I was an engineer on the ground station software for Iridium. Here are the kinds of things someone would have to do on a constant basis to use the satellites:
1) Run and maintain at least 2 ground stations devoted to telemetry, tracking, and control of the vehicles. The vehicles have a basic understanding of how to stay in orbit, but essentially this knowledge needs to be constantly tracked and maintained by multiple ground station contacts a day to obtain proper tracking data that gets fed to the orbital tracking services system.
2) Run and maintain a very complicated orbital tracking services system. This system constantly predicts where the vehicles are in relation to each other and to the various ground stations (the telemetry and control stations as well as the telephony gateways). The vehicles themselves have no understanding of their geometry in relation to each other or where they are in relation to the ground stations.
3) Run and maintain a very complicated scheduling system that precomputes the routing of EVERY packet destination that could take place in a 48 hour time span. You would think that the vehicles are smart and can figure out routes in the satellite constellation themselves, but that isn't the case. The constellation / ground station topology changes roughly every 3 seconds, creating about 18,000 topology change events that must be managed during the scheduling process. These form routing tables that are uploaded to the vehicles roughly once a day.
4) Run, maintain and staff a complicated real time satellite command center. The vehicles need pretty much constant baby sitting and attention from the ground (by well trained satellite operators, I might add) in order to function properly. This system coordinates all of the real time communication between the ground and the vehicles, uploading new routing tables, making tracking contacts, supervising vehicle burns, etc.
Basically, the Iridium network of satellites is a constellation of blind and dumb vehicles, that don't really know about each other or the ground. The whole "intelligence" of the system is in the various ground systems that I outlined above. These ground systems are constantly running and updating the constellation. Iridium was never designed as a "fire and forget" type of system, where once launched, the vehicles operated autonomously. The whole system requires constant attention to remain functioning.
I haven't even really addressed that the whole system doesn't really understand data networking. It only handles voice packets and barely handles pager traffic. The bandwidth available is also extremely low, in the vew thousand bps.
Once profitable, there were plans to put more digital traffic capability in the system, but that hasn't happened.
So, anyone who thinks they can throw an informal band of volunteers to run the system in an "open source" manner, clearly has no knowledge of how Iridium really works.
Smalltalk in the early 70's (73-74?) had overlapping graphical windows running on the Alto.
And yes, give Alan more credit. The man's a true genius. Look up some of his articles in Scientific American (Sept 77 for a real cool look at Smalltalk in the 70's, Sept 84 for an insightful article on the state of computers & humans). He has an incredible depth and breadth of knowledge that spans math, biology, computer science, music, history, the list goes on.
So much of what we do today is directly attributable to him and those working with him at PARC in the 70's (graphical interfaces, mice, object-oriented languages, incredible development environments, ethernet, laser printing, etc.). It's amazing how long it has taken the world to catch up to what they were doing way back then.
Notably, it uses a 233MHz MMX Pentium, uses 64MB RAM, has a 340MB disk, NeoMagic 128XD video chip set, and the screen resolution is 320x240 (with a note that the SVGA version is under development).
Has anyone seen the IBM commercial with the guy using one of these with voice control and wireless connection? -- very neat!
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Actually, Iridium uses hardened PowerPC, which a lot of modern space hardware uses.
I was an engineer on the ground station software for Iridium. Here are the kinds of things someone would have to do on a constant basis to use the satellites:
1) Run and maintain at least 2 ground stations devoted to telemetry, tracking, and control of the vehicles. The vehicles have a basic understanding of how to stay in orbit, but essentially this knowledge needs to be constantly tracked and maintained by multiple ground station contacts a day to obtain proper tracking data that gets fed to the orbital tracking services system.
2) Run and maintain a very complicated orbital tracking services system. This system constantly predicts where the vehicles are in relation to each other and to the various ground stations (the telemetry and control stations as well as the telephony gateways). The vehicles themselves have no understanding of their geometry in relation to each other or where they are in relation to the ground stations.
3) Run and maintain a very complicated scheduling system that precomputes the routing of EVERY packet destination that could take place in a 48 hour time span. You would think that the vehicles are smart and can figure out routes in the satellite constellation themselves, but that isn't the case. The constellation / ground station topology changes roughly every 3 seconds, creating about 18,000 topology change events that must be managed during the scheduling process. These form routing tables that are uploaded to the vehicles roughly once a day.
4) Run, maintain and staff a complicated real time satellite command center. The vehicles need pretty much constant baby sitting and attention from the ground (by well trained satellite operators, I might add) in order to function properly. This system coordinates all of the real time communication between the ground and the vehicles, uploading new routing tables, making tracking contacts, supervising vehicle burns, etc.
Basically, the Iridium network of satellites is a constellation of blind and dumb vehicles, that don't really know about each other or the ground. The whole "intelligence" of the system is in the various ground systems that I outlined above. These ground systems are constantly running and updating the constellation. Iridium was never designed as a "fire and forget" type of system, where once launched, the vehicles operated autonomously. The whole system requires constant attention to remain functioning.
I haven't even really addressed that the whole system doesn't really understand data networking. It only handles voice packets and barely handles pager traffic. The bandwidth available is also extremely low, in the vew thousand bps.
Once profitable, there were plans to put more digital traffic capability in the system, but that hasn't happened.
So, anyone who thinks they can throw an informal band of volunteers to run the system in an "open source" manner, clearly has no knowledge of how Iridium really works.
Telemetry & control of the vehicles occurs in the K-band which is one of the more useful radio astronomy areas.
Smalltalk in the early 70's (73-74?) had overlapping graphical windows running on the Alto.
And yes, give Alan more credit. The man's a true genius. Look up some of his articles in Scientific American (Sept 77 for a real cool look at Smalltalk in the 70's, Sept 84 for an insightful article on the state of computers & humans). He has an incredible depth and breadth of knowledge that spans math, biology, computer science, music, history, the list goes on.
So much of what we do today is directly attributable to him and those working with him at PARC in the 70's (graphical interfaces, mice, object-oriented languages, incredible development environments, ethernet, laser printing, etc.). It's amazing how long it has taken the world to catch up to what they were doing way back then.
IBM's page on the wearable is at http://www.jp.ibm.com/esbu/E/wpc/index. html.
Notably, it uses a 233MHz MMX Pentium, uses 64MB RAM, has a 340MB disk, NeoMagic 128XD video chip set, and the screen resolution is 320x240 (with a note that the SVGA version is under development).
Has anyone seen the IBM commercial with the guy using one of these with voice control and wireless connection? -- very neat!