Forgot your password?

Comment: Re:Remember when WSJ had a modicrum of decency? (Score 2) 629

Except the minimum wage hasn't actually increased anywhere but Seattle, Washington(and even there it's still being phased in), and more-over, one of the big principles that undercuts this argument is: "once you can automate away a job, is there any wage at which you wouldn't?"

No, there isn't any wage at which you wouldn't - and it's been happening right under our noses for thirty-forty odd years now. Most people don't notice it because "automation takes away jobs" is virtually always assumed to mean "low education, low or no skill, rote and/or repetitive" jobs.

But the microprocessor revolution changed all that. The skilled master machinist has been replaced by an unskilled worker who loads and unloads a CAM machine. The draftsmen that, under the direction of an engineer, created and maintained the drawings the machinist worked from has been replaced by a CAD program used directly by the engineer. The engineer himself has been partly replaced by electrons too... instead of spending weeks with slipstick working out a stress calculation, now sets it up in a day or two on the appropriate software, clicks the mouse, and it's finished before he gets back from freshening his coffee.

And that's just one example, consider the business my wife works at... Thirty years ago, and at a tenth the size they had a full time accountant and two full time bookkeepers (plus data entry clerks and file clerks) - now they have an (almost) full time accountant, the bookkeepers (along with the data entry clerks and the filing clerks) having been replaced by a POS system.

When it's skilled, or especially when it's white collar, we call it "productivity improvement"... but we should call a spade a spade. It's automation.

Comment: Re:Wonder if their time hasn't already passed... (Score 4, Insightful) 164

by DerekLyons (#48213695) Attached to: Ello Formally Promises To Remain Ad-Free, Raises $5.5M

I would imagine it's down to too few people being on it still.

Not just too few people... it's also feature incomplete.

How long do you suppose people will wait before just not bothering with it?

It's already started... Ello has failed to learn the lesson of G+ and odds are, it will suffer the same fate. Gatekeeping at launch is just shooting yourself in the foot - people want to try your system, and if you lock them out... they aren't coming back. First impressions matter, and a barred door with a sign saying "only kewl kids allowed" makes a powerful first impression. In addition, G+, and Diaspora, and now Ello can't seem to grasp that to most people, personal privacy is just one of the many factors that they weigh. On top of the network effect there's also the features the system supports (chat, pages/groups, games, etc...), and all of the would be pretenders have fallen short on that front. (Or added them too late to make a difference.)

On top of that... Ello is going to have to come up with some pretty impressive optional features in order to induce people to pay for them - things the users can't get elsewhere while *also* providing a complete set of the features users have come to expect. That's a very tall order.

There's no doubt that like G+, Ello might be able to eke out a meager living on the fringes... but as a Facebook killer, or even serious competitor, it's already dead.

Comment: Re:Why do I still read these comments (Score 1, Interesting) 172

by DerekLyons (#48209169) Attached to: Google Announces Inbox, a New Take On Email Organization

Could you please, please, try it before saying that it is just like [insert failed google product here] or [insert very successful google product that you don't like here]. I know this is quite a culture shift for Slashdot, but sometimes it's too much.

Why? Given Google's track record at UI and UX (generally pretty poor), their track record of 'fixing' what isn't broken (pretty good, I.E. they do it more often than not), their track record of benign neglect of their products (pretty good in the same sense as previous)... etc. etc., we have every reason in the world to be skeptical. We've been burned so many times before.

You cheerlead, I'll go with the odds.

Comment: Re:The Orion is totally over designed .. (Score 2) 43

by DerekLyons (#48196511) Attached to: A Look At Orion's Launch Abort System

No, that would NOT be much simpler and safer. There's a reason why every orbital space plane has been side-stacked (Shuttle, Buran, X-37).

X-37 is top stacked as was the X-23. On the other hand, both are small enough that they could be encapsulated in a shroud to avoid aerodynamic issues. (And you forgot the X-20 Dyna-Soar, which was also top stacked but was not encapsulated.)

Comment: If only it were that simple... (Score 5, Informative) 43

by DerekLyons (#48196413) Attached to: A Look At Orion's Launch Abort System

What would have saved Challenger was the first "all-the-way-down" human decision turtle: 15% higher cost for one-piece SRBs instead of the 4-piece propellant sections.

If only the decision was that simple... Sadly, it wasn't.

First there were performance issues; The solid motors need to match to within 5% of each other - which proved essentially impossible to achieve with a monolithic grain as the propellant tended to stratify during the extended pour and the extended curing time. The solid motors needed to have consistent and predictable performance during the burn - which was almost impossible to achieve due to the aforementioned stratification problems. Both problems were also made worse because they couldn't figure out how to safely mix and pour the grains for both boosters in a single batch. Segmented grains, which could be poured in LH and RH segments from a single (smaller) batch suffered from none of these problems.

Next, there's storage and handling problems. The larger the grain, the heavier it is, and the harder it is to prevent it from flowing and deforming under it's own weight. Equally, since the large grains have to be cast upside down they have to be rotated rightside up - and nobody knew how to do that with large monolithic grains. A flex of as little as a couple of millimeters could crack the grain or lead to delamination. Also, segments could be stored individually, reducing fire and explosion risk.

Inspecting the grains with the technology of the time was also several orders of magnitude harder for a large monolithic grain.

Lastly, while there was a only a limited base of flight experience with large segmented grains (via the Titan IIIC)... there was no flight experience with large monolithic grains.

tl;dr version - there were a lot fewer known unknowns with segmented solids than with monolithic solids. A number of the known unknowns for monolithic grains were either outright show stoppers or could result in ruinously expensive R&D programs to discover if a solution was even possible. The known unknowns for segmented grains were all issues of scaling from existing experience.

Comment: Re:This is why NASA sucks (Score 2) 43

by DerekLyons (#48193697) Attached to: A Look At Orion's Launch Abort System

Why on earth or space would you design an escape system like this?

Because it's solid fueled and thus much more reliable than liquids and, depending on design details, much faster to react. Also, it's pretty easy to build in a passive attitude control system that arcs the capsule out of the booster's path while the Draco will require active differential throttling. (Which in the case of Orion also increases reliability, as the launch abort system doesn't depend on guidance being available.)

I believe that this must be disposed of on every flight

Which also means it isn't carried to orbit and poses no further risk to the crew or mission. It also reduces total landed weight, reducing the size of the parachutes required and/or reducing landing shock for the same size parachutes.

and the separation is not without risk

Nothing is without risk - and Draco has a number of risks inherent in it's higher parts count and more complex operation that the Orion launch abort system does not have.
There are advantages and disadvantages to both approaches. Neither NASA nor Musk has the absolute One Best Design - because there isn't any such thing. (And both of them are leaps and bounds above the complex horror that is Soyuz's launch abort system. Sure, it worked when called on... but that doesn't change the nature of the beast.)

Comment: Re:Would this kind of system have saved Challenger (Score 1, Interesting) 43

by DerekLyons (#48193431) Attached to: A Look At Orion's Launch Abort System

Provided, off course, that they hadn't mounted the payload NEXT to the exploding external fuel tank... yes, I know doing it that way let you have lighter structure, but it introduced a whole range of problems and failure modes you wouldn't have had if the orbiter had been mounted on top.

Mounting the orbiter on top has it's drawbacks too... The orbiter's wings now act a lot more like fins, making it harder to maneuver during the early part of the ascent and inducing (very) high structural loads on the stack. And of course the wings are generating lift... right at the part of the stack where they have a nice long lever arm. In addition, if you screw up the stack's angle of attack, you can end up with the wings at an undesirable angle to the apparent wind. (Undesirable in this case means "the wings are trying to turn the vehicle but not the stack", I.E. tearing the vehicle off the top of the stack.)

Comment: Re:Would this kind of system have saved Challenger (Score 5, Interesting) 43

by DerekLyons (#48192917) Attached to: A Look At Orion's Launch Abort System

Second, the boosters cannot be shut off. That's the big safety drawback of solid rockets - you light them, and they aren't going out until they're out of fuel.

*sigh* This is one of the biggest pieces of misinformation about solid rockets floating about out there, spread and repeated by shuttle detractors in a cargo cult like fashion until it's now regarded as a law of nature. What most people (including engineers who should know better) don't realize is that you don't need to shut them down in the first place- you just need them to produce net zero thrust. This is done via blowout panels in the front dome, and sometimes by blowing off the nozzle as well. And it's not like this is a new fangled technique either... It was used on the Polaris A-1 and A-2, Poseidon C-3, SUBROC, ASROC, Minuteman I and -II, and Peacekeeper missiles. It would have been used of the SRB's of the Titan IIIC booster for manned Dyna-Soar and MOL launches. It's used by Minuteman III missiles...
It wasn't used by the Shuttle because during the SRB burn, the SRB's are essentially 'dragging' the ET behind it... and thrust termination would have resulted in them 'hanging' from the ET or having to be jettisoned and the resulting changes in structural loads would have shredded the ET and tossed the Orbiter into the airstream where it would be broken up. (Which is essentially what happened to Challenger.) A normal SRB jettison doesn't shred the ET, because the loads come off gradually as SRB thrust decays and they're jettisoned as the T/W ratio passes through 1.
NASA looked at using an Orbiter mounted solid rocket to power it away from the stack, but even if the motor was used on a normal flight for orbital insertion after ET jettison it was too heavy.

Third, the Main engines are nearly useless in-atmosphere. They're lit mainly because they sometimes fail to light, and having that failure occur halfway to orbit would suck. The "boosters" provide about 80% of the thrust, if memory serves. The SSMEs aren't even at full throttle for much of the flight - Challenger had just set them to full when the stack exploded.

A friend of mine, an aerospace engineer by trade, once explained it thusly - "during first stage flight, the SRB's lift the ET and the SSME's lift the orbiter". This isn't entirely true, but it's a useful first approximation. And that being said, other than a brief time right around Max-Q (when the throttles are backed off to control aerodynamic loads) and as MECO approaches (when the throttles are backed off to control G loads) the engines are in fact run at full throttle during powered flight.

Comment: Re:Baby steps (Score 1) 351

Step 1: research on the ISS focused on biosphere components and food production.

Those aren't baby steps - your step 1 is no lower than about step 5 in any rational plan. We don't even know how to build a biosphere _on the ground_. Baby steps start with the basics, not three quarters of the way up the curve in the most expensive place to perform research.

At the same time, work on high efficiency, low reaction mass propulsion systems.

We already have those. The problem is, they absolutely suck because high efficiency and low reaction mass means absurdly low thrust. (F=MA after all.) Absent new physics, that's not going to change and such drives are going to be useless for manned expansion.

Comment: Re:German illegal? (Score 2) 323

by DerekLyons (#48142775) Attached to: How English Beat German As the Language of Science

And this isn't old news either - that a Presidential candidate (JFK) was Catholic was a divisive issue within living memory.

The problem with knowing the truth of US history is, starting in the 60's the black civil rights movement co-opted the idea of discrimination and painted in simple black-and-white terms. Steadily since then, except for things like the internment of the Japanese that simply couldn't be overwritten, the story of discrimination and persecution in the US has been told solely in terms of antisemitism and Jim Crow.

Comment: Re:The Russian space program was amazing (Score 1) 122

I believe the differences between the two is mostly to the "no nonsense" approach to the Russians, and the fact that they like re-using designs and equipment that work instead of constantly re-inventing the wheel.

Except... they don't re-use designs and equipment. The current mark of the Soyuz (capsule) has almost nothing in common with the early ones other than a reasonably similar moldline. Soyuz has been modified and updated multiple times, not the least as it evolved from a general purpose Earth orbiter into a very specialized station taxi.

Sure, their spacecraft may look "ugly" (or at least, "uglier") than western or American ones, but they get the job done and they are reliable workhorses.

Reliable... is a very shaky claim given the number of near failures and almost disasters suffered by Soyuz over the years. It hasn't killed anyone in a long time, but it's come uncomfortably close an uncomfortably significant percentage of it's flights.[1] And speaking of flights and workhorses... even though it started flying over a decade earlier, it won't match the number of Shuttle flights until somewhere around the end of this decade at the current flight rate. (Last time I looked, I haven't calculated in a while.) In the same vein, while Shuttle suffered two LOCV accidents, it had zero complete mission failures and only one partial mission failure due to an abort-to-orbit placing it in too low of an orbit. Meanwhile, Soyuz had one pad abort, one failure to orbit, and at least two complete mission failures due to an inability to dock with a space station. (As well as several instances of either the orbital module or the re-entry module failing to separate properly.)
All of which is a roundabout way of saying the comparison isn't really as black-and-white as people would like it to be once you compare the actual Shuttle against the actual Soyuz (as opposed the largely fictional Soyuz the actual Shuttle is commonly compared to) and look at the actual numbers.

[1] Here's three accounts just covering reentry and landing failures.

Comment: Re:Ridiculous (Score 1) 139

by DerekLyons (#48075815) Attached to: NASA Asks Boeing, SpaceX To Stop Work On Next-Gen Space Taxi

The point is that Boeing has nothing but mockups, powerpoints, and disastrous wind tunnel tests, so Sierra Nevada doesn't have to do much to have more technical merit.

When it comes to the most important part of it's flight regime, all Sierra Nevada has is "mockups, powerpoints, and wind tunnel tests". Worse yet, that regime is actually an area in which we have very little actual experience (essentially limited to Space Shuttle re-entries).

But go ahead and keep pretending that Boeing won based on the "technical merit" of a less tested, less developed, less capable, and more expensive system.

"Less tested and lest developed" is a relative matter... Boeing has a "less tested and less developed" craft that operates in a (relatively) simple and well understood flight regime. Sierra Nevada has an all but completely untested and undeveloped craft that operates in an extremely complex and little understood flight regime. Their flight tests to date, all low altitude ad subsonic, have nowhere approached the regime where the questions reside, not even close.

That you have to have this pointed out to you *twice*... well, further proof that you're a clueless fool.

Comment: Re:Maybe affects Boeing, not SpaceX (Score 1) 139

by DerekLyons (#48074799) Attached to: NASA Asks Boeing, SpaceX To Stop Work On Next-Gen Space Taxi

I really doubt SpaceX is going to stop work on a vehicle they were developing before they were awarded the contract.

If they don't, then the costs of work they perform cannot be reimbursed under the contract. Further, not doing so may also result in significant penalties being levied for breaking the terms of the contract.

So SpaceX may or may not stop work entirely, but they *will* stop any NASA specific work and may have to stop work that's not necessarily NASA specific but is being paid for under the contract. (It can actually get pretty complicated at this level.) Your faith in SpaceX is touching and charming, but it utterly at odds with the real world.

Comment: Re:Ridiculous (Score 1) 139

by DerekLyons (#48074729) Attached to: NASA Asks Boeing, SpaceX To Stop Work On Next-Gen Space Taxi

I interpreted Firethorn's first point to be that the shuttle was designed to retrieve and bring back to Earth a large object, but none of the objects it actually did return to Earth were that large.

The Shuttle was generally limited more by CG than by weight or physical size. That being said, STS-32 did return the LDEF, which pretty much filled the payload (but was actually pretty light for it's size). Any number of ISS flights returned a Spacehab or MLPM at pretty much the maximum weight the Shuttle was capable of boosting to the that orbit.

I'm not sure why that capability was included in the original design; if it was included in case a bad but still reasonably possible scenario happened then retroactively removing it from the design seems like a bit of 20/20 hindsight.

If you take off with a payload - then you need to be able to land with that payload in an abort scenario, whether it's as (relatively) benign as an ATO or the screaming horror of the RTLS. Once you've certified the design to return with a full payload under the worst case abort scenario, that you now have the capability to do so in normal operations is pretty much axiomatic.

That being said, there were actually three payload return weight limits;

  • Normal processing - the loads were below that which would damage the shuttle.
  • Special processing - the loads could damage the shuttle and would require a mandatory OMDP on return in order to conduct an inspection and analysis of the structure.
  • One time - the loads would almost certainly damage the Shuttle and while it could land safely and intact there would be a significant chance of the vehicle subsequently being written off. This option was actually exercised once, for the Chandra X-Ray Observatory, which was the heaviest payload ever boosted by the Shuttle.

I'd rather just believe that it's done by little elves running around.