re: Japan to host space elevator conference
"Or said differently one could use a "space elevator" which was 5 miles tall instead of it being 30,000 miles tall. In other word if you get a chemical rocket to 50,000' elevation and going saying 500 to 1000 mph you would cut in half the needed mass of the rocket."
NFW does it reduce the mass by half. The Delta V budget is many times 500 or 1,000 mph.