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Why We're Not Going To See Sub-orbital Airliners
glowend writes: Sci-fi author Charlie Stross has an article about sub-orbital flight, and why we'll never see it as a common mode of transportation. Quoting: "Yes, we can save some fuel by travelling above the atmosphere and cutting air resistance, but it's not a free lunch: you expend energy getting up to altitude and speed, and the fuel burn for going faster rises nonlinearly with speed. Concorde, flying trans-Atlantic at Mach 2.0, burned about the same amount of fuel as a Boeing 747 of similar vintage flying trans-Atlantic at Mach 0.85 ... while carrying less than a quarter as many passengers. Rockets aren't a magic technology. Neither are hybrid hypersonic air-breathing gadgets like Reaction Engines' Sabre engine. It's going to be a wee bit expensive."
Stross also makes a more general proposition that's particularly interesting to me: "One of the failure modes of extrapolative SF is to assume that just because something is technologically feasible, it will happen. ... Someone has to want it enough to pay for it—and it will be competing with other, possibly more attractive options."
Stross also makes a more general proposition that's particularly interesting to me: "One of the failure modes of extrapolative SF is to assume that just because something is technologically feasible, it will happen. ... Someone has to want it enough to pay for it—and it will be competing with other, possibly more attractive options."
So, you're not going to see it, because it doesn't save money. Except, it has the potential to be many times faster. Which is a reason to use it that isn't "it costs less." So the argument can't hope to support its thesis. If it happens or not is not based on just if "because we can." It is going to happen or not based on the actual advantages of being faster, their value, and the final cost.
We can certainly say, based on our experience with Concord, that if it is fast enough and safe enough the rich will use it, and if it as safety issues, they will abandon it quickly.
I think the thing being missed here is that people are in a hurry. If I can fly a 747 from Seattle to Japan and the flight takes 14 hours, I would pay more to be able to do it in 7. That's an easy choice. Time spent in the air is generally wasted time. Turn trans-Pacific/Atlantic into a weekend trip instead of the current 3 days of travel time and there's a market for it.
The futuristic prediction that it would be economical to take a sub-orbital flight from NY to LA is probably not going to happen, but for trans oceanic and/or China/Japan to Europe. Definitely a market there.
"Freedom in the USA is not the ability to do what you want. It is the ability to stop others from doing what THEY want"
Yup, this raise one of my big complaints about some SciFi stories: lack of economic plausibility.
Science Fiction is great for looking at how we might deal with various potential technologies. Readers are perfectly happy to suspend disbelief and accept whatever technology is proposed. What readers aren't willing to do is suspend disbelief and accept people behaving implausibly.
To write good science fiction, you need to accurately portray people. You can make up the technology, but you have to get humanity right. And that means you have to get the economics right.
This is exactly the problem I had with reading the Hunger Games. Everything worked, except why would a society with hover cars and other advanced technology have need of the services of the districts? Surely they didn't need coal, and yet they had a whole district dedicated to mining it. The lack of economic sense pulled me out of the book. Instead of thinking about the characters, I was thinking about why the society that was described didn't make any sense.
An adjunct proposition to consider is that certain technologies will never disappear, no matter how many attractive alternatives arise.
I'll offer one example right now: paper.
Discuss.
If it weren't for deadlines, nothing would be late.
It's pointed to in the summary and was not missed - there were not enough people in a hurry to sustain Concorde flights.
An ironic thing is the 747 was opposed within Boeing in the late 1960s because it was thought that only supersonic airliners would have a place on long hauls in the 1970s - so very few were built in the first batch. As mentioned in the summary the 747 went on to render Concorde mostly irrelevant.
The article (well worth reading this time) argues that such a target market has left the building and is already on "bizjets" to avoid the time consuming fuss of getting onto an airliner and having to stick to a schedule. It also points out that suborbital spaceports are not going to be in the middle of cities so the time to get to and from them also has to be considered. Those factors seem to reduce the small market you suggest to zero. Expensive, fixed timetables and little or no time saved compared with "bizjets" in the same or lower price range that leave when you want and land closer to where you want to be.
Sucks, but all that extra effort to go supersonic/hypersonic prices it out of most civilian situations.
....We may see a return of supersonic flight within the next 15 years.
Thanks to better understanding of how sonic booms are generated from the shape of the plane and definitely way better jet engine technology, we may be able to very soon build a business jet seating 10 passengers capable of flying at Mach 1.6 at ranges up to 6,000 nautical miles with just about no sonic boom audible on the ground even when the plane is fly at Mach 1.6.
How is this possible? First, aerodynamic research using computational fluid dynamics have identified ways to minimize the pressure wave buildup that causes the sonic boom in the first place with very careful shaping of the fuselage and wings. This makes to possible to effectively eliminate the audible sonic at speeds up to Mach 1.6. Secondly, modern engine design using variable cycle engines (GE Aero Engines successfully tested the technology on a engine intended for the Advanced Technology Fighter program that resulted in the F-22A Raptor) means high-bypass turbofan fuel efficiency at subsonic speeds but can change configuration to fly at supersonic speeds with a small amount of reheat (afterburning) to keep fuel consumption and harmful exhaust missions as low as possible. Finally, by keeping the top speed to Mach 1.6, it means less structural heating from flying at supersonic speeds and less need to run a lot of reheat (afterburning) on the engines, which means lower fuel consumption and less need for expensive high-temperature rated stainless steel or titanium structural parts like those used on the Concorde.
I've read companies that sell fractional ownership of private jets such as FlexJet or NetJets would immediately buy 50 of these supersonic business jets once approved for production. The ability to fly from New York City to London in around 4 hours as opposed to the circa 7.5 hours with current jet airliners makes it very attractive to business customers, especially since many live by the motto of "time is money."