The total output of RTGs slowly decreases with time as the radioactive material is expended. Therefore, although the initial output of the RTGs on Voyager was approximately 470 W of 30 V DC power at launch, it had fallen off to approximately 335 W by the beginning of 1997 (about 19.5 years post-launch). As power continues to decrease, power loads on the spacecraft must also decrease. Current estimates (1998) are that increasingly limited instrument operations can be carried out at least until 2020.
So the actual power loss would be 30% over 20 years, rather my stated 50% over 10 years.
Whilst the isotopes used have a long half-life, as you state, the other components of the RTG are subject to continuous exposure to heat and radiation. So the ability to convert the available heat into power degrades over time (rather than the available heat degrading, particularly)
The Radio-Isotope-Generator (RTG) power sources on Voyager et al have some significant problems with regard to the political implications of getting them up there. You may or may not recall the farce that surrounded Cassini's launch, and the fears that a launch accident would have spread plutonium dust over the eastern seaboard.
Disregarding the above, RTG's aren't a magic bullet. After 10 years in space, Voyager was down to 1/2 the original power. I've got no idea what Hubble's power requirements are, but I wouldn't assume you can just drop a couple o' RTGs in and stop worrying...
Rather more serious than this, however, is that Hubble is a big satellite. Over 11 tonnes. 14 times heavier than the Voyager probes, which took the heaviest available launcher (a Titan-IIIc) to throw them out of earth orbit. Short of reviving the Saturn-V, there's not a lot on the shelf that'll get Hubble much out of it's current Low Earth Orbit. Oh, and when it does go out there, most of the optics are likely to be knackered by the transit through the Van Allen belts....
The exact mission you're describing - go a ways out there and look back at ourselves - has already been attempted. Lookup Triana aka "Gore-sat" for more details. To summarise: It's a great PR effort but the science is lousy.
Hubble was designed to be serviced, on-orbit, by the Shuttle. This is '70s NASA remember which was juust getting the hang of perpetually self-justifying programs. Why do we need a Shuttle? To service Hubble, of course! Ahh, but why do we need Hubble? To give the Shuttle something to do!
Rather less cynically, note that the design life[*] of most unattended satellites is 5 years. After that period of time, enough is going to have started going wrong (fading power from radiation and micro-meteorite damaged solar cells is the classic example) that it's just not worth adding extra redundancy into the design up front to cover it (remember that redundancy = mass consumed that can't be used for the primary purpose of the sat.). Hubble has been up nearly 15 years now, and still has 5 years of useful life in it. That's because all of the things that traditionally go wrong - see the solar cells - have been replaced at least once. Also note that not only was the critical design-flaw in the mirror corrected on-orbit by the first Shuttle service mission (turning what would have been a wasted sat. requiring complete replacement and relaunch into a fully-functioning success), but later service missions have replaced components with improved versions, increasing the capabilities of Hubble enormously. It's like there's been 3 Space Telescopes up there, for the cost of... well, let's not go there. NASA's more than capable of making it look like it's cost less than 3 complete new telescopes, I'm sure...
[*] = as opposed to the actual life which can be much longer, but can't be predicted in advance
Hubble is in Low Earth Orbit (LEO). It's got an orbital velocity of around 4KM/Sec.
To raise the orbit far enough to get to the Moon, takes a total deltaV of 7KM/S (or another 3KM/S on it's current speed).
The Earth orbits the sun at around 30KM/S, give or take. So to send something - anything - into the sun requires a deltaV of the same amount: you've got to cancel out the existing 30KM/Sec velocity, otherwise you're just going to send the object into a different orbit around the sun
The fastest any object has left the earth is around 8KM/S for the interplanetary probes (Pioneer, Voyager, Cassini, Galileo etc). That's as fast as the human race has ever gotten anything going[*]. Without a major advance in rocket technology (i.e. away from chemical rockets), that's about as fast as we're going to get anything going, too.
As a reference, the on-orbit manoever capability of the Shuttle, is a total of about 100M/S
Oh, and Hubble has much MUCH less manoever capability than this
This is why things are de-orbited, rather than "sent towards the sun" or further out. De-orbiting from LEO requires only a little "kiss" of deceleration before the orbit intersects the atmosphere, from where friction does the rest. The only exceptions are Satellites in higher orbits (e.g. GPS in the 12-hr / 12,000KM orbits, or Geostationary sats) which tend to be "retired" in slightly higher orbits because these are thought to be more stable over longer (geological) time periods than lower ones, and there's not enough residual manoever capability to lower the orbit enough to graze the atmosphere
[*] = However, we've learnt the trick of gravitational assists which lets Mother Nature (or Newton, or Einstein depending on your religious orientation:-) speed up our probes considerably at the expense of the orbital energy of the planet we're assisting from.
I'm a 2-year user of X-Plane, although I confess I've not been following the v7 beta stuff (I've stuck with 6.60 for now). I've logged hundreds of hours on the sim, and tinkered with the other tools available (e.g. I've modified aircraft etc).
X-Plane is a fantastic piece of work for a single person to have to his name. Probably the highest praise I can think to give it, is that it's not only the best at what it tries to do - simulate flight of all kinds - but it's also usable.
Having said all that, usable is about as far as it goes. It's not, and has never set out to be, a polished application with a glitzy UI. The interface for the sim and the tools is good enough and no better. If you need to get out and see what'll happen to an NF-104 at 100K feet when the control surfaces fail on you, then X-Plane is for you. But be prepared to adapt to it's interface, rather than have it teach you.
I've been looking at FlightGear recently too. And about all I can say about this right now is that it's clearly got promise, it looks good, but there's a looonnggg way to go. At least X-Plane lets me choose aircraft from a file selector dialog; I have to shut down FlightGear and use a different command line switch to load a new aircraft. It's clearly still very much for the Geeks for now, wheras I know there are professional pilots using X-plane.
My advice is: pick a laptop or pick a PDA. Make sure that either of them does their respective job well. Don't expect your PDA to be a laptop, and don't expect your laptop to be small enough to put in your pocket (yet!).
I reject your advice. I carry a Psion 5MX everywhere with me. It's like a PDA, only it's got a proper keyboard. Which means I can take notes and write documents on it. This is a most valuable feature, since it means I can leave my Laptop behind for nearly all meetings etc.
The fact that it's got perl5, email connectivity, a Spectrum emulator, web browser, etc also is just a complete bonus. The 20hr battery life isn't bad either. However, it is 3 years old and I'm worried about the clamshell screen giving in again so I'm looking for a replacement.
So, to refute your advice: I am looking for a device with a keyboard that I can put in a shirt pocket (and I don't mind looking like a nerd with a kingsize pocket protector to do so), that I can take notes on, and that ideally has a 2 day (~4-5 hrs) battery life. Running Linux isn't a necessary (I've gotten used to EPOC too), but definitely a plus.
They trialled OGG last year, I don't know what became of that.
The internal copyright to do so expired, ending the trial.
Then in September, they sorted this out. Ogg streaming is due to re-start, Real Soon Now(tm). As it has been since September...
See Here for more details....
There's a very good reason why you might link the ability to look way-out-there with the ability to look really-closely-down-here.
The Hubble Space Telescope is very closely based on earlier KH-series spy sat designs. So much so that it was shipped from the manufacturer to Kennedy Space Center in a KH-11 shipping container.
Indeed, a lot of the early gross design decisions on Hubble were subject to "anonymous" review from the relevant black agencies, and changes made appropriately.
Call it an early example of the Peace Dividend....
That's a pretty funny statement, considering the first shuttle didn't launch until 1981 [nasa.gov].
I'm well aware that Columbia's first flight was in 1981, since I distinctly remember watching at least 2 launch attempts on TV, the worries over the missing tiles on the OMS pods, and the subsequent safe landing at Edwards. I was 10, not that that should make a blind difference to anyone, but I was a Space Geek then and am one now (2nd class, amateur division).
Are you aware that Columbia (OV-102) is the second Shuttle Orbiter, and that the first, Enterprise (OV-101) flew in 1977, under the ALT (Approach and Landing Test) programme?
And that, despite the lack of SSME engines or indeed any sort of flight-representative thrust structure at the back of the craft, the production AP-101B computer, complete with representative software, was used on those flights (as it had to be, since Shuttle is fly-by-wire..).
Or, that on the last ALT flight (Flight 5), these very computers were if not cause then at least major contributing factor to a rather nasty Pilot Induced Oscillation (PIO) that caused Enterprise to land short? A fault that was corrected, in software, and the fix tested on the original Fly-By-Wire test aircraft, the F-8 FBW, using the exact same AP-101 computers.
Or that that FBW F8 had originally flown in 1973 using a single "DSKY" machine as flight computer, the same computer used on all Apollo spacecraft?
STS is very much a '70s design of a '60s concept (go read up on the StarClipper design to find out about what Shuttle should have been). With recent modifications it approaches the technology levels present in the early '80s, at costs comparable to '00s technologie crashes, with the reliability of a '30s airliner and the safety record of a...ah, but we don't go there any more do we?
That's still better than most linux software, just go to www.sourceforge.net and see how mony projects ever gets past alpha-stage.
That's unfair, and comparing apples with oranges.
Think of a project on sourceforge as being a low-cost representation of an idea, rather than as a product. So the first thing you do is register your idea - or, if you're a fan of Homesteading the Noosphere, you "stake your claim". Then you see if there's interest, think a bit more about the problem and/or solution you're proposing, maybe try a few bits of code out.
Often times, what you deride as "alpha" level software is perfectly acceptable v1.0 shipping product from some large commercial suppliers (er, actually most commercial vendors). Their business model appears to be ship a minimally-functional product, if it works use the proceeds to fund v2.0
Remember also that that Alpha code may just do exactly what you want it to do - no final product required! Often times within the context of these sorts of connectivity programs, alpha-code is sufficient to prove the concept, wherein it becomes more profitable to roll the actual functionality into a larger project - e.g. Evolution's palm-sync equivalent, or a specific camera's photo-download software into gPhoto2 or similar.
In short, if I expect to have to pay for software, then I expect a Beta programme to a) provide an early look at the functionality b) provide an early look at the quality of the product before committing anything to it. If, on the otherhand, I'm crusin' sourceforge for solutions, then oftentimes a demonstration-quality Alpha release is more than enough to make a decision on whether to adopt, adapt, collaborate or ignore the project...
You don't mean the kind that looks like jillions of tiny tires (or black donuts) intersecting with the wires of a chain-link fence, are you?
Yes, he does mean Core Memory, and yes, the AP-101 as flown in the Shuttle from mid-70s through to mid-90s did indeed use Core memory.
Indeed, the upgrade to the AP-101s with (I think) static-column RAM took so long because Core memory has the lovely property of retaining information even when the power dies - a key factor, sadly, in the ability to retrieve information from Challenger's onboard computers after the 1986 crash. Another key factor is that Core memory is remarkably resilient to bit-flipping caused by cosmic rays and other radiation (events known as "SEUs" or "Single Event Upsets").
All of which meant that it was a major project just to replace that memory with more modern RAM. And it's not just a couple' sticks of SDRAM either - most of the space-savings you'd expect from replacing bulky core with nice compact RAM chips is taken up with additional hardware to a) provide sufficient power support to retain memory in the event of main power failure b) continually scan through memory doing parity checks to detect and correct for SEUs...
There will be, lo, much wailing and gnashing of teeth because Random Cool Package vX+1 isn't in the STABLE release. There will be much complaining by users (of which I am one!) when RCP vX+1 takes longer than 15 nanoseconds to hit the UNSTABLE release, regardless of how complicated it is to support on N (where N>=11) different architectures.
In about 3 months time, there will be much complaining about how long the freeze for "Sid" is taking, and how out of date "Woody" has become (completely ignoring the fact that most people using Debian on servers are probably more than happy to continue to use "Potato" or earlier, just so long as they can apt-get from security.debian.org).
In about 2.5 years, there will be another announcement on/. announcing Debian 4.0.
And all through this, real honest-to-goodness users will be able to keep right up to the bleeding edge of free software just by adding a single line to their sources.list, and won't notice a thing.
By someone who's apparently been running Debian 3.0 for some time now (a number of days, anyway) and didn't even notice. Thanks, apt-get dist-upgrade!
Not to put too fine a point on it, I find your attitude wasteful and selfish. That 1.5 hours you spend in your car - engine running, CO2 emitting, space-occupying - could be reduced to a matter of minutes if you and your kind would just dien to join the rest of your fellow humanity now and again in a shared environment (AKA bus/train/tube/monorail/whatever), rather than selfishly squandering irreplaceable resources (steel, oil, asphalt) just to have your *own* air conditioning, your *own* choice of music, your *own* psuedo-privacy.
Positing good, clean, reliable, affordable public transportation, I see no good reasons other than the above for not using it. This whole "Car is good, Car is symbol of personal freedom and wealth" attitude is just so 1950's.
I agree wholeheartedly with anyone making any statements regarding the availability or otherwise of said good public transport and/or any means of providing same vs. cynical stealth taxes on motorists. But as a resident of Planet Earth along with 6 billion others, I really don't see what's so hard to understand about Sharing and Cooperating.
Hey, guess what: if they use this information to fine you then you were breaking those laws. All this materially changes is the ability to detect and prosecute, it does NOT change the laws.
I've heard it said and I wish I could remember the exact quote, but the best way to deal with bad laws is to change those laws. Not ignore them. change them.
In a perverse way, the ability of modern technology to enhance law enforcement should be seen as a universally good thing - not only can we catch more perps, but we can also use these tools as public awareness initiatives to lobby for better laws.
In this context, I would certainly and most vigourosly include the creation and enforcement of sane and reasonable data privacy laws (which we do - kinda - have). Which would or should tackle all of your remaining objections.
Clue for the clueless: they've always been able to do this, but the resources to do so have never been available for mass deployment. AKA ".Tailing A Car".. Secret services, Police, private detectives.
This is NOT an invasion of privacy, in itself. You are, after all, in a public place where your expectation of privacy is, or should be much lower than in your own home.
Note that there are risks here nonetheless, but these are th boringly normal ones around information security, ensuring authorised access only, etc etc etc. But I can't see that this is a frothing-at-the-mouth EFF/ACLU live-free-or-die Invasion Of Privacy issue.
Sorry to sound like a NIMBY, Middle-aged fuddy-duddy BUT...
What we really need is reliable, affordable and accessible Public Transport so we can avoid having to use our cars in the middle of a city anyway.
I speak as a car-owner and public transport user, and a commuter-to-London. I wouldn't dream of using my car to come in anyway (it took a colleague 2.5 hours to get from Gatwick airport to the office here in central London this morning), but relying on our trains, tube lines and buses is equally frustrating (My train was delayed 4 days out of 5 last week).
My car is for getting me from city to city, or for transporting goods and passengers on local journeys. It's just not good at taking just me from point A to point B in an urban conurbation and yet walking out of Waterloo station on any day of the week that's what you'll see: cars full of single occupants taking up 20 times the ground space of a pedestrian and 8 times the space of a bicycle.
Folks, I'm in favour of congestion charges - as long as you have an alternative to using your car, and as long as those charges are spent on those alternatives.
I'd like to agree with Ian on this one, both on the blindingly cynicalreal reason for the upgrade (more beans for Microsoft), and on the even more compelling user-centric counter view to this.
The only thing I'd like to add in this favour is that any competent organisation ought to be able to fight this push to upgrade with a really simple economic argument: Software solutions tend to get sold on a Return-On-Investment basis - If I buy an MS-Office based environment, my ROI over a period of time is given by: (increased productivity measured using appropriate methods) - (cost of software AND cost of hardware AND cost of supporting solution) (naturally, estimating the increase in productivity is where a lot of companies fall down, but you'd be amazed how many can't even estimate the second term in the above equation either)
My point here, though, is dead simple: theres an implicit time term in the above equation such that the costs are amortized over a period of time. Modulo normal accounting depreciation etc, this implies that an organisation gets better ROI if they can keep the same solution for as long as possible. This directly conflicts with MSFT's desire to force regular upgrades (which increases the costs element of the solution whilst only marginally - if at all - increasing the productivity improvement size).
As a good little corporate drone, it astounds me that more organisations haven't caught on to this and had a feedback effect on the IT industry as a whole - large corporate entities, especially financial institutions, should be cautious as all get-out when it comes to adopting new technologies or solutions. And yet we all blindly tread on the Shiny Thing treadmill, haemorraging money in a continual game of replacement and upgrade, fix and debug, for little gain.
Bah. We should have stayed on those green-screen thingies with nice reliable mainframes behind them
This has been an Old Phart Rant Courtesy of the letters M,S,F and T, and the day Monday
(side thought: Maybe in the future shows won't battle for a good time slot, they'll battle for Tivo priority. 200k for a two-day guaranteed time span on everyone's tivo, 25k for a 4 hour span, etc.)
I don't understand that. They're just competing for bytes on your Tivo's HDD that way.
Now, if they could find a way to force you to watch downloaded programming, then they'd pay. Big time.
I'd love to know which stream you were listening to because my scheduled capture of the 1830 comedy on Radio 4 failed last night, and I'm desperate to find a way to get captures before Monday's I'm Sorry I Haven't A Clue!
The BBC Ogg test page states the test period finished on 2002/05/19 however I was able to record ISIHAC from Radio 4 on Monday 2002/05/20.
Incidently I have no idea of the legality or otherwise of capturing the live stream (using nothing more than a Cronjob'd "wget" BTW) but it strikes me that if you can make personal tape recordings from trad. radio then this sort of timeshifting is no more harmful...
*sob* please tell me I'm not going to have to go dig out one of those obsolete audio tapes in time for Monday *sob*. I want my, I want my, I want my Ogg R4...
See, this here is what I don't understand about the state of the telecoms world.
Your statement:
...you degrade everyone elses service as well, even if you are paying for your chunk...
See, my immediate and overriding thought is: I'm the CUSTOMER. I give you money, you give me bandwidth. How I use it is up to me. I've bought - BOUGHT - bandwidth from you, and now you're putting all these restrictions on me because you didn't do your sums correctly and you're making a loss from insufficient service provision.
The same applies in spades to all the cable modem, ADSL, and prepaid dialup plans we see getting post-hoc restrictions placed on them. To me, this looks like the service provider is an incompetent cretin that can't do their sums, work out how much capacity they've *bought*, how much they *need* to service their paying customers, and charge appropriately right off the bat.
Seriously, folks, is the corporate world so seriously screwed up that no-one is capable of this?
The ZX80 came with 1K RAM, yes. But the expansion pack was only 4K.
"Ram Pack Wobble" was a classic symptom of the ZX81 also - cheaper connectors as I recall (not JUST that there was no connector as such - just the PCB traces run to the edge of the board - but also the positioning of the board vis-a-vie the case)
21mhz adds a link to this press release from Russia's Myasishchev Design Bureau, writing: "On close examination, it turns out to be a downscaled version of Buran."
Hmmm. Not so much Buran (AKA Shuttleski; the two vehicles look remarkably similar), but it is the spitting image of the X-20 Dynasoar (designed and almost-built in the '60s by the USAF). Pretty Pictures Here.
There's no reason to suppose copying. Both vehicles are built for approximately the same mission, so it's more concurrent evolution.
The US Military (who else?) tried this in the '60s with Minuteman ICBMs. Except they used a C5 Galaxy transport and a parachute. I believe the few tests worked well enough, but it was never adopted as an operational launch method: to be effective for nuclear deterrent would have required a fleet of C5s (only ~50 were built and they were built for heavy airlift), continuously airborne. Turns out to be cheaper to stick the Minutemans on the back of a train and drive it around the country (who'd a thunk?).
Anyway, as a commercial enterprise for smallsat launches, this would appear to be a workable solution - use a ram instead of expensive parachutes, and fly the transport down to the equator before launch (same trick that SeaLaunch uses). I just hope the launch vehicle is a bit more reliable than the competitor - Pegasus. They've had a bit of a run of bad luck recently...
There was an article on a very similar subject in New Scientist a few weeks back.. Lemme see if I can get a URL....{time passes} Oh dear, it's in the archive and you'll need to register to see it. And registration requires a subscription to the magazine.. how very lame.
Anyway, the upshot was that a research group was using consumer-type Digital Cameras to help automate surveys of Rain Forest flora.. turns out that their estimates were VERY BADLY off because the prime descriminator used was colour (think: "shades of green"). And the cameras they used (specific make/models not mentioned) basically couldn't capture the range of greens required, or distorted them. Spherical Aberations from the el-cheapo lens on the cameras just made things worse. Bottom line: years of work needs to be re-done with more expensive, calibrated equipment.
Slashdot Mirror
I was wrong about the extent of the power loss. From The NSSDC Master Catalog entry for Voyager
So the actual power loss would be 30% over 20 years, rather my stated 50% over 10 years.
Whilst the isotopes used have a long half-life, as you state, the other components of the RTG are subject to continuous exposure to heat and radiation. So the ability to convert the available heat into power degrades over time (rather than the available heat degrading, particularly)
LEO is 4KM/Sec. Earth's escape velocity is 7KM/Sec. So Getting to LEO is somewhat closer to 60% rather than 90% of getting anywhere.
Indeed, I recall the famous slogan of (I believe) Robert A Heinlein that LEO is "Half way to anywhere"
A few comments on your proposal:
Hubble was designed to be serviced, on-orbit, by the Shuttle. This is '70s NASA remember which was juust getting the hang of perpetually self-justifying programs. Why do we need a Shuttle? To service Hubble, of course! Ahh, but why do we need Hubble? To give the Shuttle something to do!
Rather less cynically, note that the design life[*] of most unattended satellites is 5 years. After that period of time, enough is going to have started going wrong (fading power from radiation and micro-meteorite damaged solar cells is the classic example) that it's just not worth adding extra redundancy into the design up front to cover it (remember that redundancy = mass consumed that can't be used for the primary purpose of the sat.). Hubble has been up nearly 15 years now, and still has 5 years of useful life in it. That's because all of the things that traditionally go wrong - see the solar cells - have been replaced at least once. Also note that not only was the critical design-flaw in the mirror corrected on-orbit by the first Shuttle service mission (turning what would have been a wasted sat. requiring complete replacement and relaunch into a fully-functioning success), but later service missions have replaced components with improved versions, increasing the capabilities of Hubble enormously. It's like there's been 3 Space Telescopes up there, for the cost of... well, let's not go there. NASA's more than capable of making it look like it's cost less than 3 complete new telescopes, I'm sure...
[*] = as opposed to the actual life which can be much longer, but can't be predicted in advance
Hubble is in Low Earth Orbit (LEO). It's got an orbital velocity of around 4KM/Sec.
To raise the orbit far enough to get to the Moon, takes a total deltaV of 7KM/S (or another 3KM/S on it's current speed).
The Earth orbits the sun at around 30KM/S, give or take. So to send something - anything - into the sun requires a deltaV of the same amount: you've got to cancel out the existing 30KM/Sec velocity, otherwise you're just going to send the object into a different orbit around the sun
The fastest any object has left the earth is around 8KM/S for the interplanetary probes (Pioneer, Voyager, Cassini, Galileo etc). That's as fast as the human race has ever gotten anything going[*]. Without a major advance in rocket technology (i.e. away from chemical rockets), that's about as fast as we're going to get anything going, too.
As a reference, the on-orbit manoever capability of the Shuttle, is a total of about 100M/S
Oh, and Hubble has much MUCH less manoever capability than this
This is why things are de-orbited, rather than "sent towards the sun" or further out. De-orbiting from LEO requires only a little "kiss" of deceleration before the orbit intersects the atmosphere, from where friction does the rest. The only exceptions are Satellites in higher orbits (e.g. GPS in the 12-hr / 12,000KM orbits, or Geostationary sats) which tend to be "retired" in slightly higher orbits because these are thought to be more stable over longer (geological) time periods than lower ones, and there's not enough residual manoever capability to lower the orbit enough to graze the atmosphere
[*] = However, we've learnt the trick of gravitational assists which lets Mother Nature (or Newton, or Einstein depending on your religious orientation :-) speed up our probes considerably at the expense of the orbital energy of the planet we're assisting from.
I'm a 2-year user of X-Plane, although I confess I've not been following the v7 beta stuff (I've stuck with 6.60 for now). I've logged hundreds of hours on the sim, and tinkered with the other tools available (e.g. I've modified aircraft etc).
X-Plane is a fantastic piece of work for a single person to have to his name. Probably the highest praise I can think to give it, is that it's not only the best at what it tries to do - simulate flight of all kinds - but it's also usable.
Having said all that, usable is about as far as it goes. It's not, and has never set out to be, a polished application with a glitzy UI. The interface for the sim and the tools is good enough and no better. If you need to get out and see what'll happen to an NF-104 at 100K feet when the control surfaces fail on you, then X-Plane is for you. But be prepared to adapt to it's interface, rather than have it teach you.
I've been looking at FlightGear recently too. And about all I can say about this right now is that it's clearly got promise, it looks good, but there's a looonnggg way to go. At least X-Plane lets me choose aircraft from a file selector dialog; I have to shut down FlightGear and use a different command line switch to load a new aircraft. It's clearly still very much for the Geeks for now, wheras I know there are professional pilots using X-plane.
I reject your advice. I carry a Psion 5MX everywhere with me. It's like a PDA, only it's got a proper keyboard. Which means I can take notes and write documents on it. This is a most valuable feature, since it means I can leave my Laptop behind for nearly all meetings etc.
The fact that it's got perl5, email connectivity, a Spectrum emulator, web browser, etc also is just a complete bonus. The 20hr battery life isn't bad either. However, it is 3 years old and I'm worried about the clamshell screen giving in again so I'm looking for a replacement.
So, to refute your advice: I am looking for a device with a keyboard that I can put in a shirt pocket (and I don't mind looking like a nerd with a kingsize pocket protector to do so), that I can take notes on, and that ideally has a 2 day (~4-5 hrs) battery life. Running Linux isn't a necessary (I've gotten used to EPOC too), but definitely a plus.
The internal copyright to do so expired, ending the trial.
Then in September, they sorted this out. Ogg streaming is due to re-start, Real Soon Now(tm). As it has been since September... See Here for more details....
There's a very good reason why you might link the ability to look way-out-there with the ability to look really-closely-down-here.
The Hubble Space Telescope is very closely based on earlier KH-series spy sat designs. So much so that it was shipped from the manufacturer to Kennedy Space Center in a KH-11 shipping container.
Indeed, a lot of the early gross design decisions on Hubble were subject to "anonymous" review from the relevant black agencies, and changes made appropriately.
Call it an early example of the Peace Dividend....
I'm well aware that Columbia's first flight was in 1981, since I distinctly remember watching at least 2 launch attempts on TV, the worries over the missing tiles on the OMS pods, and the subsequent safe landing at Edwards. I was 10, not that that should make a blind difference to anyone, but I was a Space Geek then and am one now (2nd class, amateur division).
Are you aware that Columbia (OV-102) is the second Shuttle Orbiter, and that the first, Enterprise (OV-101) flew in 1977, under the ALT (Approach and Landing Test) programme?
And that, despite the lack of SSME engines or indeed any sort of flight-representative thrust structure at the back of the craft, the production AP-101B computer, complete with representative software, was used on those flights (as it had to be, since Shuttle is fly-by-wire..).
Or, that on the last ALT flight (Flight 5), these very computers were if not cause then at least major contributing factor to a rather nasty Pilot Induced Oscillation (PIO) that caused Enterprise to land short? A fault that was corrected, in software, and the fix tested on the original Fly-By-Wire test aircraft, the F-8 FBW, using the exact same AP-101 computers.
Or that that FBW F8 had originally flown in 1973 using a single "DSKY" machine as flight computer, the same computer used on all Apollo spacecraft?
STS is very much a '70s design of a '60s concept (go read up on the StarClipper design to find out about what Shuttle should have been). With recent modifications it approaches the technology levels present in the early '80s, at costs comparable to '00s technologie crashes, with the reliability of a '30s airliner and the safety record of a ...ah, but we don't go there any more do we?
That's unfair, and comparing apples with oranges.
Think of a project on sourceforge as being a low-cost representation of an idea, rather than as a product. So the first thing you do is register your idea - or, if you're a fan of Homesteading the Noosphere, you "stake your claim". Then you see if there's interest, think a bit more about the problem and/or solution you're proposing, maybe try a few bits of code out.
Often times, what you deride as "alpha" level software is perfectly acceptable v1.0 shipping product from some large commercial suppliers (er, actually most commercial vendors). Their business model appears to be ship a minimally-functional product, if it works use the proceeds to fund v2.0
Remember also that that Alpha code may just do exactly what you want it to do - no final product required! Often times within the context of these sorts of connectivity programs, alpha-code is sufficient to prove the concept, wherein it becomes more profitable to roll the actual functionality into a larger project - e.g. Evolution's palm-sync equivalent, or a specific camera's photo-download software into gPhoto2 or similar.
In short, if I expect to have to pay for software, then I expect a Beta programme to a) provide an early look at the functionality b) provide an early look at the quality of the product before committing anything to it. If, on the otherhand, I'm crusin' sourceforge for solutions, then oftentimes a demonstration-quality Alpha release is more than enough to make a decision on whether to adopt, adapt, collaborate or ignore the project...
Yes, he does mean Core Memory, and yes, the AP-101 as flown in the Shuttle from mid-70s through to mid-90s did indeed use Core memory.
Indeed, the upgrade to the AP-101s with (I think) static-column RAM took so long because Core memory has the lovely property of retaining information even when the power dies - a key factor, sadly, in the ability to retrieve information from Challenger's onboard computers after the 1986 crash. Another key factor is that Core memory is remarkably resilient to bit-flipping caused by cosmic rays and other radiation (events known as "SEUs" or "Single Event Upsets").
All of which meant that it was a major project just to replace that memory with more modern RAM. And it's not just a couple' sticks of SDRAM either - most of the space-savings you'd expect from replacing bulky core with nice compact RAM chips is taken up with additional hardware to a) provide sufficient power support to retain memory in the event of main power failure b) continually scan through memory doing parity checks to detect and correct for SEUs...
Don't diss Core, man...
The future of Debian looks like the past.
There will be, lo, much wailing and gnashing of teeth because Random Cool Package vX+1 isn't in the STABLE release. There will be much complaining by users (of which I am one!) when RCP vX+1 takes longer than 15 nanoseconds to hit the UNSTABLE release, regardless of how complicated it is to support on N (where N>=11) different architectures.
In about 3 months time, there will be much complaining about how long the freeze for "Sid" is taking, and how out of date "Woody" has become (completely ignoring the fact that most people using Debian on servers are probably more than happy to continue to use "Potato" or earlier, just so long as they can apt-get from security.debian.org).
In about 2.5 years, there will be another announcement on /. announcing Debian 4.0.
And all through this, real honest-to-goodness users will be able to keep right up to the bleeding edge of free software just by adding a single line to their sources.list, and won't notice a thing.
By someone who's apparently been running Debian 3.0 for some time now (a number of days, anyway) and didn't even notice. Thanks, apt-get dist-upgrade!
Not to put too fine a point on it, I find your attitude wasteful and selfish. That 1.5 hours you spend in your car - engine running, CO2 emitting, space-occupying - could be reduced to a matter of minutes if you and your kind would just dien to join the rest of your fellow humanity now and again in a shared environment (AKA bus/train/tube/monorail/whatever), rather than selfishly squandering irreplaceable resources (steel, oil, asphalt) just to have your *own* air conditioning, your *own* choice of music, your *own* psuedo-privacy.
Positing good, clean, reliable, affordable public transportation, I see no good reasons other than the above for not using it. This whole "Car is good, Car is symbol of personal freedom and wealth" attitude is just so 1950's.
I agree wholeheartedly with anyone making any statements regarding the availability or otherwise of said good public transport and/or any means of providing same vs. cynical stealth taxes on motorists. But as a resident of Planet Earth along with 6 billion others, I really don't see what's so hard to understand about Sharing and Cooperating.
Hey, guess what: if they use this information to fine you then you were breaking those laws. All this materially changes is the ability to detect and prosecute, it does NOT change the laws.
I've heard it said and I wish I could remember the exact quote, but the best way to deal with bad laws is to change those laws. Not ignore them. change them.
In a perverse way, the ability of modern technology to enhance law enforcement should be seen as a universally good thing - not only can we catch more perps, but we can also use these tools as public awareness initiatives to lobby for better laws.
In this context, I would certainly and most vigourosly include the creation and enforcement of sane and reasonable data privacy laws (which we do - kinda - have). Which would or should tackle all of your remaining objections.
Clue for the clueless: they've always been able to do this, but the resources to do so have never been available for mass deployment. AKA ".Tailing A Car".. Secret services, Police, private detectives.
This is NOT an invasion of privacy, in itself. You are, after all, in a public place where your expectation of privacy is, or should be much lower than in your own home.
Note that there are risks here nonetheless, but these are th boringly normal ones around information security, ensuring authorised access only, etc etc etc. But I can't see that this is a frothing-at-the-mouth EFF/ACLU live-free-or-die Invasion Of Privacy issue.
Sorry to sound like a NIMBY, Middle-aged fuddy-duddy BUT...
What we really need is reliable, affordable and accessible Public Transport so we can avoid having to use our cars in the middle of a city anyway.
I speak as a car-owner and public transport user, and a commuter-to-London. I wouldn't dream of using my car to come in anyway (it took a colleague 2.5 hours to get from Gatwick airport to the office here in central London this morning), but relying on our trains, tube lines and buses is equally frustrating (My train was delayed 4 days out of 5 last week).
My car is for getting me from city to city, or for transporting goods and passengers on local journeys. It's just not good at taking just me from point A to point B in an urban conurbation and yet walking out of Waterloo station on any day of the week that's what you'll see: cars full of single occupants taking up 20 times the ground space of a pedestrian and 8 times the space of a bicycle.
Folks, I'm in favour of congestion charges - as long as you have an alternative to using your car, and as long as those charges are spent on those alternatives.
I'd like to agree with Ian on this one, both on the blindingly cynical real reason for the upgrade (more beans for Microsoft), and on the even more compelling user-centric counter view to this.
The only thing I'd like to add in this favour is that any competent organisation ought to be able to fight this push to upgrade with a really simple economic argument: Software solutions tend to get sold on a Return-On-Investment basis - If I buy an MS-Office based environment, my ROI over a period of time is given by:
(increased productivity measured using appropriate methods) - (cost of software AND cost of hardware AND cost of supporting solution)
(naturally, estimating the increase in productivity is where a lot of companies fall down, but you'd be amazed how many can't even estimate the second term in the above equation either)
My point here, though, is dead simple: theres an implicit time term in the above equation such that the costs are amortized over a period of time. Modulo normal accounting depreciation etc, this implies that an organisation gets better ROI if they can keep the same solution for as long as possible. This directly conflicts with MSFT's desire to force regular upgrades (which increases the costs element of the solution whilst only marginally - if at all - increasing the productivity improvement size).
As a good little corporate drone, it astounds me that more organisations haven't caught on to this and had a feedback effect on the IT industry as a whole - large corporate entities, especially financial institutions, should be cautious as all get-out when it comes to adopting new technologies or solutions. And yet we all blindly tread on the Shiny Thing treadmill, haemorraging money in a continual game of replacement and upgrade, fix and debug, for little gain.
Bah. We should have stayed on those green-screen thingies with nice reliable mainframes behind them
This has been an Old Phart Rant Courtesy of the letters M,S,F and T, and the day Monday
I don't understand that. They're just competing for bytes on your Tivo's HDD that way.
Now, if they could find a way to force you to watch downloaded programming, then they'd pay. Big time.
I'd love to know which stream you were listening to because my scheduled capture of the 1830 comedy on Radio 4 failed last night, and I'm desperate to find a way to get captures before Monday's I'm Sorry I Haven't A Clue!
The BBC Ogg test page states the test period finished on 2002/05/19 however I was able to record ISIHAC from Radio 4 on Monday 2002/05/20.
Incidently I have no idea of the legality or otherwise of capturing the live stream (using nothing more than a Cronjob'd "wget" BTW) but it strikes me that if you can make personal tape recordings from trad. radio then this sort of timeshifting is no more harmful...
*sob* please tell me I'm not going to have to go dig out one of those obsolete audio tapes in time for Monday *sob*. I want my, I want my, I want my Ogg R4...
See, this here is what I don't understand about the state of the telecoms world.
Your statement:
See, my immediate and overriding thought is: I'm the CUSTOMER. I give you money, you give me bandwidth. How I use it is up to me. I've bought - BOUGHT - bandwidth from you, and now you're putting all these restrictions on me because you didn't do your sums correctly and you're making a loss from insufficient service provision.
The same applies in spades to all the cable modem, ADSL, and prepaid dialup plans we see getting post-hoc restrictions placed on them. To me, this looks like the service provider is an incompetent cretin that can't do their sums, work out how much capacity they've *bought*, how much they *need* to service their paying customers, and charge appropriately right off the bat.
Seriously, folks, is the corporate world so seriously screwed up that no-one is capable of this?
You mean a Sinclair ZX81.
The ZX80 came with 1K RAM, yes. But the expansion pack was only 4K.
"Ram Pack Wobble" was a classic symptom of the ZX81 also - cheaper connectors as I recall (not JUST that there was no connector as such - just the PCB traces run to the edge of the board - but also the positioning of the board vis-a-vie the case)
Hmmm. Not so much Buran (AKA Shuttleski; the two vehicles look remarkably similar), but it is the spitting image of the X-20 Dynasoar (designed and almost-built in the '60s by the USAF). Pretty Pictures Here.
There's no reason to suppose copying. Both vehicles are built for approximately the same mission, so it's more concurrent evolution.
The US Military (who else?) tried this in the '60s with Minuteman ICBMs. Except they used a C5 Galaxy transport and a parachute. I believe the few tests worked well enough, but it was never adopted as an operational launch method: to be effective for nuclear deterrent would have required a fleet of C5s (only ~50 were built and they were built for heavy airlift), continuously airborne. Turns out to be cheaper to stick the Minutemans on the back of a train and drive it around the country (who'd a thunk?).
Anyway, as a commercial enterprise for smallsat launches, this would appear to be a workable solution - use a ram instead of expensive parachutes, and fly the transport down to the equator before launch (same trick that SeaLaunch uses). I just hope the launch vehicle is a bit more reliable than the competitor - Pegasus. They've had a bit of a run of bad luck recently...
There was an article on a very similar subject in New Scientist a few weeks back.. Lemme see if I can get a URL....{time passes} Oh dear, it's in the archive and you'll need to register to see it. And registration requires a subscription to the magazine.. how very lame.
Anyway, the upshot was that a research group was using consumer-type Digital Cameras to help automate surveys of Rain Forest flora.. turns out that their estimates were VERY BADLY off because the prime descriminator used was colour (think: "shades of green"). And the cameras they used (specific make/models not mentioned) basically couldn't capture the range of greens required, or distorted them. Spherical Aberations from the el-cheapo lens on the cameras just made things worse. Bottom line: years of work needs to be re-done with more expensive, calibrated equipment.