Author Topic: SpaceX Texas launch site Discussion and Updates - Thread 6  (Read 508387 times)

Online M.E.T.

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Re: SpaceX Texas launch site Discussion and Updates - Thread 6
« Reply #20 on: 10/14/2017 07:02 AM »
That's an expensive piece of equipment to leave sitting around for a few years while the launch vehicle is developed.  I suspect it may have some role in construction of the launch site.

Right.  First BFR launch appears to be no earlier than 2022, 5 years from now, and that will probably slip.

But the question remains:
Will they launch BFR from land, or from a platform a few miles offshore from Boca Chica beach?

Remember, Texas State law forbids SpaceX from closing Boca Chica Beach on any weekend or holiday between Memorial Day and Labor Day.  That's not going to change.

Also remember that each BFR Mars mission will require 6 launches: 1 for the spacecraft, and 5 more tanker launches to fuel the spacecraft.  And since BFR is highly reusable, SpaceX will presumably want to launch several spacecraft within each Mars launch window, which is only a few weeks every 2 years.  So we're talking dozens of launches within a relatively short period of time.

With this in mind, the Texas State beach closure law would really limit SpaceX's goals for colonizing Mars.

If they built a BFR launch pad just a few miles offshore, beach closures become a non-issue, but they would still need the control center and tracking station in Boca Chica Village, and they would probably also need a place next to the beach to store propellant, with fiber, hoses, etc. running out to the launch pad.  So the crane could be to build the control center building, payload processing buildings, water tower, etc.


Actually, the law doesn't say that.  It says:

(d)  The commissioners court may not close a beach or access
    points to the beach on a primary launch date consisting of any of
    the following days without the approval of the land office:
                 (1)  the Saturday or Sunday preceding Memorial Day;
                 (2)  Memorial Day;
                 (3)  July 4;
                 (4)  Labor Day; or
                 (5)  a Saturday or Sunday that is after Memorial Day but
    before Labor Day.

Which is ALMOST a ban, but not exactly a ban.   I don't doubt that it would be way easier to plan around these days, rather than engage the Land office, but the option is there.

Are the weekends that important though? They still have Monday to Friday.  You would have 5 consecutive days available for launches, followed by only 2 stand down days over the weekend, before another 5 consecutive days become available.

Offline Dave G

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Re: SpaceX Texas launch site Discussion and Updates - Thread 6
« Reply #21 on: 10/14/2017 11:17 AM »
Are the weekends that important though? They still have Monday to Friday.  You would have 5 consecutive days available for launches, followed by only 2 stand down days over the weekend, before another 5 consecutive days become available.

Remember SpaceX's long term goals.  They want 100,000 people living on Mars.  At 100 people per spacecraft, that's 1000 missions.  At 6 launches per mission, that's 6000 launches.

Question: The Mars window every 2 years - how long does it last ?  I'm assuming they need a somewhat optimum trajectory for 100 people.

Online M.E.T.

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Re: SpaceX Texas launch site Discussion and Updates - Thread 6
« Reply #22 on: 10/14/2017 11:21 AM »
Are the weekends that important though? They still have Monday to Friday.  You would have 5 consecutive days available for launches, followed by only 2 stand down days over the weekend, before another 5 consecutive days become available.

Remember SpaceX's long term goals.  They want 100,000 people living on Mars.  At 100 people per spacecraft, that's 1000 missions.  At 6 launches per mission, that's 6000 launches.

Question: The Mars window every 2 years - how long does it last ?  I'm assuming they need a somewhat optimum trajectory for 100 people.

I think most of us accept that the "100 launches per Mars window" is 30 years or so down the line, at best. We are in the exploration phase now. The colonization phase will follow later. By then, Boca Chica will long since not be the only launch site anymore.

EDITED down to 100 launches per Mars window, from 1000.
« Last Edit: 10/14/2017 11:22 AM by M.E.T. »

Offline Dave G

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Re: SpaceX Texas launch site Discussion and Updates - Thread 6
« Reply #23 on: 10/14/2017 12:37 PM »
Are the weekends that important though? They still have Monday to Friday.  You would have 5 consecutive days available for launches, followed by only 2 stand down days over the weekend, before another 5 consecutive days become available.

Remember SpaceX's long term goals.  They want 100,000 people living on Mars.  At 100 people per spacecraft, that's 1000 missions.  At 6 launches per mission, that's 6000 launches.

Question: The Mars window every 2 years - how long does it last ?  I'm assuming they need a somewhat optimum trajectory for 100 people.

I think most of us accept that the "100 launches per Mars window" is 30 years or so down the line, at best. We are in the exploration phase now. The colonization phase will follow later. By then, Boca Chica will long since not be the only launch site anymore.

EDITED down to 100 launches per Mars window, from 1000.

But still, with the launch cadence they're looking at for Mars missions, the beach closure laws will be limiting long-term.

The near term issue is getting approvals.  The current EIS limits SpaceX to to 12 launches per per year.  Nothing larger than Falcon Heavy is allowed, and even then, the EIS only allows 2 Falcon Heavy launches per year.  Reading the EIS, I found that FH is already over the legal sound limit for Boca Chica Village by 2dB, but they made an exception.  Since BFR is much larger than FH, I assume it will be much louder, and at much lower frequencies, which could break windows or crack foundations, so getting an exception would be much harder.

For these reasons, I've always assumed that, in order to launch BFR from Boca Chica Beach, SpaceX would need to buy all the houses in Boca Chica Village. There's around 40 houses there, and they're relatively inexpensive, so it would probably only cost around $5 million to buy all all of them, assuming they can get people to sell.  But still, $5 million is real money, and we've seen how that kind of money can change SpaceX's plans.  For example, instead of building BFR at Hawthorne, SpaceX now intends to build the BFR close to water.  That's because it would cost $2.5 million to move BFR from Hawthorne to the nearest seaport.

Another issue is the soil stability at Boca Chica Beach.  It seems it's a lot more shifty than they first thought.  They may need pilings up to 1000 feet deep to reach stable earth.  With that in mind, a fixed launch platform a few miles offshore may not be much more expensive.

Again, I'm assuming that an offshore launch platform would still require a lot of facilities onshore, i.e. control center, tracking station, payload processing, propellant storage, water tower, etc.  I'm also assuming they would run fiber and hoses from the beach, so the offshore platform would be relatively small, like Elon showed in the video at the end of the presentation.

Online nacnud

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Re: SpaceX Texas launch site Discussion and Updates - Thread 6
« Reply #24 on: 10/14/2017 12:44 PM »
Reading the EIS, I found that FH is already over the legal sound limit for Boca Chica Village by 2dB, but they made an exception.  Since BFR is much larger than FH, I assume it will be much louder, and at much lower frequencies, which could break windows or crack foundations, so getting an exception would be much harder.

Falcon heavy has 27 Merlins for 22.8 MN thrust
BFR has 31 raptors for 52.7 MN thrust.

In terms of numbers of engines it's not that big an increase, though it is over double the thrust. Not sure how this would impact the sound levels but interesting numbers.
« Last Edit: 10/14/2017 12:45 PM by nacnud »

Offline Dave G

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Re: SpaceX Texas launch site Discussion and Updates - Thread 6
« Reply #25 on: 10/14/2017 01:03 PM »
Reading the EIS, I found that FH is already over the legal sound limit for Boca Chica Village by 2dB, but they made an exception.  Since BFR is much larger than FH, I assume it will be much louder, and at much lower frequencies, which could break windows or crack foundations, so getting an exception would be much harder.

Falcon heavy has 27 Merlins for 22.8 MN thrust
BFR has 31 raptors for 52.7 MN thrust.

In terms of numbers of engines it's not that big an increase, though it is over double the thrust. Not sure how this would impact the sound levels but interesting numbers.

Yes, thrust is one component, but the sound level also depends on other things, like exit velocity, how the engines interact with each other, etc.

And even more important than the overall sound level is the frequency content.  It's the lower frequencies that cause damage.  I'm not an acoustics expert, but in general, it seems like a larger rocket would tend to produce more lower frequencies.

Offline Dave G

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Re: SpaceX Texas launch site Discussion and Updates - Thread 6
« Reply #26 on: 10/14/2017 02:03 PM »
I think most of us accept that the "100 launches per Mars window" is 30 years or so down the line, at best.

I think it will be sooner, for 2 reasons:

1) Remember, it takes 6 BFR launches for 1 BFS spaceship to go to Mars.

2) Look what SpaceX has achieved in the last 10 years.  Their first successful Falcon 1 flight was Sept 2008. Their first successful Falcon 9 flight was June 2010. Their first successful landing was December 2015.  They now have 18 successful landings. Their rate of progress is amazing.

Are the weekends that important though? They still have Monday to Friday.  You would have 5 consecutive days available for launches, followed by only 2 stand down days over the weekend, before another 5 consecutive days become available.

That all depends on how fast they can re-launch BFR.  For example, if they can launch BFR every day, that would take 8 days to send 1 BFR spacecraft to Mars.  Without the Boca Chica Beach closure issue, it would only take 6 days.

Offline billh

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Re: SpaceX Texas launch site Discussion and Updates - Thread 6
« Reply #27 on: 10/14/2017 06:36 PM »
I think if I were a pad guy at Boca Chica I'd be secretly glad for the rule about not launching on weekends.  :o

Online M.E.T.

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Re: SpaceX Texas launch site Discussion and Updates - Thread 6
« Reply #28 on: 10/14/2017 07:00 PM »
I think most of us accept that the "100 launches per Mars window" is 30 years or so down the line, at best.

I think it will be sooner, for 2 reasons:

1) Remember, it takes 6 BFR launches for 1 BFS spaceship to go to Mars.

2) Look what SpaceX has achieved in the last 10 years.  Their first successful Falcon 1 flight was Sept 2008. Their first successful Falcon 9 flight was June 2010. Their first successful landing was December 2015.  They now have 18 successful landings. Their rate of progress is amazing.

Are the weekends that important though? They still have Monday to Friday.  You would have 5 consecutive days available for launches, followed by only 2 stand down days over the weekend, before another 5 consecutive days become available.

That all depends on how fast they can re-launch BFR.  For example, if they can launch BFR every day, that would take 8 days to send 1 BFR spacecraft to Mars.  Without the Boca Chica Beach closure issue, it would only take 6 days.

Fair point. I was thinking how long until 100 spaceships depart for Mars in a giant convoy. You are correct that this equates to 600 launches.

Offline Cheapchips

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Re: SpaceX Texas launch site Discussion and Updates - Thread 6
« Reply #29 on: 10/14/2017 10:08 PM »
By the time they're flying 100 ships to Mars they'll be using the dedicated tanker. Presumably five launches or less for that instead? 

I'd expect more than a flight a day.  Gwynne stated that shop to ship refueling as fast as the BFR presentation is the goal. That speed, or as close as they can get to it, is going to apply to the booster turn around as well.
« Last Edit: 10/15/2017 05:18 AM by Cheapchips »

Offline biosehnsucht

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Re: SpaceX Texas launch site Discussion and Updates - Thread 6
« Reply #30 on: 10/14/2017 11:29 PM »
re: dedicated tankers

https://www.reddit.com/r/space/comments/76e79c/i_am_elon_musk_ask_me_anything_about_bfr/dodexlx/?context=10000

Quote from: Elon Musk
At first, the tanker will just be a ship with no payload. Down the road, we will build a dedicated tanker that will have an extremely high full to empty mass ratio (warning: it will look kinda weird).
« Last Edit: 10/14/2017 11:29 PM by biosehnsucht »

Offline Nomadd

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Re: SpaceX Texas launch site Discussion and Updates - Thread 6
« Reply #31 on: 10/15/2017 10:56 AM »
 I was talking to someone in Brownsville yesterday. A lot of people and agencies have invested a lot of time and money in this port, and cancelling the Falcon here in exchange for a vague idea of something happening someday is not going over well, to put it lightly. SpaceX credibility in The RGV couldn't be much lower at the moment.

Offline Dave G

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Re: SpaceX Texas launch site Discussion and Updates - Thread 6
« Reply #32 on: 10/15/2017 12:42 PM »
I was talking to someone in Brownsville yesterday. A lot of people and agencies have invested a lot of time and money in this port, and cancelling the Falcon here in exchange for a vague idea of something happening someday is not going over well, to put it lightly. SpaceX credibility in The RGV couldn't be much lower at the moment.

My guess: They'll build an F9/FH pad on Boca Chica Beach soon, and a BFR pad a few miles offshore from Boca Chica Beach.  Both will use the same control center, tracking station, oxygen production, water tower, etc.  I'm assuming an offshore platform would have electrical cables, fiber-optics, and flexible pipe run from the beach to the offshore platform, so they would need the current launch site location to support an offshore platform anyway.

To clarify, what Gwynne Shortwell recently said at Stanford was:
Quote
Boca Chica launch site under construction is the "perfect location for BFR"

She did not mention anything else about Boca Chica other than its prime suitability for BFR.

Everything else is speculation.

Nothing in her comments suggested that Falcon 9 and Falcon Heavy wouldn't fly from Boca Chica.

And given the issues with Texas State beach closure laws, and with BFR being way over the Federal legal sound limit in Boca Chica Village, and with the current EIS allowing only 12 launches per year, I suspect "perfect location for BFR" implies a fixed platform a few miles off Boca Chica Beach, like Elon showed in the presentation:
« Last Edit: 10/15/2017 12:53 PM by Dave G »

Offline philw1776

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Re: SpaceX Texas launch site Discussion and Updates - Thread 6
« Reply #33 on: 10/15/2017 01:21 PM »
I was talking to someone in Brownsville yesterday. A lot of people and agencies have invested a lot of time and money in this port, and cancelling the Falcon here in exchange for a vague idea of something happening someday is not going over well, to put it lightly. SpaceX credibility in The RGV couldn't be much lower at the moment.

OK, what is RGV?
“When it looks more like an alien dreadnought, that’s when you know you’ve won.”

Offline Jcc

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Re: SpaceX Texas launch site Discussion and Updates - Thread 6
« Reply #34 on: 10/15/2017 01:22 PM »
Rio Grande Valley

Offline DreamyPickle

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Re: SpaceX Texas launch site Discussion and Updates - Thread 6
« Reply #35 on: 10/15/2017 02:18 PM »
Switching plans from F9 to BFR isn't much of a cancellation. Construction will proceed at a similar pace except for a different rocket and at a larger scale.

Most likely Boca Chica will be the pad used for initial suborbital testing of the BFS prototype so they'll need to get this up and running relatively soon.

Online Semmel

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Re: SpaceX Texas launch site Discussion and Updates - Thread 6
« Reply #36 on: 10/15/2017 03:06 PM »
I was talking to someone in Brownsville yesterday. A lot of people and agencies have invested a lot of time and money in this port, and cancelling the Falcon here in exchange for a vague idea of something happening someday is not going over well, to put it lightly. SpaceX credibility in The RGV couldn't be much lower at the moment.

So do they _know_ that F9 is cancelled for Boca Chica or do they _guess_? So far, we have the strong suggestion that BFR is going to fly from Boca Chica but we have little to know indication if Boca Chica is also serving as a F9 launch pad much earlier.

Online envy887

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Re: SpaceX Texas launch site Discussion and Updates - Thread 6
« Reply #37 on: 10/15/2017 04:08 PM »
I was talking to someone in Brownsville yesterday. A lot of people and agencies have invested a lot of time and money in this port, and cancelling the Falcon here in exchange for a vague idea of something happening someday is not going over well, to put it lightly. SpaceX credibility in The RGV couldn't be much lower at the moment.

So do they _know_ that F9 is cancelled for Boca Chica or do they _guess_? So far, we have the strong suggestion that BFR is going to fly from Boca Chica but we have little to know indication if Boca Chica is also serving as a F9 launch pad much earlier.
These comments strongly suggest Falcon won't fly from Texas:

Quote
You have two pads in Florida, pus Vandenberg. Is it fair to say that given what you can do from your current locations, you don’t need one in Texas?
Yes, that’s correct. We have demonstrated we can launch at least twice from each of these pads. We’re talking about being able to do at least six launches a month if we wanted to. It is not our intention to do so.
What we have manifested in customer commitments are not bottlenecked by the lack of a fourth launch site. We can manage with the three. Between upgrading our production capability, having the pads — and most importantly, the visibility — between the balance of those three we don’t foresee not being able to meet customer commitments. I am happy to take on more launch commitments right now.

https://www.spaceintelreport.com/spacex-reassures-commercial-satellite-market-falcon-9-wont-soon-scrapped-bfr/

Offline Barrie

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Re: SpaceX Texas launch site Discussion and Updates - Thread 6
« Reply #38 on: 10/15/2017 04:26 PM »
If the range is serving multiple pads for multiple operators, the range is a potential bottleneck.  Wasn't that the point of having another range? What happens if/when BO start operating?  How long will an SLS launch reserve the range for?

Offline Dave G

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Re: SpaceX Texas launch site Discussion and Updates - Thread 6
« Reply #39 on: 10/15/2017 04:51 PM »
I was talking to someone in Brownsville yesterday. A lot of people and agencies have invested a lot of time and money in this port, and cancelling the Falcon here in exchange for a vague idea of something happening someday is not going over well, to put it lightly. SpaceX credibility in The RGV couldn't be much lower at the moment.

OK, what is RGV?

Rio Grande Valley

i.e. the part of South East Texas that encompasses Brownsville and Boca Chica

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