What is the cost of launching a Mars vehicle directly from Earth?
$7k/kg by Falcon Heavy pricing. Would you rather a different launch system?
Not really. But the problem is your "lowering prices" standards involves having to send things into to an entirely different gravity well (consumables), and landed propulsively, so that other different things can then be launched from said gravity well.
And it has diminishing returns
Your proposal, absolutely.
From Earth, there are no diminishing returns whatsoever. Just the opposite - the more you launch, the cheaper it gets per kg.
There is no practical way to launch a large enough manned vehicle for Mars
One: completely and utterly false. There are a huge number of different proposals for this, all of them technologically feasible.
Two: your counterproposal involves doing the same for the moon, and then doing constant resupply so that they can build things that require an entire industrial base there. It's an absurdity.
Let's take a look at the Falcon Heavy heavy lift vehicle [wikipedia.org] which is one of the heaviest available right now. The payload to Mars is about 13,000 kg. That is about the weight of 1 ISS module.
No, seriously, and? Just ignoring that you can launch to LEO, including transfer stages, and this you actually can launch over 50 tonne segments, is your notion that humans can't build things in space? If not, walk outside tonight when the ISS is due to pass overhead, and look up.
The cost per launch is $90m. Want five launches to build it? Ten? Fifty? You're still a fraction of the cost of establishing the sort of industrial infrastructure needed on the moon to support rocket launches, which in turn is still going to cost more than from the Earth due to the cost of said infrastructure's imports.
Have you ever thought why no NASA missions to outer space has been refueld?
You mean like the ISS?
The ISS station gets refueled all the time but not probes. Why is that?
Because it's cheaper to just build things on Earth and launch them, exactly the point I've been trying to get you to understand this whole time. Doing things in space increases the cost, and the further you are from Earth, the greater that cost is. Work in LEO is expensive because everything requires consumables that must be launched (humans in particular). Work on the moon is vastly moreso because it requires vastly more delta-V to get there. You're wanting to do the vast majority of the work at a place where costs make LEO look like a bargain. Work that can't even be done without developing a whole industrial base to begin with.
By your logic, NASA has no plans for Mars either.
Incorrect, and an absurd statement to make. The "Journey To Mars" program is the core of NASA's focus. (If it wasn't, nobody would ever put MOXIE on Mars 2020.
This is getting absurd. If anyone else wants to talk to this person (who actually goes by the name "UnknowingFool" - almost starting to wonder if this is trolling), go ahead - I'm out.