Nothing happens to the "cones in the sensor", sound just doesn't travel in a vacuum. Ultrasonic sound is no exception... Have you ever seen the bell in a jar experiment?
Hi guys, ·
I m somewhat new to this forum (I’m still working thru “What’s a microcontroller. I’ve been into electronics since the 70’s but I find the hardware aspect of it a lot easier than the software but I am trying – these microcontrollers are really cool) anyway I saw this thread on the lunar X prize I was enthralled. I was talking to a friend of mine recently about how this country (the USA) used to have this can do attitude and now we are nothing but bunch of whiners and crybabies. We didn’t put people into orbit or our foot prints on the moon by saying it couldn’t be done or it cost too much, hell no we went out and WE DID IT. And to see a bunch of guys seriously trying to put something on the surface of another planet with easily found off the shelf technology and a lot of garage know how….Well I’m glad that there’s still some people that still have that can do attitude. Well enough preaching for now. I was up pretty late reading all the responses to this thread and I don’t think you are thinking out of the box enough. ·First of all getting the payload from this rather steep gravity into orbit, someone suggested an under wing “piggy back” to get it up that’s a good start but most planes don’t go high enough for it to be that effective. I was thinking of balloons, weather balloons can go up to more than one hundred thousand feet and a considerably smaller rocket tethered to it or even in the middle of a cluster of them the cost of getting into orbit could be reduced from millions to thousands. ·Next getting from orbit to the moon. Looking at the forms for the X prize I didn’t see any time limits to get to the moon so how about using ion engines, the so called electric rocket motors they are very low thrust so it might take weeks or even months to get there, or solar sails they use photonic pressure from the sun for acceleration and they can be flipped over to help decelerate it into lunar orbit. Since the payload is so small the sails probably have to be only a couple of miles in diameter, and because of their size you could probably see them from earth on its way to the moon. That would be spectacular, to see the sun glinting off the sails as it made it long journey to the moon. ·Landing on the moon: I don’t see any other way than using rocket motor or some kind of compressed gas both are kinda heavy. ·The rover itself does it have to have wheels and motors? Both are extra weight – how about something that “hops” say a gimble mounted solenoid with some gyros to keep it from tipping over, it could jump over obstacles that a wheeled rover would have to go around or get stuck completely. · ·
Mike ·
···I think you're vastly overestimating the cost savings of a balloon launch. These were done early in the U.S. space program and I doubt they would have been discontinued if you got a 1000 to 1 cost savings. But having followed this matter from its beginning through a couple other venues that they have used, the decision was made quite early not to build a launch system to Earth Orbit. I think high-impulse systems like ion or plasma rockets (or maybe rail guns) have merit, but the more original research you have to do, the farther back you push the launch date and in a race, that's not such a good idea. ( I personally like the idea of using a relatively conventional air-breathing first stage, say a turbo-rocket or flashjet, but again, the more you have to do, the farther back you push the launch date.)
·· I wonder if we have actually lost that sort of can do attitude or if it just isn't the story anymore. I've lived through the whole NASA era and saw the change from a sort of gee whiz attitude about science and technology reporting, to one where it seems the first thing the media look for is some dark side to any such story.
·· By the way, the team was admonished early on to think outside the box, by an individual pushing a balloon launch system, although in that case allowing the craft to drop to develop speed to light up a ramjet. So maybe you guys are stuck in the thinking outside the box box.
Are you sure? That was during the cold war and there was a lot of one-upmanship and “we’re better and smarter than those –bleeping- Russians” kind of talk and it also seems to me that the space program of the sixty’s was also telling the Russians that ya if we can put a large heavy satellite into orbit that we can easily put a large nuclear warhead right on the kremlins front porch. Besides a lot of NASA’s support is public approval, there’s something quit dramatic and forceful about seeing an object the size of a small office building rise into the sky on a column of flame. How popular would the space program have been if all they did was have a couple of guys let a large balloon loose with a small rocket on the end of a string slowly drift up. Would have seemed kinda pathetic and lame to me. I was born in the early sixty’s and some of my best memories are of sitting with my dad watching the news as those office buildings rose up into the sky. Would it have been the same if they were just some balloons? I doubt it; would some balloons have even made the news? Would thousands of people thronged to the Cape to watch some guys release a pretty balloon? But anyway I still think that is about the cheapest way to get a payload up there even if it cost five or ten million dollars it’s still cheaper than that Pegasus rocket that was talked about in an earlier thread. ·
In doing some research I do see that an ion motor would be to experimental but I still think a solar sail would work if there was no hurry to get there, and as far as plasma drives and rail guns go you are right the R&D on those would bring the project to a skidding halt. I do like rail guns though if they ever perfect those and “bean stalks” I think space tourism would be affordable the average person. ·
Mike ·······
I'm sorry for starting a mess , we have no intention on using the ping sensor in space. I just tested it because I thought that it would not fare so well in a vacuum , I tested after it was back in normal air and it messed up it's range finding by about 3 inches.
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Thank's Brian
·"Imagination is more important than knowledge..."··Albert Einstein
· Am I sure that a balloon launch will not reduce costs by a factor of 1000? Yes. More sure than I am of death and taxes.· Getting into low Earth orbit isn't just a matter of getting to the proper altitude, you must also reach orbital velocity. A balloon launch could get you to perhaps 20% of the required altitude, but with 0% of the required velocity. I'm pretty sure you wouldn't eliminate 99.9% of you costs in that way. There are advantages to an air launch (rocket engines are more efficient in lower ambient pressure), but the commercial launch experience seems to show that this is not enough of an advantage to make air launches dominant. (I have issues with your political argument too, but I think debating in that arena about a technical matter is a total waste of time.)
····· Nothing to be sorry about, I know you don't realize it, but this was just a replay of a debate that went on earlier for the LunarX team. You've got me thinking about a lot of little details, like you get some evaporation of cyrogenic propellants, for a ground launch you can top off the tanks right up to launch, but for a balloon launch you either have to live with the loss or increase the insulation of the tanks. And with a manned flight, your guys are sitting on 100 tons of explosive, if you have to scrub a launch, you must gracefully bring them down from 100,000 feet. So there are other considerations besides costs.
····· I liked the idea of dropping a ramjet from a balloon, the guy that proposed that indicated a SCRAMJET, which would probably be beyond a bunch of amatuers, but a subsonic ramjet seemed very doable and could give you 20% altitude and velocity, the cost savings might be greater because with an airbreathing engine you don't need to provide oxidizer, which would account for perhaps 2/3 of the booster weight.
Whit,
I checked out the link, very good information .I am hoping that we don’t have to worry about coming back down :- ) . Our group has learned so much in the last 6 months that I believe we could put up a satellite in a matter of months if we wanted to.
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Thank's Brian
·"Imagination is more important than knowledge..."··Albert Einstein
I can provide the rocket, if you guys are still interested. My rockets have a 85% success rate. However, I will be happy to design, develop, and launch a rocket with enough propellant if you develop a rover and obtain the necessary permits. Email me at grclisa@rocketmail.com
First: I'm not expert, and I can't provide a rocket with a launch pad in Iowa. I can, however, repeat what I've seen before:
Have you guys considered using a weak stability boundary transfer? While I have no idea what any of that means, from what I've read you trade off time (it takes three months) for fuel savings. The Japanese (Earth)·satallite Hiten was apparently placed into lunar orbat using "only 10% of the required fuel to make it into lunar orbit." I know this is a race, but you won't get far if you can't afford the launch. I cannot for the life of me find any more information, like REAL numbers for the Hiten mission, or delta-V's or anything like that.
Also, Brian, that's one fine looking robot. I can honestly see it crawling across the lunar landscape in a few years... but the joint connecting the front and rear looks so vulnerable compared to the other systems you guys have mentioned, with their multiple redundancies. Have you tried testing what would happen if the joint failed? For instance, could the robot still drag its "belly" along the ground without the joint intact? Can the robot use differential steering in that event?
Post Edited (teraflop122) : 9/3/2008 12:40:29 AM GMT
Hi,
The group has talked about taking the "long way" to the moon, and we think we have all are plans in place to take the "straight shot" to the moon. Even thought you could send your payload on a smaller rocket going the "long way" there are too many risk to a small under funded team. We have to go with many off the shelf parts and decided it was best to get the rover and Lander there fast, less chance of components failing during the trip.
Ahh, the rover. I have seen video from one of our team members having tried to climb too big of rock and flipping one half of itself over. Amazingly it self righted itself with only a couple of tries. The design itself is very strong, but could use some redundancy in the hitch area. The 2 halves have there own systems and could run by itself if the other half was damaged.
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Thank's Brian
·"Imagination is more important than knowledge..."··Albert Einstein
Teraflop,
We have a small but dedicated team and most of our work is not done on this forum anymore. We need more people like you that think out of the box and we need all the help we can get. Please fell free to PM with your email, we would be happy to welcome you aboard.
At one point in time we were worried about sharing to much info with other teams, That’s not the case any more ,we just want to see a team get this done and we will work with any team to see it gets done !
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Thank's Brian
·"Imagination is more important than knowledge..."··Albert Einstein
Apologies for not having read all the entries of this thread, but·magnetic levitation (Maglev) is such a cool idea, it seems worth mentioning, although likely not financially feasible for the X-prise. (?)·This is probably the best way to get something off the ground:
"[noparse][[/noparse]...] Consider that the first magnetic launch systems are expected to propel payloads into orbit at a cost of roughly $750/lb, already a significant improvement over the current rocket-launched cost of around $4,000/lb. Now realize that the total cost to orbit might eventually drop below $100/lb, [noparse][[/noparse]...]"
A dream of mine was always to get some of my circutry to the edge of space - of course with a camera... But as a 14 year old boy, nobody takes me seriously :blank: But then again, do I blame them? I would most likely do the same thing. Although, it is still a dream of mine, and some day I am going to complete my dream...
Anyway, I'm not sure if this is a phesible idea or not, but my idea was always to have a system as described below:
Having x number of helium/hydrogen balloons which are attached to 4 corners of a 'launching platform'. Once this launching platform's velocity has halted, then a much smaller rocket then launches the circutry into the edge of space.
And why do I blame anyone who doesn't take me seriously? The plan is crazy, and will most likely never work. I know close to nothing about balloons, and their lift and maximum height at which they can rise to, as well as rocketry, so I have not a clue as to the sucess of the idea, also I believe the platform would be very unstable. Possibly too unstable to launch a rocket from. However, I do believe that a system such as this would drastically reduce the launch cost - From the millions, down to the thousands? I believe the lift amount of 1 square meter of helium is 1kg? It'd definatly have to be a very light item to send into space, however, I do believe that it is possible to get the amount down below 3kg.
Again, I am definatly no expert on these things - It's just a dream that I have always held with me.
Anyway, that is all I have to add - a far distant dream of a 14 year old kid...
Several years ago there was a plan to launch a large rocket in much the same manner. The rocket would be lifted up by a helium balloon into the upper atmosphere then it would ignite and fly straight through the balloon.
Also check out their earlier PARIS project...
(Paper Aeroplane Released Into Space)
Both projects use a Helium balloon.
In PARIS it was used to lift a glider made of paper up into the highest parts of the atmosphere where it was released to glide back down.
In LOHAN it'll lift a rocket-propelled craft up to the same altitude before launch.
They've pretty much decided that one balloon is the best, and that more will just make the launcher unstable.
Also,they're launching at an angle so as to not hit the aforementioned balloon...
The REHAB part is all about testing the rocket motor in correct pressure/temperature conditions.
And yes, they have a bit of a thing about acronyms... ;-)
I'm pretty sure they actually did use balloons to lift rockets in the late 40's or early 50's for some experiments. But today when the minimum goal of a launch is low Earth orbit, a system which provides 10% of the altitude and 0% of orbital velocity probably doesn't make up for the problems it introduces. But I suppose it is still attractive for a home-brew space program.
But today when the minimum goal of a launch is low Earth orbit, a system which provides 10% of the altitude and 0% of orbital velocity probably doesn't make up for the problems it introduces
I think the biggest advantage is getting above 90% of the Earth's atmosphere.
The problem with balloon-launched rockets is that it doesn't scale well to large payloads. You would need a balloon the size of the Hindenburg to launch a 1 Kg cubesat into orbit. You would need 10 Hindenburgs to orbit a 10 Kg payload. As payloads get bigger it is more economical to launch them from the ground. Atmospheric drag is inversely proportional to the payload mass. This is because the rocket mass and volume increases proportionately to the payload mass, but the cross sectional area only increases by N**(2/3), so the drag decreases as N gets larger.
My weekly schedule used to take me by the airport a lot and I usually saw a MIG parked there. 5% of orbital altitude and 8% of orbital velocity. Probably comparable to a balloon launch.
Comments
Nothing happens to the "cones in the sensor", sound just doesn't travel in a vacuum. Ultrasonic sound is no exception... Have you ever seen the bell in a jar experiment?
My apologies for the 70's style scientific presentation:
http://www.youtube.com/watch?v=_ckjttBin58
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Beau Schwabe
IC Layout Engineer
Parallax, Inc.
·
I m somewhat new to this forum (I’m still working thru “What’s a microcontroller. I’ve been into electronics since the 70’s but I find the hardware aspect of it a lot easier than the software but I am trying – these microcontrollers are really cool) anyway I saw this thread on the lunar X prize I was enthralled. I was talking to a friend of mine recently about how this country (the USA) used to have this can do attitude and now we are nothing but bunch of whiners and crybabies. We didn’t put people into orbit or our foot prints on the moon by saying it couldn’t be done or it cost too much, hell no we went out and WE DID IT. And to see a bunch of guys seriously trying to put something on the surface of another planet with easily found off the shelf technology and a lot of garage know how….Well I’m glad that there’s still some people that still have that can do attitude. Well enough preaching for now. I was up pretty late reading all the responses to this thread and I don’t think you are thinking out of the box enough.
·First of all getting the payload from this rather steep gravity into orbit, someone suggested an under wing “piggy back” to get it up that’s a good start but most planes don’t go high enough for it to be that effective. I was thinking of balloons, weather balloons can go up to more than one hundred thousand feet and a considerably smaller rocket tethered to it or even in the middle of a cluster of them the cost of getting into orbit could be reduced from millions to thousands.
·Next getting from orbit to the moon. Looking at the forms for the X prize I didn’t see any time limits to get to the moon so how about using ion engines, the so called electric rocket motors they are very low thrust so it might take weeks or even months to get there, or solar sails they use photonic pressure from the sun for acceleration and they can be flipped over to help decelerate it into lunar orbit. Since the payload is so small the sails probably have to be only a couple of miles in diameter, and because of their size you could probably see them from earth on its way to the moon. That would be spectacular, to see the sun glinting off the sails as it made it long journey to the moon.
·Landing on the moon: I don’t see any other way than using rocket motor or some kind of compressed gas both are kinda heavy.
·The rover itself does it have to have wheels and motors? Both are extra weight – how about something that “hops” say a gimble mounted solenoid with some gyros to keep it from tipping over, it could jump over obstacles that a wheeled rover would have to go around or get stuck completely.
·
·
Mike ·
·· I wonder if we have actually lost that sort of can do attitude or if it just isn't the story anymore. I've lived through the whole NASA era and saw the change from a sort of gee whiz attitude about science and technology reporting, to one where it seems the first thing the media look for is some dark side to any such story.
·· By the way, the team was admonished early on to think outside the box, by an individual pushing a balloon launch system, although in that case allowing the craft to drop to develop speed to light up a ramjet. So maybe you guys are stuck in the thinking outside the box box.
-phar
·
In doing some research I do see that an ion motor would be to experimental but I still think a solar sail would work if there was no hurry to get there, and as far as plasma drives and rail guns go you are right the R&D on those would bring the project to a skidding halt. I do like rail guns though if they ever perfect those and “bean stalks” I think space tourism would be affordable the average person.
·
Mike ·······
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Thank's Brian
·"Imagination is more important than knowledge..." ·· Albert Einstein
www.PropelX.com
-phar
Mike
I don't know how I missed the 4/20 video. Fantastic! and I love the music!
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Whit+
"We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney
····· Nothing to be sorry about, I know you don't realize it, but this was just a replay of a debate that went on earlier for the LunarX team. You've got me thinking about a lot of little details, like you get some evaporation of cyrogenic propellants, for a ground launch you can top off the tanks right up to launch, but for a balloon launch you either have to live with the loss or increase the insulation of the tanks. And with a manned flight, your guys are sitting on 100 tons of explosive, if you have to scrub a launch, you must gracefully bring them down from 100,000 feet. So there are other considerations besides costs.
····· I liked the idea of dropping a ramjet from a balloon, the guy that proposed that indicated a SCRAMJET, which would probably be beyond a bunch of amatuers, but a subsonic ramjet seemed very doable and could give you 20% altitude and velocity, the cost savings might be greater because with an airbreathing engine you don't need to provide oxidizer, which would account for perhaps 2/3 of the booster weight.
-phar
This is a interview I did at the ESC (not sure if I'm proud or embarrassed and that is·the longest I every kept a white shirt white·:- )
http://cmptv.net/TeardownTV/embedded_launcher.php
Then scroll down the "most popular videos on the right" and select the "PropelX" one
Edit: I added the machining website and lost the propelX one , just checking to see if it'e there again.
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Thank's Brian
·"Imagination is more important than knowledge..." ·· Albert Einstein
www.PropelX.com
www.NorthStarMachining.com
Post Edited (Brian Beckius) : 5/23/2008 1:23:28 AM GMT
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Whit+
"We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney
Or is this guy already on your team. Seems to have some applicable know-how.
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Whit+
"We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney
I checked out the link, very good information .I am hoping that we don’t have to worry about coming back down :- ) . Our group has learned so much in the last 6 months that I believe we could put up a satellite in a matter of months if we wanted to.
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Thank's Brian
·"Imagination is more important than knowledge..." ·· Albert Einstein
www.PropelX.com
www.NorthStarMachining.com
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Thank's Brian
·"Imagination is more important than knowledge..." ·· Albert Einstein
www.PropelX.com
Have you guys considered using a weak stability boundary transfer? While I have no idea what any of that means, from what I've read you trade off time (it takes three months) for fuel savings. The Japanese (Earth)·satallite Hiten was apparently placed into lunar orbat using "only 10% of the required fuel to make it into lunar orbit." I know this is a race, but you won't get far if you can't afford the launch. I cannot for the life of me find any more information, like REAL numbers for the Hiten mission, or delta-V's or anything like that.
http://en.wikipedia.org/wiki/Hiten
http://esto.nasa.gov/conferences/nstc2007/papers/Belbruno_Edward_C6P1_NSTC-07-0156.pdf··· Low Energy Motions in the Earth Moon System, Chaos, and Weak Capture
http://www.thespacereview.com/article/569/1
http://www.stk.com/downloads/support/productSupport/literature/pdfs/whitePapers/0800_wsb.pdf·· Calculation of Weak Stability Boundary Ballistic Lunar Transfer Trajectories (now say that three times fast!)
Also, Brian, that's one fine looking robot. I can honestly see it crawling across the lunar landscape in a few years... but the joint connecting the front and rear looks so vulnerable compared to the other systems you guys have mentioned, with their multiple redundancies. Have you tried testing what would happen if the joint failed? For instance, could the robot still drag its "belly" along the ground without the joint intact? Can the robot use differential steering in that event?
Post Edited (teraflop122) : 9/3/2008 12:40:29 AM GMT
The group has talked about taking the "long way" to the moon, and we think we have all are plans in place to take the "straight shot" to the moon. Even thought you could send your payload on a smaller rocket going the "long way" there are too many risk to a small under funded team. We have to go with many off the shelf parts and decided it was best to get the rover and Lander there fast, less chance of components failing during the trip.
Ahh, the rover. I have seen video from one of our team members having tried to climb too big of rock and flipping one half of itself over. Amazingly it self righted itself with only a couple of tries. The design itself is very strong, but could use some redundancy in the hitch area. The 2 halves have there own systems and could run by itself if the other half was damaged.
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Thank's Brian
·"Imagination is more important than knowledge..." ·· Albert Einstein
www.PropelX.com
And here I thought I had something to contribute! Oh well.
We have a small but dedicated team and most of our work is not done on this forum anymore. We need more people like you that think out of the box and we need all the help we can get. Please fell free to PM with your email, we would be happy to welcome you aboard.
At one point in time we were worried about sharing to much info with other teams, That’s not the case any more ,we just want to see a team get this done and we will work with any team to see it gets done !
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Thank's Brian
·"Imagination is more important than knowledge..." ·· Albert Einstein
www.PropelX.com
- excerpt from
http://www.launchpnt.com/Space_Launch.32.0.html
cheers,
~~ Howard in Florida ~~
(PS. We love to watch that shuttle go by!)
A dream of mine was always to get some of my circutry to the edge of space - of course with a camera... But as a 14 year old boy, nobody takes me seriously :blank: But then again, do I blame them? I would most likely do the same thing. Although, it is still a dream of mine, and some day I am going to complete my dream...
Anyway, I'm not sure if this is a phesible idea or not, but my idea was always to have a system as described below:
Having x number of helium/hydrogen balloons which are attached to 4 corners of a 'launching platform'. Once this launching platform's velocity has halted, then a much smaller rocket then launches the circutry into the edge of space.
And why do I blame anyone who doesn't take me seriously? The plan is crazy, and will most likely never work. I know close to nothing about balloons, and their lift and maximum height at which they can rise to, as well as rocketry, so I have not a clue as to the sucess of the idea, also I believe the platform would be very unstable. Possibly too unstable to launch a rocket from. However, I do believe that a system such as this would drastically reduce the launch cost - From the millions, down to the thousands? I believe the lift amount of 1 square meter of helium is 1kg? It'd definatly have to be a very light item to send into space, however, I do believe that it is possible to get the amount down below 3kg.
Again, I am definatly no expert on these things - It's just a dream that I have always held with me.
Anyway, that is all I have to add - a far distant dream of a 14 year old kid...
-John
From what I understand, LOHAN is currently going through REHAB...
LOHAN = Low Orbit Helium Assisted Navigator
REHAB = Rocketry Experimental High Altitude Barosimulator
Also check out their earlier PARIS project...
(Paper Aeroplane Released Into Space)
Both projects use a Helium balloon.
In PARIS it was used to lift a glider made of paper up into the highest parts of the atmosphere where it was released to glide back down.
In LOHAN it'll lift a rocket-propelled craft up to the same altitude before launch.
They've pretty much decided that one balloon is the best, and that more will just make the launcher unstable.
Also,they're launching at an angle so as to not hit the aforementioned balloon...
The REHAB part is all about testing the rocket motor in correct pressure/temperature conditions.
And yes, they have a bit of a thing about acronyms... ;-)
I think the biggest advantage is getting above 90% of the Earth's atmosphere.