no fins no leg for the expendable.

[QUOTE=firejuggler;462589]no fins no leg for the expendable.[/QUOTE]
Ah! Less weight for the heavy lift.
EDIT: .....and savings in material.

[QUOTE=kladner;462593]Ah! Less weight for the heavy lift.
EDIT: .....and savings in material.[/QUOTE]

The fins and legs are a pretty small percentage of the weight, though obviously if they're not needed, every percent counts

[QUOTE=Dubslow;462595]The fins and legs are a pretty small percentage of the weight, though obviously if they're not needed, every percent counts[/QUOTE]
A Reddit hardware cost guestimate puts a fairly high parts cost on the legs and and the new titanium fins so even without significant performance differences it seems a clear win to leave them off.
[URL="https://www.reddit.com/r/spacex/comments/62sq7z/cost_calculation_for_falcon_9_falcon_heavy/"]Cost calculation for Falcon 9 & Falcon Heavy[/URL]
[QUOTE]luckybipedal • 92d
OK, so this is what I had in mind: I separate cost for recovery hardware and separated booster and center core cost. I also added a column for FH with the center core expended.

For a recoverable core I used the newer $40 million number. For an expendable one I used the older $30 million with an estimated cost of recovery HW of $10 million, say $5 million for the legs and another $5 million for titanium grid fins. The cost of the second stage fuselage is estimated excluding the cost of recovery HW on the 1st stage. I also increased the cost of the center core fuselage slightly to account for structural reinforcement.

With these assumptions the cost percentage of a recoverable F9 first stage gets pretty close to the stated 75%.

There is a wrinkle in this: Flying and not reusing a recoverable booster eats most of the profit. In the current configuration it's probably not as bad because they're still using cheaper aluminium grid fins and they may be reusing legs already.[/QUOTE]

[QUOTE=only_human;462647]A Reddit hardware cost guestimate puts a fairly high parts cost on the legs and and the new titanium fins so even without significant performance differences it seems a clear win to leave them off.
[URL="https://www.reddit.com/r/spacex/comments/62sq7z/cost_calculation_for_falcon_9_falcon_heavy/"]Cost calculation for Falcon 9 & Falcon Heavy[/URL][/QUOTE]

I doubt that's particularly accurate. The fairings are very hard to make, very large monopiece carbon fiber, and they're ~$6M. I can't imagine that a titanium fin the size of a bed (which is way smaller than the fairing, and a much easier to handle material) costs as much as half of the fairing. The legs do have substantial amounts of carbon fiber IIRC, but not with the same shape/size requirements as the fairing. I could imagine those are a ~$1M apiece.


Either way though, I was never doubting the value of keeping them off, only their direct impact on rocket performance.

Woohoo, tomorrow is another day. Spacex message>
[QUOTE]
SpaceX
Twitter › SpaceX
Standing down today due to a violation of abort criteria, vehicle/payload in good health, next launch opportunity tomorrow, July 4th!
2 minutes ago · Twitter[/QUOTE]
So, don't really know why and the customer might also be grouchy by I like an Independence Day launch.

link via [URL="https://plus.google.com/u/0/107049823915731374389/posts/dgV8n7cHaoX"]Ed S [/URL] on Google+. This is just under 10 minutes. It feels long but it is pretty good and a nice injection of something needed for today. The fins come out at around 5 minutes but I still want to see an R2D2 arm making adjustments.
[QUOTE]Published on Jun 27, 2017
Here is a launch montage I've been working on for a while. I was able to finally finish it recently because of all the good day time launch and landings we have had. Each tile follows a single mission from launch to landing and they all synchronize at the end.[/QUOTE]
[YOUTUBE]4FU0l2JHhGs[/YOUTUBE]

[QUOTE]
Elon Musk
@elonmusk
Replying to @SpaceX

We're going to spend the 4th doing a full review of rocket & pad systems. Launch no earlier than 5th/6th. Only one chance to get it right …
11:01 PM - 3 Jul 2017[/QUOTE]
.

Third try. [URL="http://www.spacex.com/webcast"]Webcast just went live[/URL].

.
[QUOTE]Elon Musk
Twitter › elonmusk
@SpaceX @INTELSAT Thanks @INTELSAT! Really proud of the rocket and SpaceX team today. Min apogee requirement was 28,000 km, Falcon 9 achieved 43,000 km.[/QUOTE]

[QUOTE]
The European and Japanese satellites that make up the BepiColombo mission to the Planet Mercury are being put on display on Thursday...
The event will take place at the European Space Agency's (Esa) technical centre here in Noordwijk, Netherlands...The double mission is due to get under way in 2018...however. It is going to take seven years for the satellite duo to get to their destination.
[/QUOTE]Press article (in English): [URL]http://www.bbc.com/news/science-environment-40513818[/URL]