Author Topic: How BFR Earth-to-Earth Might Actually Get Started  (Read 110639 times)

Offline ChrisWilson68

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Re: How BFR Earth-to-Earth Might Actually Get Started
« Reply #20 on: 04/01/2018 05:32 am »
Your timeline seems reasonable...  :)
In my opinion...
One hurdle that needs overcome in time, is the current requirement to only launch big rockets out over bodies of water...
My long term sense is, future BFS/BFR spaceports will end up inland in the middle of nowhere...
Put them where no one really lives and no real commerce is being conducted within 30 miles...
In other words... Deserts
Spaceports/Airports in the middle of nowhere is where this will go long term I think...
Catch a morning flight from say DEN to SX1 somewhere in the desert southwest...
Ride a quick BFS passenger flight to SX2 somewhere in the central Australia desert...
Catch the flight SX2 to SYD...
Or take a slightly longer flight to Hong Kong or wherever in the general area...

Point is... I think the notion of offshore launch pads near major cities has too many regulatory hurdles to happen.
Just the NIMBY cry will stop many in their tracks ("it's too loud, blah, blah")

BUT regional spaceports worldwide collocated with an airport/train/highway/other access does seem doable to me.
Bear in mind, these spaceports are also launching tankers daily and payloads as needed along with the passenger trade... So it's a multi use facility as far as SpaceX is concerned...

Just my thoughts on this long term outlook discussion...  ;)

If you have to take a flight to get to the spaceport in the middle of the desert, then another from your destination desert to your destination city, then you've just lost all your speed advantage over just taking a direct flight.

Anyway, I don't know why you're trying to move the BFR flights away from the ocean offshore from big cities.  It's the perfect place for them.

Offline alang

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Re: How BFR Earth-to-Earth Might Actually Get Started
« Reply #21 on: 04/01/2018 08:26 am »
I'm struggling to think of a suitable place for a spaceport in Europe for passenger flights.
An artificial island on the Dogger bank maybe?

Offline gin455res

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Re: How BFR Earth-to-Earth Might Actually Get Started
« Reply #22 on: 04/01/2018 08:33 am »
Is there any scope for testing the market with a falcon-9 based system?
I could imagine a reusable upper-stage based on a cluster of smaller engines like the Ursa Major Ripley.



However, I think noise is a serious issue on these ideas. 
A first stage with a much lower isp, might be less noisy. How does noise scale with exhaust velocity, is it linear, quadratic, cubic, ....

Offline Hominans Kosmos

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Re: How BFR Earth-to-Earth Might Actually Get Started
« Reply #23 on: 04/01/2018 10:24 am »
Is there any scope for testing the market with a falcon-9 based system?
I could imagine a reusable upper-stage based on a cluster of smaller engines like the Ursa Major Ripley.



However, I think noise is a serious issue on these ideas. 
A first stage with a much lower isp, might be less noisy. How does noise scale with exhaust velocity, is it linear, quadratic, cubic, ....

Wrong thread? If so, where to? Consolidated reusable upper stage for Falcon thread?

Reusable Falcon upper stage is dead. It is only resurrected if the apocalypse comes, we better hope it never happens. Falcon Heavy fully reusable has no useful payload for human occupied point to point Earth travel to make a profit from. Falcon is too expensive.

Offline guckyfan

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Re: How BFR Earth-to-Earth Might Actually Get Started
« Reply #24 on: 04/01/2018 10:37 am »
I'm struggling to think of a suitable place for a spaceport in Europe for passenger flights.
An artificial island on the Dogger bank maybe?

Lands's End in England.

Lissabon in Portugal.

Some coastal location in Norway.

All on platforms 20km off the coast.


Offline Slarty1080

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Re: How BFR Earth-to-Earth Might Actually Get Started
« Reply #25 on: 04/01/2018 10:56 am »
I'm struggling to think of a suitable place for a spaceport in Europe for passenger flights.
An artificial island on the Dogger bank maybe?

Lands's End in England.

Lissabon in Portugal.

Some coastal location in Norway.

All on platforms 20km off the coast.

I think Lands End in England is out of the question. Unless you want to make BFR landings a feature of the theme park attraction there and give discounts on hotel rooms in Penzance which is only 8 miles away.

Perhaps an old oil platform could be converted in the North sea? (Perhaps) might even have a little bit of methane to hand for refueling. Question how much noise polution would be expected? Put it another way how far away would you have to be for the BFR to be just a low rumble?
« Last Edit: 04/01/2018 11:10 am by Slarty1080 »
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Offline Elmar Moelzer

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Re: How BFR Earth-to-Earth Might Actually Get Started
« Reply #26 on: 04/01/2018 04:31 pm »
I think that the best argument for a BFS based SSTO with a small payload is for SpaceX to gather a lot of experience with it relatively quickly by using it to launch their Starlink constellation. It could potentially allow for a lot of launches in a relatively short time frame.

Offline philw1776

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Re: How BFR Earth-to-Earth Might Actually Get Started
« Reply #27 on: 04/01/2018 04:57 pm »
I'm struggling to think of a suitable place for a spaceport in Europe for passenger flights.
An artificial island on the Dogger bank maybe?

Lands's End in England.

Lissabon in Portugal.

Some coastal location in Norway.

All on platforms 20km off the coast.

Sea platforms off the coast give 1st generation access to England, Scandanavia (via Norway), France, Spain & Portugal.  Hydrofoils to the ports which all have transportation infrastructure.
Later on as reliability comfort increases with some end of light populated land overflight to Italy, Greece, Croatia.
Maybe eventually tunnels from landing platforms to ports or even inland.  Economic decision.

Agree that hundreds of BFR flights for space purposes will be needed to increase reliability comfort for even initial P2P which has no population overflight, e.g. NY to off coast of France or polar routes to NZ, japan's East coast, etc.

BFR block whatever will be kept in production for P2P flights starting NET 2040 if ever.

Next gen VBFR or whatever would need years of operation to validate its reliability for P2P although the process would be faster then.
« Last Edit: 04/01/2018 04:59 pm by philw1776 »
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Offline aero

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Re: How BFR Earth-to-Earth Might Actually Get Started
« Reply #28 on: 04/01/2018 05:10 pm »
Just curious. Has anyone calculated the difference in payload capacity for a polar orbit versus an equatorial orbit? Going polar loses the initial velocity of the earth's rotation. How much propellant is needed to overcome this loss?
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Offline speedevil

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Re: How BFR Earth-to-Earth Might Actually Get Started
« Reply #29 on: 04/01/2018 05:16 pm »
Just curious. Has anyone calculated the difference in payload capacity for a polar orbit versus an equatorial orbit? Going polar loses the initial velocity of the earth's rotation. How much propellant is needed to overcome this loss?

For passenger transit, it's basically irrelevant.
You lose some 30 tons of payload perhaps, on polar or anti-spin routes.
It may slightly alter passenger capacity on certain routes.

Offline freddo411

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Re: How BFR Earth-to-Earth Might Actually Get Started
« Reply #30 on: 04/01/2018 05:19 pm »
Here's my out of the box ideas for using the BFR non-traditionally:

* P2P landing in Kenya.   High end tourists would be interested in visiting Africa, but it take literally days to get there currently.

Wrong.  I just picked a random date and asked Kayak for flights from San Francisco (near where I live) to Nairobi.  It found me one that takes 19 hours, 20 minutes.


Thanks for your contribution.  I stand corrected from 25hr to 19hrs.





* P2P landing in Antarctica.   Very hard to visit there currently.

That's because it's extremely expensive to maintain infrastructure in Antarctica.  That means the prices for regular flights would be very high, and there wouldn't be enough demand at those high prices.

Exactly the same would be true of point-to-point BFR flights to Antarctica -- they would be much more expensive that flights to other places because it would be much more expensive to maintain the infrastructure there.


BFR is supposed to require minimum infrastructure (going to Mars and what not).     Clearly, it does require refueling.  Antarctic refueling via ISRU would be an interesting test.   

One of the main reasons that there is a lack of infrastructure in Antarctica is arbitrary rules prohibiting commercial activities.   One could imagine relaxing these and making ISRU and BFR flights possible.   Of course, this would also open up the possibility to regular commercial flights as well.

Granted that the Antarctic route will never be cheap due to the low demand.   This is true regardless of the airframe flying there.   For the class of the folks flying there, would they prefer to get there (and return home) very quickly?   What is the per flight hour price difference between BFR and an aircraft that lands in Antarctica?

Offline Slarty1080

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Re: How BFR Earth-to-Earth Might Actually Get Started
« Reply #31 on: 04/01/2018 07:57 pm »
I'm struggling to think of a suitable place for a spaceport in Europe for passenger flights.
An artificial island on the Dogger bank maybe?

Lands's End in England.

Lissabon in Portugal.

Some coastal location in Norway.

All on platforms 20km off the coast.

Sea platforms off the coast give 1st generation access to England, Scandanavia (via Norway), France, Spain & Portugal.  Hydrofoils to the ports which all have transportation infrastructure.
Later on as reliability comfort increases with some end of light populated land overflight to Italy, Greece, Croatia.
Maybe eventually tunnels from landing platforms to ports or even inland.  Economic decision.

Agree that hundreds of BFR flights for space purposes will be needed to increase reliability comfort for even initial P2P which has no population overflight, e.g. NY to off coast of France or polar routes to NZ, japan's East coast, etc.

BFR block whatever will be kept in production for P2P flights starting NET 2040 if ever.

Next gen VBFR or whatever would need years of operation to validate its reliability for P2P although the process would be faster then.

I suspect that 5-10 years after BFR has first flown Elon Musk and others might well be saying hold my beer again and now watch this! Whats the expected life time for BFR before BFR II / New Armstong / EBFR / Hybrid combo improvement comes along?
My optimistic hope is that it will become cool to really think about things... rather than just doing reactive bullsh*t based on no knowledge (Brian Cox)

Offline Alkan

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Re: How BFR Earth-to-Earth Might Actually Get Started
« Reply #32 on: 04/02/2018 06:36 am »
I'm struggling to think of a suitable place for a spaceport in Europe for passenger flights.
An artificial island on the Dogger bank maybe?

Lands's End in England.

Lissabon in Portugal.

Some coastal location in Norway.

All on platforms 20km off the coast.

Sea platforms off the coast give 1st generation access to England, Scandanavia (via Norway), France, Spain & Portugal.  Hydrofoils to the ports which all have transportation infrastructure.
Later on as reliability comfort increases with some end of light populated land overflight to Italy, Greece, Croatia.
Maybe eventually tunnels from landing platforms to ports or even inland.  Economic decision.

Agree that hundreds of BFR flights for space purposes will be needed to increase reliability comfort for even initial P2P which has no population overflight, e.g. NY to off coast of France or polar routes to NZ, japan's East coast, etc.

BFR block whatever will be kept in production for P2P flights starting NET 2040 if ever.

Next gen VBFR or whatever would need years of operation to validate its reliability for P2P although the process would be faster then.

I suspect that 5-10 years after BFR has first flown Elon Musk and others might well be saying hold my beer again and now watch this! Whats the expected life time for BFR before BFR II / New Armstong / EBFR / Hybrid combo improvement comes along?

At IAC, Elon Musk said that they'd go a lot bigger than ITS eventually.

A lot bigger is 2-3 times the size. So, 4-6 BFRs. A million tons to LEO would be pretty awesome.

Offline intrepidpursuit

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Re: How BFR Earth-to-Earth Might Actually Get Started
« Reply #33 on: 04/02/2018 03:15 pm »
If BFR is safe enough that it is used for passenger transportation then the launch/landing sites will require similar safety margin. If one of these things blows up once it is past testing, rocket transportation will go the way of dirigible transportation.

The risk of a fast conflagration on launch when it is full of fuel will be the biggest danger, so safety margin to have infrastructure that far away will be the design consideration. There will be no coming back from that. The level of faith required to do this at all will probably lead to putting terminal infrastructure within the conflagration danger radius.

Think of airports now. There is a very high relative risk that a plane will crash on my house because I am right over the approach and takeoff corridor of a high volume airport. The risk of a plane losing control and smashing into a terminal fully fueled is also incredibly high relative to other locations. Such a disaster is unthinkable though because of the trust we have in these giant airliners.

Getting people to trust a rocket as much as an airliner is the challenge. Once that happens there will be more debate about noise than safety when it comes to placing launch/landing sites. Although, if you follow the lawsuits going on about noise and airports in the US right now, a noisy mode of transportation might be disallowed for that reason alone.

I guess the point I'm trying to make is that BFR P2P becomes a thing then the considerations will be very different than spaceport considerations are today.

Online meekGee

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Re: How BFR Earth-to-Earth Might Actually Get Started
« Reply #34 on: 04/02/2018 03:50 pm »
If BFR is safe enough that it is used for passenger transportation then the launch/landing sites will require similar safety margin. If one of these things blows up once it is past testing, rocket transportation will go the way of dirigible transportation.

The risk of a fast conflagration on launch when it is full of fuel will be the biggest danger, so safety margin to have infrastructure that far away will be the design consideration. There will be no coming back from that. The level of faith required to do this at all will probably lead to putting terminal infrastructure within the conflagration danger radius.

Think of airports now. There is a very high relative risk that a plane will crash on my house because I am right over the approach and takeoff corridor of a high volume airport. The risk of a plane losing control and smashing into a terminal fully fueled is also incredibly high relative to other locations. Such a disaster is unthinkable though because of the trust we have in these giant airliners.

Getting people to trust a rocket as much as an airliner is the challenge. Once that happens there will be more debate about noise than safety when it comes to placing launch/landing sites. Although, if you follow the lawsuits going on about noise and airports in the US right now, a noisy mode of transportation might be disallowed for that reason alone.

I guess the point I'm trying to make is that BFR P2P becomes a thing then the considerations will be very different than spaceport considerations are today.

All true, but it's relative to volume.  Occasionally, planes crash into cities, with lots of fatalities on the ground.

However, this happens once every millions of flights.  Billions almost.  (PSA @ San Diego, Air France @ Paris, El Al @ Amsterdam - that's about all I can think of)

Airliner crashes that involve only the airplane happen a few times a year, and most are in "second rate" markets.  The Western aviation markets experiences less than a single airliner accident per year.

An interesting fact is that many airliner accidents actually happen during take off, not landing.  And the BFR system has escape capabilities that airliners do not have.
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Offline Ludus

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Re: How BFR Earth-to-Earth Might Actually Get Started
« Reply #35 on: 04/02/2018 05:06 pm »
What’s the business case for P2P on earth? If the per flight cost is $5M, which is fantastically low for space launch purposes and quite low enough for space tourism, it still doesn’t seem to fit P2P. 100 passengers at $50k each hits $5M break even for an orbital cruise that returns to its launch point. That can have a flexible schedule since it’s an event. It doesn’t seem plausible that there are 100 people willing to spend $50k to fly at specific scheduled times between any two cities. That’s more expensive than a high end business jet charter and much less flexible. If there’s some break even point with high passenger volume for the BFS carrying hundreds of passengers (still not obvious for any route) how do you get to that volume without starting as low volume high price?

Offline speedevil

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Re: How BFR Earth-to-Earth Might Actually Get Started
« Reply #36 on: 04/02/2018 05:13 pm »
What’s the business case for P2P on earth? If the per flight cost is $5M, which is fantastically low for space launch purposes and quite low enough for space tourism, it still doesn’t seem to fit P2P.

It doesn't.
The basis of P2P on earth is launch costs well under $1M, and lots of people fly.
'Cheaper than economy air fare' - for around a thousand people, flying the airframe a dozen times a day, can really add up to a profitable vehicle.

May it start out rather more expensive than this - likely.

Offline hkultala

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Re: How BFR Earth-to-Earth Might Actually Get Started
« Reply #37 on: 04/02/2018 05:38 pm »
I think that the best argument for a BFS based SSTO with a small payload is for SpaceX to gather a lot of experience with it relatively quickly by using it to launch their Starlink constellation. It could potentially allow for a lot of launches in a relatively short time frame.

Starlink polar orbit requires considerable more delta-v than just "barely reaching some orbit" which BFS might be able to do.

No way BFS will reach starlink polar orbit without the booster, so could we stop polluting all threads with this BFS-SSTO nonsense, please.


« Last Edit: 04/02/2018 05:39 pm by hkultala »

Offline billh

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Re: How BFR Earth-to-Earth Might Actually Get Started
« Reply #38 on: 04/02/2018 05:47 pm »
What’s the business case for P2P on earth? If the per flight cost is $5M, which is fantastically low for space launch purposes and quite low enough for space tourism, it still doesn’t seem to fit P2P.

It doesn't.
The basis of P2P on earth is launch costs well under $1M, and lots of people fly.
'Cheaper than economy air fare' - for around a thousand people, flying the airframe a dozen times a day, can really add up to a profitable vehicle.

May it start out rather more expensive than this - likely.

What this actually says to me is that BFR is probably oversized for an initial P2P suborbital passenger service. What you need is a fully reusable vehicle that can carry maybe 50-100 people at super premium fares. It will be cheaper to build, cheaper to operate, require cheaper infrastructure, and generate the same revenues as 1000 people paying an economy fare.

Offline hkultala

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Re: How BFR Earth-to-Earth Might Actually Get Started
« Reply #39 on: 04/02/2018 06:06 pm »
What’s the business case for P2P on earth? If the per flight cost is $5M, which is fantastically low for space launch purposes and quite low enough for space tourism, it still doesn’t seem to fit P2P.

It doesn't.
The basis of P2P on earth is launch costs well under $1M, and lots of people fly.
'Cheaper than economy air fare' - for around a thousand people, flying the airframe a dozen times a day, can really add up to a profitable vehicle.

May it start out rather more expensive than this - likely.

What this actually says to me is that BFR is probably oversized for an initial P2P suborbital passenger service. What you need is a fully reusable vehicle that can carry maybe 50-100 people at super premium fares. It will be cheaper to build, cheaper to operate, require cheaper infrastructure, and generate the same revenues as 1000 people paying an economy fare.

No, building ANOTHER COMPLETELY DIFFERENT VEHICLE is not cheaper. It is much more expensive.

And for super premium fares, the people also want to have super premium conditions. Lots of space/person.

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