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... DesertsSpaceports/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... ;)
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, ....
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?
Quote from: alang on 04/01/2018 08:26 amI'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.
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?
Quote from: freddo411 on 04/01/2018 02:40 amHere'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.
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.
Quote from: freddo411 on 04/01/2018 02:40 am* 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.
* P2P landing in Antarctica. Very hard to visit there currently.
Quote from: guckyfan on 04/01/2018 10:37 amQuote from: alang on 04/01/2018 08:26 amI'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.
Quote from: philw1776 on 04/01/2018 04:57 pmQuote from: guckyfan on 04/01/2018 10:37 amQuote from: alang on 04/01/2018 08:26 amI'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?
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.
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.
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.
Quote from: Ludus on 04/02/2018 05:06 pmWhat’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.
Quote from: speedevil on 04/02/2018 05:13 pmQuote from: Ludus on 04/02/2018 05:06 pmWhat’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.