Author Topic: Falcon Super Heavy  (Read 48741 times)

Offline Idol Revolver

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Re: Falcon Super Heavy
« Reply #240 on: 06/12/2010 07:23 PM »
*other examples include that the avage horse has about 1.2 horse power and HD sellers clame there are 1,000,000 bytes in a MB
There are 1 million bytes in a megabyte. There are 2^10 or 1 048 576 bytes in a Mebibyte, the base 2 version.

Offline Robotbeat

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Re: Falcon Super Heavy
« Reply #241 on: 06/12/2010 07:32 PM »
When my daughter was a  teenager she used to excuse what she was doing by changing the definitions of the words to suit her. This is no different.
Why don't we just talk exactly about what we mean, then, instead of using subjective and qualitative terms? For instance, we can talk about payload to LEO (or TLI or escape). Is it really the case that what determines a "big enough" launch vehicle is going to occur exactly on the 100mt line? Why no 70 tons or 130 tons to LEO?

(Of course, why not 30 or 40 tons to LEO...)
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Online sdsds

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Re: Falcon Super Heavy
« Reply #242 on: 06/12/2010 07:35 PM »
The Delta II family included heavy variants, as does the Delta IV family and (prospectively) the Falcon 9 family.  Just because they are the heavies in their families doesn't make them heavies in the global context.  Said differently, just because they are "heavy launch vehicles" doesn't make them "heavy lift vehicles."

It's always relative, and it should always be the case that "heavy" refers to one of the vehicles with the greatest payload to orbit.  Saturn V was heavy lift.  In that context, a vehicle that doesn't provide anywhere close to that capability isn't heavy lift.

The imagined Falcon Super Heavy would be the super-heavy vehicle within the Falcon family.  It's yet to be seen whether it will even be a heavy vehicle within the global context.

The progression of vehicles MikeAtkinson imagines is a good one, based on a 2000kN engine with potential to be enhanced to 3000kN.  I hope SpaceX reviews the "five engines needed for engine out capability" requirement, though.  There's no good way to tightly pack five circular engine nozzles under a circular core tank.
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Offline simonth

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Re: Falcon Super Heavy
« Reply #243 on: 06/12/2010 07:36 PM »
When my daughter was a  teenager she used to excuse what she was doing by changing the definitions of the words to suit her. This is no different.
Why don't we just talk exactly about what we mean, then, instead of using subjective and qualitative terms? For instance, we can talk about payload to LEO (or TLI or escape). Is it really the case that what determines a "big enough" launch vehicle is going to occur exactly on the 100mt line? Why no 70 tons or 130 tons to LEO?

(Of course, why not 30 or 40 tons to LEO...)

The question then becomes, what does SpaceX mean with a "Falcon Super Heavy" if not Falcon 9H?

Offline Ben the Space Brit

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Re: Falcon Super Heavy
« Reply #244 on: 06/12/2010 09:10 PM »
When my daughter was a  teenager she used to excuse what she was doing by changing the definitions of the words to suit her. This is no different.
Why don't we just talk exactly about what we mean?
FWIW, the definintions in my head are:

Light: to 10t IMLEO
Medium: 10t to 25t IMLEO/10t TOI
Medium-Heavy: 25t to 50t IMELO/up to 20t TOI
Heavy: 50t to 100t IMLEO/up to 45t TOI
Super-heavy: 100t to 150t IMLEO/50t+ TOI
Ultra-heavy: up to 200t IMLEO
We Don't Need No Steenkeen Budget: up to 1kt IMLEO

I suspect that, if propellent transfer is proven as a technology, any IMLEO above about 100t will become obsolete as it would be simpler to launch the vehicle dry and fill its propellent tanks from pre-emplaced resources.  Unless I've got my sums very wrong, an Orion, LSAM and dry EDS should be in the 80t to 100t range.
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Offline clongton

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Re: Falcon Super Heavy
« Reply #245 on: 06/12/2010 09:13 PM »
Why don't we just talk exactly about what we mean, then, instead of using subjective and qualitative terms? For instance, we can talk about payload to LEO (or TLI or escape). Is it really the case that what determines a "big enough" launch vehicle is going to occur exactly on the 100mt line? Why no 70 tons or 130 tons to LEO?

(Of course, why not 30 or 40 tons to LEO...)

I thought that's what I did. I quoted the Von Braun Team as defining a Heavy Lift Launch Vehicle as being capable of sending at least 100mT to orbit. So the next question becomes: what did they mean by "orbit"?

The only launch vehicle that anyone on the planet has ever flown that everyone agrees was a heavy lift launch vehicle was the Saturn-V. Well the Saturn-V would put 119mT into a 190km circular orbit at 28 degrees inclination. So I would suppose that using Dr. Von Braun's definition (the only one imo that has demonstrated credibility), that Heavy Lift would put in excess of 100mT into a 190km circular orbit at 28 degrees inclination. As far as I can tell that would be the only universally agreed launch vehicle to be classified as "heavy lift".

Does it matter? Only to the extent that we need to be talking to each other using the same terms. That, and some reasoned thinking. For example, I firmly believe that it's pushing the boundaries of credibility to be talking about a launch vehicle that can only put ~30mT into orbit as heavy lift. That just does not pass the smell test. Personally, I would not have difficulty with a vehicle capable of ~70mT to LEO being classed as heavy lift, but that's just an opinion.
« Last Edit: 06/12/2010 09:15 PM by clongton »
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Offline Dave G

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Re: Falcon Super Heavy
« Reply #246 on: 06/12/2010 09:27 PM »
No, everybody is in discussion with NASA.  It is the HLV RFI.  SpaceX is just one of many contractors.  They have no advantage here.
SpaceX says they are talking with NASA about some type of public/private partnership.
http://mysite.verizon.net/vzenu6hr/ebay_pictures/SpaceX_SHLV.mp3

That would be very different than a traditional contractor arrangement.  SpaceX would presumably pay for some part of the vehicle development, and then use that vehicle for both NASA and commercial customers.

Given that there are no commercial customers for 100 mT, I'm assuming SpaceX has some type of modular vehicle in mind, something that can scale from high-end commercial (~18 tons GTO with 2 payloads) to true heavy lift (~100 tons LEO).  Otherwise, why would SpaceX be interested in a public/private partnership?   

If there were no commercial angle, SpaceX would be much better off using a traditional contractor role.  But since SpaceX is talking with NASA about a partnership, and not a contractor arrangement, I'm assuming there's some type of commercial angle.

Online ugordan

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Re: Falcon Super Heavy
« Reply #247 on: 06/12/2010 09:31 PM »
No, everybody is in discussion with NASA.  It is the HLV RFI.  SpaceX is just one of many contractors.  They have no advantage here.
SpaceX says they are talking with NASA about some type of public/private partnership.
http://mysite.verizon.net/vzenu6hr/ebay_pictures/SpaceX_SHLV.mp3

It is what Jim says it is. All the players are "in discussions with NASA" as all the players likely provided their inputs to that RFI. Nothing more to it, nothing less. You are reading too much into Musk's statement.

Offline Dave G

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Re: Falcon Super Heavy
« Reply #248 on: 06/12/2010 09:41 PM »

Does it matter?
In order to avoid the debate of what "heavy" means, I suggest we use ballpark mT to LEO to clarify things.

Since Elon mentioned "super heavy" in the same context as Pad 39, it's obvious this is something much bigger than 30mT.  He's most likely talking about something around 100 mT to LEO here.

Offline butters

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Re: Falcon Super Heavy
« Reply #249 on: 06/12/2010 10:31 PM »
The significance of the super-heavy RFI is that SpaceX is beginning to emerge as a major American manufacturer of liquid rocket engines, joining a small club with Rocketdyne and Aerojet.  If the U.S. government is shopping for a kerolox booster engine, it no longer makes sense to ignore SpaceX.

As for the "heaviness" classifications of launch vehicles, I think it's important to speak in terms of mission capabilities rather than raw mass.

The significance of a launch vehicle in the 70-120mT IMLEO range is the capability of a Constellation-class lunar mission in two launches or, at the high end of the range, a smaller Apollo-class lunar mission in one launch.

This class of launch vehicles is for lifting propellant in a minimum number of launches.  We're not considering any dry payloads approaching 70mT.  We're not going to launch such rockets without a high fraction of propellant on top.

My intention is not to derail this thread with another debate over the merits of this architecture.  My intention is to distinguish between launch vehicles that are appropriate for the largest dry payloads of the near future and another breed of launch vehicle that is exclusively useful for very wet HSF payloads.

The only payload that muddies this distinction is the Shuttle orbiter, which is on its way out, partly due to its size.
« Last Edit: 06/12/2010 10:34 PM by butters »

Offline Downix

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Re: Falcon Super Heavy
« Reply #250 on: 06/13/2010 12:10 AM »
*other examples include that the avage horse has about 1.2 horse power and HD sellers clame there are 1,000,000 bytes in a MB
There are 1 million bytes in a megabyte. There are 2^10 or 1 048 576 bytes in a Mebibyte, the base 2 version.
You just demonstrated that you know nothing about computers.  The IEEE consortium definition you refer to here has a clear exception for base-2 elements, such as computers. 

To a base-2 system, a Megabyte is 1024 kilobytes, which itself is 1024 bytes.  Any other definition breaks the computer model.  Computers don't think in base-ten, they think in base-2, on/off, that's it.  To have them count as we do, you will only add inefficiencies into the design, hurting your performance.
« Last Edit: 06/14/2010 01:48 AM by Downix »
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Offline mikegi

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Re: Falcon Super Heavy
« Reply #251 on: 06/13/2010 03:06 AM »
*other examples include that the avage horse has about 1.2 horse power and HD sellers clame there are 1,000,000 bytes in a MB
There are 1 million bytes in a megabyte. There are 2^10 or 1 048 576 bytes in a Mebibyte, the base 2 version.
You just demonstrated that you know nothing about computers.  The IEEE consortium definition you refer to here has a clear exception for base-2 elements, such as computers. 

To a base-2 system, a Megabyte is 1048 kilobytes, which itself is 1048 bytes.  Any other definition breaks the computer model.  Computers don't think in base-ten, they think in base-2, on/off, that's it.  To have them count as we do, you will only add inefficiencies into the design, hurting your performance.
No, there's a new "standard" that tries to define a megabyte in SI units, 1000*1000 bytes. It renames 1024*1024 to "mebibyte".

However, I'm an old dog and will go to my grave calling 1024*1024 a megabyte.

Offline Downix

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Re: Falcon Super Heavy
« Reply #252 on: 06/13/2010 03:39 AM »
*other examples include that the avage horse has about 1.2 horse power and HD sellers clame there are 1,000,000 bytes in a MB
There are 1 million bytes in a megabyte. There are 2^10 or 1 048 576 bytes in a Mebibyte, the base 2 version.
You just demonstrated that you know nothing about computers.  The IEEE consortium definition you refer to here has a clear exception for base-2 elements, such as computers. 

To a base-2 system, a Megabyte is 1048 kilobytes, which itself is 1048 bytes.  Any other definition breaks the computer model.  Computers don't think in base-ten, they think in base-2, on/off, that's it.  To have them count as we do, you will only add inefficiencies into the design, hurting your performance.
No, there's a new "standard" that tries to define a megabyte in SI units, 1000*1000 bytes. It renames 1024*1024 to "mebibyte".

However, I'm an old dog and will go to my grave calling 1024*1024 a megabyte.

They can try calling it whatever it is, a computer won't care, it must function in base 2.  It will not understand, nor care, for 1000x1000 as megabytes, it does not compute, nor function, within the silicon world of ones or zeros.

1024x1024 is all they understand.  All they can understand.  We cannot "standardize" around this, any more than we can standardize anti-gravity or the laws of inertia.
chuck - Toilet paper has no real value? Try living with 5 other adults for 6 months in a can with no toilet paper. Man oh man. Toilet paper would be worth it's weight in gold!

Offline mikegi

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Re: Falcon Super Heavy
« Reply #253 on: 06/13/2010 05:12 AM »
They can try calling it whatever it is, a computer won't care, it must function in base 2.  It will not understand, nor care, for 1000x1000 as megabytes, it does not compute, nor function, within the silicon world of ones or zeros.

1024x1024 is all they understand.  All they can understand.  We cannot "standardize" around this, any more than we can standardize anti-gravity or the laws of inertia.
You do realize that giving a name to a quantity of bytes is independent of any hardware implementation, correct? NIST decided to standardize on referring to 1,000,000 bytes as a "megabyte" and referring to 1,048,576 bytes as a "mebibyte". See:

http://physics.nist.gov/cuu/Units/binary.html

I'd have thought all this was an April Fools joke but apparently it's real.

Of course, this doesn't mean that computers are supposed to switch BCD addressing in hardware or anything else.
« Last Edit: 06/13/2010 05:14 AM by mikegi »

Offline kraisee

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Re: Falcon Super Heavy
« Reply #254 on: 06/13/2010 06:01 AM »
Sounds to me as though someone like Elon needs to come up with a new word for the world to use.

Byte, Kilobyte, Megabyte etc have been used consistently in computing for a lot longer than the public realizes. Those terms should remain consistent with binary 2^x counting methods -- which is what they were created for in the first place.

But for public consumption, for those that find it too difficult to handle the 24 extra bytes in a kilobyte, why not invent a brand new term specifically to differentiate the decimal counting version?   A cool sounding ultra-modern name in the style of "Google" and "Renkoo" would be a perfect fit for such a techie requirement aimed at consumers and non-binary folk.

My suggestion would be to call it a "Holz" (Kiloholz, Megaholz etc), after Dr. Werner Buchholz -- the guy who originally termed the phrase "Byte".

I wish "they" would stop messing with well understood conventions like this.

Ross.
« Last Edit: 06/13/2010 06:05 AM by kraisee »
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