IPv6 may not work out of the box for space comm
on
IPv6 Tested in Space
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· Score: 1
A lot of people are talking about how widely IPv6 is deployed here on Earth. As the article is about IPv6 in space, maybe it would be better to talk about the implications of going with any IP protocol in space?
For Earth orbit, either IP protocol (IPv4 or IPv6) is likely OK. But what happens if we really want to deploy an interplanetary internet? Say you have a station on the moon trying to relay off a satellite in Earth orbit. What does your round trip latency look like? Try three seconds round trip. How happy will TCP connections be with a three second (3000ms) ping time?
Now, lets go further. Have a satellite in Mars orbit communicate with a satellite in Earth orbit. You can easily have a one way trip of 20 minutes, or a 40 minute ping time. Show me a connection oriented protocol which can handle this.
Either IP will have to have a major overhaul or something else may be needed to move traffic around the solar system. Connection oriented just won't work for such long communication lag. You either have to accept only a few packets per hour, or you will have to have a very large sliding window to get all of the data through and reassembled.
That may be the case for the TGV, but if you take the Eurostar from London to Paris or Brussels you go through a full screening and into a secure boarding area just like at an airport. I'm sure that is because of the vulnerability of the Channel Tunnel, but with the current paranoia in the US I could see similar measures being put in place for inter-city high speed trains. Set off a backpack bomb in the lead car of a high speed train and the whole assembly is likely to fold up like an accordian with the potential to kill hundreds.
I've looked at that video something like 10 times now. After the bump the second stage did skew sideways a bit. As soon as the second stage motor fired, it straightened back out. You can use the falling away first stage as a directional guide. The oscilation didn't start up until about a minute later. After that the ocilation built for about a minute until the signal cut out.
You can tell the craft is trying to compensate. Remember that the camera is mounted on the 2nd stage body. You can see a very slight wobble in the horizon which shows the body is moving. You see a lot of wobble in the engine nozzle, which means the nozzle is moving around relative to the rocket body. The vector control system must have been working like hell trying to stabilize the craft.
Of course, this is all arm chair speculation. It will be really interesting to see what SpaceX has to say. Hopefully they won't keep us in suspense for too long.
There is another point, which is right before the second separation events (from the nose; I don't know what it's called and can't get a timecode right now), there's a ring that comes off of the 2nd stage engine. Anyone know if this was normal?
In the transcript from a post flight interview it was said that these rings are titanium and applied to the edge of the nozzle with a bonding agent. The rings are there to protect the nozzle during the first part of the firing. Once the rings heat up the bonding agent breaks down and lets the rings fall away at the point where they are no longer needed. Apparently, this is normal behavior.
From Spaceflight Now: "What you might have seen was basically titanium half-hoops that are used to stabilize the nozzle on ascent. However, once you get to a certain temperature the bonding agent for those titanium rings comes off and the titanium rings float away, which occurred as expected."
Shouldn't they use a separation ring between the stages? Drop the first stage, ignite the second, then release the ring. Seems more prudent, no?
Seems like it, but weight may be an issue. Two separation points means more hardware which means more weight. I wonder if something simpler, and lighter, such as guide rails could be used to direct the first stage past the second stage nozzle. The rails could drop after the stage is away and should be less likely to impact on the nozzle than what we saw last night.
It was carrying a demo sat, which is just a simlulator for an actual sattelite. There was no paid cargo on this flight. They did have a couple of small test packages from NASA for relaying flight data through the NASA tracking network and testing in flight destruct commanding (not to an actual destruction package I believe). Nothing was going to be in permanent orbit and the Falcon 1 i snot intended to go to the space station.
I had read about the Niobium nozzle being able to take a dent. I'd be more concerned about the bump damaging the vectoring hardware for the engine. It was also really interesting to see the glow coming through the nozzle. I was really worried we'd see a burn through of the nozzle, but I guess the glow is just the normal behavior.
Some of the early comments by Elon talked about spin causing centrifuge effect on the fuel supply to the 2nd stage engine. In the video, although the nozzle is oscilating back and forth the craft itself is not spinning up to the point where the video ends. You can tell by the Earth horizon staying mostly stable. It will be interesting to hear the analysis in the coming days or weeks.
Did anyone else notice the bump the Kestrel engine took during stage separation? On the 40MB video from SpaceX, it happend at 3:28 in or at T+00:02:52 on the screen clock. Maybe this is normal for the engine, but it was rather odd looking to me.
Also, there was a story earlier that the 2nd launch was delayed "due to concerns over a thrust vector control pitch actuator on the Falcon 1 booster's second stage". I wonder if this came back to bite them?
Finally, I'm impressed as hell that they could experience an abort after engine start yet still cycle back and launch in just another hour! When the Shuttle once aborted after engine start it took them a month to change out the engines and try again.
What kind of experiments have people done with kernel compiles on an openMOSIX cluster? If you have 10 computers and do a "make -j 10", will you see a benefit?
The Valkyrie was too squared off at the corners for me. I always thought the B-1 looked more like a fighter than a bomber. Actually, I once had a flight crew tell me it flew like a fighter. How many other bombers do you know that can execute a barrel roll and survive?
The B-1 had a lot of technical problems in it's early life, but it is turning out to be a fine plane now.
It works all the way up into the UHF television stations. There are cases of people in New England picking up Florida broadcast television stations right after a tropical storm passes up the coast.
All I have to say is give this show a chance, mainly because of Stryzinski (spelling way wrong). He does have a vision and an arc.
Just call him Great Maker.:)
I remember from interviews a few years back that JMS had a detailed history written 1000 years both forward and backward from the B5 time. He had an outline sketch for 1,000,000 years either direction. This leaves room to put several large story arcs in.
There is no denying that Crusade was slaughtered.
TNT stepped in and baught B5 when the previous producer was ready to pull the plug.
They only wanted it for the syndication/repeat capability.
It's good to see SciFi with now.
This at least gives us a chance to see some decent new material.
So far I've only tried TDK 700MB and 650MB discs and I've only written a few CD-Rs, with 701MB and 652MB as the capacities I've had on the discs without problems, not exactly 'pushing the envelope', so I'm interested to learn of other people's findings.
You could be seeing a discrepency in how KB and MB are calculated. Are the CD capacities being calculated as base 10 (1,000,000) or base 2 (1024 x 1024 = 1,048,576)?
In related news, the price of Clay Pigeons is expected to return to normal. Charlton Heston of the Shotgun Association of America stated at a press conference, "Our recent sources of cheap plastic clay pigeons are expected to dry up. We will be returning to clay clay pigeons."
You mean AOL is going to stop sending me free skeet?!?
I'll do you one better. MicroCenter was recently selling bulk 8X CD-R media at $8.99 for a 50-pack. That comes out to a whopping 18 cents per disk. Odds are, I won't be needing to buy any more disks for about two years.
ONE misstep, and Microsoft could find Linux with 10% or more of the desktop market, and StarOffice/OpenOffice being rolled out en masse on corporate desktops.
StarOffice isn't the only one out there. KOffice (part of the KDE project is also coming along nicely. It is part of the RedHat 7.1 release (despite their push for GNOME) and is quickly showing itself to be capable and fast evolving.
Once the Microsoft file formats are reverse engineered to provide full import and export capability, you could easily see something like KOffice show up in corporate offices. Most people don't use 80% of the features in MS Office, so why pay for them?
Ranks just above Extra class and requires network certification
For those not familiar with amateur radio certification, "Extra Class" is the highest level you can attain under the current FCC certification system. However, of not, if you want to communicate in the VHF band then all you need is the lowest certification, also known as a "Technican Class" license. All that requires is one 35 question test about radio theory, FCC rules, and general practices.
Over the last few weeks, I've been compiling a list of links regarding operating
Amateur Radio with Linux. There is a lot the little penguin can do over the radio waves including bouncing data off the space station and routing IP traffic through your local mountain top.
Lots of folks, when they get their Ham Radio license, end up purchasing a little handheld radio with not much range.
Those little handhelds might have better range than you give them credit for. It's just line of sight. A coworker of mine was very excited last week when he managed to pickup the International Space Station (ISS or Alpha) on his 2 meter handheld unit. This is a communication of over 200 miles, but you can see the thing going over.
Granted, this isn't like the round the world bounces you can do with HF, but it's still pretty darn exciting.
The space station and data applications for amateur radio caused me to start putting together a web page on how to operate with Amateur Radio over Linux. There is a lot of software, hardware, and resources available out there. It's not hard to get a license to operate in the 2 meter bands these days, so it's something worth exploring.
Over the last few weeks I've been assembling a page of links converning working with
amateur radio using Linux. I've managed to assemble a collection of links covering things such as:
Hardware that works with Linux
Linux software available
Protocols and standards
Books with reference information
This started after I read about how it is now possible to exchange data through and talk with astronauts on the International Space Station. I've started working on my own license which is really quite easy to attain. It's just one 35 question test which most people should be able to prepare for in under a month with just one or two books.
With luck, in a few months, I'll be ready to flood the airwaves with my own useless drivel. With a little more luck, I'll manage to get a postcard from space.
This project follows in the footsteps on a previous effort I took to compile a comprehensive list of links regarding
Bluetooth on Linux Thanks to SlashDot, this page managed to stay in the top ten list of the Bluetooth Top Sites list for all of April.
By FCC rules you can not encrypt or otherwise obscure the meaning of communications over the amateur bands. The frequencies are there for hobby use and not business use.
Over the last few weeks I've been putting together a list of links about
amateur radio over Linux. The whole area is an interesting convergence between open projects. It looks like I'll have to add another link for IRLP.
This is very, very likely. I saw a USB 2.0 card at Circuit City last week. It had four external ports and one INTERNAL port. I also own a FireWire card. That card has three external ports and the board etchings (but no hardware) for an internal port. It is very easy to imagine IDE having to compete with one of these standards for internal connection of periperals down the road.
It is very easy to imagine a future machine with only USB 2.0 ports inside and out for connecting up all peripherals. Slots won't go away, but their need and number could be vastly reduced. Now, if traditional peripheral boards such as sound cards and modems could be packaged as modules that can be installed without opening the case, we will be another step closer to truly consumer friendly computers.
Shameless plug time: Information on using Linux and Bluetooth together is available. Please help keep Linux at the front of this technology.
I won't deny there is a lot of waste in both NASA and the military. I work for the military and get to see it first hand. It's rampant all through gov't agencies.
My personal theory is that a lot of the waste comes from a lack of profit motive. What is common in gov't service is that if you screw up bad enough you either a) get promoted to get rid of you or b) get more people under you to fix things which justifies a higher position. Either way, the best way to move up is to screw up. Compare that to the commercial world where if you screw up you will end up in the unemployment line.
The primary technical jewel on this thing was the cryo-composite fuel tank. It failed miserably, and was going to be replaced with an aluminum tank.
I'd put the linear aerospike engines and the metallic thermal protection system pretty high on the list of technical jewels. Both of those technologies in themselves are worth pursuing.
The linear aerospike engines are lighter, require no gimbaling (hinges), and are less likely to suffer catastrophic failure compared to traditional bell engines. Their design is perfect for lifting body vehicles being that they spread the thrust across a large area rather than focusing it to a point.
The metallic thermal protection system (TPS) could replace the current ceramic tiles on the shuttle and cut it's turnaround cost considerably. The ceramic tiles have to be inspected and specially treated after every flight. Metallic TPS is more durable and easier to service.
The biggest problem with the X-33 was that it tried to test too many technologies in one place. Being that everyone new the fuel tanks were high risk, they should have built aliminum tanks to start with the intention of changing them out with composite tanks later. "Build a little, test a little" is a far safer method when you are putting all your eggs in one basket.
Slashdot Mirror
A lot of people are talking about how widely IPv6 is deployed here on Earth. As the article is about IPv6 in space, maybe it would be better to talk about the implications of going with any IP protocol in space?
For Earth orbit, either IP protocol (IPv4 or IPv6) is likely OK. But what happens if we really want to deploy an interplanetary internet? Say you have a station on the moon trying to relay off a satellite in Earth orbit. What does your round trip latency look like? Try three seconds round trip. How happy will TCP connections be with a three second (3000ms) ping time?
Now, lets go further. Have a satellite in Mars orbit communicate with a satellite in Earth orbit. You can easily have a one way trip of 20 minutes, or a 40 minute ping time. Show me a connection oriented protocol which can handle this.
Either IP will have to have a major overhaul or something else may be needed to move traffic around the solar system. Connection oriented just won't work for such long communication lag. You either have to accept only a few packets per hour, or you will have to have a very large sliding window to get all of the data through and reassembled.
That may be the case for the TGV, but if you take the Eurostar from London to Paris or Brussels you go through a full screening and into a secure boarding area just like at an airport. I'm sure that is because of the vulnerability of the Channel Tunnel, but with the current paranoia in the US I could see similar measures being put in place for inter-city high speed trains. Set off a backpack bomb in the lead car of a high speed train and the whole assembly is likely to fold up like an accordian with the potential to kill hundreds.
I've looked at that video something like 10 times now. After the bump the second stage did skew sideways a bit. As soon as the second stage motor fired, it straightened back out. You can use the falling away first stage as a directional guide. The oscilation didn't start up until about a minute later. After that the ocilation built for about a minute until the signal cut out.
You can tell the craft is trying to compensate. Remember that the camera is mounted on the 2nd stage body. You can see a very slight wobble in the horizon which shows the body is moving. You see a lot of wobble in the engine nozzle, which means the nozzle is moving around relative to the rocket body. The vector control system must have been working like hell trying to stabilize the craft.
Of course, this is all arm chair speculation. It will be really interesting to see what SpaceX has to say. Hopefully they won't keep us in suspense for too long.
There is another point, which is right before the second separation events (from the nose; I don't know what it's called and can't get a timecode right now), there's a ring that comes off of the 2nd stage engine. Anyone know if this was normal?
In the transcript from a post flight interview it was said that these rings are titanium and applied to the edge of the nozzle with a bonding agent. The rings are there to protect the nozzle during the first part of the firing. Once the rings heat up the bonding agent breaks down and lets the rings fall away at the point where they are no longer needed. Apparently, this is normal behavior.
From Spaceflight Now: "What you might have seen was basically titanium half-hoops that are used to stabilize the nozzle on ascent. However, once you get to a certain temperature the bonding agent for those titanium rings comes off and the titanium rings float away, which occurred as expected."
What or where are the "SA forums"? Link, please.
Seems like it, but weight may be an issue. Two separation points means more hardware which means more weight. I wonder if something simpler, and lighter, such as guide rails could be used to direct the first stage past the second stage nozzle. The rails could drop after the stage is away and should be less likely to impact on the nozzle than what we saw last night.
Interesting. Guess it is time for some slosh baffles in the fuel tank.
It was carrying a demo sat, which is just a simlulator for an actual sattelite. There was no paid cargo on this flight. They did have a couple of small test packages from NASA for relaying flight data through the NASA tracking network and testing in flight destruct commanding (not to an actual destruction package I believe). Nothing was going to be in permanent orbit and the Falcon 1 i snot intended to go to the space station.
I had read about the Niobium nozzle being able to take a dent. I'd be more concerned about the bump damaging the vectoring hardware for the engine. It was also really interesting to see the glow coming through the nozzle. I was really worried we'd see a burn through of the nozzle, but I guess the glow is just the normal behavior.
Some of the early comments by Elon talked about spin causing centrifuge effect on the fuel supply to the 2nd stage engine. In the video, although the nozzle is oscilating back and forth the craft itself is not spinning up to the point where the video ends. You can tell by the Earth horizon staying mostly stable. It will be interesting to hear the analysis in the coming days or weeks.
Did anyone else notice the bump the Kestrel engine took during stage separation? On the 40MB video from SpaceX, it happend at 3:28 in or at T+00:02:52 on the screen clock. Maybe this is normal for the engine, but it was rather odd looking to me.
Also, there was a story earlier that the 2nd launch was delayed "due to concerns over a thrust vector control pitch actuator on the Falcon 1 booster's second stage". I wonder if this came back to bite them?
Finally, I'm impressed as hell that they could experience an abort after engine start yet still cycle back and launch in just another hour! When the Shuttle once aborted after engine start it took them a month to change out the engines and try again.
What kind of experiments have people done with kernel compiles on an openMOSIX cluster? If you have 10 computers and do a "make -j 10", will you see a benefit?
The Valkyrie was too squared off at the corners for me. I always thought the B-1 looked more like a fighter than a bomber. Actually, I once had a flight crew tell me it flew like a fighter. How many other bombers do you know that can execute a barrel roll and survive?
The B-1 had a lot of technical problems in it's early life, but it is turning out to be a fine plane now.
Tropospheric ducting.
It works all the way up into the UHF television stations. There are cases of people in New England picking up Florida broadcast television stations right after a tropical storm passes up the coast.
Just call him Great Maker. :)
I remember from interviews a few years back that JMS had a detailed history written 1000 years both forward and backward from the B5 time. He had an outline sketch for 1,000,000 years either direction. This leaves room to put several large story arcs in.
There is no denying that Crusade was slaughtered. TNT stepped in and baught B5 when the previous producer was ready to pull the plug. They only wanted it for the syndication/repeat capability. It's good to see SciFi with now. This at least gives us a chance to see some decent new material.
You could be seeing a discrepency in how KB and MB are calculated. Are the CD capacities being calculated as base 10 (1,000,000) or base 2 (1024 x 1024 = 1,048,576)?
You mean AOL is going to stop sending me free skeet?!?
I'll do you one better. MicroCenter was recently selling bulk 8X CD-R media at $8.99 for a 50-pack. That comes out to a whopping 18 cents per disk. Odds are, I won't be needing to buy any more disks for about two years.
StarOffice isn't the only one out there. KOffice (part of the KDE project is also coming along nicely. It is part of the RedHat 7.1 release (despite their push for GNOME) and is quickly showing itself to be capable and fast evolving.
Once the Microsoft file formats are reverse engineered to provide full import and export capability, you could easily see something like KOffice show up in corporate offices. Most people don't use 80% of the features in MS Office, so why pay for them?
For those not familiar with amateur radio certification, "Extra Class" is the highest level you can attain under the current FCC certification system. However, of not, if you want to communicate in the VHF band then all you need is the lowest certification, also known as a "Technican Class" license. All that requires is one 35 question test about radio theory, FCC rules, and general practices.
Over the last few weeks, I've been compiling a list of links regarding operating Amateur Radio with Linux . There is a lot the little penguin can do over the radio waves including bouncing data off the space station and routing IP traffic through your local mountain top.
Those little handhelds might have better range than you give them credit for. It's just line of sight. A coworker of mine was very excited last week when he managed to pickup the International Space Station (ISS or Alpha) on his 2 meter handheld unit. This is a communication of over 200 miles, but you can see the thing going over. Granted, this isn't like the round the world bounces you can do with HF, but it's still pretty darn exciting.
The space station and data applications for amateur radio caused me to start putting together a web page on how to operate with Amateur Radio over Linux . There is a lot of software, hardware, and resources available out there. It's not hard to get a license to operate in the 2 meter bands these days, so it's something worth exploring.
Over the last few weeks I've been assembling a page of links converning working with amateur radio using Linux . I've managed to assemble a collection of links covering things such as:
This started after I read about how it is now possible to exchange data through and talk with astronauts on the International Space Station. I've started working on my own license which is really quite easy to attain. It's just one 35 question test which most people should be able to prepare for in under a month with just one or two books.
With luck, in a few months, I'll be ready to flood the airwaves with my own useless drivel. With a little more luck, I'll manage to get a postcard from space.
This project follows in the footsteps on a previous effort I took to compile a comprehensive list of links regarding Bluetooth on Linux Thanks to SlashDot, this page managed to stay in the top ten list of the Bluetooth Top Sites list for all of April.
By FCC rules you can not encrypt or otherwise obscure the meaning of communications over the amateur bands. The frequencies are there for hobby use and not business use.
Over the last few weeks I've been putting together a list of links about amateur radio over Linux. The whole area is an interesting convergence between open projects. It looks like I'll have to add another link for IRLP.
This is very, very likely. I saw a USB 2.0 card at Circuit City last week. It had four external ports and one INTERNAL port. I also own a FireWire card. That card has three external ports and the board etchings (but no hardware) for an internal port. It is very easy to imagine IDE having to compete with one of these standards for internal connection of periperals down the road.
It is very easy to imagine a future machine with only USB 2.0 ports inside and out for connecting up all peripherals. Slots won't go away, but their need and number could be vastly reduced. Now, if traditional peripheral boards such as sound cards and modems could be packaged as modules that can be installed without opening the case, we will be another step closer to truly consumer friendly computers.
I won't deny there is a lot of waste in both NASA and the military. I work for the military and get to see it first hand. It's rampant all through gov't agencies.
My personal theory is that a lot of the waste comes from a lack of profit motive. What is common in gov't service is that if you screw up bad enough you either a) get promoted to get rid of you or b) get more people under you to fix things which justifies a higher position. Either way, the best way to move up is to screw up. Compare that to the commercial world where if you screw up you will end up in the unemployment line.
I'd put the linear aerospike engines and the metallic thermal protection system pretty high on the list of technical jewels. Both of those technologies in themselves are worth pursuing.
The linear aerospike engines are lighter, require no gimbaling (hinges), and are less likely to suffer catastrophic failure compared to traditional bell engines. Their design is perfect for lifting body vehicles being that they spread the thrust across a large area rather than focusing it to a point.
The metallic thermal protection system (TPS) could replace the current ceramic tiles on the shuttle and cut it's turnaround cost considerably. The ceramic tiles have to be inspected and specially treated after every flight. Metallic TPS is more durable and easier to service.
The biggest problem with the X-33 was that it tried to test too many technologies in one place. Being that everyone new the fuel tanks were high risk, they should have built aliminum tanks to start with the intention of changing them out with composite tanks later. "Build a little, test a little" is a far safer method when you are putting all your eggs in one basket.