Hacker News new | past | comments | ask | show | jobs | submit login

The Concorde entered service in 1976, and program launch was in the Kennedy administration. It would be surprising if technology didn't advance enough to bring huge improvements over that time period.

There are broadly three enabling technologies, plus a couple of economic factors. Technologies:

1. Carbon fiber. With the 787, we finally have a transport-category aircraft with significant amounts of carbon fiber that has gone through full FAA certification, which significantly lowers the barrier to us using it. Carbon fiber does a lot for us. It is lighter and stronger than aluminum, but it is also more thermally stable. Concorde grew about 15 inches in flight as its temperature rose in flight. Our leading edges will reach over 300ºF at Mach 2.2, and our plane will grow less than an inch in flight. That is a significant maintenance cost reducer. Carbon fiber also enables more complex geometries without expensive tooling costs. Our plane won't have a straight line on it. We can take better advantage of area ruling to improve aerodynamics. In contrast, Concorde's fuselage was a cylindrical tube.

2. Engines. There is a (much slower) Moore's law for engine cores; they get better at a rate of around 1 percent a year. Move 50+ years forward from when Concorde's engines were designed and you have a real improvement. Concorde used 4 turbojets (i.e, zero bypass ratio) and we have 3 medium-bypass turbofans. Plus no afterburners are needed. When Concorde used afterburners to punch through the transonic regime, they had a 78% increase in fuel flow for a 17% increase in thrust.

3. Computational fluid dynamics. Concorde is all the more impressive for the fact that it was designed with slide rules and wind tunnels. Wind tunnel tests are expensive, taking six months and costing millions of dollars. We can do virtual wind tunnel tests in software in about 30 minutes. We still use tunnels to closely test harder aspects of the design (e.g., low-speed handling qualities), but we have much more rapid design iteration than Concorde could have hoped for.

On the economics, we are right-sizing the aircraft. Concorde had 100 seats, but it usually flew with a very low load factor (half-empty). Our design has 55 seats, which is similar to the premium cabin on today's widebody subsonic airliner. What this means is that any route that can sustain widebody subsonic service today will basically work supersonically. We expect much higher load factors, which are helped by business class fares and a lower number of seats to fill relative to Concorde.

This leads to economies of scale. Whereas Concorde really only was profitable between New York and London, Boom flights make economic sense on hundreds of global routes. Which means we'll sell more planes and drive maintenance costs down further. Only 14 Concorde units ever saw commercial service. Ultimately, when Concorde shut down, it was because Airbus stopped making spare parts. In contrast, one public report by the Boyd Group estimated supersonic demand at 1300 planes. With almost two orders of magnitude of planes in service, we'll achieve much better scale on maintenance.

Hope this answers your question about the magic.

A good way to image this is, in 1969 for the moon landing they had to code the timestamps in negative. Of course it’s a joke but it tells a lot about how far that time was.

"Shut up and take my money," -- JAL Executive

"黙ってお金を取る" - JALエグゼクティブ

medium bypass can push mach 2.2? holy intake shock. any precedent for engines having such performance?

The F-22’s engines have 0.3:1, it cruised at Mach 1.8, and it’s old 90’s tech now. Correct me if I’m wrong. Maybe 2.2 is pushing it, but the claim doesn’t seem outlandish. The Boom doesn’t need the wings of an air superiority fighter, amongst other things.

I still don't buy it.

That said, I sincerely wish you prove me wrong and pull it off.

It's a huge risk and certainly deserves to be rewarded.

What makes you think you are going to sustain that ridiculous cheap price of a ticket?

I fly to Europe constantly on first class and tickets are usually circa $8,000 round trip. When I saw your "plane" with huge seat space, huge windows and $3,500 per round trip NYC-LON I immediately looked for your phone number to send you $350,000 for my next 10 years of flying. Please just take my money!!

Bottom line it will not be sustained so some deep alteration will have to be done. I would rather spend $8,000 in first class 7 hours flight this summer, than book my 3.5hr flight with you that will happen in 2028, because you are highly overbooked. Of course adding 100x more units in flight won't cut; air space is not like bakery you just can add another oven.

> We think there's a roadmap to making supersonic flight cheaper than subsonic flight is today. It will take a few decades, but that is absolutely the path that Boom is on.

In few decades we will be catapulted into space from London without engines on "the Moon elevator" and then pull back with Earth gravity, slowed down by huge magnets and safely land in New York in less than 19 minutes, door to door. Your approach is similar to those who envisioned building harness for 100 horses in a row to go faster, right before a Diesel engine was invented.

> In few decades we will be catapulted into space from London without engines on "the Moon elevator" and then pull back with Earth gravity, slowed down by huge magnets and safely land in New York in less than 19 minutes, door to door.

I feel like this assertion deserves a big "maybe" in there somewhere.

Definitely. The commenter who can't believe supersonic flight is commercially feasible by the early 2020s thinks it's because we'll fly from London to NYC via space elevator and slow through reentry via "huge magnets." To be honest, I don't know enough about the science and business of flight to know whether this pitch for Boom is feasible, but I'm not as inclined to buy this particular argument against it after this point.

For the record, I hope Boom succeeds. When I was a kid I learned about the Concorde as the future and it's been a real shame to watch it stay in the past.

Until one day a magnet fails and "safely land" turns into "dies screaming after impacting at terminal velocity into a city center"

> In few decades we will be catapulted into space from London without engines on "the Moon elevator" and then pull back with Earth gravity, slowed down by huge magnets and safely land in New York in less than 19 minutes, door to door.

I’d like to see the trajectory that takes you from NY to London in 19 minutes without squashing you and/or causing insane amount of heating. Bonus points if the only source of thrust is a fancy air brake.

I wouldn't make predictions about things that are not possible to make today with with unlimited budgets.

One past example of predicting the future with unlimited budgets is the xerox alto.

> not possible to make today with with unlimited budgets

The Lofstrom Loop is possible today for a few billion dollars. Though "catching" an incoming capsule with a Loop is going to take a while to human-certify.

What is a few? That is the in the range of infrastructure projects for many nations. China could create it for example.

> In few decades we will be catapulted into space from London without engines on "the Moon elevator"

I used to imagine the same thing when I was a kid, that by the turn of the millenium we'll be piloting flying cars. But here we are in 2018 sitting in traffic jams in the same old boring four wherlers. Yes they're more efficient and reliable but still a chariot on wheels.

Nowadays I'd rather imagine supersonic flight is possible from an economic standpoint and wish Boom the best of luck with their enterprise.

It's a really personal opinion, but I don't think that we saw a lot of technological breakthrough in the last 50 years.

Except in genetic, chemistry and computer sciences, most other fields looks a lot like where they were 50 years ago.

It's true that there were a lot of incremental changes, greatly improving the overall efficiency, and also a far wider adoptions of these technologies. But the basis for most concepts/designs are in fact quite old.

The first computers are from the 50ies and the transistor from 1947, the 737 first flew in 1968, the 747 a few years later, the first nuclear plant dates back from 1956, Soyuz still flies despite being based on the 1957 R7 ICBM, the basic design of cars is pretty much established since the 20ies or 30ies.

Short of the internet (agree it's a big "short of"), our lives are not that much different than in the 70ies or 80ies (at least in the US/Europe).

And in fact, it's not a big surprise. A big factor in radically changing our material condition is to get energy, and a lot of it. First there was coal 200 years ago, then oil and gaz in the late XIXe century (plus electricity for its versatility and ease of distribution) and, finally, nuclear fission (and it was only a semi-success seeing the current and near future adoption). Short of a new energy source, with an output an order of magnitude higher than we currently have (Fusion? if we manage to pull it of), I don't see why we will have major technological changes.

Exponential scientific and technical advancements only happen in the early stages of the large scale adoption of a technology. Von Braun went from launching hand made rockets as part of a rocket club to leading the team that engineered the moon landings, but since then rocketry improvements have been incremental. I think with computer technology we're still in an early phase. Eventually we will reach the limitations of the current silicon transistor paradigm. Maybe something else will take over, maybe it won't.

But sometimes several things come together to lead to a new capabilty. SpaceX recoverable rockets aren't just due to incremental improvements in rocket engines, they're due to improvements in a whole host of different areas - materials technology for lighter rockets, software improvements, better heat shielding materials and frankly new economic imperatives. Those all came together to push us over the edge of a new capability. Maybe the same will happen with supersonic passenger planes.

Unless we have WW3, I can guarantee you the lightweight personal transportation will take on 3D shape (personal flying machines) within next 25-50 years, but it will not overlap with ability to control them. And that even better! In 20 years AI will drive much better than best human driver in worst road scenario. Why bother giving steering wheel to non-pilots, if AI can do better work by then ?

Space elevators will be wonderful... if they are feasible. We have yet to identify a material with sufficient tensile strength to construct a space elevator, and may never do so.

[...] it might be assumed that the flying machine which will really fly might be evolved by the combined and continuous efforts of mathematicians and mechanicians in from one million to ten million years--provided, of course, we can meanwhile eliminate such little drawbacks and embarrassments as the existing relation between weight and strength in inorganic materials.

More fun facts: https://en.wikiquote.org/wiki/Incorrect_predictions

Hence the "if". I certainly hope they will be feasible, but the fact that an alternative may be possible, contingent on the potential creation of currently nonextant materials, is absolutely not a reason to discourage development of supersonic aircraft.

That Asimov quote is actually pretty damned close to reality. Why is that exchange, of all things, sitting beside Neville "Peace for our times" Chamberlain?

Applications are open for YC Summer 2019

Guidelines | FAQ | Support | API | Security | Lists | Bookmarklet | Legal | Apply to YC | Contact