Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 



Forgot your password?
typodupeerror
Compare cell phone plans using Wirefly's innovative plan comparison tool ×

Comment Re:Protection (Score 1) 114

Right, so they're going to reengineer every last subcomponent of every last part to withstand cryogenic temperatures, specifically for production in the tiny volumes needed in the space industry? Just for the inconvenience of reusing an upper stage?

Again: contrary to would-be-rocketeer imaginations, launch costs are not the be-all end-all of expenses when it comes to space. Engineering and low-volume production is killer. Mission designers always heavily stress TRL (Technology Readiness Level) of all components, as it's such a key determiner of mission cost. If any plan you propose involves "just reengineer everything", you do not have a plan.

Comment Re:I don't get it (Score 1, Insightful) 114

What you need is: Oxygen, Radiation shielding, Water, Food, Power and some gear.

Yes, it's totally that simple! The ISS has hundreds of thousands of parts, but only because congress insisted on adding thousands of Machines That Go Ping for no good reason. And random objects totally love being submerged in liquid oxygen and liquid hydrogen. And empty tanks are totally easy to haul all the way to orbit when pre-loaded with fittings and jackets and extra tanks. And building things in space (including bloody *welding*) is such a nothing job that totally costs nothing!

Meanwhile, in the real world...

The tanks will serve as basic habitats etc., you could grow food (wasn't this successfull?) in one of them to replenish your oxygen supply.

((Snicker))

Everything which does not need to be inside, you leave it outside,

((Snicker))

Comment Re:easy peasy (Score 1) 114

What plastic are you thinking of and at what thickness, that is compatible with liquid oxygen, retains flexibility at LOX (or worse, LH) temperatures, and withstands the pressure, all without adding a massive mass penalty? How is the plastic supposed to deform around every little structure in the habitat (aka, not face multiple atmospheres of asymmetric pressure)? What sort of hardware are you thinking of where every last element is just fine with being frozen down to LOX (or worse, LH) temperatures? How many man hours are you thinking of to "rip out" the giant bag through the tiny docking port (after having to detach it where it's carefully bound around each element? Unless you were thinking of having it fully loose inside there, which is even more problematic. Where's it supposed to go on the ISS? If you're doing the (larger) hydrogen tank, how 100% sure are you that you're not making an explosive fuel-air mixture, given that hydrogen burns at just a couple percentage concentration? How positive are you that you've fully vented every last nook and cranny? And on and on and on.

Wet workshops were worked on during the Apollo era. They were ditched for dry workshops because it's easier, cheaper, and more functional.

Comment Re:Too bad they can't use the SS ext. tanks (Score 3, Interesting) 114

Shuttle ETs never got up to a stable orbit. It would have been possible to use the OMS to take them up there, but then the Shuttle would have had basically no payload capacity on that mission.

Of course, that's one of the lesser problems with the concept. Often proposed, often investigated, but never considered worth throwing serious money into.

Comment Re:I don't get it (Score 4, Informative) 114

And the US did launch a converted stage in the 70s with Skylab (albeit, Skylab was built on Earth and didn't contribute propellant / thrust... a rather different beast ;) ). That is, a dry workshop rather than a wet one.

To a rocket scientist, it's "obvious"; to a habitat designer, it's a nightmare. They're designed for dramatically different needs, and in-space construction is very difficult (and thus expensive). Orbital habitats are not just big shells, they're complex structures that take a lot of work to make. The original proponent of the wet workshop concept, George Mueller (who had worked with Von Braun on the idea), himself had switched to arguing for a dry workshop over a wet one by 1969 (this eventually became Skylab), telling congress that the wet concept had become just an inferior stopgap based on necessity rather that desirability.

There's this concept that launch costs are everything. They're not. A lot of times, it really is just cheaper to spend more in launch costs than to do more engineering, assembly, and/or in-orbit work.

Comment Re: Confused (Score 1) 127

The community in the case of Tesla (which was just an example picked from countless) was the customers. Are you saying that customers are irrelevant for a company? You also seem to be of the view that the "rally around the founder" effect is a good thing, given your comment about the TOR project being replaced.

I don't even know what OpenOffice thing you're talking about, by the way.

Comment Re: Will Internet Voting Endanger The Secret Ball (Score 1) 214

You're missing the point. The complaint about electronic voting is that someone can compel someone to vote in a particular way when voting isn't in person because they can confirm that the vote was cast in the way that they want, which they can't do at a polling place. But this situation already exists with absentee ballots, when the person is filling out the ballot.

Meanwhile, in Estonian online voting, when you vote online, you can still later go to a polling place and change your vote. Meaning that the person who watched you vote a certain way online still has no clue whether that vote is actually going to be the final say, unless they hold you hostage all of voting day. Which someone could do with likely voters for a given candidate whether online voting exists or not.

This has nothing to do with whether people at the electoral commission can match voters with their votes (which they can't do with either paper or online votes in any decent system).

Comment Re:Confused (Score 2) 127

Indeed, according to their graphic they want anyone who "supported or aided the investigation" to sever all ties with Tor.

It's the "rally around the founder no matter what" effect; I've seen it in many, many projects. That said, most people forget about it with time. Who here ever spares a second thought for Martin Eberhard these days when they think of Tesla, rather than Elon Musk? Back in the day, in the Tesla community Musk was the devil for firing Eberhard when it turned out that Eberhard had grossly understated the cost to build the Roadster, had gotten the company bogged down in contracts that were going to get it hit with penalties, and was accused of hiding negative information from the board. Martin was beloved as the founder, and thus anything negative about him was clearly just vicious smear. But since Tesla has been such a big success, who ever hears the name Martin Eberhard anymore?

Comment Re: Will Internet Voting Endanger The Secret Ball (Score 1) 214

Must say you are a moron. Voting is meant to be anonymous.

And so Estonia's solution where people can vote online but override their vote on election day by casting a vote in person isn't a solution why? And that's just one of many possible technical solutions.

And the current practice of mail voting doesn't already eliminate ballot secrecy why?

Comment Re:Stealth (Score 1) 117

If you count in dollar, not in rouble.

Also if you count in "cutting funding and repeatedly missing deadlines and production targets by massive margins"

If Russia could not produce things inside the country, that is the problem with their budget!

It's a systemic problem. Russia has shown itself quite capable of producing very advanced military hardware at the small scale in recent years, but has struggled to produce them in the sorts of volume it can for its older hardware systems. Its testing programs are also rather underwhelming by western standards.

This is one area where I think China holds an edge. China has always tended to be behind on the technology curves, but they've been catching up. And if there's anything China can do, it's produce in quantity.

Armata introduced last year.

And in its introduction in the Victory Day Parade it stalled, they had to try to tow it, failed, and eventually managed to get it working again enough to drive off. It's been delayed by two years and orders have been cut.

Mikoyan has problem because Sukhoi has been doing better both on domestic and foreign market. And, MiG is a kind of light fighter, which has less demand today.

Speaking of Sukhoi, the PAK-FA - still under development - is the result of a project that was initially supposed to deliver in the 1990s. The current concept, created in 2007, was supposed to have been delivered in 2009. Current expectations are 2020 or later, and orders have been cut to 1/10th of what was planned.

Comment Re:Stealth (Score 4, Interesting) 117

Could you remind me again, which nation is building military bases on internationally disputed islands that they lost the judgement for, and which nation recently annexed a part of one of its' neighbors and is waging a constant low-level war in a large chunk of said country's east while propping up one of the most brutal dictators in the middle east by white phosphorus and cluster bombing its cities?

Not that I'm a huge fan of the US either, but come on now....

Comment Re:Stealth (Score 3, Interesting) 117

The problem with stealth aircraft isn't finding a missile that can hit them. It's getting a reliable, targetable lock on them. You can detect stealth aircraft with low frequency radar, but you get a very poor quality return. Low frequency doesn't just make stealth aircraft more visible, it makes *everything* in the atmosphere more visible, including water vapour.

A good example of what it takes to shoot down a stealth aircraft with a low frequency radar can be seen in the one time it was accomplished, by the Serbs during the Kosovo conflict. The airplane flew right over their position almost every day. Even with it right overhead, they still couldn't target it most of the time. The time that they finally got it, it was right overhead and had its bomb bay doors open, significantly increasing its visibility.

And this was with an old generation of stealth aircraft.

No country in the world wants to have this much difficulty hitting their adversaries targets. Is the problem solveable? Probably eventually. Is it solved now? Very doubtful. As good evidence to that effect, look at how much money Russia has been throwing into their antiaircraft systems - first modernizing the S-300, then introducing the S-400, and now developing the S-500. Much of Russia's military struggles for funding (look at the sad state of their only aircraft carrier, for example, or their struggle to bring tanks like the Armata or planes like the MiG-35 into full production), but air defense gets tons of money. If they had actually solved the stealth problem and felt that they could reliably shoot down US stealth aircraft, they wouldn't be focusing so heavily on it.

Slashdot Top Deals

Due to lack of disk space, this fortune database has been discontinued.

Working...