Slashdot is powered by your submissions, so send in your scoop

 



Forgot your password?
typodupeerror
Check out the new SourceForge HTML5 internet speed test! No Flash necessary and runs on all devices. ×

Comment Fueling the fueler (Score 1) 38

Well, we do need a good OTV (Orbital Transfer Vehicle). You could use it to move stuff from orbit to orbit as needed.

So, how much fuel is this robot going to have on board? How or why would you refuel it?

The reason you put tiny fuel tanks on satellites is that it cost a lot to launch anything on a rocket. If it didn't then the engineers would put huge tanks on things sitting in orbit. Tanks designed to last as long as the next part expected to fail.

At there aren't that many kinds of propellant in use but you'd still be out of luck if you had something using hydrazine while the only thing left on the repair 'bot is nitrogen.

Orbital transfers aren't free or cheap (ask any Kerbel Space fan.) It will be interesting to see what propulsion system is proposed. There's interest in tethers for 'propelentless station keeping or orbital transfers.

Would you send up refuel cans for the robot? Would you de-orbit the robot once it ran out of fuel? Could you recover the robot to save costs, then?

Except for the Hubble Space Telescope most satellites are not designed to be serviced. What can a hypothetical servicing robot do about dead batteries or shorted out control systems or hole solar arrays on the existing fleet in orbit?

Finally, while space is pretty big, sending something on a 'soft' collision course with a dead satellite in the prime geosync orbit sounds like a great way to create more debris just where you don't want it. But it's Loral. They will have the best people Congressional pork spending can buy on staff to ask and answer these questions.

Comment Re:Amount of gravity needed? (Score 1) 77

It would also be nice to get a long term study of humans in rotating space habitats to see if it has any issues not detectable by ground models. Theory says the vestibular system shouldn't be impacted by long duration in an fast "inverse" rotating frame. It evolved on a large rotating planet after all. But Yogi Beara and any astronomer will tell you that in theory, theory and practice are the same but in practice they are different.

We have lots of experience with space craft that shuttle things off or to ground. There needs to be operational experience with vehicles that are designed to permanently remain in space. If you built your space stations strong enough and big enough you only need to attach an big engine to turn them into space ships.

Comment Re:Color Me Skeptical (Score 1) 428

Also, how hard is it to cut through an existing solar roof to add things like plumbing vents or to move a flue for a stove in a major kitchen remodel.

One advantage tar shingles, a very popular option in America, is that adding a roof vent is an hour long affair. Punch a nail up from underneath so you miss the rafters then just pull back the shingles, cut a hole, and apply the fascia kit for your vent. The tar shingles get layered right back on.

I presume these will be more like a terracotta roof but much less friendly to modification. Particularly when the shingle is generating power while exposed to light.

Still, if this is at least as durable as a class 4 "hurricane/tornado" shingle they might qualify for the common home owner insurance discounts on top of the price.

The home owner game is a market of long-term thinking. If you are only interested in next quarter or uncomfortable with 5 year break-even on your investments, just keep renting. From someone who owns a house.

Comment Re:All linked in /usr ? (Score 2) 58

I am pretty sure they also forgot that the 'S' in sbin stands for static und not superuser.

I beg to differ: http://www.linfo.org/sbin.html

These file in /sbin were system binaries. That is why /sbin directories are usually not on the default path for users.

Now, /usr/sbin, that one is confusing unless you know the sorrid history of /usr as a shared NFS mount. Files in /bin and /sbin may be statically linked or not even on real UNIX. For boot-time on Linux like Debian, static linking is for stuff in your initrd, rescue images or really really badly written software (*cough* Zabbix *cough*).

The changes directly impact two groups. Power users are going to need to know about /bin, /sbin, /usr, etc. as they are going to mess with their system directly. Package Maintainers are going to have another thing to pull hair out over when converting the raw sewage seeping out of poor developers into functional shipping things to end-users.

Until this impacts regular users or Joe X Windows who runs SteamOS it's like the mechanic changing the brand of shocks in your car. Someone who knows better will be using the correct tools to do the correct thing. Or everyone will hang them out to dry when your transmission drops out of the car on the highway.

Comment Re:Energy budget (Score 1) 151

So what am I missing? What is the actual benefit to separating heavy industry and people?

That it is really really easy to get things down into a gravity well.

In orbit? Just toss the package out the back fast enough and it comes down all on it's own. Take care to not hit anything on the way down.

Also, space colonization for real will the subject to huge limitations. Suppose you manufacture stuff in orbit and have the technology to ship it down to the ground. The landing process is the same technology for dropping a bomb anywhere with minutes notice from an effectively unreachable location. You don't even need bombs. Rods from God are a thing.

Governments have a long-term interest to ensure colonization - not industrial development - is slow, limited and guaranteed to align with their purposes. Space is the ultimate anti-government, anti-anyone position. Literally the high ground. Otherwise you'll get the plot of Heinlein's book, Moon is a Harsh Mistress.

But if you put heavy industry in space and most people still live on the ground, it takes an incredible amount of energy to get the raw resources into orbit and bring the finish products back down

Lifting anything into space to bring it back is a fool's errand. Look at how much of the Saturn V that went to the moon came back. Plenty of resources exist in space already to mine locally.

And without on-site captive customers...err, colonists, the economics dominate the situation. Industrialization is most likely to happen around the time that industrial jobs finish being taken by robots. That way you don't even need to ship messy old people with their huge life support systems. With enough resource scarcity to make market-wide recycling economic this would only be done for selected items anyway. Anything that can't be automated would be telepresence, keeping your workers and citizens safely in reach of the police and military.

You would always build wood stuff on the Earth. But if I could drop 10,000 custom-yet-completely-prefab concrete and aluminum houses, white goods and all, anywhere in 10 minutes (with clearance from traffic control) that could be a game changer for disaster relief or interesting for urban development.

But with any factory in a new area the problem is getting the first one up. Then you have the infrastructure to get many more much cheaper and quicker. Just look at how industrialization happened everywhere on the Earth.

Comment Re:"This is the one you want to protect" (Score 3, Interesting) 151

BioSphere II was a poorly planned theme-park garden now owned by the University of Arizona.

Want to see what can be done if you really understand ecology and not just theme park construction? Look at Ascension Island. Joseph Hooker, with the aid of Charles Darwin and Kew gardens, built the ecosystem on the island out of completely foreign species. This cloud rainforest was built whole cloth on a bare lump of clinker sticking out of the ocean long before electrification.

The key difference is ocean.

Biosphere II was designed with almost no significant bodies of water containing phytoplankton, which produce up to 85% of all the oxygen. The facility has a glorified wake pool that would have fit in a large cities' water park. The planners put in 50% more grassland than synthetic ocean. Much of that 850m "ocean" is dedicated to a coral reef. Unsurprisingly, the oxygen levels crashed soon after closing the doors. Both times.

If one thing was unrealistic about O'Neil Colonies it was the sheer lack of mixing oceans in all the designs. Water is one of the most abundant substances outside the dry line in the Solar system. It's also a good radiation shield and has high thermal mass. The giant magic space windows that somehow didn't let in vast amounts of cosmic radiation were more realistic.

O'Neil also wrote about Bernal Spheres. These are slightly better, but have their own engineering challenges. Artists still show the interiors as if they were a cutout of a heavily populated Italian riverside. More relaistic would be 70-80% ocean with islands or peninsula. But in Bezo's case it's probably a matter of go big or go home. And the Island Three plans are certainly Big Homes.

Comment Re:This study is garbage (Score 1) 186

The study is actually important. They showed that the brains didn't recover from the damage as expected. The radiation treatment did not trigger the plastic repair behavior expected from an injured brain.

Yes, the particles used don't resemble background Solar radiation. It doesn't even resemble the stream of lightweight charged particles from a Coronal Mass ejection. However, the model is similar to the burst of Cosmic Background Radiation (CBR). Like the kind you get on an unplanned spacewalk to fix something on the outside of your spaceship. Or if your shielding fails.

It is very hard to make a usable spacesuit for a human that shields against individual sometimes neutral particles with the energy of a fastball thrown by a world record setting baseball pitcher. It is also hard to build a light enough and thick enough shield against CBR when your astronauts insist on hanging out on the edges of your rotating spacecraft to avoid losing bone mass.

This lack of repair response is the kind of thing you have to learn about to be a space faring species. It's the science part of science and engineering.

Fixing it is the engineering part. You'll have to use better shielding. Or you can genetically engineer people to trigger the plastic response to damage like Water Bears use. Or just make all repairs outside the CBR shielding involve robots and drones.

Comment Re:Um (Score 4, Insightful) 294

Is the problem of cheap blue LEDs News worthy? The conversation certainly is. News can inform but need not always be just current events, particularly on the Internet where nothing is paper.

Slashdot is a news aggregation site. Ostensibly for 'News for nerds, stuff that matters' at founding. In practice is was a blog for Rob Malda, CmdrTaco. It was also a website with an accidentally really good commenting technology.

Been around long enough to see the jokes about not reading the article? Then you have probably been around long enough to see the argument that a lot of the people still visiting the site do so for the conversation in the articles. They provide everything from group-think arguments, good counter-arguments and funny jokes about the topic to warnings about click-bait, pay-wall free options and corrected sources.

If Slashdot had ever depended upon the quality of the articles it would have failed when it was still Chips-n-Dips hosted on a university student account. The commenting system is more than a chance to keep up your HTML skillz. People in the know are really providing the value. (Queue complaints about Facebook's model, etc.) However, getting quality articles is important to attracting the readership that does not know about the site.

For instance, this article currently doesn't shows up in Google search for annoying LEDs, being a day old. But the top link is for lifehacks.stackexchange.com for whatever reason. Stackechange and Amazon dominate the front page. I almost feel sorry for companies with products on that page. Even with no such thing as bad marketing, being known for having annoying lights on your non-party-joke product is not a good thing.

The Blue LED backlash article on McConnell's blog is page three. And he discusses a vendor that sells low intensity LEDs for computer products. But I expect - or at least hope - this slashdot article to make it to at least page three with McConnell's blog if not higher.

Comment Re:Does it work? (Score 3, Informative) 299

Does it work? No. But that depends on your definition of "work."

But Drug dogs work perfectly for law enforcement: they provide whatever answer the police want and the gullible public believe the dogs are infallible.

I fear you might not know just how accurate some critter's sense of smell is.

You might just not know how dogs behave.

If search dogs work then the dog should be fine to hunt these without the handler there at all. Just let the dog search on his or her own.

Search and rescue dogs work this way just fine every day. You let them go and they hunt down people easily that you or I cannot see or hear or smell.

But any person who raises and breeds and trains dogs professionally knows the first and only thing a well trained dog wants is to please the handler. That's the definition of well and trained for a dog. Drug sniffing dogs are very well trained.

In the hands of their handler a dog is just a dowsing rod for the man with the leash. Combine that with objects that conveniently fit in an officer's pocket and the long history of corrupt government officials. You shouldn't have plausible evidence. You should have plausible deniability. Yes, dogs are great at finding skunks or burnt joints you might be able to smell yourself. Not so much for things in air-tight closed containers on in piles of stuff that smells exactly like it.

But like you demonstrate, most people don't know how dogs behave. (Or how to spot magical thinking.)

Keep the handler away from the dog. Let it search on its own. Otherwise he or she is just a furry four-legged lie detector.

Comment Re:-based? (Score 1) 599

Is something like Debian itself Debian-based? Your answer to this philosophical question divides into two interesting camps of logic.

  • One is that a thing is most similar to itself therefore is always based on itself. The set of things similar to a thing would contain that thing.
  • The other is the idea that identity and similarity are completely separate concepts. The prototype in this latter thinking is not part of the set that classifies things into the set defined by the prototype.

It is not like asking what is the closest star to Earth (Sol, or the sun). It is more like asking what is the closest planet to the Earth. (Insert car analogy here.)

For sake of argument assume a planet is just something in the heavens that can be seen by naked eye and that moves daily against said heavens

All of this is without touching on important questions like is Debian made from Wood? Does it float? And does Debian weight as much as a duck? (No but only if you use rare double-sided, double-layer DVDs.)

Comment Re: Linux - Gentoo based (Score 1) 599

When did the package manager become more important than the operating environment?

Documentation and support information tends to be organized around how each distribution works or fails. (Or just provided for Ubuntu.) Knowing the distribution of software involved is thus important for sending the correct lmgtfy.com links.

From good Linux questions the reader can figure out or be told:

  1. Which kernel won't load your graphics drivers (Linux, Android, ntoskernel, Darwin, BSD.)
  2. Userland so you know which switches don't work (BSD, GNU, busybox, something else.)
  3. Package Manager (yum, zypper, apt, dnf, up2date, app store, etc) so you know which software won't install.
  4. Filesystem hierarchy violations so you can't find where anything got installed.

The package manager provides a really good hint to everything in that stack. apg-get implies a Debian derivative, most likely Ubuntu. Use dnf? Probably a Fedora desktop user. Got a question that shows zypper commands? openSUSE or really recent SLES. Yum instructions? RHEL or older SLES. URPMI? Mageia Linux. up2date? Really really old RedHat. Brew? You want the Mac OS channel, this is ##linux. Someone handed you a tarball and 50 pages of ./configure, make, make install? Hello, the 20th century called and wants their unpackaged software back.

Knowing which package manager is involved can also be important for supporting users. Those users who a only familiar with very basic support for their specific distribution need to be given instructions exactly for that distribution. Telling someone to do 'sudo apt-get' a bunch of stuff on Fedora will just confuse them. You'll waste time explaining the explanation. Then you'll waste time explaining that after you get a wall of hate about how everything sucks, your instructions suck, your distribution sucks and why can't we have nice things?

More advanced users can translate between Slack, Arch recipes, .rpm local flavors , .deb or Gentoo instructions. They may package stuff for themselves or others. (Whether or not you have to eat a whole bucket of mushrooms to figure out how to make said package is another matter.)

These more advanced users also know that a particular package in some Google-able documentation may have a very different name for each distributions. Those who have been around longer know that some software is not even be available on the distribution with the issue to solve.

So, yes, knowing the package manager lets people know which Linux tribe you hail from and thus which kind of hate mail to send. I mean support to charge you for. After all, all operating systems suck.

Comment Re:Length damn it! (Score 2) 148

Human factors and industrial engineering turns out to be important when working on systems used by humans.

I spent 15 years developing and writing password / pass phrase security tools used on a huge number of web site

This is the biggest argument for open source software. Security software is important software. It should work, do so correctly and be able to survive audit or exposure. Do you re-implement printf(3) to write a web page? (Usually no, but I've seen some interesting stuff. Ask a veteran C programmer to do HTML and you might get a new web server with the pages statically encoded in the binary.) But we re-implement user space stuff all the time that is really infrastructure in disguise.

The amount of time wasted re-writing stuff that should be written once and well is I guess a useful tax on the stupid. And too often that's how business works. The waste certainly keeps a lot of people employed.

"Code Monkey says maybe manager should write stupid login page himself."

In my professional opinion, where strength meters and password policies most often fail is that they greatly underestimate the importance of length. I recently encountered a site which required:

Requirements are funny things. Required fields on passwords actually reduce the strength of passwords. I don't need to guess or search the entire alphabet if I know that I only need combinations of unique characters. The result is a much smaller space to brute force. Sadly, without any requirements on variety most people just pick familiar and public information, which is even worse.

Comment Re:Driving yes, but charging? (Score 1) 990

Even with the American insane focus on the rush to get "there" the station doesn't make money off the gas. The profit is in the junk food, services and garbage for sale inside.

and it still won't be anywhere near as fast as refilling a liquid fuel tank.

And that is fine by this gas station logic.

There is money to be made in slowing down the pace of life. Just like making people queue a long time right next to the junk food stands at a Best Buy store. You might see restaurant style waiting tables inside more convenience stores with cellphone charging stations. Perhaps even possibly better bathroom cleaning schedules.

Well, one can hope about the cleaning schedules.

If you go places to do something longer than minute it fits with the EV lifestyle. This may sound like a retirement community approach instead of a high schooler's idealized speed-demon lifestyle. But the money is in gas stations that operate more like restaurants or rest stops. This is the reason charging stations pop up at malls, parks and recreational locations. Like a coffee shop with power for you in a cup and your car in a plug.

The real problem boils down to infrastructure.

For infrastructure we are only talking about the last few inch problem here. You already need a power tap to run the pumps. This just cuts out the pump between your car and the grid. Most of the remodel will be in getting those tables and chairs.

And getting those bathrooms cleaned.

Comment Re:High failure rate (Score 4, Informative) 209

If only that blackbaze pods were even remotely like other datacenter equipment. As far as vibration is concerned they are still pretty much a torture test for anything with a spinning motor. Minimal vibration protection while being mechanically coupled to a weak foundation while crammed in as tightly as geometry allows.

A temperature-controlled environment, clean power, low shock and vibration, and 1 out of 5 still fails

The density and structure of a pod is only temperature-controlled in that it is going to get hot, quickly.

Remind me never to buy Seagate.

The numbers from Backblaze you'll actually see that you shouldn't buy one particular desktop model of hard drive for your "datacenter." Numbers like Backblaze releases are quite fascinating in that you can analyze them. You can find which models at any vendor to prefer or avoid.

Oh, wait, I already vowed never to buy another Seagate- about 10 years ago after experiencing their unequaled propensity to die fast and hard.

Sorry to hear about your loss. I hope you kept backup copies. If not, I hope it taught you that if you don't have a copy then you don't have a backup.

It is certainly reasonable to avoid a vendor when a lot of their products from many lines have defects at a given time. Seagate's desktop line certainly took a hit from the initial Backblaze numbers. The DM1000's huge failure rate is almost as legendary as the IBM Death Star line or Maxtor click-of-death. But stuff from before or after a given run may have better or worse quality. And of course even manufactures can get batches of bad parts. (Hidden variables like that are one of the reasons why the singular of data isn't anecdote.)

I also wonder if we'll ever get numbers from Backblaze on things like the actual temperature, decibels and power these drives lived through. More than just avoiding a particular model. It would be nice to know how hot, loud and nasty you can get before your commodity-class storage starts pooping out.

Slashdot Top Deals

Recent investments will yield a slight profit.

Working...