Heavier, bigger, cans.. More junk to be thrown away. (yes I know its alu, but not every can gets recycled).
Whats wrong with a good old micro-fridge? Or just hang your beer up in a damp sock for a while..
Seriously, I think its about time sales taxes were put on non-environmental packaging gimmicks like this, or maybe a refundable deposit like in South Australia..
What options do we have today that we didn't have in the 1950's? How many of those are capable of outright replacing the Coal/Oil/Nuclear infrastructure?
There are a few million Ukranians who would disagree with you there.. There is still the nagging question as to what happens to the waste - the UK has given up on its nuclear program as a result.
We have barely begun to exploit natural renewable resources - just one example - offshore wind power could supply *several* times the electicity needs for the UK (British Wind Enrgy Association page).
Its an old debate, but the points are still valid..
There was an interesting article on spacedaily.com (The case against Hubble)
which, although primarily about Hubble, mentioned the fact that NASA rejected a much cheaper mission option for a Europa-only orbiter costing around $1 billion in favour of the $8 billion JIMO mission. You could have 10 or more SEP/RTG missions for the cost of JIMO.. Solar can even be used for getting to Jupiter-Neptune, by swinging in close to the sun first & picking up momentum with SEP or a solar sail.. Just carry enough fuel to enter orbit on arrival, like Cassini..
Something like JIMO will come eventually, but is it worth sacrificing so many possible missions for that one option?
Ive actually been to La Palma, its a beautiful and largely untouched island. Its interior has the 2nd largest volcano in the world, with utterly impossible and fantastic looking mountain peaks..
Do they run Linux? Or in soviet russia, does the ant colonise YOU!? Or should I imagine a beowulf cluster of ants? or.. 1) start an ant super colony in Melbourne.. 2. ??? 3. PROFIT!!
In reply to my own question - the up and coming ESA Bepicolombo mission to mercury will use.. yep.. Solar Electric Propulsion. It still uses gravity slingshots to slow down, and needs a small conventional rocket to kick it into Mars orbit.
It will launch 2012 and take 4 years to get to Mercury, compared to 7 for messenger. Now the interesting part - how much is saved in the mission profile with ion engines? Do ion engines allow for more flexible mission launch windows? How will the propellant/mass profile compare to Messenger?
SMART-1 was primarily a test-bed for lots of new technologies, including ion propulsion. Going to the moon was almost a bonus - the main objective was to see if it was possible to make very small, cheap missions ($100 million, I think). It was piggy backed (cheaply) onto an existing satellite launch, hence having the minimal boost needed to get to Low Earth Orbit.. If you used a bigger rocket (smaller than Apollo) it could get there in 3 days too.
For a bigger mission like Mercury, as you can see, it is much harder to get there quickly by chemical rocket - hence the "long burning" ion drive comes into its own..
Yes I remember that impulse was rated in seconds - I should have said per Kg of propellant - ie, I understand that an ion drive can generate 10x the thrust per Kg of propellant, it just does it slower..
The SMART-1 mission cost $100 million in *total*, not too much in terms of space exploration. The thrusters will operate for 18 months & I think newer designs allow for multiple replacement anodes to replace old ones..
Ion drive missions have spiral paths, in this case decellerating towards the sun. An ion drive mission could also exploit slingshot slowdowns, no?
At points where the craft is nearer the sun, more power is available - lots more power..
So, has anyone done the calculation for a mission profile with solar-ion propulsion?
..They are not much mass-effective (thrust per unit engine mass) at all.
Current Ion drives can deliver >10x more power overall per Kg compared to rockets - but they do it slowly, over months/years.. Rockets can deliver "punch" at a spacific time. Advantages/Disadvantages both ways really.
Messanger as-is carries 1/2 its weight as fuel, so if you can reduce that 10 fold, or get 10 times the power, thats a good thing. Faster missions are less expensive in terms of keeping support staff too, and less risky. I think a solar-ion mission that spirals inwards as it decelerates would be way more efficient than the current plan. And would be much less dependant on celestial mechanics for launch dates.
Anyone from NASA here know why they dont use solar-ion drives for these missions? Is there some sort of political bias against solar & pro old fashioned rockets or nuclear? (And yes, I know nuclear (RTG) is needed for deep space - at least for electric power for the science instruments..)
I dont understand why solar-powered ion drives are not used on missions like this. Probes like the ESA SMART-1 has shown that such craft can be small & economical, and there is an abundance of solar power available for free. I understand that final orbital insertion can be a problem - could a solar ion drive deliver enough "punch", or would a supplemental booster be needed? Otherwise I understand that solar would be way more fuel/time efficient over a few years compared to carrying rocket fuel & hanging around for gravity slingshots. Am I right?
I have even read of deep-space solar-powered mission designs that head in inside mercurys orbit, grab loads of power and then head out beyond Jupiter..
So if we say that both images are about the same res, its interesting that the CCD camera on Cassini is only about 3 times better than the Vidicon camera on Voyager, in terms of magnification.. At least on a brightish object anyway.
When Cassini gets close up, those extra pixels will tell, I guess, aqnd the CCDs are better in low light..
Getting to 5000m should not be a problem of time, at 1 m/s, even though I wander whether that speed is possible vertically? Probably a bigger problem is communicating over 5km - maybe you need "relays" at intermediate depths. It seems that groups of them can act as a sort of network. I didnt see a lot of details on such things as coms distance, etc, tho I didnt dig very deep.
As a toy for $700, I would even consider buying one.
Hmmm, I wonder if you could mount a laser.. What do you mean, why?
This is an interesting article on the Apollo Guidance Computer - with details of the internal architecture of the CPU, and its Assembly language.
Interestingly, it seems early desicions about the address/op code size gave the designers x86 type headaches when they later wanted more address space & op codes/registers..
You can thank Jupiter for catching comets like shoemaker-levy. More recent theories indicate that Jupiter acts like a giant hoover, catching debris that would otherwise end up hitting earth, which in turn would make advanced life on Earth impossible due to frequency of large impacts.
Even as it is, impacts the size of the Meteor that hit Tunguska, Siberia in 1907 probably happen every at least century or so - and if that happened over New York, you can say goodbye NY..
Slashdot Mirror
Thats the geezer out of StarGate!
Can it run on "I cant believe this is not butter"..
20000:1..
Bananas are Evil!
and if you dont believe me, read this (http://antibanana.8m.com/ )
"I will show you the power of my banana" jokes in 3.. 2.. 1..
Heavier, bigger, cans.. More junk to be thrown away. (yes I know its alu, but not every can gets recycled).
Whats wrong with a good old micro-fridge? Or just hang your beer up in a damp sock for a while..
Seriously, I think its about time sales taxes were put on non-environmental packaging gimmicks like this, or maybe a refundable deposit like in South Australia..
What options do we have today that we didn't have in the 1950's? How many of those are capable of outright replacing the Coal/Oil/Nuclear infrastructure?
Offshore wind power could almost do it alone for the UK..
(British Wind Enrgy Association page)
There are a few million Ukranians who would disagree with you there.. There is still the nagging question as to what happens to the waste - the UK has given up on its nuclear program as a result.
We have barely begun to exploit natural renewable resources - just one example - offshore wind power could supply *several* times the electicity needs for the UK (British Wind Enrgy Association page).
Its an old debate, but the points are still valid..
There was an interesting article on spacedaily.com (The case against Hubble)
which, although primarily about Hubble, mentioned the fact that NASA rejected a much cheaper mission option for a Europa-only orbiter costing around $1 billion in favour of the $8 billion JIMO mission. You could have 10 or more SEP/RTG missions for the cost of JIMO.. Solar can even be used for getting to Jupiter-Neptune, by swinging in close to the sun first & picking up momentum with SEP or a solar sail.. Just carry enough fuel to enter orbit on arrival, like Cassini..
Something like JIMO will come eventually, but is it worth sacrificing so many possible missions for that one option?
Windows is indeed a cheap system to 0wn!
..Bruce Willis!
Ive actually been to La Palma, its a beautiful and largely untouched island. Its interior has the 2nd largest volcano in the world, with utterly impossible and fantastic looking mountain peaks..
Ok, I'll be modded down for this, but..
Do they run Linux?
Or in soviet russia, does the ant colonise YOU!?
Or should I imagine a beowulf cluster of ants?
or..
1) start an ant super colony in Melbourne..
2. ???
3. PROFIT!!
Ok, ok, Im done..
McBride Says No More Lawsuits From SCO..
Bill Gates to refund every Windows XP users money "because its rubbish"..
An end to all wars in the world..
A pony for every child..
In reply to my own question - the up and coming ESA Bepicolombo mission to mercury will use.. yep.. Solar Electric Propulsion. It still uses gravity slingshots to slow down, and needs a small conventional rocket to kick it into Mars orbit.
It will launch 2012 and take 4 years to get to Mercury, compared to 7 for messenger. Now the interesting part - how much is saved in the mission profile with ion engines? Do ion engines allow for more flexible mission launch windows? How will the propellant/mass profile compare to Messenger?
SMART-1 was primarily a test-bed for lots of new technologies, including ion propulsion. Going to the moon was almost a bonus - the main objective was to see if it was possible to make very small, cheap missions ($100 million, I think). It was piggy backed (cheaply) onto an existing satellite launch, hence having the minimal boost needed to get to Low Earth Orbit.. If you used a bigger rocket (smaller than Apollo) it could get there in 3 days too.
For a bigger mission like Mercury, as you can see, it is much harder to get there quickly by chemical rocket - hence the "long burning" ion drive comes into its own..
Yes I remember that impulse was rated in seconds - I should have said per Kg of propellant - ie, I understand that an ion drive can generate 10x the thrust per Kg of propellant, it just does it slower..
The SMART-1 mission cost $100 million in *total*, not too much in terms of space exploration. The thrusters will operate for 18 months & I think newer designs allow for multiple replacement anodes to replace old ones..
Ion drive missions have spiral paths, in this case decellerating towards the sun. An ion drive mission could also exploit slingshot slowdowns, no?
At points where the craft is nearer the sun, more power is available - lots more power..
So, has anyone done the calculation for a mission profile with solar-ion propulsion?
..They are not much mass-effective (thrust per unit engine mass) at all.
Current Ion drives can deliver >10x more power overall per Kg compared to rockets - but they do it slowly, over months/years.. Rockets can deliver "punch" at a spacific time. Advantages/Disadvantages both ways really.
Messanger as-is carries 1/2 its weight as fuel, so if you can reduce that 10 fold, or get 10 times the power, thats a good thing. Faster missions are less expensive in terms of keeping support staff too, and less risky. I think a solar-ion mission that spirals inwards as it decelerates would be way more efficient than the current plan. And would be much less dependant on celestial mechanics for launch dates.
Anyone from NASA here know why they dont use solar-ion drives for these missions? Is there some sort of political bias against solar & pro old fashioned rockets or nuclear? (And yes, I know nuclear (RTG) is needed for deep space - at least for electric power for the science instruments..)
Here is a better link for SMART-1..
I dont understand why solar-powered ion drives are not used on missions like this. Probes like the ESA SMART-1 has shown that such craft can be small & economical, and there is an abundance of solar power available for free. I understand that final orbital insertion can be a problem - could a solar ion drive deliver enough "punch", or would a supplemental booster be needed? Otherwise I understand that solar would be way more fuel/time efficient over a few years compared to carrying rocket fuel & hanging around for gravity slingshots. Am I right?
I have even read of deep-space solar-powered mission designs that head in inside mercurys orbit, grab loads of power and then head out beyond Jupiter..
Why arnt ion drives used more?
Dental Amalgams and thermometers..
So if we say that both images are about the same res, its interesting that the CCD camera on Cassini is only about 3 times better than the Vidicon camera on Voyager, in terms of magnification.. At least on a brightish object anyway.
When Cassini gets close up, those extra pixels will tell, I guess, aqnd the CCDs are better in low light..
Oddly enough the death star would fit nicely into the crater...
No it wont, since one of these is "real life", and the other "fiction". Sorry to break the news to you all like that, but..
There is more on the Serafina home page.
Getting to 5000m should not be a problem of time, at 1 m/s, even though I wander whether that speed is possible vertically? Probably a bigger problem is communicating over 5km - maybe you need "relays" at intermediate depths. It seems that groups of them can act as a sort of network. I didnt see a lot of details on such things as coms distance, etc, tho I didnt dig very deep.
As a toy for $700, I would even consider buying one.
Hmmm, I wonder if you could mount a laser.. What do you mean, why?
Awwwww!
This is an interesting article on the Apollo Guidance Computer - with details of the internal architecture of the CPU, and its Assembly language.
Interestingly, it seems early desicions about the address/op code size gave the designers x86 type headaches when they later wanted more address space & op codes/registers..
You can thank Jupiter for catching comets like shoemaker-levy. More recent theories indicate that Jupiter acts like a giant hoover, catching debris that would otherwise end up hitting earth, which in turn would make advanced life on Earth impossible due to frequency of large impacts.
Even as it is, impacts the size of the Meteor that hit Tunguska, Siberia in 1907 probably happen every at least century or so - and if that happened over New York, you can say goodbye NY..