What percent of the total available fuel onboard the space shuttle, external tank, and rocket boosters was required to launch and get the space shuttle into orbit? Or phrased another way, what percent of the initial fuel load was left for maneuvering and reentry?
The Shuttle had three propulsion systems:
- the solid rocket boosters (SRB), mounted at the side
- the main engines (SSME), mounted in the orbiter and fed from the external tank
- the orbital manoeuvring system (OMS), mounted in the orbiter and fed from tanks inside the orbiter
During launch, the SRBs were fired until they burned out, and the SSMEs were run until the external tank was almost dry. The SRBs were still generating a minute amount of thrust when they were dropped, but we can effectively assume 100% fuel usage.
The external tank still had a small amount of fuel in it when it was dropped, because it was safer and more controllable to shut down the main engines rather than let them run dry. I don't have a figure to hand, but I suspect this would be <1% of the total fuel mass.
After this point, the SSMEs played no further role in the launch. The Shuttle was still on a suborbital trajectory (or a highly elliptical orbit), and the OMS was used to perform the final orbital insertion burn.
I'm finding it difficult to nail down an exact figure (it would depend heavily on mission profile and payload) but Jenkins' The Space Shuttle (2001 ed, p. 390) suggests an average of about 500fps of fuel was used during ascent, out of a total of 1000fps.
So in total - 100% (or effectively 100%) of the SRBs and external tank, and ~50% of the OMS fuel carried in the orbiter.