4 ms·
It doesn't gain anything back, what are you on. Before landing it has to shed all the speed it gained that was needed for the ballistic trajectory. That energy
by pi-e-sigma 3y ago
It doesn't gain anything back, what are you on. Before landing it has to shed all the speed it gained that was needed for the ballistic trajectory. That energy is lost. Orbital or suborbital flights will never, ever be competitive to flying with regards to required energy expended.
- bryanlarsen 3y agoIt gains efficiency compared with an airplane by spending most its trajectory outside of atmosphere with no air resistance.
- pi-e-sigma 3y agoNo it does not, because thanks to atmosphere wings on an airplane generate lift. And they do it more efficient than any kind of engine known to the mankind
- bryanlarsen 3y agoYes, an airplane can climb much more efficiently than a rocket. So on a 300km flight where all it is doing is climbing and descending it's way more efficient than a rocket. But for a 10,000km flight the airplane expends almost all of its fuel coasting rather than climbing. Luckily we don't have to rely on assertions. If I'm wrong, there should be an obvious error in my math (which is trivial) or facts (which is on Wikipedia). Please point it out.
- pi-e-sigma 3y agoYou think an airplane doesn't need lift when in a level flight? :) Thanks to the atmosphere an airplane doesn't need to carry its own oxidizer, either. I'll leave to you to check how much oxidizer a Falcon rocket needs to carry for every ton of fuel.
- bryanlarsen 3y agoWe don't have to wait long to prove you wrong. Starship using just ~1200t of Methane and 150t of payload capacity will fly East (the long way) from Texas to Hawaii in 90 minutes. That's 8x as much payload 3x as far as a 787 can do with its 100t of fuel.
- mensetmanusman 3y ago1.5 hour trips to Hawaii from the US would be crazy fun.
- bryanlarsen 3y agoThat's 1.5 hours going the long way around. It'd be under 30 going west rather than east.
- m4rtink 3y agoThere are also other benefits - avoiding weather along the route, taking a straight road where an airplane needs to take a longer route for political or safety reasons, etc.
- LeifCarrotson 3y agoThat's more efficient if most of your trips require you to go 90% of the way around the planet (maybe?). Or for sure if you coast twenty times around the planet. But half the circumference of earth is not that far.
- bryanlarsen 3y agoAirliners with extended range tanks are much less efficient than normal airliners, since they both decrease capacity and increase consumption. That's the range where Starship becomes competitive, basically trans-Pacific or further.
- cma 3y agoI estimate to hit the 2028 in active passenger service timeframe they would have probably have needed at least thousands of flights by now demonstrating safety with a perfect track record.