A passenger aircraft that flies around the world at Mach 9?

In the alleged ethical dilemma I was responding to there is clearly no claim that would bar fast passenger travel per se. There is possibly a claim in a round about way if the externalities of carbon output are not taxed at their marginal cost via a carbon tax, but that is not a reason an ethical dilemma to be considered for fast travel, it is an ethical dilemma of improperly priced externalities and would again not be a reason to bar fast passenger travel.

Near as I can tell, some people will starve regardless of if someone else is rich or not.

And some folks will be rich, regardless of if someone else starves or not.

https://history-computer.com/why-is-supersonic-flight-banned...

I mean, first class travel is not within my means either but if we're talking about rockets flying half way around the world we're not talking economy seats, not for a long time. If the prices were similar I imagine a lot of people would take an extremely comfortable long flight over a short cramped, g-force intense rocket trip.

1) fully multi-reusable rocket - not yet proven. It can happen, or can't. No need to imagine anything - Shuttle famously had been marketed and designed as super rapidly and fully reusable. We all know how it really went.

2a) food costs - negligible savings.

2b) inability to eat tasty or even gourmet food, in a normal human position and environment (jet or first class seat) is actually a negative factor. But let's disregard it.

3) passengers in pods ??? - what's a "pod" here? A space suit with a different brand name?

4) passengers without space suit - lolno, won't happen. Maybe it would be some fancy low profile suits, like new SpaceX ones for Dragon use only, without space walks and EVA capabilities. Even then they would still be pressurized airtight suits. This is actually yet another negative factor for my list above. Manufacturing thousands of unused space suits in different sizes, so that on any flight they would have a hundred suits in arbitrary random sizes ready at each start complex is a laughable idea. Just the suits cost 0.5 million dollars each (4 suits = 1 fantasy Starship launch price (fantasy price, not the ship, obviously)). And their maintenance is also not cheap, regular checks, repairs, replacements, cleaning, etc. Costs would be astronomical.

5) little to no staff - doubtful but maybe. 2 pilots would be needed at minimum, and I suspect one or two more aux flight engineers too. No service crew, yes, that would be cost savings. But lets look wider. Maintenance crews for the Starhip - much bigger and much more senior and technical. Dispatchers at the cosmodromes - a lot of people in every location, dozens of people per location. Aircraft can be controlled by a lone dispatcher, maybe with an assistant. And the list goes on. There will be much more people involved per 100 passengers than with any aircraft of any size.

6) 10 flights a day - funnily enough, some industries DO NOT benefit from economies of scale. Like almost at all. Starship is one of them. Regardless of the number of flights per time period, if you will increase number of rockets, their costs would almost wont go down. They will stabilize after first few units and stay constant. Same with all operational costs. If you need to fuel 1 Starship you pay X money. For 10 Starships you pay 10X and no less. If you service 1 flight you pay in aggregate Y human/hours of highly qualified workforce wages. If you service 10 flights, you will pay 10Y for human/hours. The only scalable component here is engine production, but after stabilizing manufacturing at some large number per year, cost drop would also stop.

And finally - 10 passengers per flight is not 20k, it is 200k dollars, which is 2-3 times more than entire top model large business jet rental for the whole flight. And jet is available on demand at the time and destination which YOU decide, airport is conveniently located almost in the city border and there are literally no restrictions of any kind in such flight for rich people. E2E rockets are not viable.

I used to love this idea, but when you actually think it through it's just not necessary / borderline plain dumb. Unless I am missing something, I really hope that US tax dollars are not thrown into this boondoggle.

1. This will come up on any ballistic missile radar as a threat. "Oh don't worry nuclear armed enemy, it's just cargo."

2. Unless it's a one-way trip, this would require huge infrastructure investment for "stage zero" and for logistics required for the oxygen and methane tank farms at both ends.

3. The trajectory is much more predictable than the flight path of say a C-17. This would greatly simplify interception.

4. The landing options are hugely limited compared to say a C-17. There is no go-around option. LZ got hot during transit? Too bad, we are landing!

5. I cannot identify the type of cargo that would be better served by the least stealthy delivery method possible, and most fragile landing infrastructure, only to save a dozen or so hours of transit time. Prepositioning the cargo closer to potential trouble zones and using traditional aircraft seems to be a much better idea in all cases that I can imagine.

I guess you're thinking that drag increases with the square of the speed, and so for very high speed the fuel consumption should be horrendous.

This is only if all things are equal. And they are not. Two things change when you increase speed: you decrease the cross-section (via decreased angle of attack, and shorter wings) and decrease the air density (because you fly higher).

A regular commercial jet flies at about 10 km height, where the air density is about 3-4 times lower than on the ground. The airplane discussed here is supposed to fly at 50km where the air density is more than 1000 times lower than at ground level [1].

By the way, I don't think this particular project has any chance of ever becoming reality. The main problem with hypersonic vehicles is the aerodynamics, not the propulsion. These guys are simply working on the wrong problem.

[1] https://www.engineeringtoolbox.com/standard-atmosphere-d_604...

This is a strange complaint to levy while the world’s largest economies aggressively electrify their transportation systems.

> we chose to do it willingly or we'll be forced to do it

These outcomes are distributed differently.

False economy. Developing e.g. rotating detonation engines requires solving flame front, detonation mechanics, additive manufacturing and materials science problems. (Off the top of my head.) Do you really not see any interdisciplinary applications for any of those?

This is the failure of top-down industry planning and scientific regulation: you miss unexpected gains.

We’re not jetting around at Mach 9 today. Or tomorrow. Rotating detonation engines [1] are closer to basic research than commerce. The earliest this could be technologically viable is in the 2030s; commercially, the 2050s. (That is ambitious.)

At the point we might consider scaling such kit, our options will be less limited (or we’ll have consigned ourselves to doom). If they aren’t, we can choose not to use it for passenger travel.

[1] https://en.m.wikipedia.org/wiki/Rotating_detonation_engine

Countries like the U.K. already charge poor tax on airlines - fly 20 people from london to paris in a 747 and you pay far less tax than than flying 100 people on an a319, despite causing far more pollution.

Instead charge based on the length of flight the the efficiency of the plane, regardless of how many people are actually on.

You’ll probably have to cap the tax on longer flights east otherwise everyone would transfer via Istanbul or ME3, but it wouldn’t require taxing fuel, or having airlines fuel up at the other end

There are big benefits to being global transit hubs. Cheaper fuel is one way to become that.

The people who plug something into the wall won’t know the difference if the electricity is generated from something other than coal.

And please don’t wait 40 years to fix the problem.

That delay likely increased climate change by a decade or so.