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SpaceX Discussion Thread


Skylon

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3 hours ago, Brotoro said:

Ms. Tree has caught a fairing!

Wahhhhhhhh!!!!!!!!!!!!!!! 

So much winning and losing! Every SpaceX launch is way more exciting than expendable rockets!

overall they made one launch and landed 2 rockets and caught a fairing! In my book that calls for a round of drinks! 

(Just about to watch it, but I was reading here first >_<)

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I wonder how many boosters SpaceX can afford to lose in a Falcon Heavy launch before it becomes unprofitable. Will they still get a net profit if they don't recover anything at all?

Edited by garwel
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6 hours ago, Xd the great said:

Was it the heat or the speed? Or not enough TEA-TAB?

I had a bad feeling that it wasn't going to work when the hosts were reporting on it and said something along the lines that the re-entry burn was "off the timeline."

 

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2 hours ago, garwel said:

I wonder how many boosters SpaceX can afford to lose in a Falcon Heavy launch before it becomes unprofitable. Will they still get a net profit if they don't recover anything at all?

My guess would be 4.

Re-use is a bonus.

Requiring recovery to make a profit would be reckless at this point.

Edited by Geonovast
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Yeah, the landing burn startup made me hold my breath for a moment.  It really looked like a RUD at first.

On the landing failure, it looks to me like the center core ran out of velocity a few meters too high.  IIRC, the Merlin engines can't throttle down enough to hover when the booster is empty, so the timing and throttling of the landing burn have to be very precise so that the booster runs out of velocity just as it runs out of altitude.  If the velocity runs out before the altitude, you can't get all the way to the barge, and if the altitude runs out first...well, we've all started a landing burn too late, right?

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5 minutes ago, zolotiyeruki said:

Yeah, the landing burn startup made me hold my breath for a moment.  It really looked like a RUD at first.

On the landing failure, it looks to me like the center core ran out of velocity a few meters too high.  IIRC, the Merlin engines can't throttle down enough to hover when the booster is empty, so the timing and throttling of the landing burn have to be very precise so that the booster runs out of velocity just as it runs out of altitude.  If the velocity runs out before the altitude, you can't get all the way to the barge, and if the altitude runs out first...well, we've all started a landing burn too late, right?

Makes as much sense as anything. I assume that it flying off sideways was an abort mode to try to spare the barge 

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It's a shame that the centre core crashed, but you need to fail in order to succeed. Landing a booster so far downrange, and at such high velocity, is imposing a set of challenges nearly as hard as those encountered when SpaceX first began to attempt landing first stages.

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Just watched the launch after coming back home. The curse of the center core continues.

But I like how they didn't cut the footage. They showed the center core exploding (and still got a huge applause!).
Frankly it's a big enough achievement to even manage to get this close to the drone ship that far downrange!

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Just now, Jaff said:

Are we getting to the point yet where it’s more reliable to fly a used rocket than a new rocket as far as recovery goes?

If I'm not mistaken, every single landing failure has been new hardware.

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2 hours ago, Delay said:

Just watched the launch after coming back home. The curse of the center core continues.

But I like how they didn't cut the footage. They showed the center core exploding (and still got a huge applause!).
Frankly it's a big enough achievement to even manage to get this close to the drone ship that far downrange!

Coverage tend to get lost as the rocket landing bump the barge around so it looses satellite up-link. 
Kind of hard to explain why you did not came home with an stage: stolen by pirates or the dog ate it is a bit weak :)
http://freefall.purrsia.com/ff500/fv00463.htm

 

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1 hour ago, tater said:

During coverage, the younger guy called out entry burn ending, then right after entry burn started. Wonder if the burn timing was wrong?

I'm inclined to think the announcer got it mixed up, because the landing burn appeared to be nominal until (literally) the last second.  If the entry burn had been that late, MaxQ on the entry would have been a whole lot higher, potentially resulting in damage to the booster.

...or maybe he was right, and one of the landing leg actuators was damaged during re-entry, and didn't extend fully, leading to an abort?  In the video, I can clearly make out two of the landing legs (top left and bottom left in the video), and *maybe* a third on the top right.  The fourth (which would be bottom right) is (or would be) hidden by the exhaust plume.  If a landing leg didn't extend, or didn't lock properly (which has happened, remember), that could certainly result in an abort that close to touchdown.

 

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20 minutes ago, tater said:

It'll be interesting to hear what went wrong with the center core.

At the moment, I’m betting on the landing burn being ever so slightly misjudged, and the booster reaching zero velocity too high up. The announcement seemed to be a bit off, anyway.

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