Follow Slashdot blog updates by subscribing to our blog RSS feed

 



Forgot your password?
typodupeerror

Comment Re:Very interesting (Score 1) 43

So every country can rule that Microsoft also supplies the US military so therefore can be banned due to national security reasons.

Whether they do that is up to them and their laws, not us and ours. And yes, of course they should do that, and they should have their own UNIX implementation, or Linux fork or whatever. Why would you trust someone else to supply you with an OS when you are so large as a national government? It used to be that there were dozens of companies which had "their own" BSD or System V port (which was just a port to their platform, with maybe some platform-specific utilities to set nvram values or what have you) and governments should be able to at least get that accomplished. It's bad enough having to use commodity hardware, but it's obviously not practical for most nations to build all their own computers.

Running your government on Windows is bananas for lots of reasons, but having it be American is a good one if you're not the USA.

Comment Re:Going in a straight line (Score 1) 67

If it was so very trivial, it seems like it would have been done by now. It's not trivial to build a car which is stable at those speeds, no matter what your powertrain looks like. On the other hand, a high voltage motor-per-wheel system with a high motor RPM can react to undesired yaw about as quickly as you can sense it, so the car can pretty much drive itself under human direction. Some of the old coots that can afford these things might pass out from the forces involved, though.

Comment Re:What's the point of such a fast car? (Score 3, Informative) 67

Supercars this fast have tires that last less than fifteen minutes, perhaps eighty miles traveled on the track of you're lucky. And since the wear isn't linear, if you go just a little bit faster, you might only get a minute or two at the speeds this car goes before you have to change all the tires, which will set you back $40,000.

The point of such a thing is the same as one of those suborbital tourist space flights. The point is to *have had* the experience, which is too brief to be practically useful.

Comment Re:Going in a straight line (Score 3, Interesting) 67

Going this fast in a street legal car is impressive, period. I prefer handling to speed myself, but that doesn't make this not an achievement. That these cars are so crazy cheap for what they can do is a real paradigm shift. The big down sides to hypercars have always been sales price and maintenance costs, but EVs have far less maintenance. If these unprecedentedly high-speed motors don't explode or something, this is not only the fastest but probably also the lowest TCO hypercar ever.

Comment Re:I am rooting for Blue Origin now. (Score 1) 30

And here is the problem: you're so bad at social interaction that you can't tell the difference between a rebuttal and "rage". You have some sort of fantasy about someone on the other side of the world smashing their keyboard and stewing over your words all day.

I hate it to break it to you, but that's just your pathetic imagination.

Comment Re:I am rooting for Blue Origin now. (Score 3, Informative) 30

I take it you believe the Apollo program shouldn't have happened

What did you pull that out of? The technology was nowhere near mature enough back then. That doesn't change the economic picture of throwing away your entire rocket every flight.

(We can argue whether "flags and footsteps" were worth spending an amount of money best measured in a percentage of your GDP, but that has nothing to do with the reuse question)

Next up

Lol, "next up"? You clearly think you hit your straw man out of the park ;)

since return is paramount - are you in agreement that only launch envelopes that allow return hold be allowed

"Be allowed"? Do you do anything other than straw men, or is that literally the only way you know how to carry out conversations on the internet?

SpaceX "allows" anyone to choose a disposable mission. Almost nobody chooses that because reuse is cheaper. In general, the only times when disposal is chosen is when there is literally no option but disposal in order to meet the spacecraft's performance needs.

Again: if you were given a choice when buying a plane ticket, either it can be cheap, or it can be expensive because they're going to wreck the plane specifically on your behalf, unless you had some really pressing need to wreck the plane, you're not choosing that option.

As a smart person who understands orbit mechanics

As an internet asshole, do you know that you actually have the option to not be an asshole online?

you do know that only very specific launch envelopes allow return.

First off, it's not even clear what you're referring to with "return". Boosters don't even reach orbit, so bringing up the concept of launch envelopes and return from them related to "orbital mechanics" is ill-formed. Booster return is entirely contingent on whether the payload needs an extreme level of performance beyond that which the system can meet with reuse, e.g. whether they absolutely have to remove the landing legs and grid fins to lighten the booster and burn every last drop of propellant. Only an extremely small fraction of launches fit into this category. Falcon 9 - the vehicle in question - only does booster return, so this conversation ends there.

If we want to talk about something other than F9, like, say, Starship, saying "only very specific launch envelopes allow return" is also wrong - again, unless your payload needs so much performance that the upper stage will not reenter the atmosphere (or you deliberately designed a trajectory to specifically make the stage come in hard). Their TPS design goal is to be able to burn off the heat of even mars transfer orbits. Now, one can argue that they'll fail in that goal, but you need to list your assumption of failure as a premise. Regardless, though, unless the entire project is a failure, the upper stage will handle return all "normal" Earth orbits. It has on-orbit reignition and can target its entry trajectory.

If a falcon 9 or heavy needs to go to a different orbit, it has to be abandoned

Again, this makes no sense. Are you positing launches where they change their mind partway through ascent or after it reaches orbit? "Nah, we don't REALLY want it in that trajectory, let's do a different one!"?

In the real world, again, the only times they expend a booster is when the performance needs of the payload are beyond what they can deliver in reusable mode, even with Falcon Heavy (or occasionally for testing, etc). And the upper stage of F9/FH never returns, because it can't, so it's not part of the discussion (they've done some work on trying to make it recoverable, but in each cases it was a "better to put the effort toward Starship" situation... which is IMHO kind of a shame, in that I'd love to see the maturation of e.g. inflatable entry systems, one of the possibilities they were considering).

Comment Re: eew gateron (Score 0) 67

I ignored it because it's not relevant to my argument. If they're going to make the device more expensive, whether it's worth it or not, then the least they can do is care about getting you some decent switches. Had the same experience with an ajazz keyboard, boy their switches suck. Just ship it without 'em FFS.

Comment Re:Starlink needs competition. (Score 2) 30

A contract is not a subsidy. They get contracts because they easily undercut their competitors.

NASA and the DoD want a service. SpaceX sells that service to them. It's not complicated. The government has saved massive amounts of money with SpaceX relative to ULA.

Also, for the record, most of SpaceX's work is internal (Starlink), and the nextmost is commercial. Government is in third place

Slashdot Top Deals

"Marriage is like a cage; one sees the birds outside desperate to get in, and those inside desperate to get out." -- Montaigne

Working...