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Aren't supersonic jets more affordable? I mean I know SpaceX is about changing the world, and I know SpaceX is about rockets, but in terms of market, I think having a new Concorde would better fit the idea of earth to earth travel.

I like how SpaceX innovates, but I think this is a "too soon", bad product idea because it will be too expensive at first, and supersonic jets would be a better competitor.

Although I have to admit I really like the disruptive way of "showing the way to the future" communication ad. But to be frank, I wonder if people at SpaceX are not full of zeal sometimes. One bigger problem for SpaceX might be "how to sell space to consumers, or make money with space?".

Maybe that is the reason NASA existed as a government agency, because there is no real, direct ROE with space exploration. In the end SpaceX might make money with wealthy people who can afford going to mars or the moon, but I doubt that many people would be interested if there is no financial gain (or maybe for the hell of it). Innovation from NASA research was shared or benefited the military.

I want SpaceX to endure and succeed but I really wonder about the money/market sides of it. It requires a lot of vision, which goes beyond the reality of capitalism.

The trouble with supersonic jets is that they aren't that fast, they're limited in where they can fly, and range is problematic because they're much less efficient than subsonic jets.

Concorde shaved about three hours off the trip between NYC and Paris or London. It burned ungodly amounts of fuel (two tons of fuel just taxiing to the runway), cost a ton, didn't have enough range for Pacific routes, couldn't fly transcontinental routes because of the sonic boom, and after all of that it only saved a few hours.

Of course, Concorde is old technology and it could be done a lot better now. But you'd still be saving a limited amount of time (roughly a factor of 2), burn more fuel, and be more limited in range compared to a traditional airliner.

BFR would have enough range to connect any two points on Earth. It would have no restrictions on overflight (although it would most definitely have restrictions on where it could launch and land). And it would save 10-20 hours over a direct subsonic flight.

Cost? Well, I don't know. Elon says it'll be pretty cheap, but I'm skeptical. However, given how much more capable it would be than a supersonic airliner, it might be worth a much greater cost. Part of the problem with Concorde is that it just didn't save that much time.

It’s a really good question. Supersonic jets were always heavily constrained due to noise pollution issues with the sonic boom. They weren’t allowed to fly over land at supersonic speeds, relegating them to trans-oceanic routes. Now yes this system will have such problems on launch, but as they go pretty much straight up out of the atmosphere compared to a jet, the vast majority of the journey is in space where that’s not a problem. Also supersonic jets had range restrictions preventing maximum use of their speed, while this thing can go literally anywhere on Earth. Finally the big killers with Concorde was recouping development costs and paying for ‘one-off’ spare parts, the costs were crippling. The BFR will (hopefully) exist anyway, so that’s not a factor.

In principle yes a supersonic airliner could be cheaper, but the noise pollution issue alone is one of those external factors that is a real killer. Now it’s quite possible this use of the BFR might run into issues like that of its own, but they’re likely to be different issues at least.

If people think supersonic jets are loud, they’re in for a treat with rockets. Anyone who’s ever witnessed a launch at KSC (I have) will probably say two things: it’s awesome, and it’s LOUD.

Not ear popping kind of loud, but VERY loud nonetheless, and you feel it too if you’re close enough. (Really recommend a viewing at the LC39 observation gantry, it’s awesome!) I was watching that video and kept thinking that platform isn’t far enough from inhabited land that people won’t go apeshit over how loud it is.

I want this future, and boy do I want to see a rocket launch again, but waking up to that nice sound of rocket fuel burning at 6.30am? Yeah, maybe no. :o)

Airports are in cities. Even 10 miles out to the ocean would make a massive difference without taking that long.

Airplanes are much, much quieter than rockets though. If you haven't seen (and heard!) a launch in person, I understand this might be difficult to appreciate. Even 10 miles out isn't enough to be ignorable.

Also the light – a launch is very bright! During the daytime this wouldn't be such a big deal I guess, but a dawn/dusk/night launch would be very noticeable, even from 10 miles out.

After the Concord was built, NASA did some research into reducing sonic booms (the Shaped Sonic Boom Experiment) which showed you could modify the fuselage to reduce the noise shock by about 30%. This would have brought the Concord below the acceptable noise threshold. Unfortunately it was never built-out commercially and we now have legislation banning supersonic flight over land.


That's the goal of the current quesst program.


Elon Musk: Cost per seat should be about the same as full fare economy in an aircraft. Forgot to mention that.

source: https://www.instagram.com/p/BZnVfWxgdLe/

Really? I'm surprised. Well then...

I think the key difference is if you're designing specifically for travel on earth then supersonic jets probably are much cheaper.

However, if you're designing for space and can allocate the R&D costs to space business units, you end up potentially developing something that has better marginal costs to transport people across the earth.

Basically, the R&D of building this is astronomically higher than the supersonic jet. But the (theoretical) promise is the marginal cost isn't that different. However, if you're already doing the R&D for other purposes, then you find yourself owning a system that's (potentially) better for global travel.

> Aren't supersonic jets more affordable?

They're currently unavailable at any price. If you make a really wild speculation based on taking the price of the most expensive airliner Airbus or Boeing sells and extrapolating from there how much a supersonic one might cost, it's not obvious that the airliner is cheaper.

They have enough money to give building the first ever BFR a shot. If it turns out good and the reusability works, they can do a lot of contracts with it, like servicing ISS, and launching a new big space telescope. From there on the advantages and possibilities of having a reusable high payload system will be very clear, and with 3-4 of them, a moon base would already be possible. We'll see what happens but the plan looks solid at least.

Supersonic jets could - maybe - more affordable, but they are slower than rockets, and the value proposition is in speed.

I'd actually worry about crowding skies above the planet. A rocket flying with suborbital speed has arguably less means to avoid collision if the possibility is detected in flight. Also rockets will need to pass heights where lots of satellites, orbital debris and even charged particles can present some danger to flying objects.

These are very short duration flights aka ~35 min from EU to Japan. So you can predict anything in their path before it's an issue.

Also, you can design flight paths so they never intersect unlike aircraft that need to deal with weather.

> but they are slower than rockets

By a hell of a lot – concorde is an order of magnitude slower than the spacex solution claims to be, only ~2000km/h

Many transportation systems are built using funds from selling land acquired at very low prices and then sold at much higher prices, once the transportation system is in place. Trolley systems in LA in the 1920's or road systems for the famous American suburbs.

Land on Mars is for the taking at the moment. What people will pay to live there is not known yet, but will be in the millions for some.

There could be a velocity at which the difficulty of flying quickly in the atmosphere is greater than the difficulty of reaching orbit. High mach number flight is not exactly easy, and the hypersonic regime has proven elusive. The atmosphere is a really hostile place at high velocity and has a lot of the same issues as space flight in terms of heating and crew protection requirments.

Aren't supersonic jets more affordable? - NO, end of story.

says who?


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