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SpaceX’s Falcon Heavy successfully launches

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Re: SpaceX’s Falcon Heavy successfully launches

#841
post #351

On the one hand this is super exciting, I even cried. On the other hand, it makes me feel miserable: am I wasting my life? What have I done? Meanwhile Elon is sending reusable rockets to the space.

You and all (7.442 billion - 1) of the rest of us buddy.

I'd count the 6 thousand employees in the same boat, as Musk's vision could not be achieved without their help

Re: SpaceX’s Falcon Heavy successfully launches

#842
post #149

Earlier quoted context omitted.

The landing barge is towed into position by tugs, and once the boosters are landed I presume it is towed back out, so there will be some tug boats nearby.

I thought the barge was a drone?

It has station-keeping thrusters to stay at precise GPS coordinates. But it can't move far under own power and is towed. The name ASDS is not really to be taken literally here.

Re: SpaceX’s Falcon Heavy successfully launches

#845
post #785

Earlier quoted context omitted.

Yep - Titanium is notoriously difficult to work with.

So difficult that the SR-71 leaked fuel before starts and had to be re-fueled right after take-off. https://en.wikipedia.org/wiki/Lockheed_SR-71_Blackbird#Fuel

The SR-71 leaked fuel before takeoff because it needed separation distance between parts to allow for expansion. It had nothing to do with the difficulty machining titanium.

From your source: "Fuselage panels were manufactured to fit only loosely on the ground. Proper alignment was achieved as the airframe heated up and expanded several inches.[30] Because of this, and the lack of a fuel-sealing system that could handle the airframe's expansion at extreme temperatures, the aircraft leaked JP-7 fuel on the ground prior to takeoff."

Re: SpaceX’s Falcon Heavy successfully launches

#846
post #785

Earlier quoted context omitted.

Yep - Titanium is notoriously difficult to work with.

So difficult that the SR-71 leaked fuel before starts and had to be re-fueled right after take-off. https://en.wikipedia.org/wiki/Lockheed_SR-71_Blackbird#Fuel

That has nothing to do with titanium and everything to do with material expansion, the design/shape of the assembly and ambient vs operating temp.

Re: SpaceX’s Falcon Heavy successfully launches

#847
post #785

Earlier quoted context omitted.

So difficult that the SR-71 leaked fuel before starts and had to be re-fueled right after take-off. https://en.wikipedia.org/wiki/Lockheed_SR-71_Blackbird#Fuel

The SR-71 took off with a small fuel load to reduce stress and improve engine-out performance, that is why it was refuelled immediately after take-off. The mental image of it leaking so much fuel on the ground such that it needed immediate refuelling is a myth propagated extensively on the internet.

The characterization is/was also propagated by people who actually refuelled them, so I'm somewhat unconvinced it is a myth.

Re: SpaceX’s Falcon Heavy successfully launches

#848

Earlier quoted context omitted.

That would be $3200k for each, but they are made out of titanium, not platinum, and most of the cost is in the work, not material. I'd like to know the price too though.

Yep - Titanium is notoriously difficult to work with.

It's not that difficult. The more common alloys machine relatively easily; some of the tougher ones can be a pain but not much more than other special purpose materials like Inconel.
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