It's about 5% of the final velocity, but that's way more than 5% fuel savings because you don't have to suspend million of pounds against gravity for a minute a

It's about 5% of the final velocity, but that's way more than 5% fuel savings because you don't have to suspend million of pounds against gravity for a minute and also don't have to accelerate that fuel. For example Saturn V used 40% of its total fuel to get up to this speed. That's a huge savings. Unless I am reading the data incorrectly: http://www.braeunig.us/apollo/SaturnV.pdf http://www.braeunig.us/apollo/SaturnV.pdf