How the IBM 7094 Gave NASA and the Air Force Computing Superiority in the 1960s (2016)
fedtechmagazine.com

... The IBM 7094 is regarded as one of the most powerful and advanced mainframe computers of the early 1960s. NASA and the Air Force used the 7094 for critical operations, and the mainframe played a large role in the Gemini and Apollo space program, as well as early missile defense systems to guard against intercontinental ballistic missiles with nuclear warheads. ...

he 7094 had a basic machine operating cycle of 2 microseconds, and a new processing unit that improved transfer instructions and let it compare operations. It also allowed for two instructions per core storage cycle, substantially reducing instruction cycle time.

A physically large device that used a cabinet to house its processing circuits, the 7094 had an amount of core memory that seems unbelievably miniscule today: 150 kilobytes, just enough to manage a handful of Microsoft Word documents.

Still, it is regarded as "the classic mainframe because of its combination of architecture, performance, and financial success: hundreds of machines were installed at a price of around $2 million," according to the book A History of Modern Computing by Paul Ceruzzi. ...

150kB of memory?

Wow.