In this case, they aren't necessary as the lander has done all the science it was planned. What's the point of keeping it alive over the winter of all it's going to do in the spring is repeat the measurements it's already taken?
RTG's and RHU's are a massive, expensive, pain in the ass and are best avoided unless absolutely necessary.
Basically -
They're heavy. They are must be designed to wishstand re-entry intact and not disperse Pu238 fuel everywhere if the rocket explodes during launch. Extra weight on the lander means there will be science instruments that have to be taken off.
They're on 24/7 and they're only about 5% efficient so they produce about 20W of heat for every W of electricity. This is a huge problem when the spacecraft is buttoned up in it's Mars-entry aeroshell during the 9 month trip to Mars. Hundreds of W of waste heat must be dumped somehow or your lander will cook.
This may well use some kind of fluid cooling loop that circulates through radiators on the crusie stage. This now gives you added problems of a pump (which must not fail or you'll lose the mission, so add a back-up pump) and how to disconnect the coolant pipes with absolute reliability when the time comes to ditch the cruise stage and enter the Martian atmosphere. More problems, cost and weight.
Pu238 is on every terrorist's Christmas wish-list. You have the added problems and of turning the spacecraft assembly facilities into highly secure spacecraft assembly facilities. Assembling a Mars lander is already hard and expensive. You really don't want to add to this the cost and disruption of post-9/11 anti-terrorist, security paranoia.
Donna Shirley discusses this in her book on the Mars Sojurner rover, and that was put together back in 96.
Robotic Suit For Rent In Japan
Why did I first read this as referring to a legal case? Possibly involving a Japanese landlord taking a robot tenant to court over unpaid rent.
The crew of Soyuz 9 http://en.wikipedia.org/wiki/Soyuz_9 played chess with the ground in 1970.
They had a zero-g chess board that the pieces could clip on to.
So... just like the London Gazette has already been digitized.
The difference is, the Gazette began publishing in 1665.
Sod the moon landings! You can read the front-line reports about the American Revolution.
According to the Wikipedia article on age of consent in North America - http://en.wikipedia.org/wiki/Ages_of_consent_in_No rth_America two 17 year-olds in Florida can legally have sex.
It's just they can't take and send dirty pictures to each other.
I suppose I'll get shot to hell for proposing a possible solution, but here goes.
Launch really large balloons (100's m in diameter) into orbit. Use a material that goes rigid under solar UV so it doesn't matter if they get punctured after inflation.
Small debris - paint flecks etc. hit the balloon and vapoise themselves and some of the surface. Larger debris hits the balloon, punches through and out the other side, but in doing so loses some of its KE and drops into a slightly lower orbit, where atmospheric drag will have a greater effect. If larger debris punching through fragments under the impact, then that'll increase the surface area to mass ratio and enhance aerodynamic drag. Try to use a material (better yet, layers of material) that doesn't fragment under impact to compound the problem with secondary debris. Although, hopefully much of the debris would be contained inside the volume of the balloon.
The balloons themselves are in middish orbits (500-1000km) where there's not much drag and debris would otherwise have a very long lifetime.
Perhaps some of the labels aren't for real, it's just lawyers trolling.
There's an urban legend of a Superman costume with the lable "Warning, does not enable user to fly." If I was on the legal team of a company, I'd have great fun tacking on nonsense warnings like this. It would be kind've the legal equivalent of an Easter Egg.
The average contractor's response won't be "Great, I'll be buildinding something twice as strong". It will be "Great, I can use half the number of nails."
So the buildings will still fall down when a hurricane hits.
But for something with such obvious military applications, I wonder if they have really been beaten to the punch by 10 years by some deep black Skunkworks research team, courtesy of about 2 orders of magnitude more funding.
After all, the F-117 first flew in 1977 - it's 30 year old technology. I bet they've not been sitting on their hands since then.
1) Develop some idea... 2) Devise some bizarre, convoluted and obscure way it could be applied to "security" - extreme hand waving is obligatory. 3) Stand by while it starts to rain money on your research group courtesy of gullible government departments, research councils and investors. 4) Don't miss any sleep worrying about exactly what terrorist attack scenario would be averted by this technology. Or whether you are, in fact, plugging a security hole that doesn't exist. 5) Next month, when the cause de jour has shifted to, say for example, back to kiddie-porn, claim your technology is will be the panacia for that - go back to (2).
IANA(copyright)L . But don't all those men automatically have copyright over those emails and all the pictures of their bits? It's probably stretching the definition*, but those surely count as 'creative works'.
Therefore, isn't republishing them without permission a copyright violation?
*Opportunity left open for silly puns in follow-up comments.
... but with a permission from Mrs. Thelma Arnold, 62...
In other words, the journalists tracked down about 20 AOL searchers, but Mrs Arnold was the only one to give permission for the article as hers was the only search term list that didn't include 'midget porn'.
Given that Iraqi insurgent snipers are smart enough to aim for the gaps in Americans' body armour - article - flexable armour, even if's only used to cover joints, would be a very good thing.
It sounds like any UK based gambling operation will have to be doubly careful. Non-British slashdot readers may not be aware of the Natwest three case. Three British bankers have just been extratited to the US under a new "anti-terrorism" fast track extradition treaty. It has been alledged they carried out a fraud in the UK in connection with the Enron case. They've not been charged in the UK, no law was broken on US territory, the US had to provide a lower standard of evidence to carry out the extradition and the treaty is currently not reciprocal - the UK can't extradite Americans in the same way.
I bet operators of a UK based company, accidently doing bets with Americans, will probably be flying to the land of the free, in orange jump suits and leg shackles, so fast it'll make their head spin.
"Let's say, hypothetically, someone's writing emails to someone else, and you want it to look like AOL. That's a proprietary look, a proprietary software," said Ms. Zea, who has worked on several films including "Silence of the Lambs" (1991) and "The Manchurian Candidate" (2004). "You're certainly not going to go online and just dial up AOL, for example. You're going to create your own."
So who would the movie-makers ask permission from in order to use Linux and Thunderbird? Precisely who would threaten to sue them if they did'nd ask permission and went ahead anyway?
More accurate seismometers would be nice. But one thing about sea-floor earthequakes is that some generate tsunamis and some do not. That's why NOAA spends a bucket-load of money maintaining a network of deep-ocean pressure sensors on the bed of the Pacific (link) These work because a tsunami in deep ocean has a wavelength vastly greater than the depth of water so it produces a small, but characteristic and detectable, pressure pulse as it passes over the sensor.
If this GPS idea works as advertised, it'll be a very useful incremental improvment to the tsunami warning networks. But it'll hardly be revolutionary. Being able to determine which events will produce a tsunami just from the seismic data - that would be revolutionary.
The fuel cell reactant will come in little cartridges that will use propriatory interfaces. These will be thoroughly patiented to keep 3rd party manufacturers away from the party. They'll use cartridges that stop working after a certain date or when there is still some reactant left. Chances are that use of another manufacturers cartridge will automatically void the warrenty on your phone or laptop.
Soon, methanol or formic acid (Formira, or whatever the hell they call it) which were previously cheap industrial chemicals will join printer ink as one of the most expensive liquids in the world
it appears that killing the largest and oldest fish has a disproportionate effect on the population as the big ones tend to be the most prolific breeders.
The Mekong giant catfish would be an awful lot better off if this particular great-great-granddaddy/grandmommy had stayed in the water.
I'm guessing this "proprietary lifting gas technology" is almost certainly a pressurised envelope.
Traditionally, stratospheric balloon gas is at the same pressure as the surrounding air - the balloons are too lightweight to withstand any real pressure difference. When the helium expands during the day, some must be vented to stop the balloon from bursting. At night, ballast must be dropped to stop the balloon from falling. Thus the balloon can only stay up for a limited number of day/night cycles.
If you use a stronger envelope, the envelope can withstand the daytime pressure buildup. And if the helium is pressurised, you have extra gas to make up for the inevitable slow leakage. It is the only way to keep something up for 18 months.
As for this proprietary nonsense... well NASA have been working on the Ultra Long Duration Balloon for a while. But even that only stays up for 100 days. I wonder how they plan to keep one of those airships up for five times as long?
2) Speeding tickets has nothing to do with safety, but everything to do with making money in the government. Don't believe me? Check the revenue at the local law enforcement office.
If this were so, the last thing the authorities would want is a perfect speed enforcement system. If each car had a black box that snitched on the driver, each time he or she went 3 mph over the limit, then nobody would speed as evading fines would be impossible. The revenue stream would quickly dry up.
To maximise revenue, an imperfect enforcement system is needed. One that will only catch some speeders. The average motorist will continue to speed as they know they have a reasonable chance of getting away with it.
This seems to be exactly what we have in the UK in our network of roadside speed cameras.
Slashdot Mirror
RTG's and RHU's are a massive, expensive, pain in the ass and are best avoided unless absolutely necessary.
Basically -
This may well use some kind of fluid cooling loop that circulates through radiators on the crusie stage. This now gives you added problems of a pump (which must not fail or you'll lose the mission, so add a back-up pump) and how to disconnect the coolant pipes with absolute reliability when the time comes to ditch the cruise stage and enter the Martian atmosphere. More problems, cost and weight.
Robotic Suit For Rent In Japan Why did I first read this as referring to a legal case? Possibly involving a Japanese landlord taking a robot tenant to court over unpaid rent.
The crew of Soyuz 9 http://en.wikipedia.org/wiki/Soyuz_9 played chess with the ground in 1970. They had a zero-g chess board that the pieces could clip on to.
So... just like the London Gazette has already been digitized. The difference is, the Gazette began publishing in 1665. Sod the moon landings! You can read the front-line reports about the American Revolution.
Thief-proofing and iPod reduces the chance of a mugging victim needing to go out to buy another iPod.
According to the Wikipedia article on age of consent in North America - http://en.wikipedia.org/wiki/Ages_of_consent_in_No rth_America two 17 year-olds in Florida can legally have sex.
It's just they can't take and send dirty pictures to each other.
I suppose I'll get shot to hell for proposing a possible solution, but here goes.
Launch really large balloons (100's m in diameter) into orbit. Use a material that goes rigid under solar UV so it doesn't matter if they get punctured after inflation.
Small debris - paint flecks etc. hit the balloon and vapoise themselves and some of the surface. Larger debris hits the balloon, punches through and out the other side, but in doing so loses some of its KE and drops into a slightly lower orbit, where atmospheric drag will have a greater effect. If larger debris punching through fragments under the impact, then that'll increase the surface area to mass ratio and enhance aerodynamic drag. Try to use a material (better yet, layers of material) that doesn't fragment under impact to compound the problem with secondary debris. Although, hopefully much of the debris would be contained inside the volume of the balloon.
The balloons themselves are in middish orbits (500-1000km) where there's not much drag and debris would otherwise have a very long lifetime.
Perhaps some of the labels aren't for real, it's just lawyers trolling.
There's an urban legend of a Superman costume with the lable "Warning, does not enable user to fly." If I was on the legal team of a company, I'd have great fun tacking on nonsense warnings like this. It would be kind've the legal equivalent of an Easter Egg.
If it's possible to hide a lethal bomb in a phone, then a bug should be easy.
See: http://en.wikipedia.org/wiki/Yahya_Ayyash
The average contractor's response won't be "Great, I'll be buildinding something twice as strong". It will be "Great, I can use half the number of nails."
So the buildings will still fall down when a hurricane hits.
But for something with such obvious military applications, I wonder if they have really been beaten to the punch by 10 years by some deep black Skunkworks research team, courtesy of about 2 orders of magnitude more funding.
After all, the F-117 first flew in 1977 - it's 30 year old technology. I bet they've not been sitting on their hands since then.
1) Develop some idea...
2) Devise some bizarre, convoluted and obscure way it could be applied to "security" - extreme hand waving is obligatory.
3) Stand by while it starts to rain money on your research group courtesy of gullible government departments, research councils and investors.
4) Don't miss any sleep worrying about exactly what terrorist attack scenario would be averted by this technology. Or whether you are, in fact, plugging a security hole that doesn't exist.
5) Next month, when the cause de jour has shifted to, say for example, back to kiddie-porn, claim your technology is will be the panacia for that - go back to (2).
IANA(copyright)L . But don't all those men automatically have copyright over those emails and all the pictures of their bits? It's probably stretching the definition*, but those surely count as 'creative works'.
Therefore, isn't republishing them without permission a copyright violation?
*Opportunity left open for silly puns in follow-up comments.
In other words, the journalists tracked down about 20 AOL searchers, but Mrs Arnold was the only one to give permission for the article as hers was the only search term list that didn't include 'midget porn'.
Given that Iraqi insurgent snipers are smart enough to aim for the gaps in Americans' body armour - article - flexable armour, even if's only used to cover joints, would be a very good thing.
Nonsense!
They're finally pulling the plug on WOPR. Although they'll be doing so very carefully!
I bet operators of a UK based company, accidently doing bets with Americans, will probably be flying to the land of the free, in orange jump suits and leg shackles, so fast it'll make their head spin.
"Let's say, hypothetically, someone's writing emails to someone else, and you want it to look like AOL. That's a proprietary look, a proprietary software," said Ms. Zea, who has worked on several films including "Silence of the Lambs" (1991) and "The Manchurian Candidate" (2004). "You're certainly not going to go online and just dial up AOL, for example. You're going to create your own."
So who would the movie-makers ask permission from in order to use Linux and Thunderbird? Precisely who would threaten to sue them if they did'nd ask permission and went ahead anyway?
If this GPS idea works as advertised, it'll be a very useful incremental improvment to the tsunami warning networks. But it'll hardly be revolutionary. Being able to determine which events will produce a tsunami just from the seismic data - that would be revolutionary.
Soon, methanol or formic acid (Formira, or whatever the hell they call it) which were previously cheap industrial chemicals will join printer ink as one of the most expensive liquids in the world
1 - Take any keyboard. 2 - Remove the printed characters on the keys with cotton buds soaked in acetone. 3 - ????? 4 - Profit!
I use a five pound cell-phone.
At least, last time I checked eBay, that was the going price for a 1999 Phillips Savvy.
it appears that killing the largest and oldest fish has a disproportionate effect on the population as the big ones tend to be the most prolific breeders.
The Mekong giant catfish would be an awful lot better off if this particular great-great-granddaddy/grandmommy had stayed in the water.
Traditionally, stratospheric balloon gas is at the same pressure as the surrounding air - the balloons are too lightweight to withstand any real pressure difference. When the helium expands during the day, some must be vented to stop the balloon from bursting. At night, ballast must be dropped to stop the balloon from falling. Thus the balloon can only stay up for a limited number of day/night cycles.
If you use a stronger envelope, the envelope can withstand the daytime pressure buildup. And if the helium is pressurised, you have extra gas to make up for the inevitable slow leakage. It is the only way to keep something up for 18 months.
As for this proprietary nonsense... well NASA have been working on the Ultra Long Duration Balloon for a while. But even that only stays up for 100 days. I wonder how they plan to keep one of those airships up for five times as long?
If this were so, the last thing the authorities would want is a perfect speed enforcement system. If each car had a black box that snitched on the driver, each time he or she went 3 mph over the limit, then nobody would speed as evading fines would be impossible. The revenue stream would quickly dry up.
To maximise revenue, an imperfect enforcement system is needed. One that will only catch some speeders. The average motorist will continue to speed as they know they have a reasonable chance of getting away with it.
This seems to be exactly what we have in the UK in our network of roadside speed cameras.