5 ms·

I wonder if anyone with sufficient experience in rockets could comment on whether that idea is at all plausible.

by gameswithgo 7y ago

chasd00 7y ago
i have no experience but, man, it would be so freaking noisy. where would they take off and land?
- donkeyd 7y ago
  Yup, that's the big issue. Being able to fly London to NY in 30 minutes is great, but the landing/launch sites will have to be pretty far from the cities to have the sonic booms not break windows all the time. That increases total travel time.
  - ralusek 7y ago
    And then you can just travel through Boring tunnels.
  - deadbunny 7y ago
    Some routes would definitely be worth it. Opposite sides of the world would become connected like never before. If I could catch a "flight" to Australia (from the UK) in the time it takes to fly to New York it would be game changing. Hell even 4 hours to LA would be preferable to the 11 hour flight time + 2 hours either side it takes now.
    - jandrese 7y ago
      But would you be willing to pay 10x or 20x the cost of a "slow" conventional airline ticket for it? The fuel costs may be low by space launch standards, but they'll be huge by commercial airline standards.
      - bryanlarsen 7y ago
        According to Glynne Shotwell, ticket costs would be less than the price of a first-class ticket on an airliner. Being able to do 12 trans-pacific flights a day rather than 2 makes a big difference for cost reduction.
        jandrese 7y ago
        That was the same argument people tried to use for Concorde. I'll believe it when I see it.
      - deadbunny 7y ago
        IIRC the plan was for 100 passengers per launch to Mars. Assuming only Earth based point to point travel this could probably be increased as you're not also running supplies & equipment. But assuming 100 passengers and assuming they get the launch cost down to $5MM (as proposed in the article) that is $5000/seat which is easily comparable to a first class ticket. Further (optimistic) extrapolating with more and more Starships available, the tech becoming cheaper/more reliable as time goes on I could see that price dropping over the decades. Just as air travel changed over the years from being out of most people's reach to being routine I could see something like this supplanting planes for those ultra long haul routes.
  - pintxo 7y ago
    The breaking window problem will be gone after the first start. /s
- bryanlarsen 7y ago
  The plan is to do it from water based launch platforms. Gwynne Shotwell said that the boat ride to & from the launch pads would take longer than the ~40 minute rocket trip, so definitely several miles away from inhabited areas.
  - TotempaaltJ 7y ago
    Alternatively, by that time we might have electric air taxis...
    - isostatic 7y ago
      Or you just do what every airport outside of America does and have a high speed rail service to the centre of town. 20 minutes woo get you 30-50km away.
  - tiborsaas 7y ago
    I live in downtown of a capital and the airport is 40 minutes away with a taxi. I still hear clearly the aircrafts from my balcony as they take off on their route. I'd imagine that a Starship would be orders of magnitude louder and once in the air, nothing would stop the low rumbling noise. It would be a fun math exercise to calculate an acceptable distance.
- Tuna-Fish 7y ago
  Platforms far offshore.
- danpalmer 7y ago
  I believe one idea being explored is offshore platforms, a few km from the coast in harbours and things like that. This would theoretically be a pretty safe (and quiet) way of getting very close to a large city, with only a short boat ride to get to the shore.
  - Rebelgecko 7y ago
    As long as your destination is out across the ocean and doesn't involve flying back over the city. I suppose if it's fast enough you can go "the long way" anywhere on Earth.
- Robotbeat 7y ago
  Ultimately, at least 10 miles out to sea. https://www.youtube.com/watch?v=zqE-ultsWt0 https://www.youtube.com/watch?v=zqE-ultsWt0 (And to make this fast enough, probably want those electric seaplane taxis that Harbour Air is getting.)
  - MayeulC 7y ago
    It would be cool to see ground-effect seaplanes (ekranoplan) used to that effect. I bet they could quickly transport a full starship payload... But that's an engineering problem for an other day (and they require calm weather).
    - growlist 7y ago
      What about a ground effect Starship :)
      - MayeulC 7y ago
        Well, how would that work? First, it wouldn't be a starship anymore (well, not a spaceship, at least). Then, the main advantage it has being a spaceship, is that it can "coast" in space without running its engines for a long time. This advantage disappears if you were to try leveraging the ground effect. That said, I imagine that ground effect helps a lot at low heights (like during the landing, and early ascent phase). It could probably help much more by deploying some sort of sleeve/skirt for the booster. And I guess that if you just want to move your rocket a few hundred meters and don't care for the ground, you could leverage it as well. Going back to the sleeve idea (which would be like a nozzle for the rocket, a chute or a flying saucer), I would like someone to run the numbers on that. And I always wondered if firing current rockets inside a cannon (or just a trench) would help with initial acceleration (as there is a pressure differential that helps, just like the ground effect).
0xffff2 7y ago
Gwynne Shotwell is someone with sufficient experience in rockets to comment on whether that idea is at all plausible.
SideburnsOfDoom 7y ago
I'd like to see the risk assessment: There's huge kinetic impact risk in landing a big rocket from orbit near a city.

I wonder if anyone with sufficient experience in rockets could comment on whether that idea is at all plausible.

chasd00 7y ago

i have no experience but, man, it would be so freaking noisy. where would they take off and land?

donkeyd 7y ago
Yup, that's the big issue. Being able to fly London to NY in 30 minutes is great, but the landing/launch sites will have to be pretty far from the cities to have the sonic booms not break windows all the time. That increases total travel time.
- ralusek 7y ago
  And then you can just travel through Boring tunnels.
- deadbunny 7y ago
  Some routes would definitely be worth it. Opposite sides of the world would become connected like never before. If I could catch a "flight" to Australia (from the UK) in the time it takes to fly to New York it would be game changing. Hell even 4 hours to LA would be preferable to the 11 hour flight time + 2 hours either side it takes now.
  - jandrese 7y ago
    But would you be willing to pay 10x or 20x the cost of a "slow" conventional airline ticket for it? The fuel costs may be low by space launch standards, but they'll be huge by commercial airline standards.
    - bryanlarsen 7y ago
      According to Glynne Shotwell, ticket costs would be less than the price of a first-class ticket on an airliner. Being able to do 12 trans-pacific flights a day rather than 2 makes a big difference for cost reduction.
      - jandrese 7y ago
        That was the same argument people tried to use for Concorde. I'll believe it when I see it.
    - deadbunny 7y ago
      IIRC the plan was for 100 passengers per launch to Mars. Assuming only Earth based point to point travel this could probably be increased as you're not also running supplies & equipment. But assuming 100 passengers and assuming they get the launch cost down to $5MM (as proposed in the article) that is $5000/seat which is easily comparable to a first class ticket. Further (optimistic) extrapolating with more and more Starships available, the tech becoming cheaper/more reliable as time goes on I could see that price dropping over the decades. Just as air travel changed over the years from being out of most people's reach to being routine I could see something like this supplanting planes for those ultra long haul routes.
- pintxo 7y ago
  The breaking window problem will be gone after the first start. /s
bryanlarsen 7y ago
The plan is to do it from water based launch platforms. Gwynne Shotwell said that the boat ride to & from the launch pads would take longer than the ~40 minute rocket trip, so definitely several miles away from inhabited areas.
- TotempaaltJ 7y ago
  Alternatively, by that time we might have electric air taxis...
  - isostatic 7y ago
    Or you just do what every airport outside of America does and have a high speed rail service to the centre of town. 20 minutes woo get you 30-50km away.
- tiborsaas 7y ago
  I live in downtown of a capital and the airport is 40 minutes away with a taxi. I still hear clearly the aircrafts from my balcony as they take off on their route. I'd imagine that a Starship would be orders of magnitude louder and once in the air, nothing would stop the low rumbling noise. It would be a fun math exercise to calculate an acceptable distance.
Tuna-Fish 7y ago
Platforms far offshore.
danpalmer 7y ago
I believe one idea being explored is offshore platforms, a few km from the coast in harbours and things like that. This would theoretically be a pretty safe (and quiet) way of getting very close to a large city, with only a short boat ride to get to the shore.
- Rebelgecko 7y ago
  As long as your destination is out across the ocean and doesn't involve flying back over the city. I suppose if it's fast enough you can go "the long way" anywhere on Earth.
Robotbeat 7y ago
Ultimately, at least 10 miles out to sea. https://www.youtube.com/watch?v=zqE-ultsWt0 https://www.youtube.com/watch?v=zqE-ultsWt0 (And to make this fast enough, probably want those electric seaplane taxis that Harbour Air is getting.)
- MayeulC 7y ago
  It would be cool to see ground-effect seaplanes (ekranoplan) used to that effect. I bet they could quickly transport a full starship payload... But that's an engineering problem for an other day (and they require calm weather).
  - growlist 7y ago
    What about a ground effect Starship :)
    - MayeulC 7y ago
      Well, how would that work? First, it wouldn't be a starship anymore (well, not a spaceship, at least). Then, the main advantage it has being a spaceship, is that it can "coast" in space without running its engines for a long time. This advantage disappears if you were to try leveraging the ground effect. That said, I imagine that ground effect helps a lot at low heights (like during the landing, and early ascent phase). It could probably help much more by deploying some sort of sleeve/skirt for the booster. And I guess that if you just want to move your rocket a few hundred meters and don't care for the ground, you could leverage it as well. Going back to the sleeve idea (which would be like a nozzle for the rocket, a chute or a flying saucer), I would like someone to run the numbers on that. And I always wondered if firing current rockets inside a cannon (or just a trench) would help with initial acceleration (as there is a pressure differential that helps, just like the ground effect).

0xffff2 7y ago

Gwynne Shotwell is someone with sufficient experience in rockets to comment on whether that idea is at all plausible.

SideburnsOfDoom 7y ago

I'd like to see the risk assessment: There's huge kinetic impact risk in landing a big rocket from orbit near a city.