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I was a little disappointed he didn't give any timeline at all on that not even a aspirational one. I also assume it's gonna be really expensive due to frequent

I was a little disappointed he didn't give any timeline at all on that not even a aspirational one. I also assume it's gonna be really expensive due to frequent heat shield replacement. I wouldn't be surprised if it never became economically viable. Too few passengers and too high cost.

stretchwithme 9y ago
I imagine they can fit 400 passengers though. No need for those cabins or even a need to give passengers drinks.
- perilunar 9y ago
  For 30 minute trips you barely even need toilets.
  - Cshelton 9y ago
    I think personally I'd keep my seat belt on regardless even if there were restrooms
    - modeless 9y ago
      You kidding? There's no way I'm staying in my seat during zero gravity. I might pay more to do a couple of extra orbits and play around before coming down.
      - perilunar 9y ago
        I reckon everyone would be out of their seats as soon as boost is done. Getting everyone back into their seats in time for re-entry might be the issue ("take the nearest available"). Earth to earth flights would be sub-orbital though, so no opportunity for extra orbits.
        c0ndu17 9y ago
        I'm gonna miss the ding of the seatbelt sign.
  - agildehaus 9y ago
    I'd just shit my pants on liftoff.
    - stretchwithme 9y ago
      That's where the vacuum of space will clean up.
    - perilunar 9y ago
      Free adult diapers for all passengers!
    - pmontra 9y ago
      That's really on spot but maybe it won't be your case. Many people don't like accelerations. Braking and turning a car a little harder than usual is much less that 1 g but some people don't feel comfortable with it, even when there is no danger. Remember motion sickness and the puke bags on planes. Lifting off with a rocket is always going to be higher g than with a plane. Furthermore it's probably going to require some amount of fitness. Too young or too old: fly on a plane. In the middle: it depends.
- stretchwithme 9y ago
  Actually, an A380 can hold 853, so BFR could probably hold the same. If he can get the cost down to US $10 million per trip, that's US $12K per person.
modeless 9y ago
He said the heat shield ablates for Mars trips but not Earth trips (not sure why). If so then propellant should be the only important consumable. Of course this level of reusability and reliability has never been achieved before, but the whole thing depends on it.
- greglindahl 9y ago
  Dragon 1 has already gone through a couple of iterations of heat shields. Mars entry is expected to be hotter, that's straightforward math.
- grondilu 9y ago
  > the heat shield ablates for Mars trips but not Earth trips (not sure why). I suppose the reentry speed on mars is much higher, since it happens at the end of an interplanetary trip.
  - rkangel 9y ago
    For E2E routes, the rocket doesn't have to be given as much kinetic energy - it doesn't have to escape Earth's gravity well.
- Tuna-Fish 9y ago
  > He said the heat shield ablates for Mars trips but not Earth trips (not sure why) Falcon 9 presently lands completely without any heat shield, because it just uses it's engines to reduce velocity until they are not needed. In principle, you can always replace heat shields with fuel like this. Mars trips need to bleed velocity aerodynamically because the craft cannot bring enough fuel. Presumably a sub-orbital hop on Earth can save enough fuel to act as the brakes.
  - ygra 9y ago
    Falcon 9 has a heat shield around the engines. Since they are going into the atmosphere engines-first it's going to be hot there. The engine bells sticking out from there don't care (much, since the entry burn reduces speed enough). Most of the speed reduction for the landing happens via aerobraking, not by using the engines.

stretchwithme 9y ago

I imagine they can fit 400 passengers though. No need for those cabins or even a need to give passengers drinks.

perilunar 9y ago
For 30 minute trips you barely even need toilets.
- Cshelton 9y ago
  I think personally I'd keep my seat belt on regardless even if there were restrooms
  - modeless 9y ago
    You kidding? There's no way I'm staying in my seat during zero gravity. I might pay more to do a couple of extra orbits and play around before coming down.
    - perilunar 9y ago
      I reckon everyone would be out of their seats as soon as boost is done. Getting everyone back into their seats in time for re-entry might be the issue ("take the nearest available"). Earth to earth flights would be sub-orbital though, so no opportunity for extra orbits.
      - c0ndu17 9y ago
        I'm gonna miss the ding of the seatbelt sign.
- agildehaus 9y ago
  I'd just shit my pants on liftoff.
  - stretchwithme 9y ago
    That's where the vacuum of space will clean up.
  - perilunar 9y ago
    Free adult diapers for all passengers!
  - pmontra 9y ago
    That's really on spot but maybe it won't be your case. Many people don't like accelerations. Braking and turning a car a little harder than usual is much less that 1 g but some people don't feel comfortable with it, even when there is no danger. Remember motion sickness and the puke bags on planes. Lifting off with a rocket is always going to be higher g than with a plane. Furthermore it's probably going to require some amount of fitness. Too young or too old: fly on a plane. In the middle: it depends.
stretchwithme 9y ago
Actually, an A380 can hold 853, so BFR could probably hold the same. If he can get the cost down to US $10 million per trip, that's US $12K per person.

modeless 9y ago

He said the heat shield ablates for Mars trips but not Earth trips (not sure why). If so then propellant should be the only important consumable. Of course this level of reusability and reliability has never been achieved before, but the whole thing depends on it.

greglindahl 9y ago
Dragon 1 has already gone through a couple of iterations of heat shields. Mars entry is expected to be hotter, that's straightforward math.
grondilu 9y ago
> the heat shield ablates for Mars trips but not Earth trips (not sure why). I suppose the reentry speed on mars is much higher, since it happens at the end of an interplanetary trip.
- rkangel 9y ago
  For E2E routes, the rocket doesn't have to be given as much kinetic energy - it doesn't have to escape Earth's gravity well.
Tuna-Fish 9y ago
> He said the heat shield ablates for Mars trips but not Earth trips (not sure why) Falcon 9 presently lands completely without any heat shield, because it just uses it's engines to reduce velocity until they are not needed. In principle, you can always replace heat shields with fuel like this. Mars trips need to bleed velocity aerodynamically because the craft cannot bring enough fuel. Presumably a sub-orbital hop on Earth can save enough fuel to act as the brakes.
- ygra 9y ago
  Falcon 9 has a heat shield around the engines. Since they are going into the atmosphere engines-first it's going to be hot there. The engine bells sticking out from there don't care (much, since the entry burn reduces speed enough). Most of the speed reduction for the landing happens via aerobraking, not by using the engines.