What would have happened if NASA had kept using Apollo hardware (like Russia with Soyuz) and never built the shuttle?

The Space Shuttle was what remained after NASA's planned manned Mars mission was cancelled. The Shuttle was not originally intended to have as many flights as it did. NASA was extremely derelict to have eventually retired the Shuttle without having a replacement orbital-access vehicle available. As things stand now, NASA has to pay the Russians millions of dollars every time an American astronaut visits the International Space Station.

Good question.

The Saturn V would have become standardized and could be built far more cheaply than what the first few prototypes were. However it is questionable what could realistically be done with such a heavy lift rocket. Recall that the Saturn could place about 120 tons into low earth orbit. There is not much demand for such heavy payloads. Such a rocket could send about 24 tons to the outer solar system. Once again: not much requirement.

The Saturn was designed in an age where robotics was in it's infancy and the only way to get complex jobs done in space was to send an astronaut. TImes have sure changed since then. Robotics is vastly more advanced, and a lot can be done with even a small, light robot that a human could never do.

So in many ways, rockets with the lift capacity of the Saturn and Proton are something of an anachronism. Most of the breathtakingly successful missions of the last few decades have been launched on rockets such as the Titan or Atlas. Think of the Voyagers, Cassini, Dawn, Mars rovers, New Horizons etc.

Cheers!

The Apollo capsules has NO space for external storage.

The ISS would never have been built, as there was no way to carry the larger components, especially the Canadian-built Retractable Arm

There'd be a much smaller space station.

We might have had a fly-by of Venus or Mars by now.

It's possible there'd be a lunar base in operation.

The public would have more confidence in the effectiveness of NASA. At first the shuttle seemed like a fantastic high tech idea. But as time went on, it became more obvious that a "reusable" rocket was an expensive experiment that NASA was forced to continue using.

Fewer people would have died. We need to create the perfect inner space (on the Earth) before we waste trillions trying to get into outer space.

The shuttle was incredibly far behind schedule and seems to have eaten money at a time when NASA wasn't getting enough anyway. The initial plan was to continue with missions to the moon, build space habitats and have a mission to Mars. This is what would've happened. Having said that, Apollo is very wasteful because it involves throwing away practically an entire spaceship the size of a skyscraper for a single mission.

We would have been able to go to the moon the whole time.

But people got bored with the few moon shots that we did have. And Apollo rockets are not suitable for putting people or other payloads into low earth orbit. It was designed for heavy payloads to go into high earth orbit (where the moon is).

But your question is one of "what if"

And sad to say we can not run the clock backwards and do things differently.

We stuck with the reality that it was 1972 when we last went to the moon -- 46 years ago.

People that are 45 years old or less simply were not even old enough to have experienced it.

It looks like we will rely on China or India to show us the way. China has a plan to go to the moon in the next decade.