Can we stop referring to these high altitude balloon payloads as going "into space"? At 91000 feet up, he is over 70 km from the official edge of space, and 130 km from lowest satellite orbits.
EDIT: The soon to be MIT student correctly refers to it as a "near space" flight, but the context was changed to increase the link bait factor.
Even worse, the reporter says "She took her admissions letter and then rocketed it into space." As if there were a rocket involved.
I mean, I like high-altitude ballooning, don't get me wrong. I'm just saying that this sentence primed me to expect something an order of magnitude cooler, someone strapping 250 grams of aluminum-based rocket fuel to their acceptance letter and watching it blast off.
how hard and expensive would it be to make amateurish spacecraft and go into the space? and obviously (which I think makes is so hard to do) come back to Earth in one piece?
Running the numbers, you need at least 1 MJ/kg to get past the 100km limit into what's officially considered "outer space". That's only factoring in Earth's gravity.
If we could do it with purely electrical motors, then assuming you pay 20 cents per kilowatt hour and only have a conversion efficiency of 10% into actual lifting power, it would only cost you $0.60/kg energy-wise to get up there. Assuming that you'd need to take an environment of, say, 10,000 kg with you, the marginal cost would still only be about $6,000. That's something of an ideal case, the "space elevator" proposal.
Solid rocket fuel, the numbers are a little harder to come by. It sounds like the active ingredient is usually aluminum. One page on Wikipedia suggests that aluminum has an energy density of 31 MJ/kg (and my calculations based on Wikipedia's "aluminum oxide" page agree) and that only 16% of solid rocket fuel is aluminum. So that's 5 MJ/kg. Or roughly 4 MJ/kg if you take into account that the fuel more or less has to push its own way up with you. (Not all the way, of course, but I'm too lazy to do the calculation properly and there's wind resistance anyway.) The first rocketry site on Google says that they'll sell you 20 pounds of the stuff (9 kg) for something like 200 bucks, or $22/kg. With the conversion factor of (4 MJ/kg fuel)/(1 MJ/kg lifted) = 4 kg lifted / kg fuel, the equivalent number is about 10 times higher -- you $6 per kg that you want to send into space, so the marginal cost is presumably then something like $60,000.
Can we do better by bulk? Google says people sell the main ingredient -- ammonium perchlorate -- at $3,000 per metric ton. Aluminum is a bit pricier, but I can find people selling large chunks at about $500/50kg, adding about $1,500 to the above. Adding in the cost of the plastic binding, the raw fuel components might cost $5/kg. So you're not going to get cheaper with rocket fuel than around $15,000 per flight.
Of course, the spacecraft is going to be the more expensive bit, I'm sure. But that's more complicated because maybe you can share that cost over five successful runs before it accidentally kills someone dramatically and no one buys it. I'm just saying that, even without that, based on fuel alone, it's still going to be an order of magnitude more expensive than a trip to a far-off land.
But these balloonists have the right idea. If you could instead send up a camera, you could potentially get up there at a fraction of the cost, something that hobbyists can do. "You know where this hat has been?" you could say: "OUTER SPACE."
(Incidentally, getting to the height mentioned in the above article requires only about 0.3 MJ/kg, so divide all the costs by 3. The 100km distance is where you're officially in outer space as internationally recognized.)
I had thought I might buy the necessary material and write out the required instructions to do this and give them to three six and seven year olds for them to assemble and launch (with adult help to carry the tank & fill the balloon).
So far their mothers say yes, they have a sense of humour & don't think I will actually let the kids do it without a lot of help. Their fathers say no, likely because of their own selfish lack of input in building it and they think they might have to pay for the project (ie the damages if it goes wrong). I will have to try some more and hopefully in a few weeks will have convinced them to try this experiment.
Just wondering: how do you get into MIT at 16, and is it worth it? I mean would you be missing out as a 16 year old at MIT (or any other university) because your peers are into other things than you, or is it an overall net plus?
I assume that it is not some inherited genius that enables kids to get into university, but some unique "strategy". Of course I could be wrong. I also assume it would be doable without ruining the childhood, that is, the kid should be naturally excited about science and stuff, not forced into it.
To be accepted into college at 16, you simply need to skip one grade and have your birthday be later in your school year than your acceptance to college.
I skipped a grade, then I got into Stanford "early action", which means I found out in December when I was still 16. I turned 17 fairly soon thereafter, and was 18 for roughly half of my freshman year of college.
So one doesn't have to be that far ahead of schedule to "be 16" (even if that means almost 17) when getting into college.
Being one year young doesn't really inhibit my ability to take advantage of Stanford in a serious way. The fact that there will only be one quarter when I am eligible to take the wine tasting course is about the extent of it.
She probably skipped a grade. I was 17 when I started college and this wasn't unusual; I wasn't even nearly the youngest person in my class.
I doubt that age is that big a factor. I don't think a gap of two years makes it any harder to find people with the same interests; if that was true, freshman and seniors could never be friends. Throughout my past ~5 years I've been friends with people 5 or more years younger and older than me; I never noticed any sort of dramatic issue.
When I went to first grade, they did the usual testing, and then told my parents they wanted me to skip every other grade. Which would have had me in college at what, 13?
At the time I was disappointed my parents vetoed the crazy scheme, but in retrospect, it was a crazy scheme.
I got into MIT at 16 and turned 17 during my freshman year. I can't say I ever suffered socially as a result; I'm a very social person and had a large group of friends at school.
As far as the strategy, if you can call it that: I wasn't getting much out of high school and realized I could finish all my required classes in 3 years, so I did. By far my most time consuming extracurricular activity was studying the violin; until I entered MIT, I'd been primarily a musician, and I certainly wasn't forced into science or engineering. I'd taught myself to program and decided that EE/CS was an interesting career path, so I applied to MIT.
I wait for the day one of those "space" experiments by some high-school student (and his parents) ends up crashing a jet engine or lands on a windshield of a van going 80 miles/hour.
It's all fun until reality and hits you right in the face and you pay for your YouTube video for the rest of your life. Is it likely to happen? No, but that wont save you afterwards.
There are actually pretty strict rules for the high-altitude balloon people in terms of payload weight/volume, and being visible to aircraft, both visually and on radar.
Basically they have to be made so that on any collision the payload will break off safely, and that when it falls it won't seriously damage anything that it hits.
What am I seeing in the video? It's not zoomed out enough to be the whole Earth, but I see the Earth as a circle as if we can see one whole half of the planet. Am I confused about how curvature appears from space?
Wow a lot of jealous comments in this thread. I'm feeling it too. Why didn't my dad work at JPL and teach me physics and electrical engineering on his knee!?!
Seriously, not everyone with her opportunities wouldve converted it into her accomplishments. Sure she had chances, but she brought her own drive and determination.
Allow me to relate a bit of personal history. I'm kind of a nerd, shocking I know, but its true. And have a fairly large number of toys around the house and have lived the 'hacking' lifestyle for my whole life. When my daughter was 9 [1] she was part of a team I put together to compete on the short lived 'Robotica' series. When she was 10 and wanted a computer for her room I gave her a VAX running NetBSD. (and VMS although NetBSD was much more approachable). She went to Reed College as an art major! (although when she graduates her degree will be in physics, go figure).
The point though (besides being able to brag about my kids, another sin I'm guilty of) is that if your parents did work at JPL and do rocket science there is no guarantees that you would be interested in rockets. As a parent all we can do is try to expose the kids to as many things as possible in an effort to allow them to discover their passions earlier rather than later. It is tremendously challenging as a parent to help your kids discover these things, but it is so valuable to them later on.
Too bad they don't list what GPS receiver they used. Most GPS receivers, to satisfy export restrictions, do not function above 60k ft or 1000 knots speed.
There is some ambiguity there, so some receivers only disable themselves if you are above 60k AND above 1000 knots, so people doing high altitude balloon work look for those, or they look for imported receivers.
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[ 3.5 ms ] story [ 68.8 ms ] threadEDIT: The soon to be MIT student correctly refers to it as a "near space" flight, but the context was changed to increase the link bait factor.
I mean, I like high-altitude ballooning, don't get me wrong. I'm just saying that this sentence primed me to expect something an order of magnitude cooler, someone strapping 250 grams of aluminum-based rocket fuel to their acceptance letter and watching it blast off.
I want to do this. Anyone have a link to a set of instructions? It looked like she was following some printed instructions in the video.
http://forums.somethingawful.com/showthread.php?threadid=327...
Running the numbers, you need at least 1 MJ/kg to get past the 100km limit into what's officially considered "outer space". That's only factoring in Earth's gravity.
If we could do it with purely electrical motors, then assuming you pay 20 cents per kilowatt hour and only have a conversion efficiency of 10% into actual lifting power, it would only cost you $0.60/kg energy-wise to get up there. Assuming that you'd need to take an environment of, say, 10,000 kg with you, the marginal cost would still only be about $6,000. That's something of an ideal case, the "space elevator" proposal.
Solid rocket fuel, the numbers are a little harder to come by. It sounds like the active ingredient is usually aluminum. One page on Wikipedia suggests that aluminum has an energy density of 31 MJ/kg (and my calculations based on Wikipedia's "aluminum oxide" page agree) and that only 16% of solid rocket fuel is aluminum. So that's 5 MJ/kg. Or roughly 4 MJ/kg if you take into account that the fuel more or less has to push its own way up with you. (Not all the way, of course, but I'm too lazy to do the calculation properly and there's wind resistance anyway.) The first rocketry site on Google says that they'll sell you 20 pounds of the stuff (9 kg) for something like 200 bucks, or $22/kg. With the conversion factor of (4 MJ/kg fuel)/(1 MJ/kg lifted) = 4 kg lifted / kg fuel, the equivalent number is about 10 times higher -- you $6 per kg that you want to send into space, so the marginal cost is presumably then something like $60,000.
Can we do better by bulk? Google says people sell the main ingredient -- ammonium perchlorate -- at $3,000 per metric ton. Aluminum is a bit pricier, but I can find people selling large chunks at about $500/50kg, adding about $1,500 to the above. Adding in the cost of the plastic binding, the raw fuel components might cost $5/kg. So you're not going to get cheaper with rocket fuel than around $15,000 per flight.
Of course, the spacecraft is going to be the more expensive bit, I'm sure. But that's more complicated because maybe you can share that cost over five successful runs before it accidentally kills someone dramatically and no one buys it. I'm just saying that, even without that, based on fuel alone, it's still going to be an order of magnitude more expensive than a trip to a far-off land.
But these balloonists have the right idea. If you could instead send up a camera, you could potentially get up there at a fraction of the cost, something that hobbyists can do. "You know where this hat has been?" you could say: "OUTER SPACE."
(Incidentally, getting to the height mentioned in the above article requires only about 0.3 MJ/kg, so divide all the costs by 3. The 100km distance is where you're officially in outer space as internationally recognized.)
So far their mothers say yes, they have a sense of humour & don't think I will actually let the kids do it without a lot of help. Their fathers say no, likely because of their own selfish lack of input in building it and they think they might have to pay for the project (ie the damages if it goes wrong). I will have to try some more and hopefully in a few weeks will have convinced them to try this experiment.
I assume that it is not some inherited genius that enables kids to get into university, but some unique "strategy". Of course I could be wrong. I also assume it would be doable without ruining the childhood, that is, the kid should be naturally excited about science and stuff, not forced into it.
I skipped a grade, then I got into Stanford "early action", which means I found out in December when I was still 16. I turned 17 fairly soon thereafter, and was 18 for roughly half of my freshman year of college.
So one doesn't have to be that far ahead of schedule to "be 16" (even if that means almost 17) when getting into college.
Being one year young doesn't really inhibit my ability to take advantage of Stanford in a serious way. The fact that there will only be one quarter when I am eligible to take the wine tasting course is about the extent of it.
I doubt that age is that big a factor. I don't think a gap of two years makes it any harder to find people with the same interests; if that was true, freshman and seniors could never be friends. Throughout my past ~5 years I've been friends with people 5 or more years younger and older than me; I never noticed any sort of dramatic issue.
At the time I was disappointed my parents vetoed the crazy scheme, but in retrospect, it was a crazy scheme.
As far as the strategy, if you can call it that: I wasn't getting much out of high school and realized I could finish all my required classes in 3 years, so I did. By far my most time consuming extracurricular activity was studying the violin; until I entered MIT, I'd been primarily a musician, and I certainly wasn't forced into science or engineering. I'd taught myself to program and decided that EE/CS was an interesting career path, so I applied to MIT.
(Now I'm an integrated circuit designer.)
It's all fun until reality and hits you right in the face and you pay for your YouTube video for the rest of your life. Is it likely to happen? No, but that wont save you afterwards.
http://www.eoss.org/pubs/far_annotated.htm
Basically they have to be made so that on any collision the payload will break off safely, and that when it falls it won't seriously damage anything that it hits.
The odds of it happening on any given trip are low. But in the long run every weird coincidence will happen.
Seriously, not everyone with her opportunities wouldve converted it into her accomplishments. Sure she had chances, but she brought her own drive and determination.
Allow me to relate a bit of personal history. I'm kind of a nerd, shocking I know, but its true. And have a fairly large number of toys around the house and have lived the 'hacking' lifestyle for my whole life. When my daughter was 9 [1] she was part of a team I put together to compete on the short lived 'Robotica' series. When she was 10 and wanted a computer for her room I gave her a VAX running NetBSD. (and VMS although NetBSD was much more approachable). She went to Reed College as an art major! (although when she graduates her degree will be in physics, go figure).
The point though (besides being able to brag about my kids, another sin I'm guilty of) is that if your parents did work at JPL and do rocket science there is no guarantees that you would be interested in rockets. As a parent all we can do is try to expose the kids to as many things as possible in an effort to allow them to discover their passions earlier rather than later. It is tremendously challenging as a parent to help your kids discover these things, but it is so valuable to them later on.
[1] http://www.mcmanis.com/chuck/robotics/killerB.html
There is some ambiguity there, so some receivers only disable themselves if you are above 60k AND above 1000 knots, so people doing high altitude balloon work look for those, or they look for imported receivers.