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Comment Linking back to Slashdot (Score 1) 1817

One thing that kind of grinds my gears is stories that link back to previous Slashdot stories. A good example is this one. Near the end it says "SpaceX successfully landed its Falcon 9 rocket at Cape Canaveral in December." I would expect to be able to follow that link to a relevant news site, not a Slashdot discussion. (Obviously, if the line went "As we discussed here, SpaceX successfully landed its Falcon 9 rocket at Cape Canaveral in December.", that would be a different story.)

Perhaps if the links in the story were post-fixed with the sites in square brackets the same way that they are in the comments...

Comment Re: What's the deal... (Score 1) 262

Brushless DC motors have electronic circuits to energize the coils in the proper sequence. Trying to run such a motor as a generator will not work. To use such a motor as a generator, you have to replace the drive circuitry with rectifiers. Now, you could combine both circuits and switch between them, but it is not something that all brushless motors can do out of the box. Brushed motors are a different story. They CAN run as generators without modification.

...that is, assuming the motors in question are permanent magnet motors to begin with.

Comment Re:One word (Score 1) 170

I think the problem with the US system is that it does not allow for minority governments. In places where minority governments are allowed, there is no difference between voting for your preferred party and voting for a third party as a vote against the popular and hated rival. Either way removes votes from the undesired candidate, and they may end up with a minority government. When you have a minority government, the majority gets to halt their reign of suck via a vote of no confidence.

Comment Re:Who is whipslash? (Score 1) 91

No stage has successfully landed on a barge, so you've never seen the part where the support team boards the barge and secures the rocket against those winds and waves you spoke about.

Oh, and as for that pencil analogy, due to the rockets, most of the weight is in the tail end, so the center of mass is quite low (unlike a pencil).

Comment I don't get it. (Score 1) 91

I don't understand what's going on with SpaceX. Back in May, they did a pad abort test, which is a full up systems test with as close to actual flight hardware as possible. Then in November they do, not a live hover test, but a captive hover test (indicating that they don't trust the dragon's control software not to crash the thing). Now they are doing a parachute test using a block of metal. Not a parachute deploy from a dragon mockup, but they just heaved a chunk of metal with parachutes attached out of the back of a plane.

Are they working backwards in time or something?

It should be:
1 - Parachute test, first with a mass simulant, then with a mockup dragon.
2 - Hover test, first a captive hover, then later a drop test from a plane/helicopter to a hover landing.
3 - Once you've got the kinks worked out in the above, and you've got a close handle on the mass of the actual flight hardware, then you can do a pad abort test to show that you can get the crew out of Dodge when the time comes.

So what's with the backwards schedule?

Comment Re:Who is whipslash? (Score 2) 91

Not needed, desired, nor practical. The last attempt landed square and true about a metre from the center of the barge. The engine shut down on time and all was well until one of the legs collapsed. If that hadn't happened, it would have been an unqualified success. Don't forget that the Falcon 9 first stage is taller than the Statue of Liberty, about the size of a twelve storey apartment building. Designing something capable of capturing it would be far more expensive than simply fixing the problem with the legs.

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