/sci/ - Science & Math

https://ntrs.nasa.gov/citations/19750016730

1975 Boeing study of future space program possibilities. A lot of the 1969 integrated program plan stuff shows back up here as they try to figure out ways to make it happen with a shuttle infrastructure.

The most interesting part is their preferred choice of heavy-lift launcher:

>a configuration using either two or four SRB's clustered around a modified shuttle external tank (ET) made into a stage, fitted with three space shuttle main engines (SSMEs) in a recoverable propulsion package.

So Boeing came up with a better shuttle-derived rocket than SLS in 1975, without really putting much effort into it even.