"Before Beagle landed, a colleague reported that in a lecture the previous summer, Prof. Pillinger said that the parachute's size wasn't critical as it 'collects air' which helps slow the lander down..."
But in a sense that's true: provided it's big enough to slow the lander to the correct terminal velocity before the landing, the size doesn't matter... make it ten times bigger and you'll just be floating down for longer under the parachute.
On the other hand, if it's 10% too small, you're probably screwed.
"I'm not so enamoured of HD quality that I'm willing to put up with the "Next Generation DIVX" player in my home."
Ditto. I have an HDTV camcorder, I'd love to be able to buy HDTV DVDs, but I'm sure not going to do so if they put this kind of crap on them.
I just don't think the early adopters are going to accept this, and if they don't then Joe Sixpack will continue watching his DVDs. To me this seems to be DAT Mark 2, where a good format is destroyed by stupid 'copy protection' nonsense.
"Except it isn't possible to reach space using only one stage, unless you make absolutely massive sacrifices on all other fronts."
_Reaching_ space with a single stage isn't that hard: the Atlas could do so, though it did drop two engines along the way, and in theory the SII stage of the Saturn V could do so, though it would have needed major changes to be able to launch itself.
It's reaching space with a worthwhile payload and getting back in a single stage which is hard:).
"Fuels that are used in space must carry their own oxygen, but when going at high speeds in the earth's atmosphere, why not make like a jet engine and get oxygen from the atmosphere?"
Because rockets generally don't 'go at high speeds in the earth's atmosphere'. Typically the job of the first stage is to lob the second stage pretty much out of the atmosphere so it can accelerate to orbital velocity with very low drag and vacuum-optimised engines.
You really don't want to be flying at Mach 20 in an atmosphere thick enough to provide oxygen to your engines: I believe the NASP design would have required active cooling with liquid hydrogen to keep the skin from melting. Developing such a system is a lot more expensive than throwing some more liquid oxygen in the tanks, and fatal if the cooling fails.
"There's absolutely no way that White Knight / Spaceship One will scale up to an orbital vehicle."
Sigh. Where did they say it would use the same design as the current vehicles? Ah, they didn't.
"If Rutan thinks he can build a vehicle capable of travelling ten times faster than SS1 with high enough SI and all the rest of that engineering detail, great, let him try"
Putting people into space is 1960s technology: anyone with a few brain cells and enough money can do it. The only question is whether Rutan can do it cheaply enough to make space tourism viable.
"Where the heck do you get that from? EVERY shuttle accident was caused by a problem from those boosters. From 'O' Rings to insulation. They were not shuttle poblems, but booster problems."
No it wasn't. The foam came off the tank, not the SRB.
Equally, had the astronauts been in a capsule on top of the SRB when Challenger's SRB started to leak, they'd have hit the 'Abort' button and come floating down by parachute. The only reasons Challenger was destroyed were because the SRBs were on the _side_ of the fuel tank and the escaping hot gas burnt through the tank, and because it was a winged vehicle that broke up easily under aerodynamic stress, not a simple capsule that can take a beating and hold together.
Re:Whatever happened to single-stage-to-orbit?
on
NASA's Shuttle Plans
·
· Score: 2, Insightful
"Because single stage to orbit is the dumbest idea anyone ever came up with. Why in the world would you carry a ton of extra weight past a normal staging point?"
Because fuel is dirt-cheap, at least by the standards of spaceflight costs.
What costs is high maintenance and long turn-around times... if you want cheap access to space, you want fully reusable, low-stressed, low-maintenance spacecraft which can operate like airliners (or, at least, like DC-3s).
If carrying a ton of extra weight will give you that, then you carry a ton of extra weight and burn another dozen tons of kerosene on each flight. Kerosene is cheap, overhauling engines, assembling shuttle/ET/SRBs, fixing heat-shield tiles and all the other junk NASA do costs a lot.
"people who cause massive damage on an any scale - economic, physical, emotional - are sociopaths."
Then killing them is the only solution, since 'curing' them is basically impossible and locking them up only gives them a chance to escape.
Theodore Dalrymple had an interesting article printed a few years ago when he was talking to prisoners about their thoughts on the death penalty: the conclusion was that prisoners were vastly _MORE_ supportive of the death penalty than the law-abiding. After all, they live in a world full of crime, and see the consequences on a regular basis.
"By the time these come out, (somewhat)affordable HD camcorders will also be hitting the market"
Um, 'somewhat affordable' ($5,000-7,000-ish) HD camcorders have been available for months: I have one. Sony are also just about to release a $2,000 HD camcorder with cheaper ones on the way.
Possibly by you, but from what I've heard, most astronauts don't consider it survivable. There's a good reason why the RTLS demonstration flight was cancelled... the odds simply weren't good enough to risk a shuttle and crew.
TAL, I believe, puts _more_ heat stress on the shuttle than a normal re-entry, so it's almost certainly not survivable with a damaged heat shield. Same, as you say, with ATO.
If you take major heat shield damage in the first two minutes you're basically stuck with bailing out into the Atlantic, or RTLS. Neither is a good choice.
"I am impressed, though, that Amazon actually hung in there through years and years of losses and now actually has a profitable, reasonably sustainable business."
Of course they'd have made more money just by sticking all the cash they got from shares into a Euro or Sterling bank account and forgetting all that tedious book-selling business...
LOL. The Hobbit is a guaranteed money-spinner if Jackson directs it: New Line aren't going to throw away a few hundred million from the Hobbit just because Jackson sued them.
"and, in Germany at least, an unwillingness to cover the entire country in tarmac as the UK is doing"
Back in reality-land, Germany has substantially more miles of road per capita than Britain: the UK's per-capita road density is about _HALF_ the EU average. They also have unlimited speed motorways in many places, unlike the crap 70mph motorways in the UK.
Transport infrastructure in the UK is an utter disaster, and another four years of anti-car NuLab is only going to make it worse. We're a 'first-world' nation with roads and railways that would embarass many third-world nations.
"1. Exploring space (could be key to our future if something ever happens to earth)"
The shuttle ain't doing much exploring, it's just going round and roung in circles: and it's far cheaper to send robots to do the job of actually exploring than humans.
"2. Testing and developing new technologies to advance space flight, aviation, and other areas that wind up being useful here (velcro, etc.)"
The spin-off argument is totally bogus and has been debunked numerous times. The fact that you believe NASA developed velcro shows you don't know what you're talking about.
"3. Eventually building space habitats that more people will be able to visit. ISS is for scientific purposes,"
What science, exactly, has ISS produced?
"but several private companies have already put forward plans to put up space hotels, resorts, etc. A lot of them use technology developed by NASA."
No-one in their right mind would use NASA technology for a space station: it's way too complex, expensive and maintenance-intensive. The only 'space hotel' likely to fly in the next decade, if at all, is based on inflatable modules, not NASA-style spam-cans.
"4. AI. Robotics has made large advancements thanks to NASA and the space program."
For which the shuttle is absolutely irrelevant, except to the extent that it takes billions of dollars away from useful robotic exploration programs to blow on 'Buck Rogers'.
"5. Developing new propulsion methods. Several preliminary designs for commercial hypersonic aircraft are based on NASA tech."
For which the shuttle is absolutely irrelevant. Equally, we don't have any 'commercial hypersonic aircraft', so the fact that NASA blew a few bucks studying them is irrelevant too.
"My significant other's Windows XP account is set up as a "Limited Account", and she has no problems using it to check email, run Firefox and MS Money, and so forth."
That's odd. I tried setting up a similar account for my girlfriend and she had no problem running Mozilla... except that it was impossible to view anything on the Internet because the DSL dialer _REQUIRES ADMINISTRATOR PRIVILEDGES TO CONNECT_.
So you're right: for a few people running a few specific simple applications, you can manage with a non-admin account. But most people need to run at least one program which requires admin, and it's far too much hassle to try to make an OS with a totally broken user model work properly.
I for one am glad to see this story come out while Bliar is trying to push internal passports on us. Labour MPs really, really hate seeing Bliar bend over for some right-wing Yank with the IQ of a cucumber, so this is a strong incentive for them to vote against their leader on this law... which would almost certainly mean it would fail.
Slashdot Mirror
"Before Beagle landed, a colleague reported that in a lecture the previous summer, Prof. Pillinger said that the parachute's size wasn't critical as it 'collects air' which helps slow the lander down..."
But in a sense that's true: provided it's big enough to slow the lander to the correct terminal velocity before the landing, the size doesn't matter... make it ten times bigger and you'll just be floating down for longer under the parachute.
On the other hand, if it's 10% too small, you're probably screwed.
"A while ago there was some research into giant tinfoil equipped satellites which could redirect sunlight onto the earth during darkness."
g ov/19790076663_1979076663.pdf
Indeed. Here's one plan that would only have cost a couple of billion dollars a time:
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.
Actually makes this EU boondoggle look cheap!
"The only thing that could be done to curtail this practice would be to require single-purpose bills that can't be loaded full of non-related crap"
Alternatively you could just enforce the Constitution: then 99% of laws would be thrown out immediately... including this one.
"I found the best way to avoid false incrimination is to not leave my DNA at crime scenes."
So what will you do when a criminal _does_ leave your DNA at a crime scene?
"I'm not so enamoured of HD quality that I'm willing to put up with the "Next Generation DIVX" player in my home."
Ditto. I have an HDTV camcorder, I'd love to be able to buy HDTV DVDs, but I'm sure not going to do so if they put this kind of crap on them.
I just don't think the early adopters are going to accept this, and if they don't then Joe Sixpack will continue watching his DVDs. To me this seems to be DAT Mark 2, where a good format is destroyed by stupid 'copy protection' nonsense.
"Except it isn't possible to reach space using only one stage, unless you make absolutely massive sacrifices on all other fronts."
:).
_Reaching_ space with a single stage isn't that hard: the Atlas could do so, though it did drop two engines along the way, and in theory the SII stage of the Saturn V could do so, though it would have needed major changes to be able to launch itself.
It's reaching space with a worthwhile payload and getting back in a single stage which is hard
"When Rutan has a Falcon-1 equiv engine (covered on Slashdot a while back), *then* I'll pay attention to the press releases."
Why develop an engine from scratch when you're not an engine developer and there are dozens of proven engines you can just buy?
"Fuels that are used in space must carry their own oxygen, but when going at high speeds in the earth's atmosphere, why not make like a jet engine and get oxygen from the atmosphere?"
Because rockets generally don't 'go at high speeds in the earth's atmosphere'. Typically the job of the first stage is to lob the second stage pretty much out of the atmosphere so it can accelerate to orbital velocity with very low drag and vacuum-optimised engines.
You really don't want to be flying at Mach 20 in an atmosphere thick enough to provide oxygen to your engines: I believe the NASP design would have required active cooling with liquid hydrogen to keep the skin from melting. Developing such a system is a lot more expensive than throwing some more liquid oxygen in the tanks, and fatal if the cooling fails.
"There's absolutely no way that White Knight / Spaceship One will scale up to an orbital vehicle."
Sigh. Where did they say it would use the same design as the current vehicles? Ah, they didn't.
"If Rutan thinks he can build a vehicle capable of travelling ten times faster than SS1 with high enough SI and all the rest of that engineering detail, great, let him try"
Putting people into space is 1960s technology: anyone with a few brain cells and enough money can do it. The only question is whether Rutan can do it cheaply enough to make space tourism viable.
"Where the heck do you get that from? EVERY shuttle accident was caused by a problem from those boosters. From 'O' Rings to insulation. They were not shuttle poblems, but booster problems."
No it wasn't. The foam came off the tank, not the SRB.
Equally, had the astronauts been in a capsule on top of the SRB when Challenger's SRB started to leak, they'd have hit the 'Abort' button and come floating down by parachute. The only reasons Challenger was destroyed were because the SRBs were on the _side_ of the fuel tank and the escaping hot gas burnt through the tank, and because it was a winged vehicle that broke up easily under aerodynamic stress, not a simple capsule that can take a beating and hold together.
"Because single stage to orbit is the dumbest idea anyone ever came up with. Why in the world would you carry a ton of extra weight past a normal staging point?"
Because fuel is dirt-cheap, at least by the standards of spaceflight costs.
What costs is high maintenance and long turn-around times... if you want cheap access to space, you want fully reusable, low-stressed, low-maintenance spacecraft which can operate like airliners (or, at least, like DC-3s).
If carrying a ton of extra weight will give you that, then you carry a ton of extra weight and burn another dozen tons of kerosene on each flight. Kerosene is cheap, overhauling engines, assembling shuttle/ET/SRBs, fixing heat-shield tiles and all the other junk NASA do costs a lot.
"people who cause massive damage on an any scale - economic, physical, emotional - are sociopaths."
Then killing them is the only solution, since 'curing' them is basically impossible and locking them up only gives them a chance to escape.
Theodore Dalrymple had an interesting article printed a few years ago when he was talking to prisoners about their thoughts on the death penalty: the conclusion was that prisoners were vastly _MORE_ supportive of the death penalty than the law-abiding. After all, they live in a world full of crime, and see the consequences on a regular basis.
"By the time these come out, (somewhat)affordable HD camcorders will also be hitting the market"
Um, 'somewhat affordable' ($5,000-7,000-ish) HD camcorders have been available for months: I have one. Sony are also just about to release a $2,000 HD camcorder with cheaper ones on the way.
"Same, as you say, with ATO"
:).
Of course that should have been AOA, too many acronyms
"It is definately survivable"
Possibly by you, but from what I've heard, most astronauts don't consider it survivable. There's a good reason why the RTLS demonstration flight was cancelled... the odds simply weren't good enough to risk a shuttle and crew.
TAL, I believe, puts _more_ heat stress on the shuttle than a normal re-entry, so it's almost certainly not survivable with a damaged heat shield. Same, as you say, with ATO.
If you take major heat shield damage in the first two minutes you're basically stuck with bailing out into the Atlantic, or RTLS. Neither is a good choice.
"AFAIK there is an ejection system."
Nope. The only options are:
1. bail out the side door and ditch the shuttle in the Atlantic.
2. RTLS abort back to KSC, which is probably unsurvivable.
"I am impressed, though, that Amazon actually hung in there through years and years of losses and now actually has a profitable, reasonably sustainable business."
Of course they'd have made more money just by sticking all the cash they got from shares into a Euro or Sterling bank account and forgetting all that tedious book-selling business...
LOL. The Hobbit is a guaranteed money-spinner if Jackson directs it: New Line aren't going to throw away a few hundred million from the Hobbit just because Jackson sued them.
"and, in Germany at least, an unwillingness to cover the entire country in tarmac as the UK is doing"
Back in reality-land, Germany has substantially more miles of road per capita than Britain: the UK's per-capita road density is about _HALF_ the EU average. They also have unlimited speed motorways in many places, unlike the crap 70mph motorways in the UK.
Transport infrastructure in the UK is an utter disaster, and another four years of anti-car NuLab is only going to make it worse. We're a 'first-world' nation with roads and railways that would embarass many third-world nations.
"1. Exploring space (could be key to our future if something ever happens to earth)"
The shuttle ain't doing much exploring, it's just going round and roung in circles: and it's far cheaper to send robots to do the job of actually exploring than humans.
"2. Testing and developing new technologies to advance space flight, aviation, and other areas that wind up being useful here (velcro, etc.)"
The spin-off argument is totally bogus and has been debunked numerous times. The fact that you believe NASA developed velcro shows you don't know what you're talking about.
"3. Eventually building space habitats that more people will be able to visit. ISS is for scientific purposes,"
What science, exactly, has ISS produced?
"but several private companies have already put forward plans to put up space hotels, resorts, etc. A lot of them use technology developed by NASA."
No-one in their right mind would use NASA technology for a space station: it's way too complex, expensive and maintenance-intensive. The only 'space hotel' likely to fly in the next decade, if at all, is based on inflatable modules, not NASA-style spam-cans.
"4. AI. Robotics has made large advancements thanks to NASA and the space program."
For which the shuttle is absolutely irrelevant, except to the extent that it takes billions of dollars away from useful robotic exploration programs to blow on 'Buck Rogers'.
"5. Developing new propulsion methods. Several preliminary designs for commercial hypersonic aircraft are based on NASA tech."
For which the shuttle is absolutely irrelevant. Equally, we don't have any 'commercial hypersonic aircraft', so the fact that NASA blew a few bucks studying them is irrelevant too.
"This guy obviously has no background in anything scientific, has absolutely no clue about what the space shuttle or NASA are trying to accomplish"
I have a background in science, I've been a VIP at several space shuttle launches, met numerous astronauts and NASA employees.
And I agree with everything that he says.
Maybe you could explain exactly what NASA has accomplished with the Space Shuttle and the Great White Elephant in the sky?
"I thought one of the benefits of DSL over dial-up networking was that DSL is always on."
It's always on, but not always connected. It only connects the first time I try to access the Internet after logging in.
"can't the dialer be set up to run as a service?"
Possibly, but that's something my ISP would have to fix, not my girlfriend.
"My significant other's Windows XP account is set up as a "Limited Account", and she has no problems using it to check email, run Firefox and MS Money, and so forth."
That's odd. I tried setting up a similar account for my girlfriend and she had no problem running Mozilla... except that it was impossible to view anything on the Internet because the DSL dialer _REQUIRES ADMINISTRATOR PRIVILEDGES TO CONNECT_.
So you're right: for a few people running a few specific simple applications, you can manage with a non-admin account. But most people need to run at least one program which requires admin, and it's far too much hassle to try to make an OS with a totally broken user model work properly.
It's people like you who make the destruction of freedom so easy. I seem to remember the commies had a name for them: 'useful idiots'.
I for one am glad to see this story come out while Bliar is trying to push internal passports on us. Labour MPs really, really hate seeing Bliar bend over for some right-wing Yank with the IQ of a cucumber, so this is a strong incentive for them to vote against their leader on this law... which would almost certainly mean it would fail.