Wiki Discussion of Possible Launch Sites and Platforms

[ecarfan]

From that article:

Shotwell said the company needed to first start launching Starship and better understand that vehicle before building offshore launch platforms. “We really need to fly this vehicle to understand it, to get to know this machine, and then we’ll figure out how we’re going to launch it.”

She said she expected offshore platforms to eventually play a role to support an extraordinarily high launch cadence. “We have designed Starship to be as much like aircraft operations as we possibly can get it,” she said in the conference presentation. “We want to talk about dozens of launches a day, if not hundreds of launches a day.”

I know that Elon has talked about that kind of launch cadence in the past, but every time I hear it mentioned it blows my mind. I just hope I am around to see it actually happen! I would guess it is at least a decade away.

 

[petit_bateau]

An article with the details:

SpaceX drops plans to convert oil rigs into launch platforms

SpaceX has abandoned efforts to convert two oil rigs into launch platforms for its Starship vehicle but could develop offshore platforms in the future.

spacenews.com

These semis are relatively standardised designs for floating semi subs.

We are at peak oil, which is a somewhat bumpy plateau with all sorts of other summits on the ridge, chiefly peak gas and peak liquids.

Arguably we are also at peak offshore oil, gas liquids. Arguably most of the future growth will come from low risk (and low cost) onshore, though we will of course continue to work out the low risk tails from the known offshore plays around the world.

Once off-peak the liquidity in the relevant engineering design and manufacturing to construct these semi-submersibles will rapidly dissipate and be hard to re-assemble. Whilst the rigs themselves may have an economic lifetime of (say) 20-years in a single usage pattern, they will not have that same economic lifetime if they are to be significantly converted in a safe and cost-effective manner to another usage. You only have to inspect a 10-year-old semi to understand what I mean.

SpaceX might want to do (say) a dozen launches a day per rig. That is only a launch per rig every 2-hours. Not so difficult for stack - tank - and go. You only need a few rigs to do that at a rate of (say) thity or so per fleet per day (ex-Terra). That would be 11,000 per year ........ of which quite a few would be tankers, but sheesh ...

The point being that whilst SpaceX may conside these are disposable items, and that may be a fair assessment of the market now, that may not be the case in the future.

Different littorals have different rquirements. some may lend themselves to relatively easily assembled offshore islands of dredged sands in <50m water depth. Others may require floaters in >80m water depths. (The intermediate bit in 50-80m using jackups is I think not of interest). The floaters required for 20MW wind are a world apart from these O&G floaters.

Maybe enough littoral desert coast is the way to do this. There is a lot of Chile, Peru, Namibia, Morocco, Australia. Maybe Texas even. All sorts of offshore islands.

 

[ecarfan]

SpaceX might want to do (say) a dozen launches a day per rig. That is only a launch per rig every 2-hours. Not so difficult for stack - tank - and go.

Imagine the size of the onshore GSE tank farm required to support that many Starship launches per day. I can’t quite wrap my head around it.

 

[petit_bateau]

Imagine the size of the onshore GSE tank farm required to support that many Starship launches per day. I can’t quite wrap my head around it.

As a comparison it is instructive to look at large scale LNG liquefaction plants which gives a feel for the size of the cryogenic problem. I appreciate that the long term goal for SpaceX is to get renewable methane (CH4) but for now taking hydrocarbon CH4 will be what they are doing. There is also the need to get liquid oxygen (LOX) so for comparison purposes it is worth summing both the CH4 + LOX

"the LNG market typically differentiated between small- to mid-scale production facilities and world-scale plants. Whereas the small- to mid-scale segment usually produces up to 0.5 million tonnes per annum (mtpa), world-class plants have liquefaction capacities of anywhere between 3.5 and almost 8 mtpa."

https://www.linde-engineering.com/en/images/LNG-technology_tcm19-4577.pdf

If you want to read more widely try also

World LNG Report 2022 – IGU

www.igu.org

Anyway popping those numbers into a spreadsheet it looks like a typical very large 2-train LNG plant can do about 22,000 tons/day of cryogenic liquid gas. So to get to a launch cadence of 12 per day that would require a 4-train plant.

Now it would be possible to put that in an offshore floating vessel such as Shell has done with the Prelude FLNG that only (!) does 3.6 mt/yr and still weighs in at 600,000 t when fully loaded, more than five times the displacement of a Nimitz-class aircraft carrier. It is the world's largest floating liquefied natural gas platform as well as the largest offshore facility ever constructed. But far better/easier/safer to put that on a very large piece of coastal flat deserted land where you can avoid a lot of the problems of going to a floater.

Prelude FLNG - Wikipedia

en.wikipedia.org

So a good equivalent would be Bintulu LNG which is the 21mt/yr exemplar for a very-large facility - note train sizes have increased over the years hence this being a 9-train.

Malaysia LNG - Wikipedia

en.wikipedia.org

And if you are going to build on such a large piece of empty coastal land you might as well put the launch & recovery pads somewhere within sensible pieline distance. An artificial island in shallow water offshore (say <30m water depth) would seem to be the better way to go for a series of offshore pads that are sufficiently segregated from each other, and from the onshore LNG/LOX plant

Again to get a feel for that, here is a shot of Bintulu - a good planning guesstimate would be a 10km x 10km chunk of empty coastline, with space nearby for a fairly large township to provide the workforce.

 

[ecarfan]

here is a shot of Bintulu - a good planning guesstimate would be a 10km x 10km chunk of empty coastline, with space nearby for a fairly large township to provide the workforce.

Thanks for your very informative post. I’m wondering how SpaceX is going to manage constructing a similar facility. I don’t see how they could get permission to do that at or near KSC or in the Boca Chica area due to the environmental impact.

This discussion — which I initiated — is going off topic for this thread. @Grendal, is there a better place for it?

 

[petit_bateau]

Thanks for your very informative post. I’m wondering how SpaceX is going to manage constructing a similar facility. I don’t see how they could get permission to do that at or near KSC or in the Boca Chica area due to the environmental impact.

This discussion — which I initiated — is going off topic for this thread. @Grendal, is there a better place for it?

Thank you.

Personally I think here is a good enough place. It is not as if I interrupt that often. There are other threads where I am more (or less) vociferous. These infrastructure issues will become more obvious at the right moment. Until then it is not such a big deal.

Construction of these things is actually quite easy. Especicially in a simples location like USA. Been there, done that.

 

[Grendal]

I created a new thread but left the old posts in place.

Bintulu is on the West coast of the island. It's not all that close to the equator. Unless SpaceX is planning a lot of polar launches then that location is unlikely.

If it could be politically worked out, I'd say that launching from French Guiana is a good possibility. There is already a large launch facility in place and a lot of infrastructure to go with it.

If we're going for an equatorial possibility, then the East coast of Malaysia near Singapore would be a possibility.

Zero chance for Somalia...

 

[petit_bateau]

The only reason I grabbed a sat photo of Bintulu was to give folk an indication of the typical scale of an LNG plant so that they could calibrate their site size expectations. However it does make quite a lot of sense to locate near-ish to an existing plant as that would save a lot of cost and time, and I had not considered that. As it happens Bintulu is closer to the equator than either Florida or Texas. The area of the island to the east of Bintulu is not exactly a high density residential neigbourhood. It would be quite ironic if we were to repurpose LNG plants in this way.

 

[ecarfan]

If SpaceX were to someday build a large scale LNG facility with an adjacent spaceport for multiple launch sites, for the purpose of performing multiple launches per day to Mars, over a time period of many decades, it would be critical to do that from a country that is politically stable with good infrastructure.

Obviously it is impossible to predict the future decades in advance. But Indonesia or French Guiana would not be good choices, in my opinion.

The other factor to consider is climate change. Building a such a spaceport a few feet above sea level in hurricane prone regions — like Boca Chica and KSC — is risky long term. While we cannot predict political stability 40 years from now with much reliability, we can predict with some confidence that sea levels will rise significantly and extreme weather events like hurricanes/cyclones/typhoons will become much more frequent and intense.

With that said, I don’t know where the best locations would be. It’s a difficult problem.

 

[ecarfan]

New info about Starship launch site work in Florida. All pieces of the third Stage Zero tower have been seen and they look about ready for stacking. Still not known where it will be located. Also, the chopsticks have been mounted on the Stage Zero tower at LC39A. (Also, evidence of the start of construction of a new crew tower at SLC40)

 

[ecarfan]

BTW that video said that the chopsticks for the third Stage Zero have been sighted in the construction yard and they appear to be noticeably shorter than the ones at Boca. That is odd. SpaceX is many months away from the first attempt to use the chopsticks to catch a vehicle and they’ve already significantly changed the design.

And why have the components for a third Stage Zero tower been built when there is no sign of where it will be located? A lot of foundation work is needed before the tower can be stacked.

 

[SpaceXaddict]

As a comparison it is instructive to look at large scale LNG liquefaction plants which gives a feel for the size of the cryogenic problem. I appreciate that the long term goal for SpaceX is to get renewable methane (CH4) but for now taking hydrocarbon CH4 will be what they are doing. There is also the need to get liquid oxygen (LOX) so for comparison purposes it is worth summing both the CH4 + LOX

...

Anyway popping those numbers into a spreadsheet it looks like a typical very large 2-train LNG plant can do about 22,000 tons/day of cryogenic liquid gas. So to get to a launch cadence of 12 per day that would require a 4-train plant.


View attachment 907668

Now it would be possible to put that in an offshore floating vessel such as Shell has done with the Prelude FLNG that only (!) does 3.6 mt/yr and still weighs in at 600,000 t when fully loaded, more than five times the displacement of a Nimitz-class aircraft carrier. It is the world's largest floating liquefied natural gas platform as well as the largest offshore facility ever constructed. But far better/easier/safer to put that on a very large piece of coastal flat deserted land where you can avoid a lot of the problems of going to a floater.

Prelude FLNG - Wikipedia

en.wikipedia.org

So a good equivalent would be Bintulu LNG which is the 21mt/yr exemplar for a very-large facility - note train sizes have increased over the years hence this being a 9-train.

Malaysia LNG - Wikipedia

en.wikipedia.org

And if you are going to build on such a large piece of empty coastal land you might as well put the launch & recovery pads somewhere within sensible pieline distance. An artificial island in shallow water offshore (say <30m water depth) would seem to be the better way to go for a series of offshore pads that are sufficiently segregated from each other, and from the onshore LNG/LOX plant

Again to get a feel for that, here is a shot of Bintulu - a good planning guesstimate would be a 10km x 10km chunk of empty coastline, with space nearby for a fairly large township to provide the workforce.

View attachment 907669

So here's an idea. There's a lot of "stranded" natural gas in West Texas. A lot of natural gas pipelines in Texas too. Seems and ideal place for a plant to make propellants like you are describing. The plant could be on land, and then it could feed *multiple* launch points offshore. I'm not sure how far offshore makes sense for a pipeline vs the noise abatement tradeoff.

But the Launch Cadence may not be even. For example, say there are 10 Starships going up per day from Cape Canaveral on their way to mars for a colony trip. Each one of those ships requires (let's just say) 5 launches of tankers to refuel them. The tankers could all launch from Texas to meet the starships launched from Florida.

Texas has lots of natural gas, natural gas pipelines, and a second place launch location. While Florida has the human rated spaceflight facilities. (and NASA Will want a hand in things so NASA is unlikely to support human flight from Texas in the short term.)