A) No lab manufactured nano tube to date of any manufacturing technique has yet to produce strands close enough to the theoretical max strength to prove It is possible to create a space elevator.
B) No one yet knows how or even if its realistic to draw them out into suffcient lengths to stretch across a room much less 70,000 kilometers. Similar problems with joining smaller strands to make larger ones without loosing strength.
Those two little hicupps mean the whole idea is still in the stage of "Is it possible?".
Like I said don't get me wrong. There is nobody who would love to see the above issues solved more than me. I just find it hard to get worked up about timelines and budgets for a pie in the sky idea that dosn't have its fundamental technology in existence. Talking about timelines and budgets is absolutely ridiculose until they actually make the first nanotube with sufficient strength to justify the basic premise of space elevator construction. Right now given what we have it wouldn't matter if you had thousands of years and unlimited budget you could not build a space elevator. By comparison give me a steady stream of workers, nothing but hand tools and I will give you a tunnle through the alps, just a matter of time.
Its possible sufficient nano tube technology is also just a matter of time. Its also possible it won't be sufficient ever. Thats the problem with technology that dosn't yet exist. Its like the proverbial wings that would keep bullfrogs from busting ther @$$ everytime they jump... if only they had them.
Call me when they make a strong enough tube. Course then I will say call me when they prove manufacturing it in sufficient length with suficent strength is only a matter of how long you want to make it or limited at such a margin that length to Geosync is no issue. THEN and ONLY THEN talk to me about budgets and timelines becasue then it will be a question of "Will it be done?" vrs "Can it be done?".
Very poor buisness logic in that story. Granted given current launch needs an RLV faces a problem in that if we had one tommorrow we wouldn't have enough work for it. However the logic of that argument is like saying in the day of Charles Lindberg had a 747 been available not enough people would be intrested in being able to fly across the atlantic. How many buisness models utilizing space transportation are deemed non-viable due to launch costs. How many new ideas might be born if cheap access to space were a reality ? The logic in the story fails to even discount the possibility of new uses for space instead choosing to focus on the current launch schedule and projected launch demand based on current launch capacities.
Just to give one concrete example take the telecom needs. Telecom stats are expensive. They are expensive to build because they have to last ( ie that have to be uber reliable ). This is because they cost a butt load to launch and backup launches are almost unthinkable. Now decrease launch costs to say the truly optomistic $100 a kg. for simplicty of agument and satalite designs need not be so intollerant. Expanding capacity ( IE stalite broad band ) becomes a non-issue. Most stalite launch demands are similarly governed, expensive launch makes for even more expensive development due the the fact you don't get second chances.
Changing the cost to orbit changes the entire dynamics in a way that simply can't be predicted. Perhaps the payloads will not be there... but just like trans-atlantic flight took off almost overnight once a suitable technology came around I imagine there will be an expansion of launch needs once a more viable and cheaper access to space becomes available.
Re-useable launch vechicles make obviouse finacial sense... the question is can we actually make one more than should we make one. If we can't then maximising one time use designs is the path to highest payload margins. If its possible ( and the case can be made ) then you do the math. A re-useable design that reduces cost to orbit has to cost more than is currently being projected to not be able to pay for itself... the catch of course is if it can truly reduce the cost to orbit enough. Having said that I grant the reality of the current launch needs means a system that sufficiently drops the cost of reaching orbit likely could not recoup its development costs without a corresponding increase in launch schedules except by comparison to what a launch would have cost without the new RLV ( IE phantom accounting ).
Arguing that the technology to build an RLV from one time designs is somewhat inaccurate. Granted some progress will undoubtably be made however there will be no enginerring imperitive to make a system durable enough to be re-used because any excess weight above and beyond what is needed for a single launch cycle will be spurious. Technology advances follow the engineering goal. Metal skin and honey comb composites in plane designs did not come about from pefecting wood and cloth planes, it was a direct improovment driven by the desire for faster designs that could sustain higher loads with less maintenence. If you want RLV technology then at some point you have got to aim for RLV's... not SLV's.
Critical technology which is yet to be viable in a lab environment much less a space mass production facility. But more importatly this timeline does not appear to account for the source of material to build the cable. Surely they are not suggesting ligting a million plus kg to orbit the old fashioned way ? THe ability to move a near earth object of the proper composition is also another technology that is yet to be developed as well that is pretty key. 20 years with one break through... phunny there is more than one roadblock for that timeline.
I would love to see an elevator but I have yet to hear a convincing argument. Instead of touting what might be possible IF IF IF IF lets get about the buisness of actually making the key material a reality before going hog wild about what we could do with it. There are other uses for such a strong material other than space elevators. When we have carbon nano tubes strong enough and the ability to mass produce at the needed quality is demonstrated I will get a little more excited about this possibility. Till then lets hatch the eggs before we count chickens.
The report is nutz. Imagery denied becasue no one knew who if anyone 'officially' requested it despite the fact it was requested and they knew they had a significant impact that at the time of the deinal was classified as an out of family event. At the very worst it may have put to rest any doubts regarding the impact. There are stories from old timers here ( MSFC ) talking about photos with legible tile serial numbers on the first shuttle flight were provided by military assests. However the people that denied the requests and thought the imagery would not be sufficient were not cleared to know the level of detail that could be provided if needed. Jevuss.
Granted after reading the report I still hold that most likely once the foam hit they were fucked. The repair option borders on the insane and the Atlantis rescue scenario was at the raw edge of feasibility before considering how perfect everything would have had to be just to get Atlantis up there before they died from a toxic atmosphere. Granted both options have the edge of sounding just crazy enough to actually work.
However I think that question is moot. The system is inherrently flawed. Failure is inevitable and in a system this far on the ragged edge merely a question of time. The culture of living with that fact is inevitably going to become callous. People question how the program could continually ignore impact damage from the foam and the answer is because that it wasn't the only thing that was on their plate. It was part of a never ending stream of items with potentially catastrophic results. It was background noise. It wasn't like Tile damage was the one glaring fault to an otherwise perfect system. In that kind of environment if you obessess over every possible failure the way it should be all the time on a system as problematic as SHuttle has prooven to be the only possible outcome is insanity. The callousness and complacency were an almost inevitable result. An independent safety board will help but only so much. The reactor managment example is somewhat deciving. The margin for error in running a nuclear reactor is far more manageable than the safety margin of rocket and re-entry operations.
In otherwords the complacent management is merely the means by which the system failed. You could have had an entirely techncially savvy decision making process appropriately concious at ever step of the process and perhaps in this case you would have had a dramatic rescue or on orbit repair story to talk about now instead of a man made meteor shower over Texas. However it would be just as likely that given that level of management a critical system would have catastrophcially failed or hull integrity compromised by an un-avoidable piece of space junk that no amount of management could avoid or recover from. In that case a system would be redesigned. In this case managment needs and over haul... and a serious influx of technical knowledge with which to assess the lower level analysis infomration provided.
THe statistics regarding shuttle system dictate failure at some point on some level. The system is to complex and to far out on the edge with to little margin. In this case the system that failed was the human system. Next time we may have a mechanical system go down. Its not an excuse to fail to improove, its just reality.
Abuse of the system can go both ways. Once UNION's form they create a power structure that is just as capable of rapeing and pillaging the peons just as surely as corporate management. Power currupts period. A currupt management system with unfair distribution of proceeds is bad but so is a Union run amuck that has hamstrung a managements ability to deal with substandard employees. Unions will fight to protect the job of a worker or to prevent layoffs regardless of whethere they are substandard or not, regardless of whether the situation calls for it or not. So instaed of 16 VP's sitting around on the sinking ship you have everyone sitting around and the ship sinks faster. Unreasonable unionized labor demands are one of the largest reasons we see increasing numbers of jobs heading over seas.
Don't get me wrong. Unions have done a great deal of good in this nation and still perform a needed counterpoint to corporate greed however please.... PLEASE don't try and tell me the need today is anywhere near as strong as it once was. Today most unions are in a quagmire. They exist and wield extrodinary amounts of influence which they do whether they need to or not to justify their continued existence not to mention the slice taken out of union members checks which often wind up funding salaries of union managers just as exorbant as those greedy VP's in managment and who have an equal disregard for the plight of the average Joe Shmuck union worker other than that they don't break ranks.
First progress is not a re-entry vehicle and whether or not it can make Shuttle's typical orbit is more or less moot, perhaps they could have used it for a life boat though I do not belive progress has self sustained life support, I believe it is reliant on connections to ISS for that. I could be wrong. A quick fix jury rig is always possible but IF it could make it its payload would be severely limited. More likely it carries life support supplies for Shuttle then you have to figure out how to get the goodies with no arm and no docking ability and no EVA pack.
Soyuz can't make it that I am aware of and it is even smaller than an apollo command module. It is also a squeeze just to get 3 people in it. If you could whistle up two of them and squeeze every one in AND they could make it, great.
When I say Its not possible that is because its not a real qustion of nominal vrs emergency use as much as simple can't get there from here. Perhaps the engineers would correct me and I certainly am not a rocket scientist but I am pretty sure Orbital mechanics and liquid fuel rocket limitations mean its not doeable for Soyuz. 5% payload to orbit is a fantastic margin from a launch platform ( shuttle gets 2.5% counting the entire mass of the orbiter/engines/payload which is about as good as it gets among current systems). To get to shuttle inclination from Russia's launch facility or to Soyuz inclination from Kennedy requires you to take the scenic route to orbit and no system currently has that much performance margin. If your still not sure why get a globe and connect the dots between KSC and the Russian launch facility, that determines the inclination both can launch to equally well. Then go find Columbia's orbital inclination and draw that circle. Now to get to that inclination you have to turn taking a longer path. THe problem becomes one of fuel capacity. There is not much spare capability in ANY launch system today. To take a longer path to orbit means a longer burn which means more fuel. For Soyuz/Shuttle etc... its not like a typical launch is with 3/4's of a tank but even if you could stuff enough more fuel to make it you then change the equation regarding the engines, agains its not like they run them at 3/4's power. Launch systems work on a margin that IS emergency levels by most any other standard. Most systems have to work at 99% of their possible capacity just to lift ANY cargo at all to orbit. IF launching to shuttle inclination was possible the extra fuel weight would have to be gained by subtracting the margin allowed for cargo and the amount needed would have to be withen the cargo capacity. IE for shuttle 2.5% more fuel would mean no orbiter/engines ( kinda necesarry ) or payload. so likely you would only be able to increment Soyuz fuel by 1% ( given you could even squeeze 1% more in the tanks ) at the expense of cargo and that would have to be enough added capacity to reach the needed orbital inclination. Thats not a debate about nominal vrs emergency, its a question of can you pack enough energy in the system to even think about it.
Also SS as an abriviation in space discussions generally stands for Space Shuttle, ISS is used for the international space station so I apologise for that misunderstanding on my part. That is inventive however you have the same orbital inclination change problem only to a greater degree. Shuttle can reach more inclinations from launch and change more once on orbit than Soyuz but both are very limited once on orbit. Pretty much all Soyuz can do once on orbit is a de-orbit burn and again its not a question of putting more gas in the tank as it is needing a larger tank.
I agree the impossible is sometimes possible but I think references to Apollo 13 are a little misleading. True enough they used the lunar module for a life boat but essentially they used it for its designed purpose.. IE a sustained life support in a vacume environment. The only odd part of its use was housing all three astronaughts and burning the engine for a return burn instead of a d
Resupply with progress.... intresting notion but progress can't make Shuttle's primary orbit which is where Columbia was. That is the reason for ISS's odd orbit, it is the compromise position between shuttles ability and soyuz.
Rescue with long march... ummmm they havn't even sent a person up yet that I know of in a long march. Also questions about orbital inclnation possibilities.
SPace age duct tape.. right let me go down to wally world and pick some up. It dosn't exist. Tile is custom fitted and fixing the projected hole on orbit ad hoc simply wasn't an option. Docked at ISS with full EVA and both arms ( SHUTTLE and STATION ) would be almost as useless. Vacume and conditions in space make it extremely difficult to effect repair operations. COuld they weld, could they apply fixatives in the temprature environment, could they seal and control the temprature at the necesarry areas to do so ? These are questions that have been around for ages regarding space construction and they have no answer as yet.
Escape pod in the SS ???? What the hell are you talking about ?
Dust off an Appollo. feasible but problematic. One is time to 'dust off', two is docking, three is can you fit 7 people in one much less how to get any of them at all.. probably 8 seeing as a truly dusted off Appollo module would likely have ot have at least a pilot to even try to rendezvous lets not even talk about the fact the quesiton of who the hell would fly it. perhaps Jim Lovel or another one the Appollo era who are the only remaining people trained to fly the thing ?
From a Can do attitude the best option was Atlantis, possibly with a docking node and a spare node to install on columbia ( no idea if thats possible ) with a canada arm. Possibly loaded with payload assist modules to boost to ISS orbit.. not sure if the delta V needed would be possible to achieve, I know its out of the question with a fully charged OMS system once your on orbit.
If you could launch and install a docking collar on orbit and carry enough boost capacity in one form or another to match ISS orbit what you do is install the docking collar transfer the crew and boost Columbia to ISS orbit if possible and dock it there while you try to figure out what to do with it. Everyone else returns on Atlantis. If ISS is impossible then you use assit modules to boost the shuttle to as high an orbit as possible and figure out what to do with it later, or do a planned re-entry ditch.
In either case launching Atlantis incurrs the exact same risk that Columbia had just run afoul of. To launch Atlantis you risked having two injured birds and even more crew loss. I would choose to launch the rescue had we known Columbia was incapable of re-entry and had at least a real snowball's chance in hell of succeeding. However, thats becasue I think trying to rescue and fialing is easier to deal with than some chilling dcision to cut losses.
Nice stats. I was going by more generic numbers you see out there often for simplicity sake.. and giving benifit of the doubt for future advances. Goofed the power per sq meter though I always get mixed up on that one. But bravo, excellent post.
I agree to some extent about the battery comparison except for one thing. As hard as it is to store significant amounts of hydrogen, batteries have a greater power density issue which makes them much heavier. Not sure how likely it is we will manage to store more juice in them. If you could just make them faster to charge, more durable, and cheaper I could see a viable city transport vehicle but not much else.
You point out the increased efficiency of fuel cell conversion Vrs ICE but did not seem to take into account the effect on the overall system in your assesment. Granted LH2 is less dense but in a 20 gallon tank you maintain roughly.25 or 5 gallons worth of gas ( in terms of power density ) but that 5 gallons nets you 50% more than 5 gallons in an ICE so instead of.25 its more like.38 final equivalent... or 7.5 gallons. Nothign to scream and shout about however you are then talking about a system with a useable range. Say a typical rice burner ICE gets 30mpg, a similar Fuel cell will get 45mpg. So 5*45 = 225 mile range or about the same as a 70's gas guzzler in a tank the same size. With a bigger tank you of course increase your range... my guess is you use a bigger tank(s) but stick to highly compressed gas vrs liquid and net the same 5 gallons of equivalence. Basically you have less trunk space but you get a useable car. By contrast I have heard of no purely electric vehicle with so much as an honest 100mile range and they geenrally take 8+ hours to re-charge, in addition their 75% energy return is offset by the fact a battery bank that stores even that measley range will be several times heavier than the fuel cell system so some of that efficiency is offset by having to move a heavier vehicle. Also not only is the battery bank heavier, that necesitates a heavier braking system and heavier frame etc.... That means that 96 mile range on the GE vehicle is hit much harder in stop and go situations ( IE inner city traffic which is about the only place that kind of range is practical in the US ).
Cost of the stacks is a biatch though. Platinum Catalysts will never be viable unless we can turn 'lead into gold' and Nafion isn't much better and has durability issues to boot. I think that is the fuel cells tragic flaw far more than the storage issue... after all you can reform gas/methane etc to get hydrogen in high quantities and methane can be produced ( ie the article he he ) but battaries are severely lacking in storage capacity and nothing seems ot be on the horizon to improove that fact.
Great comment about the Hindenburg fiasco. However I am going to have to take some exception to much of the rest of your comment. If you take the average roof for your average suburbanite yuppie with 2.1 kids a white picket fence and dog mixed with average exposure to sunlight IE not optimal what your suggesting is a pipe dream without a serious decrease in power usage. Also there is the small problem of efficiency of conversion. You get roughly 1hp of energy per square meter of sunlight as I recall.. IE 750 watts but solar panels only claim about 15% of that for roughly 112 watts. You only get about 4 hours of peak sunlight on average so thats almost one hole half kw of energy per square meter per day. With 10 square meters thats roughly 5kw hours.. lets be really generous and call it 6kw hours. At $3 a watt that array will cost you around 1120 * 3 or ~$3300.. plus inverters, battery bank and for electrolysis an electrolysis rig and hydrogen storage tanks... Aaaaaannnnndd lets not forget the fuel cell to convert your hydrogen back into energy. Lets be optomistic and call it 5k for the whole system with economy of scale, and yes that includes a cheaper per watt cost on the panels. Thats not very big, but to cover the whole roof gets really pricey.
Hydrogen and electrolysis... OK lets be generous and say you store 80% of your 6kw hours via electrolysis. That gets you 4.8kw hours of stored energy on average per day. Converting that stored energy back to useable energy nets you another conversion loss, again 80% so you wind up with 3.84kw/hr of net energy on average. Typical home power consumption is around 15kw/hr day. Efficient appliances and less power hungry lifestyle can easily get around 10kw/hr and perhaps even less, but to cut much under that you have to seriously curtail climate control IE A/C and heat. THey are you big guzzlers in the house, normally A/C Heat and Fridge account for 75% or more of your power consumption.
Now obviously you use some of the direct solar energy during the day but at $5k for a system your going to have limits like little A/C, lukewarm water, no big TV, limited lighting and we havn't even begun to talk about replacing your cars engine with an electric motor driven by hydrogen... much less the average two cars per family now a days. You could make the system roughly 10 times bigger for a $50k system providing 38.4 net kw/hrs per day which is about where it becomes practical for a distributed grid ( regarding home power use ) but it still dosn't even come close to providing for cars, those suckers are seriously power greedy. Even efficent ones. Think of it this way. Average household consumption is 15.5kw/hr a day. An average car engines weighs in at around 200hp which is roughly 150kw. Even considering you average about 30% power rating when driving means an hour of driving uses ~45kw/hr. A geo metro or some other glorified go kart is only marginally better, in terms of average power consumption they will use 75% of what an efficent V-6 car will use ( their efficiency is related much more strongly to their light weight than to their underpowered engines ). SO to have enough hydrogen to fuel 2 hours of driving per day for a single decently powered car ( ie one people want to own ) and an average home you need 45*2+15 or 105 kw/hr average per day. Or 105/3.84 or about 27 of those 5k systems. With economy of scale lets say you can build that system for 75k instead 100k+ or in other words the cost of a small home. Even if the house and car are 50% more efficient you still need a system that provides around 50kw/hr net energy per day which still is going to cost a serious amount of money, more than houses in some areas... and keep on adding for additional cars.
Distributed power is a good idea, I like it and would like to see it. However Solar is not a very reasonable PRIMARY source of power at this time. Small supplamental systems could help but I doubt they could be made cost efficient enough to also include the ability to electrolize water and store the hydogen for
Ergo you don't have a problem therefore nobody else in that position should ?
I agree its not ONLY a medical issue, but please don't tell me you think it plays no part at all ? People with a pre-disposition for addiction are the provebial one legged man in an ass whoopin contest. I agree personal choice and responsibility is huge but todays society often deals people a pretty shitty hand with which to fend off addiction, especially regarding drinking.
Still out for debate last I checked.. IE ever expanding vrs contracting vrs balanced. May be out of touch though. At anyrate the universes days are numbered a good deal longer than the sun's whatever the verdict. Perhaps Entropy wins, Perhaps it dosn't.... but if we stay here it certainly will.
one nit.. thats true only so long as biomass consumption of Co2 remains equal to or greater than our relase of Co2 from Biomass... otherwise we create the same problem we have now, net increase in Co2 emmissions.
Your correct from a point of view. For the billions here now and to come in the future the majority of their destinations are irrevocably linked to the earth. However the fate of humanity is linked to our decision regarding that 'dead end'. If we stay here Humanities days are numbered. Be it an asteroid, Be it going past the carrying capacity and poisioning the world irrevocably or be it the sun running out of its fuel. The days are numbered. There is most likely a whole crap load of them, possibly billions upon billions. But numbered all the same.
The only way to change that is to increase the number of places where we can live independantly. I agree the ocean is an untapped frontier that we will sooner or later explore. I have long held we will go down before we truly go up and still hold to it. However we still must leave. First to the rest of the solar system if for no other reason than to lessen our weakness in living on only one planet, and then beyond. Do not think in terms of evacuating the earth but in terms of the destiny of humanity as a whole. This is our home and will remain so forever, unfortunately it will not last forever. So if humanity does not exist elsewhere we will only know it as our home as long as it can support us. If Humanity expands beyond the realm of earth it can outlive the earth, if it expands beyond the solar system it can outlive the solar system and on and on. In my mind that is a worthy goal and most certainly not a 'dead end'.
eh if its on a lift system you could get it to whatever hight necesarry to not limit the field of view... or design the doors to open/fold more out of the way than they currently do. Some complexity issues so there is no real telling how long you could reasonably expect it to work... but the mechanisim wouldn't have to be too stout since Lunar gravity is pretty weak and you don't have issues like cross winds/weather etc, and the door design would only have to be able to survive launch stresses instead of the more strenuous re-entry stresses. The real biatch I think would be thermal issues encountered dealing with 15+ days of direct sunlight.... perhaps a buried radiator system in the lunar surface ???? No idea really but thats what we pay the smart boys with pocket protectors the big bucks for.
True enough but there is also the issue of no parasitic atmospheric drag ( well very miniscuel at Hubble's altitude ) or loss of efficiency of nozzels for various pressure levels etc.... so while in terms of pure delta V its ~60-70 some odd percent.. in terms of a full on engineering excercise in practice getting the LEO, or out of any gravity well in general is by far the hardest thing to do which is all I was saying.
As for actually sending Hubble out into deep space I doubt it would work very well..... but an interesting idea would be putting it in a Lunar Orbit. Better vacume and dark side pics would be nice indeed.... better yet lets put together a mission to take it to the moon and use it to build a dark side observational base. I would preffer a ground up design.. taking the existing system and hodgepodging a dark side observation base could be intersting though.
basic idea
Take a shuttle.. strip the heat shield (shuttle C concept), use the oldest flight certified SSME's, fly boosters in the cargo hold to be placed where the SSME's are on orbit ( SSME's either stay in orbit for a shuttle recovery flight or are burned up on re-entry ). only other cargo is an apollo cmd module ( already plans on the books for refurbing old ones or making new ones to original specs ) and a construction pod containing the base to attach hubble too. Park the cmd module in orbit ( at station ? ) for the ride home.. possibly the base pod as well, pick up Hubble and stow it in the cargo bay... Rig a frame to mount the base pod on top of Hubble once its in the bay ( doors stay open for the trip ). boosters kick you to lunar orbit... then land on the dark side and build the observation facility ( ???? ).... PROFIT.....
laugh I know that last bit is the show stopper, I would imagine the issues of getting a heatshield stripped shuttle C to lunar orbit and back are surmountable. But landing would be a whale of a different story, not to mention the RMS likely could not manipulate significant enough loads in Lunar Gravity to unload the base pod and Hubble from the cargo bay if you could get the thing on the ground, not to mention any extra manipulation needs beyond its range on the surface... Lastly if you did the impossible, or actually designed an appropriate mission you would also need a couple relay sat's in lunar orbit to keep in contact with the dark side seeing as the moon is phase locked the 'dark side ' is a ZOE for any earth locked communication system... namely all communcation systems currently. THen if ou do park the return capsule there are timming and delta V issues on your return trip....
If you purpose built a stretch shuttle C ( heatshield, wing and tail less ) with the idea it would be the observational base and you put a boost stage on the apollo cmd module ( so it could sit in the cargo bay with hubble in a launch position ) the mission IDEA would be capture Hubble, land on the moon return striaght to earth in the apollo module without a rendezvous in LEO after returning from the moon... build the cargo bay to fit hubble on a mount system that can lift to the cargo lip and pan/tilt Hubble... also build into it the power supply etc ( RTG's or possibly the trashcan reactor).. possibly even include the relay sats to be placed in lunar orbit prior to landing.... during the dark side day Hubble could be lowered and the cargo bay doors cloosed to help shield it.... viola a dark side telescope with 24 hour night and a more stationary location than can be achieved on earths surface or in LEO.
One small nit.... the hard work on moving Hubble has been done so no worries about reviving the sat V to boost it further. Getting to LEO is 90% of the effort to get anywhere, if there were a propulsion option the amount of prop to boost would be doable ( IE you would lift pretty much only the prop needed instead of the whole satallite and the prop needed ).
thinks he goofed that a bit.... 300kw is about 400hp, and a 400hp engine will use a great deal more than 8 gallons of gas in an hour of operation... and a 300kw generator would likely need somewhere in the neighborhood of a 500hp engine to get the 300kw output due to inefficiencies of conversion. The energy contained in 8 gallons is about right actually, but engines are of course not perfect in converting that potential into energy.
Thus to do this you take gas, convert to kenetic energy via the engine, then convert to electric energy via a generator then convert your electric output to HV energy which in turns generates ionic thrust by ionizing air and pushing it with the charge difference.
Thats four energy conversions and there is loss at every step because nothing is 100% efficient. The big losses here are converting the gas to kenitic ( lot of thermal energy lost ) and in converting kenetic to electrical. Probably %80 conversion at both points would be close to tops.
on the other hand if you use the engine to directly drive a propeller you loose the conversion to kenetic and the efficiency of the propeller at turning that kenetic energy into moved wind. My guess is it comes out pretty close with a deffinate edge to the propeller... how ever that is a very tricky drive system that has a very low tolerance for imperfection and high speed moving parts that can fail. THe real attractiveness of this technology is that if it can be as efficient or almost as efficient as propellers and varients ( jets ) are this would present far fewer moving parts and hoepfully be more reliable. COurse the voltage invovled and its habit for arcing with potential grounds at a distance could make for a an intersting safety issue.
for lifter 4 he claims and shows pictures that it lifts a pound off of a 250 watt power supply dilivering around 100,000kv. Thats roughly 3 pounds of lift per 750 watts ( or about a horsepower ) and 4 per kw or 9.2 lbs of thrust (at least) for 2.3 kw. Why is this interesting ?
DS-1 generates.02 lbs of thrust per 2.3kw.
I understand DS-1 generates its ions from an onboard fuel but it seems the process is far less efficient than ionizing plain old air. Seems like NASA could do better with some more voltage and a bottle of highly condensed air than they can with xeon.
I have to disagree with the shit tonne of money. The price of the space program tends to get blown up out of proportion, even if NASA had double the budget tommorrow it would be a small percentage of the military budget, or welfare for that matter. In fact most of the individual branches of the armed services have programs with budgets larger than NASA's. The thing is 15 billion to fuel/maintain/support air operations around the world and 15 billion invested in a one off space ship design that explodes unexpectedly are two very different situations for determining how well the money was spent. Personally I would rather see some failures in the name of expanding the envelope of space exploration ( going to Mars for instance ) than failures in maintaining what we know we can do ( ie Columbia ). The space program is dangerous and risky and there is no way to avoid putting lives at risk to expand manned exploration capabilities but for gods sake if we have to risk lives lets do it while covering new ground instead of while jogging in place.
Hmmmm you mean the infrastructure is there if we replace the stations. You would have better luck saying the infrastructure exists in the natural gas pipeline systems in most cities.. IE pipe hydrogen instead.. or reform hydrogen from natural gas or methane shipped through those pipes... thus most homes become their own gas stations. much more likely ( reforming methane/natural gas ) than replacing all the tanks and pumps at gas stations.
Even if you did you have to figure out how to supply the hydrogen. Most people seem to not realize to create hydrogen means either extracting it from fossile fules or spliting it from water which is a process that takes more energy than you can recover from it... that second law of theromdynamics is a real biatch.
Solar takes insane size panel farms to even consider splitting enough hydrogen to replace gas and don't even think about residential and industrial to boot... its insane. Nuclear offers the power surplus needed to split sufficient quanity in a dense enough package but you know its problems.. some real some imagined but they are there for Fission... and that leaves Fusion which we need... but fusion is going to be problematic till we crack the second level reaction ( hydrogen and helium ) which has fewer nutrino emmisions ( nutrino containment methods create radioactive material waste ).
hmm damn formatting... that was supposed to be a discuss xxxx passage and tell me what the consequeces of yyyy characters are in relation to zzzzz or something like that.
First off you have to embrace computers and the internet if you intend to teach a class with a live internet connection.
By embrace I mean do not try and treat it like a regular classroom. Students WILL type constantly either on topic or off topic especially if they have a live internet connection and if that is disruptive to your method of instruction run far and run fast from the lab NOW !!! Seriously it will never work and even if it does all your going to do is frustrate the students sitting there with computers and not being able to use them. Quiet click keyboards would help immensly but boards in labs are generally loud clackers and the very lively accoustics of most rooms don't help.
My suggestion would be to not plan on Verbal lecturing at all, if you do need to have lectures schedule them in a room away from the computers if at all possible. I would suggest some sort of obvious progression where students read and post their thoughts as directed by your questions to answer or discuss etc.... Classtime can be used for class discussion thread style. I would set up some sort of scoring system with you as the score keeper... IE offtopic and flamebait takes points off, pertinent posts score according to some scale you have. Goal of students is to reach a passing point.
*** random idea which would need software that could handle it *** Student is given 5 posts per topic. Posts are rated by the teacher in say two or three categories ( say grammer, quality of content for starters ) score is on a 1-10 scale which can be multiplied by 2, added all together and divided by the number of categories for ye olde 100 point scale
At anyrate you get the idea. Instead of verbal lectures you outline the discussion in a written aggenda. I personally would say take the lecture notes, note the pertinent areas of discussion and link in the text to the appropriate place to post responses... In passage I want you to the consequences of actions. Then Repeat ad neaseum for all needed points of discussion. Include your lecture material in addition as well. Then spend the time during calss monitoring what is being added to the discussion and offering one on one feedback going around the room.... constant moving will also enable you to keep something of an eye on poor choices of web pages for information sources.
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There are very few IF's ?????
many or few there are a couple huge honking ones.
A) No lab manufactured nano tube to date of any manufacturing technique has yet to produce strands close enough to the theoretical max strength to prove It is possible to create a space elevator.
B) No one yet knows how or even if its realistic to draw them out into suffcient lengths to stretch across a room much less 70,000 kilometers. Similar problems with joining smaller strands to make larger ones without loosing strength.
Those two little hicupps mean the whole idea is still in the stage of "Is it possible?".
Like I said don't get me wrong. There is nobody who would love to see the above issues solved more than me. I just find it hard to get worked up about timelines and budgets for a pie in the sky idea that dosn't have its fundamental technology in existence. Talking about timelines and budgets is absolutely ridiculose until they actually make the first nanotube with sufficient strength to justify the basic premise of space elevator construction. Right now given what we have it wouldn't matter if you had thousands of years and unlimited budget you could not build a space elevator. By comparison give me a steady stream of workers, nothing but hand tools and I will give you a tunnle through the alps, just a matter of time.
Its possible sufficient nano tube technology is also just a matter of time. Its also possible it won't be sufficient ever. Thats the problem with technology that dosn't yet exist. Its like the proverbial wings that would keep bullfrogs from busting ther @$$ everytime they jump... if only they had them.
Call me when they make a strong enough tube. Course then I will say call me when they prove manufacturing it in sufficient length with suficent strength is only a matter of how long you want to make it or limited at such a margin that length to Geosync is no issue. THEN and ONLY THEN talk to me about budgets and timelines becasue then it will be a question of "Will it be done?" vrs "Can it be done?".
Very poor buisness logic in that story. Granted given current launch needs an RLV faces a problem in that if we had one tommorrow we wouldn't have enough work for it. However the logic of that argument is like saying in the day of Charles Lindberg had a 747 been available not enough people would be intrested in being able to fly across the atlantic. How many buisness models utilizing space transportation are deemed non-viable due to launch costs. How many new ideas might be born if cheap access to space were a reality ? The logic in the story fails to even discount the possibility of new uses for space instead choosing to focus on the current launch schedule and projected launch demand based on current launch capacities.
Just to give one concrete example take the telecom needs. Telecom stats are expensive. They are expensive to build because they have to last ( ie that have to be uber reliable ). This is because they cost a butt load to launch and backup launches are almost unthinkable. Now decrease launch costs to say the truly optomistic $100 a kg. for simplicty of agument and satalite designs need not be so intollerant. Expanding capacity ( IE stalite broad band ) becomes a non-issue. Most stalite launch demands are similarly governed, expensive launch makes for even more expensive development due the the fact you don't get second chances.
Changing the cost to orbit changes the entire dynamics in a way that simply can't be predicted. Perhaps the payloads will not be there... but just like trans-atlantic flight took off almost overnight once a suitable technology came around I imagine there will be an expansion of launch needs once a more viable and cheaper access to space becomes available.
Re-useable launch vechicles make obviouse finacial sense... the question is can we actually make one more than should we make one. If we can't then maximising one time use designs is the path to highest payload margins. If its possible ( and the case can be made ) then you do the math. A re-useable design that reduces cost to orbit has to cost more than is currently being projected to not be able to pay for itself... the catch of course is if it can truly reduce the cost to orbit enough. Having said that I grant the reality of the current launch needs means a system that sufficiently drops the cost of reaching orbit likely could not recoup its development costs without a corresponding increase in launch schedules except by comparison to what a launch would have cost without the new RLV ( IE phantom accounting ).
Arguing that the technology to build an RLV from one time designs is somewhat inaccurate. Granted some progress will undoubtably be made however there will be no enginerring imperitive to make a system durable enough to be re-used because any excess weight above and beyond what is needed for a single launch cycle will be spurious. Technology advances follow the engineering goal. Metal skin and honey comb composites in plane designs did not come about from pefecting wood and cloth planes, it was a direct improovment driven by the desire for faster designs that could sustain higher loads with less maintenence. If you want RLV technology then at some point you have got to aim for RLV's... not SLV's.
Critical technology which is yet to be viable in a lab environment much less a space mass production facility. But more importatly this timeline does not appear to account for the source of material to build the cable. Surely they are not suggesting ligting a million plus kg to orbit the old fashioned way ? THe ability to move a near earth object of the proper composition is also another technology that is yet to be developed as well that is pretty key. 20 years with one break through... phunny there is more than one roadblock for that timeline.
I would love to see an elevator but I have yet to hear a convincing argument. Instead of touting what might be possible IF IF IF IF lets get about the buisness of actually making the key material a reality before going hog wild about what we could do with it. There are other uses for such a strong material other than space elevators. When we have carbon nano tubes strong enough and the ability to mass produce at the needed quality is demonstrated I will get a little more excited about this possibility. Till then lets hatch the eggs before we count chickens.
The report is nutz. Imagery denied becasue no one knew who if anyone 'officially' requested it despite the fact it was requested and they knew they had a significant impact that at the time of the deinal was classified as an out of family event. At the very worst it may have put to rest any doubts regarding the impact. There are stories from old timers here ( MSFC ) talking about photos with legible tile serial numbers on the first shuttle flight were provided by military assests. However the people that denied the requests and thought the imagery would not be sufficient were not cleared to know the level of detail that could be provided if needed. Jevuss.
Granted after reading the report I still hold that most likely once the foam hit they were fucked. The repair option borders on the insane and the Atlantis rescue scenario was at the raw edge of feasibility before considering how perfect everything would have had to be just to get Atlantis up there before they died from a toxic atmosphere. Granted both options have the edge of sounding just crazy enough to actually work.
However I think that question is moot. The system is inherrently flawed. Failure is inevitable and in a system this far on the ragged edge merely a question of time. The culture of living with that fact is inevitably going to become callous. People question how the program could continually ignore impact damage from the foam and the answer is because that it wasn't the only thing that was on their plate. It was part of a never ending stream of items with potentially catastrophic results. It was background noise. It wasn't like Tile damage was the one glaring fault to an otherwise perfect system. In that kind of environment if you obessess over every possible failure the way it should be all the time on a system as problematic as SHuttle has prooven to be the only possible outcome is insanity. The callousness and complacency were an almost inevitable result. An independent safety board will help but only so much. The reactor managment example is somewhat deciving. The margin for error in running a nuclear reactor is far more manageable than the safety margin of rocket and re-entry operations.
In otherwords the complacent management is merely the means by which the system failed. You could have had an entirely techncially savvy decision making process appropriately concious at ever step of the process and perhaps in this case you would have had a dramatic rescue or on orbit repair story to talk about now instead of a man made meteor shower over Texas. However it would be just as likely that given that level of management a critical system would have catastrophcially failed or hull integrity compromised by an un-avoidable piece of space junk that no amount of management could avoid or recover from. In that case a system would be redesigned. In this case managment needs and over haul... and a serious influx of technical knowledge with which to assess the lower level analysis infomration provided.
THe statistics regarding shuttle system dictate failure at some point on some level. The system is to complex and to far out on the edge with to little margin. In this case the system that failed was the human system. Next time we may have a mechanical system go down. Its not an excuse to fail to improove, its just reality.
Abuse of the system can go both ways. Once UNION's form they create a power structure that is just as capable of rapeing and pillaging the peons just as surely as corporate management. Power currupts period. A currupt management system with unfair distribution of proceeds is bad but so is a Union run amuck that has hamstrung a managements ability to deal with substandard employees. Unions will fight to protect the job of a worker or to prevent layoffs regardless of whethere they are substandard or not, regardless of whether the situation calls for it or not. So instaed of 16 VP's sitting around on the sinking ship you have everyone sitting around and the ship sinks faster. Unreasonable unionized labor demands are one of the largest reasons we see increasing numbers of jobs heading over seas.
Don't get me wrong. Unions have done a great deal of good in this nation and still perform a needed counterpoint to corporate greed however please.... PLEASE don't try and tell me the need today is anywhere near as strong as it once was. Today most unions are in a quagmire. They exist and wield extrodinary amounts of influence which they do whether they need to or not to justify their continued existence not to mention the slice taken out of union members checks which often wind up funding salaries of union managers just as exorbant as those greedy VP's in managment and who have an equal disregard for the plight of the average Joe Shmuck union worker other than that they don't break ranks.
Blazing Saddles was a fine movie and I understand your point. Just think your going a bit far afield.
First progress is not a re-entry vehicle and whether or not it can make Shuttle's typical orbit is more or less moot, perhaps they could have used it for a life boat though I do not belive progress has self sustained life support, I believe it is reliant on connections to ISS for that. I could be wrong. A quick fix jury rig is always possible but IF it could make it its payload would be severely limited. More likely it carries life support supplies for Shuttle then you have to figure out how to get the goodies with no arm and no docking ability and no EVA pack.
Soyuz can't make it that I am aware of and it is even smaller than an apollo command module. It is also a squeeze just to get 3 people in it. If you could whistle up two of them and squeeze every one in AND they could make it, great.
When I say Its not possible that is because its not a real qustion of nominal vrs emergency use as much as simple can't get there from here.
Perhaps the engineers would correct me and I certainly am not a rocket scientist but I am pretty sure Orbital mechanics and liquid fuel rocket limitations mean its not doeable for Soyuz. 5% payload to orbit is a fantastic margin from a launch platform ( shuttle gets 2.5% counting the entire mass of the orbiter/engines/payload which is about as good as it gets among current systems). To get to shuttle inclination from Russia's launch facility or to Soyuz inclination from Kennedy requires you to take the scenic route to orbit and no system currently has that much performance margin. If your still not sure why get a globe and connect the dots between KSC and the Russian launch facility, that determines the inclination both can launch to equally well. Then go find Columbia's orbital inclination and draw that circle. Now to get to that inclination you have to turn taking a longer path. THe problem becomes one of fuel capacity. There is not much spare capability in ANY launch system today. To take a longer path to orbit means a longer burn which means more fuel. For Soyuz/Shuttle etc... its not like a typical launch is with 3/4's of a tank but even if you could stuff enough more fuel to make it you then change the equation regarding the engines, agains its not like they run them at 3/4's power. Launch systems work on a margin that IS emergency levels by most any other standard. Most systems have to work at 99% of their possible capacity just to lift ANY cargo at all to orbit. IF launching to shuttle inclination was possible the extra fuel weight would have to be gained by subtracting the margin allowed for cargo and the amount needed would have to be withen the cargo capacity. IE for shuttle 2.5% more fuel would mean no orbiter/engines ( kinda necesarry ) or payload. so likely you would only be able to increment Soyuz fuel by 1% ( given you could even squeeze 1% more in the tanks ) at the expense of cargo and that would have to be enough added capacity to reach the needed orbital inclination. Thats not a debate about nominal vrs emergency, its a question of can you pack enough energy in the system to even think about it.
Also SS as an abriviation in space discussions generally stands for Space Shuttle, ISS is used for the international space station so I apologise for that misunderstanding on my part. That is inventive however you have the same orbital inclination change problem only to a greater degree. Shuttle can reach more inclinations from launch and change more once on orbit than Soyuz but both are very limited once on orbit. Pretty much all Soyuz can do once on orbit is a de-orbit burn and again its not a question of putting more gas in the tank as it is needing a larger tank.
I agree the impossible is sometimes possible but I think references to Apollo 13 are a little misleading. True enough they used the lunar module for a life boat but essentially they used it for its designed purpose.. IE a sustained life support in a vacume environment. The only odd part of its use was housing all three astronaughts and burning the engine for a return burn instead of a d
Resupply with progress.... intresting notion but progress can't make Shuttle's primary orbit which is where Columbia was. That is the reason for ISS's odd orbit, it is the compromise position between shuttles ability and soyuz.
Rescue with long march... ummmm they havn't even sent a person up yet that I know of in a long march. Also questions about orbital inclnation possibilities.
SPace age duct tape.. right let me go down to wally world and pick some up. It dosn't exist. Tile is custom fitted and fixing the projected hole on orbit ad hoc simply wasn't an option. Docked at ISS with full EVA and both arms ( SHUTTLE and STATION ) would be almost as useless. Vacume and conditions in space make it extremely difficult to effect repair operations. COuld they weld, could they apply fixatives in the temprature environment, could they seal and control the temprature at the necesarry areas to do so ? These are questions that have been around for ages regarding space construction and they have no answer as yet.
Escape pod in the SS ???? What the hell are you talking about ?
Dust off an Appollo. feasible but problematic. One is time to 'dust off', two is docking, three is can you fit 7 people in one much less how to get any of them at all.. probably 8 seeing as a truly dusted off Appollo module would likely have ot have at least a pilot to even try to rendezvous lets not even talk about the fact the quesiton of who the hell would fly it. perhaps Jim Lovel or another one the Appollo era who are the only remaining people trained to fly the thing ?
From a Can do attitude the best option was Atlantis, possibly with a docking node and a spare node to install on columbia ( no idea if thats possible ) with a canada arm. Possibly loaded with payload assist modules to boost to ISS orbit.. not sure if the delta V needed would be possible to achieve, I know its out of the question with a fully charged OMS system once your on orbit.
If you could launch and install a docking collar on orbit and carry enough boost capacity in one form or another to match ISS orbit what you do is install the docking collar transfer the crew and boost Columbia to ISS orbit if possible and dock it there while you try to figure out what to do with it. Everyone else returns on Atlantis. If ISS is impossible then you use assit modules to boost the shuttle to as high an orbit as possible and figure out what to do with it later, or do a planned re-entry ditch.
In either case launching Atlantis incurrs the exact same risk that Columbia had just run afoul of. To launch Atlantis you risked having two injured birds and even more crew loss. I would choose to launch the rescue had we known Columbia was incapable of re-entry and had at least a real snowball's chance in hell of succeeding. However, thats becasue I think trying to rescue and fialing is easier to deal with than some chilling dcision to cut losses.
Nice stats. I was going by more generic numbers you see out there often for simplicity sake.. and giving benifit of the doubt for future advances. Goofed the power per sq meter though I always get mixed up on that one. But bravo, excellent post.
.25 or 5 gallons worth of gas ( in terms of power density ) but that 5 gallons nets you 50% more than 5 gallons in an ICE so instead of .25 its more like .38 final equivalent... or 7.5 gallons. Nothign to scream and shout about however you are then talking about a system with a useable range. Say a typical rice burner ICE gets 30mpg, a similar Fuel cell will get 45mpg. So 5*45 = 225 mile range or about the same as a 70's gas guzzler in a tank the same size. With a bigger tank you of course increase your range... my guess is you use a bigger tank(s) but stick to highly compressed gas vrs liquid and net the same 5 gallons of equivalence. Basically you have less trunk space but you get a useable car. By contrast I have heard of no purely electric vehicle with so much as an honest 100mile range and they geenrally take 8+ hours to re-charge, in addition their 75% energy return is offset by the fact a battery bank that stores even that measley range will be several times heavier than the fuel cell system so some of that efficiency is offset by having to move a heavier vehicle. Also not only is the battery bank heavier, that necesitates a heavier braking system and heavier frame etc.... That means that 96 mile range on the GE vehicle is hit much harder in stop and go situations ( IE inner city traffic which is about the only place that kind of range is practical in the US ).
I agree to some extent about the battery comparison except for one thing. As hard as it is to store significant amounts of hydrogen, batteries have a greater power density issue which makes them much heavier. Not sure how likely it is we will manage to store more juice in them. If you could just make them faster to charge, more durable, and cheaper I could see a viable city transport vehicle but not much else.
You point out the increased efficiency of fuel cell conversion Vrs ICE but did not seem to take into account the effect on the overall system in your assesment. Granted LH2 is less dense but in a 20 gallon tank you maintain roughly
Cost of the stacks is a biatch though. Platinum Catalysts will never be viable unless we can turn 'lead into gold' and Nafion isn't much better and has durability issues to boot. I think that is the fuel cells tragic flaw far more than the storage issue... after all you can reform gas/methane etc to get hydrogen in high quantities and methane can be produced ( ie the article he he ) but battaries are severely lacking in storage capacity and nothing seems ot be on the horizon to improove that fact.
Great comment about the Hindenburg fiasco. However I am going to have to take some exception to much of the rest of your comment. If you take the average roof for your average suburbanite yuppie with 2.1 kids a white picket fence and dog mixed with average exposure to sunlight IE not optimal what your suggesting is a pipe dream without a serious decrease in power usage. Also there is the small problem of efficiency of conversion. You get roughly 1hp of energy per square meter of sunlight as I recall.. IE 750 watts but solar panels only claim about 15% of that for roughly 112 watts. You only get about 4 hours of peak sunlight on average so thats almost one hole half kw of energy per square meter per day. With 10 square meters thats roughly 5kw hours.. lets be really generous and call it 6kw hours. At $3 a watt that array will cost you around 1120 * 3 or ~$3300.. plus inverters, battery bank and for electrolysis an electrolysis rig and hydrogen storage tanks... Aaaaaannnnndd lets not forget the fuel cell to convert your hydrogen back into energy. Lets be optomistic and call it 5k for the whole system with economy of scale, and yes that includes a cheaper per watt cost on the panels. Thats not very big, but to cover the whole roof gets really pricey.
Hydrogen and electrolysis... OK lets be generous and say you store 80% of your 6kw hours via electrolysis. That gets you 4.8kw hours of stored energy on average per day. Converting that stored energy back to useable energy nets you another conversion loss, again 80% so you wind up with 3.84kw/hr of net energy on average. Typical home power consumption is around 15kw/hr day. Efficient appliances and less power hungry lifestyle can easily get around 10kw/hr and perhaps even less, but to cut much under that you have to seriously curtail climate control IE A/C and heat. THey are you big guzzlers in the house, normally A/C Heat and Fridge account for 75% or more of your power consumption.
Now obviously you use some of the direct solar energy during the day but at $5k for a system your going to have limits like little A/C, lukewarm water, no big TV, limited lighting and we havn't even begun to talk about replacing your cars engine with an electric motor driven by hydrogen... much less the average two cars per family now a days. You could make the system roughly 10 times bigger for a $50k system providing 38.4 net kw/hrs per day which is about where it becomes practical for a distributed grid ( regarding home power use ) but it still dosn't even come close to providing for cars, those suckers are seriously power greedy. Even efficent ones. Think of it this way. Average household consumption is 15.5kw/hr a day. An average car engines weighs in at around 200hp which is roughly 150kw. Even considering you average about 30% power rating when driving means an hour of driving uses ~45kw/hr. A geo metro or some other glorified go kart is only marginally better, in terms of average power consumption they will use 75% of what an efficent V-6 car will use ( their efficiency is related much more strongly to their light weight than to their underpowered engines ). SO to have enough hydrogen to fuel 2 hours of driving per day for a single decently powered car ( ie one people want to own ) and an average home you need 45*2+15 or 105 kw/hr average per day. Or 105/3.84 or about 27 of those 5k systems. With economy of scale lets say you can build that system for 75k instead 100k+ or in other words the cost of a small home. Even if the house and car are 50% more efficient you still need a system that provides around 50kw/hr net energy per day which still is going to cost a serious amount of money, more than houses in some areas... and keep on adding for additional cars.
Distributed power is a good idea, I like it and would like to see it. However Solar is not a very reasonable PRIMARY source of power at this time. Small supplamental systems could help but I doubt they could be made cost efficient enough to also include the ability to electrolize water and store the hydogen for
Ergo you don't have a problem therefore nobody else in that position should ?
I agree its not ONLY a medical issue, but please don't tell me you think it plays no part at all ? People with a pre-disposition for addiction are the provebial one legged man in an ass whoopin contest. I agree personal choice and responsibility is huge but todays society often deals people a pretty shitty hand with which to fend off addiction, especially regarding drinking.
Still out for debate last I checked.. IE ever expanding vrs contracting vrs balanced. May be out of touch though. At anyrate the universes days are numbered a good deal longer than the sun's whatever the verdict. Perhaps Entropy wins, Perhaps it dosn't.... but if we stay here it certainly will.
one nit.. thats true only so long as biomass consumption of Co2 remains equal to or greater than our relase of Co2 from Biomass... otherwise we create the same problem we have now, net increase in Co2 emmissions.
Your correct from a point of view. For the billions here now and to come in the future the majority of their destinations are irrevocably linked to the earth. However the fate of humanity is linked to our decision regarding that 'dead end'. If we stay here Humanities days are numbered. Be it an asteroid, Be it going past the carrying capacity and poisioning the world irrevocably or be it the sun running out of its fuel. The days are numbered. There is most likely a whole crap load of them, possibly billions upon billions. But numbered all the same.
The only way to change that is to increase the number of places where we can live independantly. I agree the ocean is an untapped frontier that we will sooner or later explore. I have long held we will go down before we truly go up and still hold to it. However we still must leave. First to the rest of the solar system if for no other reason than to lessen our weakness in living on only one planet, and then beyond. Do not think in terms of evacuating the earth but in terms of the destiny of humanity as a whole. This is our home and will remain so forever, unfortunately it will not last forever. So if humanity does not exist elsewhere we will only know it as our home as long as it can support us. If Humanity expands beyond the realm of earth it can outlive the earth, if it expands beyond the solar system it can outlive the solar system and on and on. In my mind that is a worthy goal and most certainly not a 'dead end'.
at 40 detonations a second plus this would not be a likely candidate for the donut on a rope poerplant.
eh if its on a lift system you could get it to whatever hight necesarry to not limit the field of view... or design the doors to open/fold more out of the way than they currently do. Some complexity issues so there is no real telling how long you could reasonably expect it to work... but the mechanisim wouldn't have to be too stout since Lunar gravity is pretty weak and you don't have issues like cross winds/weather etc, and the door design would only have to be able to survive launch stresses instead of the more strenuous re-entry stresses. The real biatch I think would be thermal issues encountered dealing with 15+ days of direct sunlight.... perhaps a buried radiator system in the lunar surface ???? No idea really but thats what we pay the smart boys with pocket protectors the big bucks for.
that was supposed to be viola a dark side telescope with 27 DAY night and more stationary location ......
True enough but there is also the issue of no parasitic atmospheric drag ( well very miniscuel at Hubble's altitude ) or loss of efficiency of nozzels for various pressure levels etc.... so while in terms of pure delta V its ~60-70 some odd percent.. in terms of a full on engineering excercise in practice getting the LEO, or out of any gravity well in general is by far the hardest thing to do which is all I was saying.
.... PROFIT.....
.. possibly even include the relay sats to be placed in lunar orbit prior to landing.... during the dark side day Hubble could be lowered and the cargo bay doors cloosed to help shield it.... viola a dark side telescope with 24 hour night and a more stationary location than can be achieved on earths surface or in LEO.
As for actually sending Hubble out into deep space I doubt it would work very well..... but an interesting idea would be putting it in a Lunar Orbit. Better vacume and dark side pics would be nice indeed.... better yet lets put together a mission to take it to the moon and use it to build a dark side observational base. I would preffer a ground up design.. taking the existing system and hodgepodging a dark side observation base could be intersting though.
basic idea
Take a shuttle.. strip the heat shield (shuttle C concept), use the oldest flight certified SSME's, fly boosters in the cargo hold to be placed where the SSME's are on orbit ( SSME's either stay in orbit for a shuttle recovery flight or are burned up on re-entry ). only other cargo is an apollo cmd module ( already plans on the books for refurbing old ones or making new ones to original specs ) and a construction pod containing the base to attach hubble too. Park the cmd module in orbit ( at station ? ) for the ride home.. possibly the base pod as well, pick up Hubble and stow it in the cargo bay... Rig a frame to mount the base pod on top of Hubble once its in the bay ( doors stay open for the trip ). boosters kick you to lunar orbit... then land on the dark side and build the observation facility ( ???? )
laugh I know that last bit is the show stopper, I would imagine the issues of getting a heatshield stripped shuttle C to lunar orbit and back are surmountable. But landing would be a whale of a different story, not to mention the RMS likely could not manipulate significant enough loads in Lunar Gravity to unload the base pod and Hubble from the cargo bay if you could get the thing on the ground, not to mention any extra manipulation needs beyond its range on the surface... Lastly if you did the impossible, or actually designed an appropriate mission you would also need a couple relay sat's in lunar orbit to keep in contact with the dark side seeing as the moon is phase locked the 'dark side ' is a ZOE for any earth locked communication system... namely all communcation systems currently. THen if ou do park the return capsule there are timming and delta V issues on your return trip....
If you purpose built a stretch shuttle C ( heatshield, wing and tail less ) with the idea it would be the observational base and you put a boost stage on the apollo cmd module ( so it could sit in the cargo bay with hubble in a launch position ) the mission IDEA would be capture Hubble, land on the moon return striaght to earth in the apollo module without a rendezvous in LEO after returning from the moon... build the cargo bay to fit hubble on a mount system that can lift to the cargo lip and pan/tilt Hubble... also build into it the power supply etc ( RTG's or possibly the trashcan reactor)
One small nit.... the hard work on moving Hubble has been done so no worries about reviving the sat V to boost it further. Getting to LEO is 90% of the effort to get anywhere, if there were a propulsion option the amount of prop to boost would be doable ( IE you would lift pretty much only the prop needed instead of the whole satallite and the prop needed ).
thinks he goofed that a bit.... 300kw is about 400hp, and a 400hp engine will use a great deal more than 8 gallons of gas in an hour of operation... and a 300kw generator would likely need somewhere in the neighborhood of a 500hp engine to get the 300kw output due to inefficiencies of conversion. The energy contained in 8 gallons is about right actually, but engines are of course not perfect in converting that potential into energy.
Thus to do this you take gas, convert to kenetic energy via the engine, then convert to electric energy via a generator then convert your electric output to HV energy which in turns generates ionic thrust by ionizing air and pushing it with the charge difference.
Thats four energy conversions and there is loss at every step because nothing is 100% efficient. The big losses here are converting the gas to kenitic ( lot of thermal energy lost ) and in converting kenetic to electrical. Probably %80 conversion at both points would be close to tops.
on the other hand if you use the engine to directly drive a propeller you loose the conversion to kenetic and the efficiency of the propeller at turning that kenetic energy into moved wind. My guess is it comes out pretty close with a deffinate edge to the propeller... how ever that is a very tricky drive system that has a very low tolerance for imperfection and high speed moving parts that can fail. THe real attractiveness of this technology is that if it can be as efficient or almost as efficient as propellers and varients ( jets ) are this would present far fewer moving parts and hoepfully be more reliable. COurse the voltage invovled and its habit for arcing with potential grounds at a distance could make for a an intersting safety issue.
for lifter 4 he claims and shows pictures that it lifts a pound off of a 250 watt power supply dilivering around 100,000kv. Thats roughly 3 pounds of lift per 750 watts ( or about a horsepower ) and 4 per kw or 9.2 lbs of thrust (at least) for 2.3 kw. Why is this interesting ?
.02 lbs of thrust per 2.3kw.
DS-1 generates
I understand DS-1 generates its ions from an onboard fuel but it seems the process is far less efficient than ionizing plain old air. Seems like NASA could do better with some more voltage and a bottle of highly condensed air than they can with xeon.
I have to disagree with the shit tonne of money. The price of the space program tends to get blown up out of proportion, even if NASA had double the budget tommorrow it would be a small percentage of the military budget, or welfare for that matter. In fact most of the individual branches of the armed services have programs with budgets larger than NASA's. The thing is 15 billion to fuel/maintain/support air operations around the world and 15 billion invested in a one off space ship design that explodes unexpectedly are two very different situations for determining how well the money was spent. Personally I would rather see some failures in the name of expanding the envelope of space exploration ( going to Mars for instance ) than failures in maintaining what we know we can do ( ie Columbia ). The space program is dangerous and risky and there is no way to avoid putting lives at risk to expand manned exploration capabilities but for gods sake if we have to risk lives lets do it while covering new ground instead of while jogging in place.
Hmmmm you mean the infrastructure is there if we replace the stations. You would have better luck saying the infrastructure exists in the natural gas pipeline systems in most cities.. IE pipe hydrogen instead.. or reform hydrogen from natural gas or methane shipped through those pipes... thus most homes become their own gas stations. much more likely ( reforming methane/natural gas ) than replacing all the tanks and pumps at gas stations.
Even if you did you have to figure out how to supply the hydrogen. Most people seem to not realize to create hydrogen means either extracting it from fossile fules or spliting it from water which is a process that takes more energy than you can recover from it... that second law of theromdynamics is a real biatch.
Solar takes insane size panel farms to even consider splitting enough hydrogen to replace gas and don't even think about residential and industrial to boot... its insane. Nuclear offers the power surplus needed to split sufficient quanity in a dense enough package but you know its problems.. some real some imagined but they are there for Fission... and that leaves Fusion which we need... but fusion is going to be problematic till we crack the second level reaction ( hydrogen and helium ) which has fewer nutrino emmisions ( nutrino containment methods create radioactive material waste ).
hmm damn formatting... that was supposed to be a discuss xxxx passage and tell me what the consequeces of yyyy characters are in relation to zzzzz or something like that.
First off you have to embrace computers and the internet if you intend to teach a class with a live internet connection.
By embrace I mean do not try and treat it like a regular classroom. Students WILL type constantly either on topic or off topic especially if they have a live internet connection and if that is disruptive to your method of instruction run far and run fast from the lab NOW !!! Seriously it will never work and even if it does all your going to do is frustrate the students sitting there with computers and not being able to use them. Quiet click keyboards would help immensly but boards in labs are generally loud clackers and the very lively accoustics of most rooms don't help.
My suggestion would be to not plan on Verbal lecturing at all, if you do need to have lectures schedule them in a room away from the computers if at all possible. I would suggest some sort of obvious progression where students read and post their thoughts as directed by your questions to answer or discuss etc.... Classtime can be used for class discussion thread style. I would set up some sort of scoring system with you as the score keeper... IE offtopic and flamebait takes points off, pertinent posts score according to some scale you have. Goal of students is to reach a passing point.
*** random idea which would need software that could handle it *** Student is given 5 posts per topic. Posts are rated by the teacher in say two or three categories ( say grammer, quality of content for starters ) score is on a 1-10 scale which can be multiplied by 2, added all together and divided by the number of categories for ye olde 100 point scale
At anyrate you get the idea. Instead of verbal lectures you outline the discussion in a written aggenda. I personally would say take the lecture notes, note the pertinent areas of discussion and link in the text to the appropriate place to post responses... In passage I want you to the consequences of actions. Then Repeat ad neaseum for all needed points of discussion. Include your lecture material in addition as well. Then spend the time during calss monitoring what is being added to the discussion and offering one on one feedback going around the room.... constant moving will also enable you to keep something of an eye on poor choices of web pages for information sources.