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Comment Re:Overboard, Sad! (Score 1) 338

Of those, flying over crowds is a problem, and if there are bystanders (admittedly likely) around tall buildings as well, but the others are risks of losing the drone only, not a problem for the rest of us.

Wildly optimistic manufacturer claims are a problem in general, not restricted to drones.

And yes, some people are deeply resistant to learning from their mistakes. That's why things are generally more harsh for repeat offenders.

Comment Re: The problem - taking off again (Score 1) 349

I think normal landing will be rockets only, and if they fail it will be too late to parachute, so they are already trusting the landing rockets in a safety critical role. The chutes are there for emergency escape during launch. In this case, the landing rocket fuel has been expended getting away from the exploding launcher.

Comment What can SpaceX do with their hardware? (Score 2) 349

I have considered before that the hardware SpaceX have or are building come quite close to supporting moon landing, and wondered how much of a gap there is and what it would take to bridge it. Unfortunately the article here is very light on detail and does not address my questions.

The Saturn V could put 140 tonnes into LEO. The Falcon Heavy will be able to put 55 tonnes into LEO. If you can split the Apollo hardware into three approximately equal bits, three FH launches could put them into orbit, then they rendezvous and head to the moon. You could probably use the existing second stage as a third stage to take the stuff from LEO to lunar orbit. (I couldn't quickly find the mass of a fuelled Falcon second stage, nor how much mass it could deliver to low lunar orbit.) You could use a Dragon in place of the Apollo command module. Whether you could use a second Dragon as the lunar lander is less clear.

Wikipedia ( says lunar surface to low lunar orbit requires 1.9km/s delta-v. If you wanted to land and takeoff with the same vehicle, that would be 3.8km/s. SpaceX are planning a 'Red Dragon' mission to land a Dragon capsule on Mars. Low Mars orbit to surface is 4.1km/s (assuming no aerobraking/parachuting) so Red Dragon should be able to land on the moon and return to orbit. However, Red Dragon is unmanned - I don't know whether you have space and mass budget to stuff some people and life support in there also.

The manned Dragon capsule has rockets allowing it to propulsively land - taking from terminal velocity falling through the atmosphere to zero velocity on a landing pad. I don't know how much delta-v this requires, but I expect much less than 3.8km/s.

(Falcon Heavy and manned Dragon capsule have been under development for some time and should fly this year. I don't know how advanced Red Dragon is, but they want to launch in 2020.)

Submission + - Why Don't Mobile OSs offer a Kill Code? 1

gordo3000 writes: Given all the recent headlines about border patrol getting up close and personal with phones, I've been wondering why phone manufacturers don't offer a second emergency pin that you can enter and it wipes all private information on the phone?

In theory, it should be pretty easy to just input a different pin (or unlock pattern) that opens up a factory reset screen on the phone and in the background begins deleting all personal information. I'd expect that same code could also lock out the USB port until it is finished deleting the data, to help prevent many of the tools they now have to copy out everything on your phone.

This nicely prevents you from having to back up and wipe your phone before every trip but leaves you with a safety measure if you get harassed at the border.

So slashdot, what say you?

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