For example, electric wire insulation... I'm assuming this bacteria will go pretty slowly, not having a negative impact on all the disposable stuff we go through. However, there are lots of plastic uses that are expected to maintain their integrity for decades, in places that can't/won't be checked or replaced.
I recently returned from 2+ years volunteering in tropical Bolivia (see our blog here http://bo.teeks99.com/ ), doing a lot of what you are looking for. Right off the bat, you need to know it isn't going to be as easy as you think it will right now.
Important Issues
1. Shipping - The cost to ship a single 3-year old computer to a developing nation (don't forget import duties!) will probably be more than just buying a comperable computer in-country. Even though there aren't a lot of people with money in bolivia, there is still a great demand for computers. Thus the markets had lots of low-cost deals, not the latest technology but it was enough. Parts for a Core 2 Duo setup were ~$200, another $120 for a monitor. I would guess Guatemala would be similar.
2. Power - In every developing nation I've ever been in, electricity has been an issue for computers. In Bolivia it was rare that we would lose electricity completely (once every couple months), but very common where we would have brown-outs where there just isn't enough electricity in the wires. This is very bad for computers...so we had to hook every computer up to a battery (usually 2-3PCs for to a 1300VA battery). Unfortunately heat is the primary killer of batteries and the tropics is always hot. Over two years we probably spent 50% of the money spent on the lab on the original batteries and their replacements.
3. Administrator - Someone will need to be in-charge of the lab long-term. If you're there for a month you may have time to get it all setup and start training someone. However, it might not be that easy to get them up to speed on the basics of linux that they would need to know to keep it running. If there is just one big problem they can't solve they'll probably just go and install a pirated copy of windows on all the machines.
4. Cirriculum - I also wanted very much to teach the benefits of Open Souce, but that just wasn't what was needed by the students. The problem is that skills employers look for can be absurdly specific (probably due to the very different learning styles of students). It would not be uncommon for someone not to get a job because they had experience with Word 2003 instead of Word 2007. If you say..."I learned how to use Libre Office" the employer won't know what you're talking about, if you try to tell them it's basically the same as Microsoft Office they won't believe you. If you don't put "Learn to use Windows" or "Learn to use Office 2007" on the flyers for a course, you won't get very many students.
That said, I was able to make a decent multimedia course using Open Source: Gimp, Inkscape, Audacity, Kdenlive, etc., but to get students I also had to promise to teach them Photoshop, Illustrator, etc. What I ended up doing was speding a month with GIMP then just one day going through all the things they already learned in Photoshop...just so they could put it on their resume. (If you're interested, the text I wrote for my multimedia course is all open sourced too: http://mediaintro.sagradocorazon.info/ )
5. Teachers - Who is going to teach a cirriculum based on open source? There probably aren't already people there who can do it. Do you have a whole semester you could team-teach with one of the current teachers so that they would be equipped to continue on? What about when they get a different job, who will take over then?
I'm sorry if all this is a bit negative, I really do hope you have success. It would be amazingly helpful to the people in many developing countries if they had the tools of open source at their disposal (you could only imaging the countless hours wasted because of computer viruses that infect illegal copies of windows). I hope addressing these issues I had up front helps you save time in the long-run.
Launching the fuel station in such a way that matching its velocity is substantially close to being on the escape trajectory you eventually want to be on would be stupid, since you would have to accelerate the entire fuel station to nearly that escape trajectory instead of just bringing the fuel with you, and you'd also have to launch the fuel station close in time to launching your actual mission.
That's the magic of the Lagrange Orbits. They're very cheap to get to from an escape trajectory, but they hang around the body(ies) that they're attached to.
That's where the "Strategic Spots" come in. There are certain points along the orbit from earth to X (moon, mars, asteroid, etc) where it would take extremely little thrust from the space ship to drop by there (stop is the wrong word).
Also, as others have mentioned, it would be possible for the "Gas Station" or at least a module of it to come to you as well.
You pretty much nailed it all on the head. The only thing that I wanted to add was that there has been one probe to move between two massive bodies (Earth and the Moon) using a continuous thrust system: the SMART-1 probe with its Ion engine. The downside: it took 13 months (it only took the Apollo astronauts a couple days) and used a series of really strange, constantly expanding orbits (basically a spiral), on the plus side it only took 1/10th of the total propellant mass that a chemically powered spacecraft would.
Ion/Hall/Plasma thrusters are great for moving cargo where you don't care too much about how long it takes (especially in the beginning of the mission). This type of technology could easily be used to move fuel to one of these "Gas Stations" in earth, moon, sun, or mars orbit. You could start this years before the need date (before you get busy testing out the manned space craft) then the chemical fuel could already be there when you're ready to launch the manned space craft.
That Discover article was pretty hit-or-miss. They nailed the real solution in two of their pieces (tethers and sails), in that the best (easiest, cheapest, only-one-that-will-probably-ever-happen) are technologies that are built into space objects (satellites and boosters) before launch. There's lots of options here from tethers, sails, balloons, or just using existing thrusters. If we can stop leaving big pieces up there (which can run into other big pieces and make LOTS of pieces), the problem will start getting less severe.
On the other hand, on of Discover's pages was about blowing up the debris...this makes sense, until you really think about it. The problem is that when you blow up something, it makes a huge number of new pieces, with all sorts of different velocities and orbits. On average, these pieces will fall to earth more quickly than the unexploded satellite, however, that's just the average. There are many pieces that will stay up there even longer. And when you're talking about things moving that these incredible velocities, it doesn't matter a whole lot if you get hit by a 6,000lb. satellite or a 5lb. piece of a satellite, either one will destroy anything we've put in orbit.
A few ounces of force isn't much as most satellites experience hundreds or thousands of pounds of force during the launch.
Since you're trying to de-orbit the satellite, you probably don't care too much about what attitude it is in, so as long as the part of the balloon that attaches to the satellite is capable of handling those few ounces of force, I'm not sure what else there would be to go wrong.
No, it will be dragging behind the satellite, in the lower density area that has been swept out by the satellite. Because this area is lower density, it won't create as much aerodynamic drag as it would if it was perpendicular to the path of travel.
Quite easily. Well, moderately easily...most normal GPS receivers would work in space except they have an arbitrary limit of 60,000ft and Mach 1 (?? not sure of the exact speed off the top of my head) that keep them from being turned into guidance systems for ballistic missiles. GPS is already routinely used for spacecraft navigation, you just need a more expensive receiver without the imposed limit.
If this were air, you'd be completely correct. However, in the vacuum of space and with a very light balloon (we're talking on the order of 10lbs for a football-field size one) there isn't much of a moment arm. The force due to drag would probably be measured in ounces and then you have just the weight of the actual structure. Generally when satellites attitude control systems fail, they don't immediately start spinning like crazy, probably just a few degrees per minute.
I think the ribbon would just end up moving to being in a line behind the satellite along the path it just came from in orbit...think of how a ribbon follows behind a car...in its slipstream. Anyway, being behind the satellite doesn't really help increase drag, so it wouldn't help bring it down quicker.
That's all fine and good if you have great attitude (direction) control of your spacecraft. If you lose your gyros or something during the lifetime of the spacecraft, then you wouldn't be able to control an Ikaros like sail. Having a spherical balloon that doesn't care about direction and can inflate with minimal mechanical effort seems a lot more reliable.
Many satellites change their orbit...because of the speeds they are moving, distances covered, etc. even a small change in orbit can mean that a day or two later you're in a completely different part of the world than where you would have been, had you not done anything. The space station does this all the time, they routinely move 100mi or more over the course of a day or so to avoid space debris. Other, smaller, satellites do this too, however there are also many that don't have engines on them and can't really move themselves.
They should have a competition....launch a bunch of micro-satellites...one with a sail like surrey's, one with a balloon like this article, one with a small rocket, and one with nothing special on it....then the first one to burn up wins!
Actually most spacecraft (including "secret" government satellites) are tracked by both governments and private entities. Since the last collision the US Air Force has actually started expanding their capability for this even more. They are very open to working with other parties to solve space debris issues and avoid collisions with their satellites or between other satellites.
The most important part is to get a system working for future spacecraft (and rocket stages) that are going up. Once that is solved, then we can go and work on the stuff that is already up there.
I think that this balloon could be attached to a lot of space junk with a (very small) robotic space craft of its own. That robotic craft could use gps and cameras to rendezvous with the debris, then some type of manipulator arm could grab onto the debris. Since the force applied by this balloon would be *VERY* small (but applied over a long period of time - months) the bond between the two spacecraft wouldn't have to be very strong.
Yeah, the simpler the system, the better. Unfortunately parachutes and solar sails require the spacecraft to control what direction they are pointing in...that's why I like balloons for it, because they are spheres and work the same from every direction.
This mass of a giant balloon could actually be incredibly small...on the order of 10lbs. This would almost certainly be lighter than the amount of propellant needed to deorbit. The down side is that with propellant you could be down in a matter of days, the large balloon could still take months.
The other nice part about a balloon is that its roughly spherical...so you don't have to worry about what direction the spacecraft is pointing. This isn't a problem for spacecraft that already have guidance/engines for them...just add more propellant, but some spacecraft don't have guidance/engines so you'd have to add a lot more than just propellant.
Something like this would be really great for the industry. If we could cut in half the amount of time it took every satellite to re-enter, the orbital debris problem would quickly get a lot better.
However, the idea proposed by this team seems rather complex, because the polymer sheet is two-dimensional, it requires an active control system to keep the width of the sheet oriented towards the direction of travel. They talked about changing the center of mass and using magnetic torque control systems...all of which could fail over the years it would take to deorbit (after years of sitting dormant during the spacecraft's operational lifetime).
Instead, why not inflate a balloon? There are already large weather-balloon type ones available, and it wouldn't take much gas to inflate it, since the external pressure is zero! Once the balloon is inflated, it would have a orbital cross section that is similar to the polymer sheet, but since the balloon is roughly a sphere, you don't have to worry about controlling it.
The downside to this is that if a balloon gets hit by a micrometeorite, it could pop (I imagine SSTL's polymer sheets wouldn't handle one too well either). Luckily, NASA and others have been working on an inflatable structure that uses gas to inflate, then once it is inflated it hardens so that it no longer relies on the pressure of the air to keep it in place. This would allow for it to be punched full of holes and still keep providing some drag benefit.
There's also a pretty good article from space.com that talks about a couple of the different points
They go into some more detail about the commercial space transportation part paving the way for more "space tourist" like stuff. Obviously this will still be extremely expensive, but I hope that it could increase the total number of launches, and help bring some economies of scale.
This is also the reason I'm excited about the orbital propellant storage and automated rendezvous technology. These items will allow us to launch big (weight wise) missions by using a bunch of smaller launch vehicles, instead of one really huge (and really expensive) one.
I tried this out for the first time a couple weeks ago (after several years of Visual Studio usage) and was very hopeful...however I left feeling that it wasn't quite finished all the way. I got the impression that it was just a bunch of tools glued together with a rapid-development type GUI framework.
That said, I was quite pleased with it overall. I definitely will strongly consider using it next time I start a project. For my two cents, I think this is a great example of what the author is looking for, a tool that will help FLOSS developers that could use a bit more help:-)
This is absolutely true...you have to look at it end-to-end. However, if you can get all the internet communication to be over the VPN, that leaves an impossibly small vector for penetration from the internet (just the server with its one VPN port could be attacked).
Obviously (or maybe not so), you'd need to also think about the security of all the devices out there...what happens if one gets physically compromised, etc., but getting them so they're not accessible to the public from the internet is a great first step and would make a HUGE difference.
Slashdot Mirror
For example, electric wire insulation... I'm assuming this bacteria will go pretty slowly, not having a negative impact on all the disposable stuff we go through. However, there are lots of plastic uses that are expected to maintain their integrity for decades, in places that can't/won't be checked or replaced.
I recently returned from 2+ years volunteering in tropical Bolivia (see our blog here http://bo.teeks99.com/ ), doing a lot of what you are looking for. Right off the bat, you need to know it isn't going to be as easy as you think it will right now.
Important Issues
1. Shipping - The cost to ship a single 3-year old computer to a developing nation (don't forget import duties!) will probably be more than just buying a comperable computer in-country. Even though there aren't a lot of people with money in bolivia, there is still a great demand for computers. Thus the markets had lots of low-cost deals, not the latest technology but it was enough. Parts for a Core 2 Duo setup were ~$200, another $120 for a monitor. I would guess Guatemala would be similar.
2. Power - In every developing nation I've ever been in, electricity has been an issue for computers. In Bolivia it was rare that we would lose electricity completely (once every couple months), but very common where we would have brown-outs where there just isn't enough electricity in the wires. This is very bad for computers...so we had to hook every computer up to a battery (usually 2-3PCs for to a 1300VA battery). Unfortunately heat is the primary killer of batteries and the tropics is always hot. Over two years we probably spent 50% of the money spent on the lab on the original batteries and their replacements.
3. Administrator - Someone will need to be in-charge of the lab long-term. If you're there for a month you may have time to get it all setup and start training someone. However, it might not be that easy to get them up to speed on the basics of linux that they would need to know to keep it running. If there is just one big problem they can't solve they'll probably just go and install a pirated copy of windows on all the machines.
4. Cirriculum - I also wanted very much to teach the benefits of Open Souce, but that just wasn't what was needed by the students. The problem is that skills employers look for can be absurdly specific (probably due to the very different learning styles of students). It would not be uncommon for someone not to get a job because they had experience with Word 2003 instead of Word 2007. If you say..."I learned how to use Libre Office" the employer won't know what you're talking about, if you try to tell them it's basically the same as Microsoft Office they won't believe you. If you don't put "Learn to use Windows" or "Learn to use Office 2007" on the flyers for a course, you won't get very many students.
That said, I was able to make a decent multimedia course using Open Source: Gimp, Inkscape, Audacity, Kdenlive, etc., but to get students I also had to promise to teach them Photoshop, Illustrator, etc. What I ended up doing was speding a month with GIMP then just one day going through all the things they already learned in Photoshop...just so they could put it on their resume. (If you're interested, the text I wrote for my multimedia course is all open sourced too: http://mediaintro.sagradocorazon.info/ )
5. Teachers - Who is going to teach a cirriculum based on open source? There probably aren't already people there who can do it. Do you have a whole semester you could team-teach with one of the current teachers so that they would be equipped to continue on? What about when they get a different job, who will take over then?
I'm sorry if all this is a bit negative, I really do hope you have success. It would be amazingly helpful to the people in many developing countries if they had the tools of open source at their disposal (you could only imaging the countless hours wasted because of computer viruses that infect illegal copies of windows). I hope addressing these issues I had up front helps you save time in the long-run.
Launching the fuel station in such a way that matching its velocity is substantially close to being on the escape trajectory you eventually want to be on would be stupid, since you would have to accelerate the entire fuel station to nearly that escape trajectory instead of just bringing the fuel with you, and you'd also have to launch the fuel station close in time to launching your actual mission.
That's the magic of the Lagrange Orbits. They're very cheap to get to from an escape trajectory, but they hang around the body(ies) that they're attached to.
That's where the "Strategic Spots" come in. There are certain points along the orbit from earth to X (moon, mars, asteroid, etc) where it would take extremely little thrust from the space ship to drop by there (stop is the wrong word).
Also, as others have mentioned, it would be possible for the "Gas Station" or at least a module of it to come to you as well.
You pretty much nailed it all on the head. The only thing that I wanted to add was that there has been one probe to move between two massive bodies (Earth and the Moon) using a continuous thrust system: the SMART-1 probe with its Ion engine. The downside: it took 13 months (it only took the Apollo astronauts a couple days) and used a series of really strange, constantly expanding orbits (basically a spiral), on the plus side it only took 1/10th of the total propellant mass that a chemically powered spacecraft would.
Ion/Hall/Plasma thrusters are great for moving cargo where you don't care too much about how long it takes (especially in the beginning of the mission). This type of technology could easily be used to move fuel to one of these "Gas Stations" in earth, moon, sun, or mars orbit. You could start this years before the need date (before you get busy testing out the manned space craft) then the chemical fuel could already be there when you're ready to launch the manned space craft.
That Discover article was pretty hit-or-miss. They nailed the real solution in two of their pieces (tethers and sails), in that the best (easiest, cheapest, only-one-that-will-probably-ever-happen) are technologies that are built into space objects (satellites and boosters) before launch. There's lots of options here from tethers, sails, balloons, or just using existing thrusters. If we can stop leaving big pieces up there (which can run into other big pieces and make LOTS of pieces), the problem will start getting less severe.
On the other hand, on of Discover's pages was about blowing up the debris...this makes sense, until you really think about it. The problem is that when you blow up something, it makes a huge number of new pieces, with all sorts of different velocities and orbits. On average, these pieces will fall to earth more quickly than the unexploded satellite, however, that's just the average. There are many pieces that will stay up there even longer. And when you're talking about things moving that these incredible velocities, it doesn't matter a whole lot if you get hit by a 6,000lb. satellite or a 5lb. piece of a satellite, either one will destroy anything we've put in orbit.
A few ounces of force isn't much as most satellites experience hundreds or thousands of pounds of force during the launch. Since you're trying to de-orbit the satellite, you probably don't care too much about what attitude it is in, so as long as the part of the balloon that attaches to the satellite is capable of handling those few ounces of force, I'm not sure what else there would be to go wrong.
No, it will be dragging behind the satellite, in the lower density area that has been swept out by the satellite. Because this area is lower density, it won't create as much aerodynamic drag as it would if it was perpendicular to the path of travel.
Also, the big stuff (many of which are rocket stages with some fuel left in them) sometimes explodes: http://www.newscientist.com/article/dn10979
If we can deorbit even one *before* it explodes, we can cut the number of space debris by hundreds or thousands.
Quite easily. Well, moderately easily...most normal GPS receivers would work in space except they have an arbitrary limit of 60,000ft and Mach 1 (?? not sure of the exact speed off the top of my head) that keep them from being turned into guidance systems for ballistic missiles. GPS is already routinely used for spacecraft navigation, you just need a more expensive receiver without the imposed limit.
If this were air, you'd be completely correct. However, in the vacuum of space and with a very light balloon (we're talking on the order of 10lbs for a football-field size one) there isn't much of a moment arm. The force due to drag would probably be measured in ounces and then you have just the weight of the actual structure. Generally when satellites attitude control systems fail, they don't immediately start spinning like crazy, probably just a few degrees per minute.
Only if it has substantial mass. If it is a low mass device, than the drag on it will make it parallel (behind) the satellite.
I think the ribbon would just end up moving to being in a line behind the satellite along the path it just came from in orbit...think of how a ribbon follows behind a car...in its slipstream. Anyway, being behind the satellite doesn't really help increase drag, so it wouldn't help bring it down quicker.
That's all fine and good if you have great attitude (direction) control of your spacecraft. If you lose your gyros or something during the lifetime of the spacecraft, then you wouldn't be able to control an Ikaros like sail. Having a spherical balloon that doesn't care about direction and can inflate with minimal mechanical effort seems a lot more reliable.
Many satellites change their orbit...because of the speeds they are moving, distances covered, etc. even a small change in orbit can mean that a day or two later you're in a completely different part of the world than where you would have been, had you not done anything. The space station does this all the time, they routinely move 100mi or more over the course of a day or so to avoid space debris. Other, smaller, satellites do this too, however there are also many that don't have engines on them and can't really move themselves.
They should have a competition....launch a bunch of micro-satellites...one with a sail like surrey's, one with a balloon like this article, one with a small rocket, and one with nothing special on it....then the first one to burn up wins!
Actually most spacecraft (including "secret" government satellites) are tracked by both governments and private entities. Since the last collision the US Air Force has actually started expanding their capability for this even more. They are very open to working with other parties to solve space debris issues and avoid collisions with their satellites or between other satellites.
The most important part is to get a system working for future spacecraft (and rocket stages) that are going up. Once that is solved, then we can go and work on the stuff that is already up there.
I think that this balloon could be attached to a lot of space junk with a (very small) robotic space craft of its own. That robotic craft could use gps and cameras to rendezvous with the debris, then some type of manipulator arm could grab onto the debris. Since the force applied by this balloon would be *VERY* small (but applied over a long period of time - months) the bond between the two spacecraft wouldn't have to be very strong.
Yeah, the simpler the system, the better. Unfortunately parachutes and solar sails require the spacecraft to control what direction they are pointing in...that's why I like balloons for it, because they are spheres and work the same from every direction.
This mass of a giant balloon could actually be incredibly small...on the order of 10lbs. This would almost certainly be lighter than the amount of propellant needed to deorbit. The down side is that with propellant you could be down in a matter of days, the large balloon could still take months.
The other nice part about a balloon is that its roughly spherical...so you don't have to worry about what direction the spacecraft is pointing. This isn't a problem for spacecraft that already have guidance/engines for them...just add more propellant, but some spacecraft don't have guidance/engines so you'd have to add a lot more than just propellant.
Also they have developed materials that, once inflated in the vacuum of space, can hold their shape without any internal pressure.
Something like this would be really great for the industry. If we could cut in half the amount of time it took every satellite to re-enter, the orbital debris problem would quickly get a lot better.
However, the idea proposed by this team seems rather complex, because the polymer sheet is two-dimensional, it requires an active control system to keep the width of the sheet oriented towards the direction of travel. They talked about changing the center of mass and using magnetic torque control systems...all of which could fail over the years it would take to deorbit (after years of sitting dormant during the spacecraft's operational lifetime).
Instead, why not inflate a balloon? There are already large weather-balloon type ones available, and it wouldn't take much gas to inflate it, since the external pressure is zero! Once the balloon is inflated, it would have a orbital cross section that is similar to the polymer sheet, but since the balloon is roughly a sphere, you don't have to worry about controlling it.
The downside to this is that if a balloon gets hit by a micrometeorite, it could pop (I imagine SSTL's polymer sheets wouldn't handle one too well either). Luckily, NASA and others have been working on an inflatable structure that uses gas to inflate, then once it is inflated it hardens so that it no longer relies on the pressure of the air to keep it in place. This would allow for it to be punched full of holes and still keep providing some drag benefit.
There's also a pretty good article from space.com that talks about a couple of the different points
They go into some more detail about the commercial space transportation part paving the way for more "space tourist" like stuff. Obviously this will still be extremely expensive, but I hope that it could increase the total number of launches, and help bring some economies of scale.
This is also the reason I'm excited about the orbital propellant storage and automated rendezvous technology. These items will allow us to launch big (weight wise) missions by using a bunch of smaller launch vehicles, instead of one really huge (and really expensive) one.
I tried this out for the first time a couple weeks ago (after several years of Visual Studio usage) and was very hopeful...however I left feeling that it wasn't quite finished all the way. I got the impression that it was just a bunch of tools glued together with a rapid-development type GUI framework.
That said, I was quite pleased with it overall. I definitely will strongly consider using it next time I start a project. For my two cents, I think this is a great example of what the author is looking for, a tool that will help FLOSS developers that could use a bit more help :-)
This is absolutely true...you have to look at it end-to-end. However, if you can get all the internet communication to be over the VPN, that leaves an impossibly small vector for penetration from the internet (just the server with its one VPN port could be attacked).
Obviously (or maybe not so), you'd need to also think about the security of all the devices out there...what happens if one gets physically compromised, etc., but getting them so they're not accessible to the public from the internet is a great first step and would make a HUGE difference.