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To: mvpel

I’m not “missing” anything.

Here are “some” of the offsets:

Additional:
Propellant to lift the landing prop load.
The Landing prop load.
Structural additions for both.
Overall add’l structure for entire vehicle to support both.
Add’l structure & test to support reuse.
Fac/labor for recycle & test (dif from original factory location.
More robust engines to support reuse.

Range safety changes to support this landing profile.

Did anyone point out that these vehicles don’t go straight up and down?
They fly several hundred miles down range....OVER THE OCEAN, before MECO (Main Engine Cut-off)
Soooo....WHERE are they going to land?

Highly unlikely that we’ll be re-writing Range Safety rules to allow over-land space launches.
We’ll leave that to Russia and China.....


28 posted on 04/22/2014 4:46:04 AM PDT by G Larry (There's the Beef!)
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To: G Larry
... And? ... The offsets are not more than 100%, so I guess I'm not sure what your point is.

"The payload penalty for full and fast reusability versus an expendable version is roughly 40 percent," Musk says. "[But] propellant cost is less than 0.4 percent of the total flight cost. Even taking into account the payload reduction for reusability, the improvement is therefore theoretically over a hundred times."

And the downrange distance 11 seconds before MECO and 14 seconds before staging on the CRS-3 launch was about 60km (about 40 miles), not "several hundred miles."

If you have more robust engines to support reuse, that could offset the offsets, right? You can use titanium instead of stainless steel even though it costs four times more because you're going to reuse the engine 30 times or more, and so you get a higher thrust-to-weight ratio.

29 posted on 04/22/2014 7:43:54 PM PDT by mvpel
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To: G Larry

He says that the boost stage is about 70% of the cost of the launch, per the press conference, so recovery and reuse of only that piece is apparently a pretty large savings.


34 posted on 04/25/2014 1:58:27 PM PDT by mvpel
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To: G Larry

He says that the turnaround time to reuse an ocean-recovered stage would be about 2 months, but with a dry land recovery they could in principle relaunch it the same day.


35 posted on 04/25/2014 2:01:48 PM PDT by mvpel
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