Author Topic: Where will BFR launch from?  (Read 97592 times)

Offline envy887

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Re: Where will BFR launch from?
« Reply #500 on: 07/15/2016 01:10 AM »
BFR will have much more propellant (if any of the speculation is close to correct) with greater destructive potential than F9 or FH.  Minimums assume it goes boom on the pad, and why minimums for guided and unguided are the same, and why those minimums increase with increasing vehicle size; FTS or no FTS.

That is why it is applicable and why BFR may not be allowed to launch from places F9 and FH launches are allowed.
...
Note that analysis of the debris impact area, distant focused overpressure (DFO), reasonably accurate expected casualty calculations (among other things) are difficult to impossible based on public information.

BFR will be 3 to 4 times bigger than FH according to both Musk and Shotwell, and methane is less energetic than LH2/LOX which in turn is roughly 40% more energetic than RP-1/LOX. Even assuming methalox and hydrolox are equivalent, the worst case BFR explosion will be less than 5.6 times more energetic than Falcon Heavy.

However, most energy dissipation phenomena fall off with the cube of radius from the energetic event; for those effects BFR only needs 1.75 times the standoff distance, and more likely 1.5 times, compared to Falcon Heavy.

Can anyone point out a debris impact, DFO, expected casualty, or other similar analysis for a launch vehicle, preferably a large one? Is this information available from Shuttle or DIVH launches?

Offline BobHk

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Re: Where will BFR launch from?
« Reply #501 on: 07/15/2016 11:09 PM »
https://forum.nasaspaceflight.com/index.php?topic=35425.msg1559579#msg1559579

Over on the Texas Launch Site thread, Jim says he doesn't think the MCT will launch from Boca Chica because of safety reasons and notes the size of the exclusion zone around the Saturn V launches.

Ask yourself where are you going to get the LNG/Methane for all those Mars launches if not south Texas?  With any site named please indicate the proximity of cheap ergtons of LNG nearby, thanks.
Any major city in the US has access to super cheap natural gas (super cheap in this context). And just like oxygen, SpaceX can liquify it themselves.

Access is NOT the same as, hey its right over there.  You also need to X out any MAJOR CITY right?  No BFR launches from near New York or are you considering launching from just anywhere?
« Last Edit: 07/15/2016 11:11 PM by BobHk »

Offline philw1776

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Re: Where will BFR launch from?
« Reply #502 on: 07/15/2016 11:23 PM »
IMO, wiping out NY is a feature, not a bug.
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Offline Robotbeat

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Re: Where will BFR launch from?
« Reply #503 on: 07/16/2016 01:43 AM »
https://forum.nasaspaceflight.com/index.php?topic=35425.msg1559579#msg1559579

Over on the Texas Launch Site thread, Jim says he doesn't think the MCT will launch from Boca Chica because of safety reasons and notes the size of the exclusion zone around the Saturn V launches.

Ask yourself where are you going to get the LNG/Methane for all those Mars launches if not south Texas?  With any site named please indicate the proximity of cheap ergtons of LNG nearby, thanks.
Any major city in the US has access to super cheap natural gas (super cheap in this context). And just like oxygen, SpaceX can liquify it themselves.

Access is NOT the same as, hey its right over there.  You also need to X out any MAJOR CITY right?  No BFR launches from near New York or are you considering launching from just anywhere?
Only North Carolina (and a few states far north)  doesn't have natural gas pipelines on its coast.

There may be other reasons to prefer Texas over other places in the continental US, but none of them are "natural gas isn't available elsewhere."
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

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Offline BobHk

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Re: Where will BFR launch from?
« Reply #504 on: 07/25/2016 02:39 AM »
https://forum.nasaspaceflight.com/index.php?topic=35425.msg1559579#msg1559579

Over on the Texas Launch Site thread, Jim says he doesn't think the MCT will launch from Boca Chica because of safety reasons and notes the size of the exclusion zone around the Saturn V launches.

Ask yourself where are you going to get the LNG/Methane for all those Mars launches if not south Texas?  With any site named please indicate the proximity of cheap ergtons of LNG nearby, thanks.
Any major city in the US has access to super cheap natural gas (super cheap in this context). And just like oxygen, SpaceX can liquify it themselves.

Access is NOT the same as, hey its right over there.  You also need to X out any MAJOR CITY right?  No BFR launches from near New York or are you considering launching from just anywhere?
Only North Carolina (and a few states far north)  doesn't have natural gas pipelines on its coast.

There may be other reasons to prefer Texas over other places in the continental US, but none of them are "natural gas isn't available elsewhere."

I look forward to the BFR/MCT FAA application for anywhere west of Texas' coast and north of the southermost tips of Florida or Texas.  If only for practical (its BFR not a bottlerocket) reasons: travel over a populated area without nearby splash space in an ocean.  Just how nervous is the FAA/will the FAA be of a BFR/MCT splashing down into open land in the western US?

What is the FAA's comfort zone?  I suspect its over an ocean.



Offline envy887

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Re: Where will BFR launch from?
« Reply #505 on: 07/25/2016 02:53 AM »
30 casualties per million flights is the FAA expected casualty limit. Basically, it will have to be airliner-reliable before flying over anywhere populated, including the Western US.

Offline Ludus

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Re: Where will BFR launch from?
« Reply #506 on: 09/27/2016 09:24 PM »
Florida, specifically LC39A.

It's the only thing that makes sense.

Consider NASA and DOD payloads, as they will be the big dollar clients.

I think the BFR structure and it's integration should be done at CCAFS as well.

Elon agrees.  :)

Offline the_other_Doug

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Re: Where will BFR launch from?
« Reply #507 on: 09/27/2016 10:41 PM »
Elon did not say that LC-39A will be the only launch complex from which the ITS will fly, just that this is where they will fly it from at first.

I still believe, especially with the implied launch cadence, that there will be multiple launch sites, and that we ought not rule out Boca Chica for ITS launch operations at this point...
-Doug  (With my shield, not yet upon it)

Offline yokem55

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Re: Where will BFR launch from?
« Reply #508 on: 09/27/2016 10:55 PM »
So what improvements to the 39A flame trench will be needed to allow 28 million pounds of thrust off that pad?  :o ??? :-\

Does SpaceX think that the 11 million pounds limit is too conservative?

Offline Toast

Re: Where will BFR launch from?
« Reply #509 on: 09/27/2016 10:55 PM »
I still believe, especially with the implied launch cadence, that there will be multiple launch sites, and that we ought not rule out Boca Chica for ITS launch operations at this point...

He did actually mention eventually launching it from the coast of Texas (obviously a reference to Boca Chica) during his speech.

Offline Lar

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Re: Where will BFR launch from?
« Reply #510 on: 09/28/2016 04:33 PM »
See also http://forum.nasaspaceflight.com/index.php?topic=41292  ("Launching the ITS Rocket") (there may be a merge or rename, discussion underway)
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
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Offline Chris Bergin

Re: Where will BFR launch from?
« Reply #511 on: 09/28/2016 09:26 PM »
ITS as a realignment! ;D

New thread for this subject:
http://forum.nasaspaceflight.com/index.php?topic=41303.0

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