How BFR Earth-to-Earth Might Actually Get Started

[Tulse]

Good point (and, I suppose, one could also argue that such issues did not prevent Space Shuttle landings, and the portion of its trajectory in-atmosphere and thus boom-producing would have been much larger than for a BFS).

[DaveGee66]

Chicago could have a platform in Lake Michigan.  But is the problem for landlocked cities a lack of launch sites, or noise?  The US does not currently permit supersonic overflights of the country due to sonic boom, and I would think the problem would be similar for BFR.  In addition, overflight of populated areas brings potential for huge loss of life if the vehicle fails, which is another reason most launches are over ocean.

Also the reason for the ocean platform launch isn't so much about it being in/near the water as much as it was being far enough away from land & people so while Lake Michigan is certainly full of water the area isn't wide enough (or long enough I'd think) to tick the same boxes as an ocean launch would... I'd think you'd need to be 100-150 miles away from people maybe more? So the noise isn't an issue and at that given you are in the ocean the chances of something unspeakable happening and lots of derby falling back to earth it would land in the water and not on some city...

[RoboGoofers]

Chicago could have a platform in Lake Michigan.  But is the problem for landlocked cities a lack of launch sites, or noise?  The US does not currently permit supersonic overflights of the country due to sonic boom, and I would think the problem would be similar for BFR.  In addition, overflight of populated areas brings potential for huge loss of life if the vehicle fails, which is another reason most launches are over ocean.

There is a sonic boom around the landing area, for both vehicles. This isn't likely to be an issue beyond the distance that launch noise is also an issue.

That's going to be a big enough issue that i'm sure many inland places will forgo a spaceport in lieu of an airport. afterall, not every town has an international airport; people take connecting flights.

but ultimately market demand is going to dictate which routes are economical, regardless of where spaceports are built, just like with airlines.

[DistantTemple]

Another big issue is the large capital expense for myriad offshore platforms and the suggested capital intensive and long permit & construction timeframe (tunnels, hyperloops, undersea bridges) means of access to the platform for passengers, aside from relatively inexpensive 300 passenger hydrofoils for passengers and barges/whatever to deliver propellant.

You need massive capital ground investment for a global fully deployed network.
You do not need such a network for orbital tourism, or picked one-off routes that happen to need minimal investment.
The capital for investment comes - rapidly - from your deployed routes.

I firmly believe, tunnels with "loops", or "hyper-loops" will be used to link platforms to urban centres, as it deals with the extra delays using conventional transport from these locations, and automatically puts departing and arriving passengers in a blast proof location so risky rocket operations (lifting, fuelling, landing) can proceed. However, initially, helicopters, hovercraft , hydrofoils or similar will be used, as they are cheap and quick, and so allow a quick roll out and demonstration, and spread out the need for capital investment.

EM does think big, and within a larger perspective than we have gotten used to. 
Edit: It will allow the platform to be offset so the BFS launch and landing trajectory and its ballistic trajectory to go over less populated areas. And to further reduce noise nuisance when there are launches every hour!

[Ludus]

Chicago could have a platform in Lake Michigan.  But is the problem for landlocked cities a lack of launch sites, or noise?  The US does not currently permit supersonic overflights of the country due to sonic boom, and I would think the problem would be similar for BFR.  In addition, overflight of populated areas brings potential for huge loss of life if the vehicle fails, which is another reason most launches are over ocean.

BFR/BFS does not produce a sonic boom during overflight, as it is exoatmospheric.

There is a sonic boom around the landing area, for both vehicles. This isn't likely to be an issue beyond the distance that launch noise is also an issue.

There can also a downrange sonic boom during launch, although trajectory shaping could likely eliminate it. This is not the same as a supersonic transport, since the boom is localized to a specific area, rather than continuous under the entire flight from launch to landing point.

This is an under appreciated advantage of the idea. It’s the ultimate in getting above the weather quickly and traveling in low air resistance and mostly eliminates the sonic boom over Land issue.

[docmordrid]

>
Also the reason for the ocean platform launch isn't so much about it being in/near the water as much as it was being far enough away from land & people so while Lake Michigan is certainly full of water the area isn't wide enough (or long enough I'd think) to tick the same boxes as an ocean launch would... I'd think you'd need to be 100-150 miles away from people maybe more?
>

Max. length (N/S): 307 miles (494 km)
Max. width (E/W): 118 miles (190 km)

Then it's a short hop over the sparsely populated Upper Peninsula of Michigan and you have another ~200 miles (336km) over Lake Superior. Next is  a hop over central Canada before you cross the Arctic.

[Robotbeat]

Don’t need to be 100 miles away. Maybe 15 or 20 miles. In which case Lake Michigan is fine.

[DaveGee66]

>
Also the reason for the ocean platform launch isn't so much about it being in/near the water as much as it was being far enough away from land & people so while Lake Michigan is certainly full of water the area isn't wide enough (or long enough I'd think) to tick the same boxes as an ocean launch would... I'd think you'd need to be 100-150 miles away from people maybe more?
>

Max. length (N/S): 307 miles (494 km)
Max. width (E/W): 118 miles (190 km)

Then it's a short hop over the sparsely populated Upper Peninsula of Michigan and you have another ~200 miles (336km) over Lake Superior. Next is  a hop over central Canada before you cross the Arctic.

So 118 miles divided by 2 comes to 56 miles since all shores around the lake are assumed populated, however if any populated islands exist those to could get in the way as would commercial or even recreational boat/shipping lanes next to oceans lakes are the next most popular place to live. Now maybe the upper lake would be possible but there is a reason why to date rockets get launched over oceans, Florida, California and soon (maybe not soon enough) Texas.

[DaveGee66]

Don’t need to be 100 miles away. Maybe 15 or 20 miles. In which case Lake Michigan is fine.

Really 15 miles off the coast of SF, L.A., DC, NYC etc would be far enough away to avoid sound complaints... I was under the impression you needed substantial distance if one was planning to do hourly launches off the coast of a major city.

[JamesH65]

Don’t need to be 100 miles away. Maybe 15 or 20 miles. In which case Lake Michigan is fine.

Really 15 miles off the coast of SF, L.A., DC, NYC etc would be far enough away to avoid sound complaints... I was under the impression you needed substantial distance if one was planning to do hourly launches off the coast of a major city.

How deep is the ocean at that point? A bit, a lot, or very? How do you get from an underground (and sea) hyperloop tunnel to the floating platforms if that tunnel is a km underwater? Even a few hundred feet would be a nightmare. Is there anything even remotely like it in existence today?

The engineering to do all this stuff is immense, and hugely expensive, way more than the cost of developing the rocket. And its has to be done for every single launch site.

[envy887]

>
Also the reason for the ocean platform launch isn't so much about it being in/near the water as much as it was being far enough away from land & people so while Lake Michigan is certainly full of water the area isn't wide enough (or long enough I'd think) to tick the same boxes as an ocean launch would... I'd think you'd need to be 100-150 miles away from people maybe more?
>

Max. length (N/S): 307 miles (494 km)
Max. width (E/W): 118 miles (190 km)

Then it's a short hop over the sparsely populated Upper Peninsula of Michigan and you have another ~200 miles (336km) over Lake Superior. Next is  a hop over central Canada before you cross the Arctic.

So 118 miles divided by 2 comes to 56 miles since all shores around the lake are assumed populated, however if any populated islands exist those to could get in the way as would commercial or even recreational boat/shipping lanes next to oceans lakes are the next most popular place to live. Now maybe the upper lake would be possible but there is a reason why to date rockets get launched over oceans, Florida, California and soon (maybe not soon enough) Texas.

There are no populated islands within 200 miles of Chicago.

Upper stage overflight is going to be acceptable if stuffing 500 passengers on a rocket is acceptable. You can't have one without the other. By the time the reliability is enough for the expected passenger casualties to be acceptable, the risk to people under the flight path will be minuscule.

[DaveGee66]

>
Also the reason for the ocean platform launch isn't so much about it being in/near the water as much as it was being far enough away from land & people so while Lake Michigan is certainly full of water the area isn't wide enough (or long enough I'd think) to tick the same boxes as an ocean launch would... I'd think you'd need to be 100-150 miles away from people maybe more?
>

Max. length (N/S): 307 miles (494 km)
Max. width (E/W): 118 miles (190 km)

Then it's a short hop over the sparsely populated Upper Peninsula of Michigan and you have another ~200 miles (336km) over Lake Superior. Next is  a hop over central Canada before you cross the Arctic.

So 118 miles divided by 2 comes to 56 miles since all shores around the lake are assumed populated, however if any populated islands exist those to could get in the way as would commercial or even recreational boat/shipping lanes next to oceans lakes are the next most popular place to live. Now maybe the upper lake would be possible but there is a reason why to date rockets get launched over oceans, Florida, California and soon (maybe not soon enough) Texas.

There are no populated islands within 200 miles of Chicago.

Upper stage overflight is going to be acceptable if stuffing 500 passengers on a rocket is acceptable. You can't have one without the other. By the time the reliability is enough for the expected passenger casualties to be acceptable, the risk to people under the flight path will be minuscule.

Oh I agree about the risk being small (once this gets going on a regular basis) however I also know old laws are very very hard to undo and no launching rockets over populated areas is one that I'd imagine is going to be a difficult one to have revoked.

I will happen and if it's anything that will do it it's this project so yes I am sure eventually rockets will be launching from places like Chicago but I'm also sure Chicago won't be at the top of the list when it comes to figuring out where the _ very first _ space ports will be located because even 50 miles or so off the coast of NY, DC, FL, TX, LA, SF, WA, etc they will have enormous amounts of resistance even WITHOUT the  BFR/BFS flying over any land in the first place.  A year or two of smooth operations then yes those old laws will likely get re-considered since the demand for super fast flights to .... anywhere in the world ... is just so appealing.

[envy887]

Oh I agree about the risk being small (once this gets going on a regular basis) however I also know old laws are very very hard to undo and no launching rockets over populated areas is one that I'd imagine is going to be a difficult one to have revoked.

I will happen and if it's anything that will do it it's this project so yes I am sure eventually rockets will be launching from places like Chicago but I'm also sure Chicago won't be at the top of the list when it comes to figuring out where the _ very first _ space ports will be located because even 50 miles or so off the coast of NY, DC, FL, TX, LA, SF, WA, etc they will have enormous amounts of resistance even WITHOUT the  BFR/BFS flying over any land in the first place.  A year or two of smooth operations then yes those old laws will likely get re-considered since the demand for super fast flights to .... anywhere in the world ... is just so appealing.

There is no "old law" that prohibits launching a rocket over a populated area. Rockets launch over populated areas all the time. Launches to ISS go over Europe, and the IIP trace always goes all the way around the world for an orbital flight.

The FAA standard is 30x10^-6 casualties per flight. If you can prove reliability high enough to meet this standard they will let you launch over pretty much anything.

[DaveGee66]

here is no "old law" that prohibits launching a rocket over a populated area. Rockets launch over populated areas all the time. Launches to ISS go over Europe, and the IIP trace always goes all the way around the world for an orbital flight.

The FAA standard is 30x10^-6 casualties per flight. If you can prove reliability high enough to meet this standard they will let you launch over pretty much anything.

Okay its clear you are far more well informed than I - I am only going by 'what I have read in forums such as this' - if what you say is accurate then we should expect NO demand that Chicago be one of the top five places where they initally break ground on a space port - after all Chicago is the fourth largest international airport in the US.

If and when this doesn't happen maybe you can help me understand why since all of my reasons were clearly way off base.

The FAA standard is 30x10^-6 casualties per flight. If you can prove reliability high enough to meet this standard they will let you launch over pretty much anything.

Also since you said it yourself ... Getting this proof can be done on paper?  Or does it take a huge number of actual flight to offer as proof and if it is a huge number of flights then aren't you making my point for me that places inland will have to wait for some time until a space port is cleared for their region?

[Functor]

Are there any theories on the discrepancy between Shotwell’s comments that it is only  “10 kilometers out from a city...maybe it’s only 5 kilometers...” from her TED talk (about 16:01 in the video) and the distance implied by Elon’s tweet? Perhaps this will be clarified tonight.

[envy887]

here is no "old law" that prohibits launching a rocket over a populated area. Rockets launch over populated areas all the time. Launches to ISS go over Europe, and the IIP trace always goes all the way around the world for an orbital flight.

The FAA standard is 30x10^-6 casualties per flight. If you can prove reliability high enough to meet this standard they will let you launch over pretty much anything.

Okay its clear you are far more well informed than I - I am only going by 'what I have read in forums such as this' - if what you say is accurate then we should expect NO demand that Chicago be one of the top five places where they initally break ground on a space port - after all Chicago is the fourth largest international airport in the US.

If and when this doesn't happen maybe you can help me understand why since all of my reasons were clearly way off base.

The FAA standard is 30x10^-6 casualties per flight. If you can prove reliability high enough to meet this standard they will let you launch over pretty much anything.

Also since you said it yourself ... Getting this proof can be done on paper?  Or does it take a huge number of actual flight to offer as proof and if it is a huge number of flights then aren't you making my point for me that places inland will have to wait for some time until a space port is cleared for their region?

It will take hundreds of flights, if not thousands. So yes, you're probably looking at 10 years at a minimum.

But mostly that will be due to the need to establish reliability before starting regular passenger service, offshore or not. If it's safe enough to stuff 500 passengers into, it's safe enough to overfly just about anything.

[philw1776]

Are there any theories on the discrepancy between Shotwell’s comments that it is only  “10 kilometers out from a city...maybe it’s only 5 kilometers...” from her TED talk (about 16:01 in the video) and the distance implied by Elon’s tweet? Perhaps this will be clarified tonight.

Sometimes #s from Elon don't quite compute either.  Possible off the cuff comment by Gwynne.  We'll see what happens.  I'm in the 15-20Km minimum distance from LARGE seaside cities camp.  Noise.  NOTAM exclusions. Lots of possible regulatory issues.
I predict we have to wait until the 2030s at earliest, the 2040s more likely and maybe not this half century to find out.

[Ludus]

Don’t need to be 100 miles away. Maybe 15 or 20 miles. In which case Lake Michigan is fine.

The 2017 IAC video mentions LA to Toronto early in its list. Lake Ontario is the smallest of the Great Lakes but still works for a spaceport 15 or 20 miles offshore.

Great Lakes would require the spaceport platform be brought in in pieces via St.Lawrence.

[docmordrid]

>
Great Lakes would require the spaceport platform be brought in in pieces via St.Lawrence.

Dunno about that. Fincantieri Marinette Marine in Wisconsin is producing Freedom-class Littoral Combat Ships for the US Navy; 115.3 m, 3,500 tonnes. Also, the Great Lakes Shipyard in Cleveland.

[Ludus]

>
Great Lakes would require the spaceport platform be brought in in pieces via St.Lawrence.

Dunno about that. Fincantieri Marinette Marine in Wisconsin is producing Freedom-class Littoral Combat Ships for the US Navy; 115.3 m, 3,500 tonnes. Also, the Great Lakes Shipyard in Cleveland.

It wouldn’t hurt if the business could go to local shipyards. I was assuming these Spaceports are much larger, 10x or 20x that size.