Oh, dear, you aren’t that familiar with the field, are you?
You’d have to properly define “Big Budget” – Dark Star was a student film, and doesn’t by any metric qualify as “Big Budgwet”, but it was a “space movie”. I’d include Silent Running as a “Big Budget” Space movie.
the 1950s were filled with space movies. This Island Earth was definitely “Big Budget” – they bragged about it on the posters. And there was Destination Moon (and Rocketship X-M, which rushed production to get there first, along with its follow-up Conquest of Space. Then there was the cataclysmic When Worlds Collide, which featured nothing less than the destruction of the Earth by a collision with a rogue planet, along with people escaping in a hastily-assembled rocket.
Lots of other fifties films, some big budget, some not., Some very good, others awful:
It! The Terror from Beyond Space (from which Alien stole its plot)
**War of the Worlds
The Lost Missile
Operation Moonbase
Worls Without End
Catwomen of the Moon
Queen of Outer Space
Abbott and Costello go to Mars
From the Earth to the Moon
Twenty Million Miles to Earth
War of the Satellites
Battle in Outer Space
**
et cetera et cetera.
Space movies continued into the 1960s and 1970s, with
Robinson Crusoe on mars (pretty good flick, in spite of the title)
**First Spaceship on Venus
Ikarie XB-1/Voyage to the End of the Universe
Countdown
Moon Zero-Two
Journey to the Far Side of the Sun
Marooned
The Green Slime
**
I’m barely scratching the surface here – these are all off the top of my head. Note that there were a great deal more science fiction films, and ones with aliens visiting earth (The Thing, The Day the Earth Stood Still, The Man from Planet X etc.), but I’m trying to limit this to “space movies”, where we see people going up and travelling through space. It was an established genre in the 1970s.
What made star Wars unique was that it took the namby-pamby pussy-footing aroiund of trying to do a space movie without alienating the rubes and threw it out the window. Despite the example of TV’s Star Trek, moviemakers are a conservative lot, and they were convinced that Middle America would be freaked out by things if they got too weird, so they didn’t want to embrace full-out science fiction, lest they offend somebody or freak them out (recall the entire brouhaha over Mr. Spock’s pointed ears in TV’s Star Trek). So they’d timidly give you some little bit of science fictional stuff, but surround it with a movie of otherwise normal goodness.
Star Wars threw all that out the window. It deluged you with a tidal wave of science fiction tropes – faster-than-light starships plying space between different suns, aliens of all different kinds, the Cantina scene, alien music, alien cultures, robots, blasters, planet-destroying weapons. And it made it seem familiar and comfortable (The Cantina bar music sounds more 20th century American than the Krel music in Forbidden Planet did 20 years earlier).
This was stuiff that science fiction and comic book fans knew and had been comfortable with for years, but hadn’t been put up on the Big Screen before. They loved it. To the surprise of the rest of Hollywood, so did a LOT of other people. After that, they decided that Weird Space Mpvies were OK. But this – the first real wholesale indulgence in unmitigated, nerdy, SF, was the stuff of yourv early thrills.