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Comment Re: drone ship landings require a lot less fuel? (Score 1) 101

I don't need to stand by the rotation theory. However, the 2.5 degrees that the Earth rotates are about equivalent to the downrange distance.

The first stage is going about 1/5 of the target LEO orbital velocity at separation. While you might well model the trajectory as a parabola over flat ground, given the lack of fuel I would expect that SpaceX puts a lot more care into their trajectory. So far I've failed to attract the attention of the person responsible for Flight Club, the most trusted modeling of SpaceX flights, but I'll message him directly.

Comment Re: drone ship landings require a lot less fuel? (Score 1) 101

Well, Alastair, you should probably not get snotty and ad-hominem, unless you want me to comment on how a one-time sci-fi author and the Unix guy at Dish doesn't really have more authority than the random person one might find in the SpaceX group on Reddit.

It happens there are a few people over there who are rocketry professionals, have the math, and have followed SpaceX long enough. So, sure, their opinion can indeed be trusted.

So far, we have a suggestion from one of the lesser folks there that raising the apogee takes advantage of the Earth's rotation. We'll see if we get the attention of the right people.

Comment Re: drone ship landings require a lot less fuel? (Score 1) 101

It seems to be a common misconception that orbital mechanics somehow knows when you are in orbit and does not work otherwise. But that is as silly as saying that relativity only works near light speed. These things always work regardless of speed, it's just that their effects are macroscopic at greater speeds.

Comment Re:Liability (Score 1) 161

Then hope that they decide to implement there limited-capacity safe-mode feature rather than completely refusing to boot the phone. If they do that then you won't have a problem dialing in the first place.

I would think that thy would still allow 911 calling and possibly other numbers as well. They could even boot into a special phone only OS that is sandboxed from all the apps et on the normal OS so at minimum you have a working phone. Of course, you won't be able to do a minute by minute twitter feed of you bleeding out...

Comment Re: drone ship landings require a lot less fuel? (Score 1) 101

Here's an illustration of the boost-back to RTLS trajectory. You can see that it very definitely goes up. And to prove from observation, you can actually see where the two trajectories separate in photos from yesterday's launch. It's a rather dim curl up, and another continuing East, in Jason Ruck's photo and John Kraus's photo.

At the speed of stage separation, they rocket isn't going fast enough to stay in orbit, but it is definitely in the regime where orbital mechanics has a macroscopic effect. If you think about it, this is going to be the case at some reasonable fraction of orbital velocity.

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