As for the fiber optics -- replacing all of the copper would impose a massive weight and cost burden because you'd need to add converters on both ends, while still running a "wire" albeit a glass one. However, there is some fiber optic use in aircraft.
I'd expect there to be a lot of cell phone usage by people in the airport, and that would (probably) cause as much interference as people in the plane.
actually wouldn't be true. Signal strength drops as 1/r^2. A single cell phone in the cabin of the plane looks a lot stronger (to the plane's avionics) than 100 cell phones in the terminal.
The limitation on RC aircraft is for the reason you mentioned -- if two people are using the same frequency then you likely end up with two self destructing (upon impacting the ground) aircraft.
Interference, by definition, can happen even if the devices aren't in your limited bandwidth window. I've seen a 10Mhz transmitter interfering with audio equipment. I've seen a desktop computer interfere with a radio receiver. I've seen a supposedly shielded RF source (used as a frequency reference inside some equipment) interfere with supposedly shielded instruments.
It's not a likely scenerio; but, imagine if you will: Your sitting in a seat in the passenger cabin, next to the window. Your cell phone is on and actively seeking a cell site -- transmitting at around 1 watt. In the wall (or floor) of the plane, exactly where you're sitting, is a cable (wiring) for the flight controls -- including perhaps a connector. The connector's not technically bad, but, there's enough contact resistance that it acts somewhat like a diode and rectifies the RF imposed onto the wire(s) by your cell phone's transmission. This becomes a slight DC bias in flight controls signal. Your plane crashes because the bias causes the plane's computer to overestimate the amount of fuel in the tank by several inches, resulting in an engine stall when that tank unexpectantly runs out of fuel...
As I said, not likely; but, plausible. Murphy's Law is like that...
One major part of the problem is the age of the avionics. A modern aircraft is going to be vastly different from a 30-year old plane in terms of susceptibility. There are a lot of 30-year old planes still in use.
Actually, this is, unfortunately, a future possibility, once the technology reaches a level that Osama (or whomever) could build a home-made EMP bomb. Nuclear technology isn't far off either -- hence the impetus to knip it in the bud now, while we still can...
The airline steward(ess) will be knowledgeable to know which ones have such a mode
The owner of the phone will remember to actually switch modes before take-off (wouldn't it suck to have a plane crash because Bob the Executive was distracted and forgot to switch the phone to Airline mode)
The Founding Fathers originally intended the states to be, more or less, independant. Read the Constitution. Over the past 200+ years, the power at the Federal level has grown and grown and grown...
Re:Deep Space Network
on
SOHO Is Back
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· Score: 4, Interesting
Actually it's kind of misleading. They're using the low gain antenna now which, using the original uplink, was only capable of low bandwidth. Basically, it was for sending control commands, etc; not for transmitting back the images and other data. By using the big antennas in the deep space network, they increase the sensitivity on this end; and, they've worked out an algorithm (uploaded to the SOHO) which allows them to transmit the data collected back to Earth, using the low gain antenna for higher bandwidth.
I bet the electrical engineers and software people missed a few nights sleep working this out...
Re:Long distance repairs
on
SOHO Is Back
·
· Score: 1
I wholeheartedly agree. However, Viking's still there, with it's batteries long dead...
Wouldn't it be a hoot if, say, 50 years from now, a couple of astronauts found it, dusted it off, replaced the batteries, hit the master reset button (or whatever) and it sprang back to life!
It's gone down a couple of times before for various reasons. Through patients, effort, and some creative software they've always managed to bring it back to life.
noise in the high numbered channels is a sign of why you've got signal problems with the cable modem. They've got a bad filter in their network which is causing the problem. They need to track it down (it's not hard) and replace it; otherwise, it's only going to get worse.
I'm not advocating that the calculator requirement is a good thing; but...
I'm one of those (rare?) people who was nearly held back in grade school for math (had to get tutoring after school), still can't do the basic math (add, subtract, mult., divide, etc.) well, yet have NO problem at all with the advanced stuff...
At the time(designed in the early '70's, remember), this wasn't as much of an option; although, from my friends at NASA, I understand it was considered. They do use a 747 to transport the shuttles around...
The plane does need to be enormous. Imagine what would be required to lift the shuttle, it's payload, AND the fuel necessary to make it the remaining 150 miles up. Some of the proposals made by Boeing (which is seriously considering re-visiting this idea) have them building just such a plane, or using a two stage to orbit vehicle that is really a shuttle riding on a big rocket powered plane.
distance comes with time... The plane could, for all intensive purposes, simply circle the airport from which it takes off, all the while climbing to launch altitude. (It does help if the plane flies to the equator) speed is the ultimate requirement: In orbit you're in freefall. (constantly accelerating radially inward at 32ft/sec) Your orbital (tangential) speed needs to be high enough to offset this -- so you end up going in a circle. Of course, the higher up you go, the faster you have to be travelling...
Well, I've said in another post somewhere: I don't believe We'll be ready to actually venture out in a more permanent fashion for decades. It'll probably be (in my estimation) 50 years or more before we see any kind of (semi) permanent hab on the Moon again, or on Mars.
There may be a push to get a manned Mars mission going, with a short stay (30-90 days) in, say, 10-20 years. However, this will depend heavily on LEO infrastructure from which we can assemble the ship.
I think NASA knows this; and, they're taking baby steps in that direction.
Commercial interests will eventually be what causes "mass population" of space, through developing enterprise (mining, space based power generation, transport, support & logistics, etc.) This is probably like not going to happen in our lifetime (although I still have hope).
Hmmm... Why is it I can picture a kevlar coated balloon envelope, a compact fusion generator powered by hydrogen extracted from the moisture in the air, with the heated "waste" helium being pumped into the envelope for boyancy, and an AI computer...
Sorry your depressed; but, it's been that way since the design phase of the current Shuttle. It was designed to act as a transport to allow us to build up the LEO infrastructure we need before we can do the more interesting stuff (permanent space stations, more Moon landings with research bases or even a permanent settlement, a manned Mars excursion) Unfortunately, they've taken too long to build the infrastructure; and, now the Shuttle is showing it's age.
It's going to be decades before we actually see a Mars landing. And more than 1/2 century before anyone actually puts a "permanent" hab on the Moon or Mars.
It's been somewhat of a sad time in our history. Buzz Aldrin was right; the astronauts are trained to explore. The problem has been that there's been no money to send the men anywhere interesting (unless you call LEO interesting).
Keeping a working astronaut core group (which implies at least some of them have experience in space) right now means using them as "truck drivers"
It never hurts to get second (or third) opinions...
But, Honda, Mitsu, Toyota, et. al. make efficent vehicles that travel along the ground
Mitsubishi is the only one with any aircraft experience; and, that was 60 years ago. A space plane is (please don't take offense) simply out of their league. Not to say they couldn't catch up -- Boeing and Lockheed simply have much more experience.
The Chinese will be laughing at it from the moon in ten years
Let em. a space station is going to be required as a base from which to build a Mars mission or as a staging point for any permanent Moon settlement (requires some assembly in orbit...) They can go dance on the surface of the moon for a few days and return, like we did in the 30 years ago. We'll be working on LONG TERM solutions.
There are two reasons this may work more efficiently: You're using air as the oxidizer for the first stage (the 747)... Instead of using brute force, you can take advantage of aerodynamic lift to get you up the first 9-10 miles; after which you're above most of the atmosphere.
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Even so, it's RTG's are likely... dead. They do have a limited useful life span you know.
I'd expect there to be a lot of cell phone usage by people in the airport, and that would (probably) cause as much interference as people in the plane. actually wouldn't be true. Signal strength drops as 1/r^2. A single cell phone in the cabin of the plane looks a lot stronger (to the plane's avionics) than 100 cell phones in the terminal.
If the flight crew knew what was good for them, the'd ban them too using this as the excuse.
Interference, by definition, can happen even if the devices aren't in your limited bandwidth window. I've seen a 10Mhz transmitter interfering with audio equipment. I've seen a desktop computer interfere with a radio receiver. I've seen a supposedly shielded RF source (used as a frequency reference inside some equipment) interfere with supposedly shielded instruments.
It's not a likely scenerio; but, imagine if you will: Your sitting in a seat in the passenger cabin, next to the window. Your cell phone is on and actively seeking a cell site -- transmitting at around 1 watt. In the wall (or floor) of the plane, exactly where you're sitting, is a cable (wiring) for the flight controls -- including perhaps a connector. The connector's not technically bad, but, there's enough contact resistance that it acts somewhat like a diode and rectifies the RF imposed onto the wire(s) by your cell phone's transmission. This becomes a slight DC bias in flight controls signal. Your plane crashes because the bias causes the plane's computer to overestimate the amount of fuel in the tank by several inches, resulting in an engine stall when that tank unexpectantly runs out of fuel...
As I said, not likely; but, plausible. Murphy's Law is like that...
One major part of the problem is the age of the avionics. A modern aircraft is going to be vastly different from a 30-year old plane in terms of susceptibility. There are a lot of 30-year old planes still in use.
Actually, this is, unfortunately, a future possibility, once the technology reaches a level that Osama (or whomever) could build a home-made EMP bomb. Nuclear technology isn't far off either -- hence the impetus to knip it in the bud now, while we still can...
The airline steward(ess) will be knowledgeable to know which ones have such a mode
The owner of the phone will remember to actually switch modes before take-off (wouldn't it suck to have a plane crash because Bob the Executive was distracted and forgot to switch the phone to Airline mode)
The Founding Fathers originally intended the states to be, more or less, independant. Read the Constitution. Over the past 200+ years, the power at the Federal level has grown and grown and grown ...
I bet the electrical engineers and software people missed a few nights sleep working this out...
Wouldn't it be a hoot if, say, 50 years from now, a couple of astronauts found it, dusted it off, replaced the batteries, hit the master reset button (or whatever) and it sprang back to life!
It's gone down a couple of times before for various reasons. Through patients, effort, and some creative software they've always managed to bring it back to life.
noise in the high numbered channels is a sign of why you've got signal problems with the cable modem. They've got a bad filter in their network which is causing the problem. They need to track it down (it's not hard) and replace it; otherwise, it's only going to get worse.
I'd never seen this before... And it's Way Cool!!! Wow.
I'm one of those (rare?) people who was nearly held back in grade school for math (had to get tutoring after school), still can't do the basic math (add, subtract, mult., divide, etc.) well, yet have NO problem at all with the advanced stuff...
speaking to you with Physics degree in hand...
The plane does need to be enormous. Imagine what would be required to lift the shuttle, it's payload, AND the fuel necessary to make it the remaining 150 miles up. Some of the proposals made by Boeing (which is seriously considering re-visiting this idea) have them building just such a plane, or using a two stage to orbit vehicle that is really a shuttle riding on a big rocket powered plane.
distance comes with time... The plane could, for all intensive purposes, simply circle the airport from which it takes off, all the while climbing to launch altitude. (It does help if the plane flies to the equator) speed is the ultimate requirement: In orbit you're in freefall. (constantly accelerating radially inward at 32ft/sec) Your orbital (tangential) speed needs to be high enough to offset this -- so you end up going in a circle. Of course, the higher up you go, the faster you have to be travelling...
There may be a push to get a manned Mars mission going, with a short stay (30-90 days) in, say, 10-20 years. However, this will depend heavily on LEO infrastructure from which we can assemble the ship.
I think NASA knows this; and, they're taking baby steps in that direction.
Commercial interests will eventually be what causes "mass population" of space, through developing enterprise (mining, space based power generation, transport, support & logistics, etc.) This is probably like not going to happen in our lifetime (although I still have hope).
Never mind, we'll just print more money = )
Next time, the Balloon wants a non-removable nuclear generator installed... Long live the Balloon.
They had a plan. Congress said it was too expensive. They stepped back and punted into LEO...
It's going to be decades before we actually see a Mars landing. And more than 1/2 century before anyone actually puts a "permanent" hab on the Moon or Mars.
Keeping a working astronaut core group (which implies at least some of them have experience in space) right now means using them as "truck drivers"
But, Honda, Mitsu, Toyota, et. al. make efficent vehicles that travel along the ground
Mitsubishi is the only one with any aircraft experience; and, that was 60 years ago. A space plane is (please don't take offense) simply out of their league. Not to say they couldn't catch up -- Boeing and Lockheed simply have much more experience.
Let em. a space station is going to be required as a base from which to build a Mars mission or as a staging point for any permanent Moon settlement (requires some assembly in orbit...) They can go dance on the surface of the moon for a few days and return, like we did in the 30 years ago. We'll be working on LONG TERM solutions.
There are two reasons this may work more efficiently: You're using air as the oxidizer for the first stage (the 747)... Instead of using brute force, you can take advantage of aerodynamic lift to get you up the first 9-10 miles; after which you're above most of the atmosphere.