. As Congressional hearings leading to just this past Tuesday’s, Sep 9th have amply demonstrated, there increasingly appears to be some veracity to these claims. https://m.youtube.com/watch?v=LBKRr5OvF6E&t=1056