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I'll have to go reread the source selection document but I don't think the advantage for CST-100 was so much "more cargo" as just having a really specific plan for how they were going to accommodate it. I may have missed it, but I haven't seen a rendering or mockup of Dragon2 or Dreamchaser in an ISS mission configuration, but well before the CCtCap bids went in there were renderings and mockups of CST in its ISS configuration showing exactly where all the lockers and freezers were, how they would be accessed, etc.
NASA does like a well presented picture.  :(
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SpaceX General Section / Re: Red Dragon Discussion Thread (2)
« Last post by tesla on Today at 10:15 AM »
Is Red Dragon on the proposal list of NASA's 2015 discovery missions?
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This is utter crap.  Someone made a serious error.  Including the 42 "heritage" cores in the cost calcuation is hugely distorting; to call it "misleading" is beyond charitable.  Someone appers to have been counting--and worse averaging--since the inception of the EELV program (or close to it) for stuff long ago bought and launched.

There are a few of those "heritage" cores under acquisitions prior to the FY2013 block buy still to launch; there are nowhere near 42 (there might be 4).  Not only is there no budget for purchase of those hypothetical 42 cores, there are nowhere near enough payloads to make use of them without budget commitments well beyond 2020 (which there are not).

From the USAF FY2016 budget request, the ELC cost through FY2016-2020 is projected to be ~$3B.  ELC pays and provides for 8 launches/year (or did), not "approximately 10".  NRO pays an additional 25%, so the total for USAF+NRO is ~$4B.

Present and future EELV $400M unit launch cost is much closer to the truth than $225M.
The 42 heritage cores might not be the correct number, but a certain number of heritage cores still will be needed in the equation. You see, the first cores from the infamous block-buy are scheduled for delivery in late 2017.

In between the public announcement of the block-buy contract signing (early 2014) and launch of the first cores from the block-buy is a period of approximately four (4) years. With an average launch rate of 8 missions per year (for USAF and NRO) that adds up to at least 32 cores (not counting any additional cores due to the  Delta IV-H configuration).

Even if we use today's date as starting point there will still be the need for at least 24 (and possibly more) heritage cores to cover USAF and NRO launch needs until the first cores of the block buy are put into action:
Having a look over at Gunter's space page I see the need for at least 10 Delta IV cores up to late 2017 and no less than 14 Atlas 5 cores up to late 2017.

So, assuming that the 42 "heritage" cores don't belong in the equation is (at least partially) wrong IMO.
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SpaceX picks up another lot, just across the street from the launch site area.  Animated gif below.
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I'll have to go reread the source selection document but I don't think the advantage for CST-100 was so much "more cargo" as just having a really specific plan for how they were going to accommodate it. I may have missed it, but I haven't seen a rendering or mockup of Dragon2 or Dreamchaser in an ISS mission configuration, but well before the CCtCap bids went in there were renderings and mockups of CST in its ISS configuration showing exactly where all the lockers and freezers were, how they would be accessed, etc.
NASA does like a presented picture.  :(
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Didn't someone at SpaceX say the BFR would have 15 million lbs of thrust minimum?  That is twice Saturn V, and with modern construction it might get a little over twice the payload.

That someone was Elon Musk in an AskMen article.

http://www.askmen.com/entertainment/right-stuff/elon-musk-interview.html

Quote
Falcon Heavy, at over 4 million pounds of thrust, will be two-thirds the size of the Apollo Saturn V and is expected to be tested next year.

The rockets will get even bigger. “We’re looking at our Mars transporter being around 15 million pounds of thrust,” says Musk. “And that one will switch to methane [fuel] for a high specific impulse system.”
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The following information is from a post by someone else on another forum. I take no credit for it and cannot vouch for it's facts.
Why not provide the source? From a quick google the original appears to be http://www.chemicalforums.com/index.php?PHPSESSID=64c3a115705beb2f2b80cc660771b8d2&topic=183.msg799#msg799

I think before we talk about other fuel sources that may be more fuel efficient or supper fuels we need to understand what is fuel efficient or why some fuels are more fuel efficient and other fuels are less fuel efficient.

I thought the densely of the molecules define fuel efficiency. A fuel that is more densely packed molecules is more fuel efficient than a fuel that is less densely packed molecules. A fuel that is less densely packed molecules is less fuel efficient.

But you also say lightest element are more fuel efficiency where heavy elements are less fuel efficiency.

And Hydrogen is the lightest element we know of so far? That the holy grail is finding elements that are lighter than that?
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STARGATE Attracting Technology Giants
http://utbcollegian.com/index.php/news/on-campus/item/3891-stargate-attracting-technology-giants
Quote
The director of UT Brownsville’s STARGATE says the program has started to attract many of the “big players” in technology, including Google and the National Radio Astronomy Observatory...

STARGATE is a public-private partnership between UT Brownsville’s Center for Advanced Radio Astronomy (CARA) and SpaceX.

The STARGATE research center, which will be located next to SpaceX’s future command and control center at Cameron County’s Boca Chica Beach, will develop “new radio-frequency-based (RF) technologies for a wide range of academic and commercial applications,” according to the program’s page on the utb.edu website.

“Since its inception, the center has been striving to attract big companies, national labs … by creating a talent pool that is very attractive, both for hightech industry as well as science and engineering,” Jenet said.
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FWIW I am guessing it is for testing of new technology, maybe even testing hi res imaging techniques or mirror technology and perhaps even testing off the shelf technology to see how long and how well it works for in the space environment. But I do think there'd be an element of not telling anyone to "keep 'em guessing" and also to simply imply there is more going on than perhaps there really is.

How about crystal growth in micro gravity over an extended period, doesn't obtaining certain very pure and perfect crystals take an extremely long period of time?
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Advanced Concepts / Re: Realistic, near-term, rotating Space Station
« Last post by TakeOff on Today at 09:04 AM »
@Paul451
You make several good points. I appreciate your input.

Especially that there might not be any need for two opposing habitation modules. At first a dumb counterweight will surely be used against ta single habitation module, like a spent upper stage, a hijacked piece of space debris, waste disposals. The ISS already generates lots of all of that. Later the counterweight could be made up of a nuclear power plant and other robotic service functions. As long as the mass of the habitat doesn't exceed half of the total mass of the spacecrafts by too much, a longer tether clearly seems to be a much more practical solution. The elevator problem might not be relevant. In the long run a rotating spacecraft obviously needs to be circular anyway, and the tube ring you propose is a concept stepping stone between a capsule and the von Braun torus.

I still want to point out that an elevator crossing the center of a rotating spacecraft requires both acceleration and deceleration, with the power dictated by the gravitation simulated. A circulating elevator can move with very much less effort (like the mass moving in your proposed tube).
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