Follow Slashdot stories on Twitter

 



Forgot your password?
typodupeerror
Get HideMyAss! VPN, PC Mag's Top 10 VPNs of 2016 for 55% off for a Limited Time ×

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 Converse (Score 1) 337

Actually I've had a problem recently in that I wanted to get some good Converse knockoffs and Amazon was facing limited supply because of attempts on the part of Converse to crack down on this helpful customer-friendly business practice.

[Birkenstock] added that it will also ban any sales of its products by third-party sellers on Amazon

How can they even do that? Amazon isn't their site, and they aren't even going to be an Amazon seller any more. I suppose what they mean is that they won't sell to resellers who sell on Amazon, perhaps? Good luck with that whackamole game.

I guess we'll all turn to Birkenstock knockoffs! :D

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:Thanks to (Score 1) 337

It's an interesting poll, but the ability to comment anonymously and the moderation system are part of what make Slashdot Slashdot. I don't see most of the trolls because I read at +5 and only dig into something when I am interested in a particular line of discussion. I used to read at +4 back when I had more time. :) I also give a +1 bonus to anything that is modded insightful and that usually gives me a great stream of great comments.

Comment Re:License to work (Score 4, Insightful) 637

What I suspect is REALLY going on here is that John Deere and other manufacturers have adopted a model of selling their equipment to farmers either at a loss or at cost, with the understanding that they'll make their profit in implicit servicing contracts. And the farmers, now that they have the equipment in hand on the cheap, have decided to "alter the deal" (to quote the great Darth Vader) to save a buck.

If I buy somebody's loss leader and then don't want to participate in the business model they were expecting, that doesn't mean I've "altered the deal" unless there was an actual deal.

And if somebody's trying to save a buck that doesn't make him bad. In fact if he's the guy supplying our food or something else we need that makes him good.

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.

Slashdot Top Deals

"Though a program be but three lines long, someday it will have to be maintained." -- The Tao of Programming

Working...