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Comment Re:Speaking of delays... (Score 1) 79

Could you remind me how many people SpaceX has killed? Boeing and Lockheed have certainly killed people in the past.

If you're referring to the AMOS 6 ground failure, ignoring that part of the whole point of flying a stack unmanned as much as you can before you fly it manned is to shake out any problems, is that a manned mission would have almost certainly survived that. Unless the launch escape system failed, despite the drama, that was an eminently survivable. How do we know this? Because AMOS-6's hypergolic propellant tanks didn't ignite until the satellite hit the ground. AMOS-6 had the fairing as some extra protection, but on the other hand, the satellite itself isn't nearly as durable as a crew dragon.

The launch escape system ignites within milliseconds of a failure being detected and almost immediately reaches full thrust, accelerating away at 10gs. Here's a graphic of Dragon's abort test superimposed over the AMOS-6 failure. Things like this are the very reason that launch escape systems exist. NASA's last manned space vehicle lacked such a system entirely. And while their design for the Shuttle ultimately wasn't chosen, you know what? Lockheed's proposal didn't have one either. And it had a strong impact on influencing the final Shuttle design outcome.

Comment Re:What governmen brought to the table (Score 1) 79

SpaceX and Blue Origin would not use solids, not because there's something wrong with solids per se, but because they're not "fuel and go", which makes them expensive to reuse - and SpaceX and Blue Origin are all about reuse.

A lack of experience with hydrolox surely factors into the picture for SpaceX and Blue Origin; they'd get significantly higher payload fractions by using a hydrolox upper stage. But they're willing to accept lower payloads in order to simplify their manufacture and ground infrastructure, and in particular because the need their propellants to be storable, and storing LH for long periods is a PITA. Storing methalox is quite difficult, but nothing compared to hydrolox.

Comment Re:What governmen brought to the table (Score 1) 79

Solids really aren't that bad when reusability isn't a concern. They're very high thrust, which is exactly what you want out of a booster, and they're structurally very simple. Their low impulse and high structural mass are not particularly important aspects for boosters. Reuse of solids however gains you very little, because there's so much work in refurbishing them.

Comment Re:What governmen brought to the table (Score 3, Informative) 79

That's not the reason you don't use it for a first stage. The disadvantages of hydrolox (which are numerous) are offset by its incredible specific impulse. But for a first stage, specific impulse doesn't matter that much, while thrust matters a lot. Thrust is in large part proportional to fuel density, as a turbopump sweeps out a fixed volume per rotation, so the denser the fuel, the more mass (and generally all else being equal, energy) it pumps per rotation.

Another aspect is that first stages are big, meaning that cost is more important than specific impulse. By contrast, when dealing with an upper stage, a small increase in mass has a huge increase in first stage size, and since first stages are so large and expensive, that's a big cost. So you generally want a higher ISP upper stage. With the caveat that "storability" requirements for engines that need to restart can shift the balance; because hydrogen is so deeply cryogenic it's difficult to store for protracted lengths of time. Also, the longer you plan to have a stage in usage without maintenance, the more you tend to favour simple propellants over high performing ones, particularly when you're dealing with small, light engines. So for example if you have an interplanetary probe you'll tend to favour a self-pressurizing hypergolic system so that you only have to rely on a couple valves working, even though self-pressurizing propellant tanks are heavier and hypergolics tend to be lower specific impulse. Engines that are smaller still are often monoprops for an even greater degree of simplicity.

Comment What *could* happen? (Score 1, Interesting) 194

Yep. Hey, you know what's great? Talking to people. Sex. Building models. Organizing one's rock/stamp/severedhead collections. Writing code. Playing with the cat/dog/cockatrice. Martial arts. Photography. Reading. Taking courses. Exercising. Working out a sane budget. Listening to music. Playing music. Sewing. Legos. Fooling with hardware. Home improvements. Giving the domicile a good once-over at the ultra-picky level, just for the fun of it. Putting the yard in tip-top order. Walking the canine or the cat. Visiting Rome, Paris or Venice (while pretending to be Canadian, of course.) Or just going to see a friend. You know, in person, not with that phone-tumor. Taking a walk, preferably somewhere you haven't been or really love. Etc. Lots and lots of etc.

Television... I just can't bring myself to call that "great." The couch, it really does make for potato generation.

Comment Que? (Score 1) 35

you maintain that anyone from any other country in the world has a right to live in the U.S., but U.S. citizens have no right to live in any other country?

No. However, I maintain that Trump's wall is one of his stupidest ideas.

That's English for "Trump's wall is one of his stupidest ideas", BTW.

Which is not to say that most of his other ideas aren't stupid, because they really, really are. But the wall is special. Like Trump. Short-bus special. Profoundly without merit while at the same time comprising a financial boondoggle of titanic proportions, at the very same time when the country's actual useful infrastructure (not in any way to be confused with border "walls") needs money and effort.

So without regard to political party

Oh, yes. Completely without regard to political party. Just in regard to Trump and any bewildered sycophant who thinks building that wall is anything but a complete waste of time, effort and money.

Also, I like vegetables. So I'm rather appreciative of the workers who pick them. No matter where they come from. I like tacos, too. I would not be in the least bit offended by a taco truck on every corner. Especially if they offered a nice selection of vegetables, but, you know, either way, really.

U.S. citizens have no right to live in any other country

Hmmm. That's a very... interesting... postulate. Let me guess: you live in one of the states that has legalized pot, and you just got back from a test run of every heavy-hitting variety offered, is that it? Did you know that at some taco stands, I've been able to buy Fritos? FRITOS! Lovely, crispy corn chips! And Soda! MMMMMM! Don't Bogart that joint, my friend. Pass it over to Juan.

Comment It is true (Score 2) 467

However, like everything, if a technology comes along to supplant it, in this case, the cost of greener alternatives is lower than coal, it'll simply dwindle and fade over time, with absolutely no need for liberals trying to regulate the crap out of it.

This flawed argument ignores the incontrovertible fact that allowing coal to continue to provide energy on equal terms with other energy supplies rather than pressuring the market to switch to less environmentally damaging sources of energy would do real and substantial harm to us all. The bottom line is: the less energy produced from burning coal and supplied instead from less polluting resources, the better off the world is.

So in fact, there is a need for it to have the crap regulated out of it in a context where it can be replaced with (considerably) less polluting energy sources, which is exactly where we are today.

Comment Re:(sigh) You people still think you're engineers (Score 1) 717

Instead of identifying himself as an engineer, he should have said, "You are dicks." They clearly would not have been able to argue that.

Response probably would have been somewhat along the lines of "You are fined $500 for falsely representing yourself as an anatomist."

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