shuttle originally designed to use something other than solid rocket boosters?

Just listening to NPR Science Friday, and a couple callers commented that NASA did not want to use solid rocket boosters with the Shuttle when it was designed in the 70’s, but that the governement asked them to build a cheaper solution than the one they originally proposed, and viola our reliance on solid rocket boosters.

My question is - what did NASA orignally propose?

One of the best online histories of the space shuttle design process I’ve found is here: http://history.nasa.gov/SP-4221/sp4221.htm. “The Space Shuttle Decision. NASA’s Search for a Reusable Space Vehicle.” This is from the NASA History Office.

I don’t know the exact history, but I’m sure NASA would have preferred to use liquid-fuel rockets only. The reason for this is that they can be throttled back or shut down completely, as opposed to the SRBs, which, once lit, will burn at full power until there’s nothing left. However, SRBs are tremendously cheaper and simpler to build.

From Diane Vaughan’s The Challenger Launch Decision (Chicago, 1996, p21):

Vaughan tends to take this Mathematica projection as the core of all STS planning. (I’ve omitted her various references.)
She has a relatively detailed discussion of the design decisions once NASA commited to SRBs. And, of course, she describes the evolution of the final design in detail.