
The Race to Build the First Sustainable Supersonic Jet - jstelz7
https://www.worth.com/inside-the-race-to-build-the-first-sustainable-supersonic-jet/
======
jpeanuts
In my opinion it is disingenuous to call any supersonic aircraft sustainable.
Independently of any clever aerodynamic design to moderate the drag
coefficient, aerodynamic drag always increases like the velocity squared.
Doubling the speed will mean applying 4x the force for 1/2 the time, so all
propulsive efficiencies being equal, you will expend twice the fuel to go the
same distance - at an absolute minimum. In reality engine efficiencies
decrease at high-speeds, and you won't be able to completely eliminate the
Mach 1 "barrier" (drag peak), or design an aircraft that is equally efficient
in takeoff/landing... so the factor will be bigger than that. But x2 fuel
consumption is a hard lower bound.

I don't believe this can be called sustainable. Air transport is already a
major contributor to CO2 emissions. We as a civilization badly need
significantly _more_ efficient ways to fly, not _less_ efficient ways. To even
slightly suggest that this might be helping the environment is deplorable.

Also, air transport is already miraculous. Going around the world in a day is
not enough for you? Really? Buy a book.

~~~
melling
Nope, air transportation is not a major contributor to CO2.

There are over 100,000 flights daily. They account for about 2.5% of CO2
emissions yearly.

You know what is? Coal power plants that generate electricity.

Maybe we should focus on electricity generation from coal. I’m a little
surprised that more hasn’t been done.

[https://www.carbonbrief.org/mapped-worlds-coal-power-
plants](https://www.carbonbrief.org/mapped-worlds-coal-power-plants)

13 years ago Google attempted their RE<C project.

[https://www.forbes.com/sites/williampentland/2014/11/30/why-...](https://www.forbes.com/sites/williampentland/2014/11/30/why-
google-stopped-trying-to-make-renewable-energy-cheaper-than-coal/)

~~~
mrpopo
Air transportation is a major contributor to CO2, if you limit the scope to
the people who use it. It is estimated that about 80% of the world's adults
have never taken a flight, and 94% of the world's adults have not taken a
flight in over a year.

So, the real picture is that this 2.5% of global CO2 emissions are caused by
as few as 6% of the population, who also are incidentally the richest and bear
a high personal carbon footprint in other domains than transportation.

EDIT: I'll add to this that the aviation sector is growing, and therefore its
global contribution to GHG emissions will grow as well in the future.
Discounting the carbon footprint of the aviation sector based on today's
numbers is a mistake.

------
johncalvinyoung
I was surprised the article didn't mention Boom, which is targeting the
business-class airliner tier. Their value proposition is different, and closer
to Concorde: no plans for 'boomless' supercruise, but also vastly higher
supersonic cruise at Mach 2.2. They haven't started constructing their
airliner yet (named Overture) but XB-1, their supersonic demonstrator and
testbed, is in fabrication right now.

~~~
theothermkn
It's clearly a submarine
([http://www.paulgraham.com/submarine.html](http://www.paulgraham.com/submarine.html))
article. The article is so light, and so full of hot air, that it practically
advocates for balloon travel, not supersonic flight.

------
smachiz
Feels like a losing battle against physics, combined with it only being really
valuable in a single direction.

Overnight flights from east coast to EU are late enough that they don't impact
productive time, and largely get in early enough for a full day of work.

Making that flight shorter - as anyone who's done a DEN-NYC redeye will tell
you - doesn't actually help productivity.

Sure, on the return flight, it would be great to shave a couple hours off, but
on the way there, with the time changes required, faster doesn't so much help
with productivity. Especially with inflight internet these days.

~~~
polalavik
Sounds like you only fly first class. Have you ever flown 10+ hours in economy
and felt ready for work (or even vacation) stepping off the plane?

~~~
vilhelm_s
This will be a private jet, and they are pretty expensive. Apparently flying
in a Bombardier Learjet costs something like $7000/hour [1], while a first-
class ticket is more like $1000/hour.

[1] [https://www.aircharterserviceusa.com/about-us/news-
features/...](https://www.aircharterserviceusa.com/about-us/news-
features/blog/how-much-does-it-cost-to-charter-a-private-jet)

~~~
ryanlol
> while a first-class ticket is more like $1000/hour.

I usually pay like 160eur/hour for top tier F products like the Emirates A380.

I just paid a little over 4000 euros for a 32h round trip with that particular
offering. I don’t chase after deals, I just tend to depart from a city without
many F pax.

Of course, YMMV.

~~~
GordonS
This doesn't seem possible - I have never seen first tickets that cheap from
anywhere to anywhere. Can you provide a few example routes?

~~~
FDSGSG
Most Emirates long haul flights departing from AMS,BCN or MXP seem to be that
cheap, I'm sure there are other cheap airports but I'm too lazy to look. This
is probably the case with all the euro airports that don't charge super high
fees and lack large quantities of F pax.

I'm seeing MXP-HKG at 4000eur for a round trip, MXP-BKK for 3800eur. There are
probably even better deals available if departing from some third world
countries.

I guess you're from the UK, I'm seeing BHX-HKG priced at around 151GBP/hr.
Shockingly, LHR-HKG looks even cheaper at somewhere around 100GBP/hr.

~~~
smachiz
I think you’re seeing corona virus at work. Those F tix are usually more from
what I’ve seen.

~~~
ryanlol
I was paying those prices last year. Only the LHR rates there seem highly
unusual.

------
syntaxing
I think contrary to what people think, Supersonic jets is actually sustainable
from a physics perspective. One of the things I'm most excited about is active
flow controls on planes. The whole idea is to dynamically create laminar
seperation at strategic locations. The effects of this is pretty astounding.
It can drastically minimize the drag of the plane and can be also used as
flight controls. I can't remember the exact year but NASA did a presentation
about this and project the technology to become more prevalent by 2035.
Another thing NASA is working on is to use the same jet technology to create
perturbations in the wake of the plane to minimize the noise from the Sonic
boom.

------
grizzles
I flown many long haul flights. The first time I heard Musk propose using
rockets for international travel I thought it was insane. I still do. But if
they are accident free for the next 10 years; would I then? Probably - if they
could manage to keep my trip under ~3Gs.

~~~
jabl
Yeah, I wonder, would a suborbital ballistic trajectory save fuel compared to
chugging along in the atmosphere?

If this were to become common, would need some thinking how to distinguish
this from a ballistic missile attack, though.

~~~
AceyMan
Even in conventional aircraft a parabolic flight plan (the vertical path) is
optimally efficient, all other things being equal.

In practice it'd be a nightmare to separate traffic. Additionally it'd
increase the pilot workload significantly considering the cruise phase of
flight is typically the "ahh, I'll order some coffee from back" time as the
primary duties then are (a) monitoring aircraft state (i.e., scanning the
gages) and, (b) changing the radio frequency each time the flight moves into a
new sector and checking in with ATC.

[me: aircraft dispatcher for a US carrier in a previous life]

------
philjohn
One thing they got wrong in the article was on profits - whilst the Air France
operation struggled, the British Airways Concorde operation was profitable,
especially when they did research that showed most people thought seats on
Concorde were more expensive than they actually were.

------
ncmncm
The only way this thing could be honestly sustainable would be if it were
hydrogen-powered.

That might also be a prerequisite for profitability. But the airframe would
need to be quite different from current designs because hydrogen tankage needs
a lot more room than kerosene fuel would. Extra space on an aircraft is fairly
cheap to provide. What is difficult is more weight, including extra fuel
needed to get enough range at higher speed. Hydrogen fuel fixes that by having
3x energy per kg.

~~~
jillesvangurp
Methane is a more than viable alternative and there are a few others. Of
course for both we'd need infrastructure to generate it from renewable energy
(as opposed to extracting using or extracting hydrogen from natural gas). In
terms of energy density, methane is good enough for space flight. E.g. the
spaceX raptor engines burn methane. The long term plan for SpaceX is to use
renewable energy to generate methane; which as solar & wind cost drops, might
actually become cheaper than using natural gas. On Mars this will actually be
the only way to generate methane as there is no natural gas there.

Even just switching to natural gas would already be more sustainable as it
burns a lot cleaner and there's less need for energy intensive processing of
crude oil to produce kerosine (not to mention shipping oil around the globe
using oil tankers & trucks powered by bunker & diesel fuel). Kerosine is nasty
stuff in terms of sustainability.

So, there's a path to 0 carbon for jets (supersonic and otherwise). Even
compressed natural/synthesized methane gas is viable for GA and there have
been some prototype planes for that. For jets, you'd want the cryogenically
cooled liquid variety because it's easier to store (lighter tanks).

Of course this would require the usual suspects to get off their ass and start
innovating. E.g. Boeing had some plans for this
[https://www.wired.com/2012/03/boeing-freezes-design-with-
liq...](https://www.wired.com/2012/03/boeing-freezes-design-with-liquid-
natural-gas-powerd-airliner/) but not much seems to be happening. In light of
Boeing's recent trouble with the 737 Max, this might be worth revisiting for
them. Also the blended wing concept that Airbus demoed recently would
apparently be quite good for holding liquid methane tanks. Also a 60%
reduction in fuel cost sounds like it should be a nice incentive.

I wouldn't be surprised to see SpaceX pivot to producing jet engines at some
point as it's an obvious thing to do and they seem to have a lot of competence
around the logistics and technology involved with generating, handling,
storing, and burning methane.

In any case, SpaceX is already doing supersonic flights powered by methane
every time they launch a Falcon 9 and they have some wacky notion of actually
using their spaceship to enable 90 minute hops to the other side of the
planet.

Guilt free sustainable supersonic travel is possible but it requires people to
start thinking out of the box. IMHO the first aviation company that nails this
is going to do extremely well.

~~~
lm28469
> Methane is a more than viable alternative

Is it?

[https://www.sightline.org/2019/02/12/methane-climate-
change-...](https://www.sightline.org/2019/02/12/methane-climate-change-
co2-on-steroids/)

[https://www.sciencedaily.com/releases/2019/12/191216140715.h...](https://www.sciencedaily.com/releases/2019/12/191216140715.htm)

[https://www.livescience.com/52715-natural-gas-not-as-
clean-a...](https://www.livescience.com/52715-natural-gas-not-as-clean-as-
people-think.html)

We're already coming to the conclusion that electric cars aren't that clean so
when I hear about carbon neutral supersonic planes I kind of feel like I'm in
a bad dream.

~~~
jillesvangurp
You make a good argument why synthesized methane is a great alternative to
natural gas.

Also, electric cars are way cleaner than ICE vehicles over their life-time. I
don't think there's any dispute about that.

------
phunctional
What about Boom Supersonic? They are partnering with Prometheus fuels that
pulls carbon out of the air and turns it into fuel and also focusing on a
commercial jet rather than private. There isn't even any mention of
sustainability other than in the title of this article.

~~~
kelnos
This definitely read to me like a paid (by Aerion) puff piece. No surprise
there's no mention of competitors.

------
growlist
The CO2 emissions argument is easily resolved: just price tickets high enough
that journeys can be made carbon negative.

------
new_realist
The race to spend excess liquidity injected by central banks: a bubble story.

