this post was submitted on 15 Apr 2025
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Space travel is not the same.
Strictly considering low earth orbit, one needs to accelerate a payload to 25,000 km/h and like 500km above the ground. This is not computation or atmospheric flight. There's no shortcut, no engineering to work out, the physics dictates this is a hard problem. Solutions:
You go up with a chemical rocket, where almost all the launch mass is fuel. To get the ratio in your head, think the liquid in a coke can vs the can that holds it... that's the mass/fuel ratio we're dealing with, and tricks like hybrid engines or booster returns barely soften the MASSIVE cost for even the tiniest things you send up.
You assist it from the ground. "Gun" launches, as some are developing (and that I'm quite enthusiastic about), can't launch humans. Stratolaunches (from planes) only get you partway there, more like a booster.
You go nuclear. This is the only way to increase energy density vs. chemical rockets enough to make a difference. Needless to say, there are significant environmental/safety concerns when doing this on the ground, and I'm as pro-nuclear as anyone you'll find. Check out Atomic Rockets for more on this, with concrete theoretical designs that are still batshit crazy: https://projectrho.com/public_html/rocket/engineintro.php
You develop a space elevator or some analogue. No commercial launch research is even pretending to develop this, and it would require massive materials science breakthroughs.
...That's it. That's how you get to space. This isn't a "Wright Brothers vs modern jets" thing, that kind of cost optimization is just not physically possible. And whenever Musk lies through his teeth about practically colonizing Mars, people need to understand that...
Oh how I wish the X-33 / VentureStar had actually worked out...
https://wikipedia.org/wiki/VentureStar
Either something like that, or somekind of... craft that has both a RAMJet and also some kind of rocket propulsion... that or a SCRAMJet that actually works... could maybe help get us to, or toward, at least an SSTO craft, or system.
Hah, or we can go full conspiracy theorist and find and publicize the anti gravity field generator equipped TR 3B in Hangar 18 or whatever, haha.
You're looking for the SABRE hybrid engine! It's super cool: https://en.wikipedia.org/wiki/SABRE_%28rocket_engine%29
It flash freezes air to liquid using a mad heat exchanger, until the atmosphere is thin enough to warrant switching to liquid oxygen. It's better than what you describe, as it saves a tone of weight over separate jets and rockets! It was tested, and seems to work!
...But out timeline sucks, hence it was canceled in 2024 :(
https://www.flightglobal.com/aerospace/reaction-engines-to-close-as-cutting-edge-sabre-fails-to-advance/160565.article
Aerospike engines are awesome, but I'm skeptical of the X-33 TBH. It would've been cool if it had worked out.
Where you should be looking now is the "gun launch" startups. Once that's figured out, it's so much cheaper to launch "sturdy" payloads that way. Nuclear upper stages are a good option, too (with fission fragment drives being my personal favorite: https://www.projectrho.com/public_html/rocket/enginelist2.php#fissionfragment)
I'm going to approach this from the perspective of someone playing Kerbal Space Program. Early on in the career mode, you need money to build new rockets, gather science, and develop new designs that take you further into space. Without early on tourists, you're sunk. They provide a lot of the hype and money so you can research/get to that next phase.
Real life is different, I get it. I doubt these celebrities paid much if anything. It's just rich people doing rich people stuff.
Play Kerbal Space Program Realism Overhaul if you want a ... much closer to 'real' taste of how much more complicated and difficult an orbital flight is than a subortial flight, a lunar flight is than an orbital flight, an extraplanetary flight is than a lunar flight.
I'm not sure if it is still the unofficial motto of the mod... but it used to be 'if you cannot figure out how to install this mod, you will not be capable of playing it anyway', or something to that effect.
That sounds like a time sink but I may give it a try lol
... Hopefully the setup process is a bit more streamlined now, lol.
Also, this is KSP 1.
KSP 2 kinda... failed to launch, you might say.
Also... I haven't messed with the Realism Overhaul in a few years, but uh... you're gonna need a fairly poweful machine.
God speed, try not to instantly kill Jeb lol.
Yeah, low volume space tourism is fine. Bezos and such are funding quite a bit.
What I was getting at is the meme that “mass” space flight (much less interplanetary colonization) is in any way practical. It is not. It will not be, at least not until civilization is more along the lines of Orion's Arm or similar sci-fi. KSP is a fantastic illustration of that, as (even with a much smaller planet than Earth) one pays for every ounce that has to move in space.
So, you've never heard of asteroid mining?
And remember, there was a time when "Around The World In Eighty Days" was science fiction.
Per the point above, setting development/equipment costs aside, it would be like needing an oil tanker of fuel to bring back a small mass of ore.
...Can you do it? Sure. It's already been done for scientific return missions, and that makes total sense.
...Is it economical? Hell no. Mining the ocean floor, a volcano, or under the antarctic ice sheet would be orders of magnitude cheaper, much less just prospecting new suface deposits.