Japan's New Hypersonic Engine Could Make 2-Hour Flights to the US a Reality
50 points by rmason 2 hours ago | 30 comments

darkteflon 2 hours ago
Cool science. But the article fails to take even a cursory stab at contextualising the plan against the economic, environmental and political backdrop - doesn’t even mention that there’s already been one failed supersonic commercial flight programme. This is as pie-in-the-sky as it gets.
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hdndjsbbs 35 minutes ago
I think a lot of the Concorde failure is tied to its status as a British-French project. Trans-Pacific flights are much longer and there's a lot of money in PEK -> LAX than in JFK -> LHR.

Qantas wanted to offer London to Sydney, but they couldn't fly supersonic over land. Mainland China or Japan to Australia is a feasible route for high-margin, low-capacity supersonic flights.

If you could make the flight from Beijing to California take less than 5 hours that seems like a premium product many ultra wealthy people would spring for. Dubai to SFO is also a possible route.

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decimalenough 23 minutes ago
There is a lot of money in NYC-LHR, that's why Concorde continued to fly that route and profitably too, once they realized how high they could yank the prices and still fill the plane.

Also, Concorde's maximum range was 4,488 mi, which was calibrated to allow trans-Atlantic but not much more. Trans-Pac was not an option and even Australia to North Asia would be a stretch.

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bobthepanda 3 minutes ago
I think they are agreeing with you re: the range.

There is money in NYC-LHR (it brings BA alone $1B in revenue annually) but the market for supersonic basically vanished. In the 70s when Concorde started flying, it was certainly a step up. However, the market niche basically disappeared when the lie flat seat was developed; for a lot cheaper, you could have a sleep for six hours in a really cushy lie flat, or you could spend a crapton more to be in a much louder, more cramped cabin for only about three hours less. If you were halving a 12-16 hour journey instead, there would still be a market left, but Concorde just didn't have the ability to do so.

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gottorf 32 minutes ago
> Dubai to SFO is also a possible route

Is there really that much premium traffic between Dubai and the Bay Area?

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bobthepanda 60 seconds ago
The Middle East (was) a pretty common stopover for India flights, since India's not that well connected to the US due to a lack of capacity.
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WorldPeas 27 minutes ago
I think the more interesting question is /will/ there be that much premium traffic ongoing
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VerifiedReports 25 minutes ago
ORD -> Vatican
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rdl 13 minutes ago
Vastly more favorable today than it was when Concorde flew.

1) Rich people are WAY richer, and time is even more valuable 2) Businesses have some very important employees and "2 day trip" vs "3-4 day trip" is worth $50-100k 3) Larger population of people able to pay $20-30k for a flight than ever before.

The biggest practical impact is there's probably going to be a private jet version instead of just a commercial one, and there will likely be transpacific demand exceeding transatlantic. Also government/military use.

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HNisCIS 2 hours ago
Whenever you look at supersonic or hypersonic commercial aircraft plans you should assume one of two things.

A. It's a bait and switch by a founder who wants to pivot to weapons/military aircraft but wants to be able to hire high grade talent without paying the "we're gonna kill people" premium, can pivot once a good chunk of the workforce is complacent with a paycheck. You laugh but this happens SO FUCKING MUCH.

B. It's for business jet scale operations for billionaires. There are >3000 billionaires and however many corporate aviation departments and if you can build a super/hypersonic private jet that's not horribly expensive to operate the "time savings"* for that class of person will demand they buy one.

* when I say time savings I mean dick measuring contest

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nradov 45 minutes ago
Defense contractors don't pay premium wages. Rather the opposite. Many employees specifically want to work in the field in order to contribute to the national security mission.
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HNisCIS 42 minutes ago
I'm being a bit obtuse here to make the point, it's more complicated than that. The reality is if you create a defense startup you end up hiring defense employees which comes with its own set of issues.

That said, go look at salaries right now in the defense space.

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picture 38 minutes ago
From my experience with working for defense/aerospace companies as well as civilian b2b ones in the US, the general situation is that defense/aero companies pay less but demands less of a grind. People usually take the lower pay (usually 70% of equivalent role in commercial sector) for the better culture
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HNisCIS 35 minutes ago
For pure generic full-stack-whatever devs yes. For EEs, embedded, FPGA, RF, etc you can pull waaaaay more in the defense world, especially if you're willing to do cleared work.
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nine_k 3 minutes ago
But if you need clearance to do your work, how can it be bait-and-switch? You need to hire people who are able and willing to obtain a clearance.
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Seattle3503 53 minutes ago
What companies are examples of that bait and switch strategy?
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nine_k 2 minutes ago
Google tried to become a national security contractor, and the backlash among the engineers was very intense.
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Onavo 51 minutes ago
Can't give any examples but I have definitely heard the same about a lot of aerospace startups through the grapevine. As for OP's point about private jets, Boom supersonic is your classic example.
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HNisCIS 37 minutes ago
I can't name names but 3 of the startups I've worked at.

Places I haven't worked:

Skydio

Applied Intuition

Saildrone

Planet Labs

Boom

Scale AI

Also worth noting that sometimes it's on purpose, sometimes the founders are all "we're gonna save the world" then AFWERX enters the chat with a big fucking check and the founders yell "Nevermind! Guess we're the baddies now! How many slaughterbots did you say?"

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Grosvenor 50 minutes ago
> * when I say time savings I mean dick measuring contest

And in this case smaller is better?

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loeg 53 minutes ago
Safety should probably also be considered.
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Padriac 4 minutes ago
I imagine passengers will be exposed to very high noise levels during flight.
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rbanffy 2 hours ago
People say this like it's a simple engineering problem.

No. By itself, a new hypersonic engine can't make 2-hour flights between Japan and the US a reality. We are not even close to being able to build an aircraft that can do that - we don't even have the materials for that. What seems "easier" (as in "less impossible") is a hypersonic glider design that enters a suborbital trajectory and does shuttle-like aerobraking while it glides to its destination, before reengaging propulsion prior to landing on an airstrip (because passenger planes need to be able to abort landings and do multiple attempts). Not sure how reverse thrust would work there - variable geometry rocket bells?

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kelseyfrog 3 minutes ago
How long of a weightlessness period does this entail?
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atoav 2 hours ago
The actual time to skim off IMO is all the airport procedures.
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whiplash451 57 minutes ago
This is already a solved problem for the class of customers they are going after.
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holoduke 2 hours ago
What would a ticket cost like? 50k? Aren't those people in their own fancy private jet with whiskey, massages and party?
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Ekaros 2 hours ago
Or have their own room in first class... Maybe time trade off isn't worth it for most of the people who can afford it at that point.
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superkuh 2 hours ago
>At that elevation at Mach‑5, air around the nose and leading edges can reach temperatures exceeding 1,000 degrees Celsius (1,832°F), a challenge...

It is not the conical nose or leading edges that are the show stopper problem(s). There the shockwave generally does not touch the craft. The internal shockwaves that touch the walls of the engine ducting are. The heat loading and heat soak ability on those shockwave impingement sites will limit the duration of hypersonic travel.

Hypersonic travel through the atmosphere is easy, a problem solved in the 1950s. Be conical and carry your oxygen internally. Hypersonic travel that is air-breathing is an entirely different class of problem and I don't think it is anywhere near to being solved.

The only silver lining is that at hypersonic speeds you don't need to be propulsive for very long to get anywhere.

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Insimwytim 5 minutes ago
[dead]
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domoregood 22 minutes ago
Ahh, but can it run DOOM...?
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