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§ 5.3 Communications Satellites and Wireless Multi-Media This section focuses mainly on emerging markets and demand, but this issue cannot be addressed in a realistic and competant way unless you also look at the supply technologies. The next generation satellite systems currently being launched up or on the drawing board will become obsolete when "larger" satellites made mostly from near-Earth asteroidal and lunar materials come online. Larger satellites and platforms will offer much enhanced services and push down demand for the presently emplaced and currently designed systems by Teledesic and others. In the new space race, private sector companies will strive for more capable communications satellites which will offer better service with the capability for users to have smaller ground-based personal devices. The market forces that will reward the most competitive satellite producer and its suppliers will be the exploding global internet bandwidth market and the countless mobile, wireless applications discussed in this article. § 5.3.1 Why Bigger is Better
§ 5.3.2.2 Wireless internet Links § 5.3.2.3 Wearable Multi-Media Devices § 5.3.2.4 Year 2000 - Automobiles Already § 5.3.2.5 Additional Products and Services § 5.3.3 Why Optical Fiber and Other Land Lines Won't Undercut This
§ 5.3.3.1 Power Line Networks?
§ 5.3.4 Lower Orbits vs. Higher Orbits
A bigger station in orbit allows smaller, cheaper stations for Earth consumers. The ultimate goal is to reach users with handheld phones and a wide variety of other wireless, mobile communications devices as discussed in this article. One or more companies will arise to supply all these different satellite companies with large satellite components made from materials derived from near-Earth asteroids (and/or lunar materials as argued by some). The satellite electronics (intricate and lightweight) will be made on Earth and launched up for assembly in space, but the next generation big platforms (orbital antenna farms), much larger antennas, power supply utilities, heat rejection radiators, radiation shielding and deployment & stationkeeping fuel propellant will be made of mostly near-Earth asteroidal materials. The latter simple-but-massive components will make up the vast majority of the weight of future communications systems. Hence, most of future communications systems can be produced from asteroidalmaterials relatively easily. Today, satellites are small because of the high cost per kilogram of Earth launch, and the fact that there is no commercial construction and assembly capability in space so that a satellite must fit into one launch payload. Currently, even NASA and Russia have limited construction capability in orbit. Whoever embarks upon a commercial space resources program will also implement greater construction capability in orbit. The technology is there in the public domain, government-sponsored research literature. A bigger broadcasting facility in orbit would consist of:
Notably, space industrialisation will lower the costs and risks of conventional satellites by increasing our ability to service satellites that fail in one respect or another, thereby reducing today's very high insurance costs, as well as high interest rates for money borrowed for satellite projects (it's considered a risky business -- they don't exactly get the prime rate). One of the reasons satellites are extremely expensive to build is the expense incurred in equipment to make sure it does not fail once it's up there, since there are no repair crewes or infrastructure in space. Once we have some infrastructure up there, alot of "indirect" costs will also come plummetting down. For less developed countries which must still establish large and effective communications networks in the least expensive way, assistance by space-based systems serving small ground-based systems will save them the costs of laying copper and fiber cables all over their country, while providing greater services via wireless links. Satellites in low Earth orbit will by their very nature cross all the territory on Earth. When they're above, say, Africa, the don't need to be idle but can serve Africa as well. Thus, low orbit satellites by their very nature offer global coverage. § 5.3.2 Services to be offered The reason today's satellites cannot deal directly with handheld mobile phones decently are the limitations of the handheld phone's antenna size and power transmission. Regarding the handheld device's battery power and lifetime -- lower power transmissions mean longer lasting batteries. Another limitation is the fact that mobile phones are held against the user's head, and people are concerned with the possible effects of a high powered transmitter on the brain. It's practically impossible to design a handheld phone antenna to direct the transmission into the direction of the satellite. The transmission is omnidirectional. All this means that the satellite would need a very large antenna to pick up the signal from handheld mobile phones. To make such large antennas in space commercially, capable of a decent signal, we may need to use asteroidal materials and develop construction capabilities in space. For example, Iridium, the first satellite based mobile handphone provider, went bankrupt because the satellites couldn't communicate well enough with the hand phones. The following comments posted on Usenet by a user are typical: "The problem is it doesn't work. I have tested the Iridium phones and have talked to other who have tested the phones. The people I have talked to have the same story. 50% of the time you can't complete a call and if you do it is vary rare to manage to keep the call up for more than 5 minutes. Most of the time the sound of the caller is so bad you have a hard time making them out. These are people whom would pay the price that Iridium is asking if it would live up to half of what it claimed. The problem is it is design badly. From the phones and that stupid card you have to use to the satellite network that has only one satellite above the horizon if you are in North America or Europe. And the satellite you can see is probably near the horizon so that any thing that gets in the way will drop the call." The market is there, if only an entity can provide the service. It's remarkable that I, the author of this article, Mark Prado, have found mobile phones much more popular outside the US, and have found that the mobile phone quickly turns into a necessity once you have it. When I came to Thailand, I was surprised to find a high per capita usage of mobile phones in this country in 1995 with a fraction the per capita income of the US. Many people pay for them in installments. I bought one outright myself. Then, when I travelled to Japan in 1998, I found them dirt cheap on the roads and seemingly in everyone's hands. The pioneering mobile phone companies are in Scandinavia, and the leading mobile phone company, Nokia, comes from Finland, population 5 million. It is remarkable that an arctic country with such a tiny population has a company that's beaten the pants off of such American giants as Motorola. The world's first digital cellphone network was started in Finland in the early 1990s, and in 1994 moved from Scandinavia to the rest of Europe, Japan, the US and elsewhere. (The Scandinavian countries have the world's highest density of digital cellphones per capita, due to Nokia and the Swedish Ericsson. In Finland, the number of cellular phones in 1999 was around 4 million, which means virtually everybody willing and able to use a phone already has got one. Notably, practically all the European networks are compatible, whereas the US and European networks aren't, since the phone technology is slightly different. However, the SIM cards that determine the "identity" of a cellphone are compatible, so it's simply a matter of renting a different cellphone if you travel overseas. In effect, we already have a "global mobile network" although it is restricted to industrialized and densely populated areas where there are many, many ground transponders which are in turn limited by ground obstructions.) § 5.3.2.2 Wireless internet links It is generally said that it's internet bandwidth which is pushing investments in major expansion of communications infrastructure today ... and tomorrow, e.g., Teledesic. Already, the World Wide Web is called the World Wide Wait, which limits the potential applications of internet to text information with limited graphics capabilities. There is demand for replacing the TV with a computer screen with menus to diverse information sources under your command and navigation, but bandwidth limits this, especially motion videos and sound. Another pressure to come to bear will be wireless internet. Notably, a portable computer can hold a larger antenna, e.g., built in around its perimeter. Further, its horizontal position makes the antenna point straight up. Since the size of a portable PC is determined by its fold-down screen and its keyboard with hand rest, the portable PC is not likely to get smaller, only thinner and lighter in weight. The keyboard base makes for an excellent antenna for satellite connections, and the vertical screen can handle any ground-based links. In fact, the limiting weight of a portable PC will eventually become its battery, which is considerably heavier than that of a mobile phone. With a larger antenna shaped to focus the transmission better, the portable PC is a significantly more natural communicating device. With the advent of e-mail, web-based information services, and even internet phone, the portable PC with a wireless, worldwide internet account is high on the list of markets. The multimedia jacks for external speakers and microphone can easily be used for a headset for an internet phone. It's also worth looking at changes in the PC and internet market. With the advent of internet, there are market pressures to have a minimal "internet PC" which is basically a screen, keyboard and minimal CPU capacity. The main CPU, hard disk, and programs will be on internet servers, and the user will be able to access their data from anywhere in their town or in the world. This is how the Microsoft monopoly will be transcended, and is the current, cutting edge focus of Netscape, America online, Sun Microsystems, Oracle, IBM, and other industry giants. This is associated with the emerging Application Service Provider (ASP) market, which is a cutting edge extension of the internet Service Provider (ISP) market. With an "internet computer" designed for ASP, you don't need MS Windows, as your programs run on the ASP and essentially all you need are a keyboard and monitor. As of November 1999, as reported in The Wall Street Journal, companies planning to build internet computers without any Microsoft software at all include Gateway (with joint marketing with America online and Netscape), Compaq and Dell. "Every PC manufacturer is thinking hard about and working on a lot of these devices in their labs", said Kevin Hause, an executive analyst who tracks the market for International Data Corp. "The internet gives people a platform to do most of the things they need to do..." Apple's been hinging its recovery largely on handheld, wireless devices. Microsoft's MSN.com "portal" service is also an attempt to catch up in this market, though the future of Microsoft is now in doubt due to the 1999 U.S. Dept. of Justice ruling. The prices for these internet PC's is projected to be $199 (for cheap screen) on down to free as part of a package deal whereby sold in combination with a subscription to the ASP or ISP service for, say, three years. § 5.3.2.3 Wearable multi-media devices Don't laugh. Bill Gates isn't. Wearable multimedia devices is a merge of several other technologies such as mobile phones, pagers and portable computers. Palm computers have been around for a long time. For example, since around 1995, Nokia has had a palm computer that does e-mail and web browsing, albeit at low speeds to date. Web browsing at only 9600 to 14400 bps is a bit slow unless you turn off the graphics. Microsoft has tried to market a Windows operating system called Windows CE for palmtops, a pared down version of its Windows, but other industry giants are using alternative operating systems built from the ground up for mobile devices. 3Com is catching up. While I've found palmtops to be a little tedious, there are millions who don't, and who even punch away with proficiency at their cryptic multifeatured pagers and mobile phones. The main limiting problem, as I analyze it, is in the very high pricing for the initial high end market which is required to maximize profits and pay for the development and infrastructure. There is currently (as of December 1999) limited urban coverage and the capacity is not real good, e.g., surprisingly limited bandwidth and communications features -- mainly short messages and very limited web. As with practically all such products to date, the features will go up and the price come down dramatically with time as market penetration and competition grows. For example, go to 3Com's palmtop section (first on the list of products) at www.3com.com or better yet their site www.palm.com and do a search for the word "coverage". Note also their rates -- 1 megabyte of data per month for $40/mo, and you get 700 kilobytes of extra data for free if you sign up for a 6 month service plan. Overall, these systems seem limited not by price, but by limited bandwidth, features and coverage. The merge of the palmtop and the mobile phone will be a key step. Right now, the evolving industry standard is so-called Wireless Application Protocol, or WAP, and it is being adopted by some mobile phone makers, e.g., Siemens, in conjunction with many cellular phone broadcast services, though this is only beginning to "e-merge" as of December 1999. § 5.3.2.4 Year 2000 - automobile "smart cars" already We spend a lot of time in our cars, and wireless services address what would otherwise be an inefficient use of our valuable time, and may be a service which users subscribe to. Driving is also a time when one has the leisurely and nearly undivided attention of the recipient, which adds advertising value for auditory ads by internet information sites. Third on the list of revenue generation may be specific car-related services such as internet maps, navigational aids and shopping information. Major contracts were signed in 1999 by industry giants including Ericsson, Motorola, IBM and many others to create competing consortia to develop communications systems for automobiles. These have been talked about for years but 1999 meant a major step forward, due partly to cellular infrastructure being in place and the advent of mainstream internet. By the year 2003, it's estimated that approximately 10 million smart cars will be manufactured in the US and Europe with smart car features built in at the factory (rather than retrofitted later). How much these devices help sell cars, and expand the demand for wireless bandwidth, has yet to be seen, of course. The first application was navigational, as first proposed in the 1980s and already popular in Japan (with limited features), whereby the car is equipped with a satellite Global Positioning System (GPS) receiver to determine its position and can tell the driver when and where to turn based on a CD-based map (with CD drive in car and purchased CD's) or wireless internet query to a central map database (e.g., of the entire country). However, with new maps becoming available in the late 1990s, the system can direct drivers to particular banks, ATM machines, restaurants, hotels, you name it, and the best routes based on expressways, one-way streets, and potentially even traffic congestion. Revenues can come not only from sales and transmission services, but also from advertising. Other applications where demand is more speculative include mobile hands-free telephony via wireless internet, voice message reception, internet radio and news, audio books (like "books-on-tape") and other auditory programs such as class lectures and information on stocks and business, plug-ins for palmtops PC's, voice recognition, take-away drive-through ordering, distress service calls, transmission of stolen vehicle location, and various screen-based applications (which I hope would be available only to the passengers, not the driver, while the car is moving). Notably, auditory programs may include webpages (such as this one) which are not designed for audio. All that is needed is a voice system which can read words on the net and speak them for the driver. However, auditory websites for drivers will emerge which will be adjusted for these car readers so that the superfluous menus and text aren't read, just the main text and menu selections, and the driver can respond to menus by speaking whereby voice recognition can be the selector. One advantage of advertising this way is that a voiceover can't be skipped as in banner ads that many users never read. Another is that you have nearly the full, undivided attention of the driver when the advertisement is read, and audio is a one-dimensional, time-sequential medium. Software to convert the written word to the spoken word is well developed, with one longtime, major application being to serve the blind. Already, RealNetworks has started a news service for the user who wants to select audio content from news and entertainment services for playback, and the Lycos search engine is developing a feature to search for information within audio clips. General Motors Chairman Richard Wagoner is the most vocal proponent of productivity in the automobile using wireless internet, creating an e-GM division in August 1999 and vowing to GM consumers to help them "stay connected, informed and productive" while on the go, but the European car makers are already heavy competition in this regard according to analysts keeping up with the research and product development in this market. GM began an OnStar network in 1996 but needs new internet options. The current design has a "My OnStar" personal webpage where you store your user preferences for news, information and MP3 music for audio-only driving services. GM customers will also have vehicle systems auto-diagnostics via the wireless network. If you need a repair or service, then guess what ... it's planned that in the first quarter of the year 2000, the parts can be ordered by the GM Goodwrench joint venture at http://www.gmgoodwrench.com, and AutoXchange, which may be able to claim to be the world's largest business-to-business electronic network, an extended parts-supply network dong approximately $300 billion annually. The satellite bandwidth providers could have an incentive to take a cut of this market, too. The struggling Microsoft Windows CE version 2.1.2 already has "Auto PC extensions", and Intel launched a product shortly thereafter that fits into a car's dashboard, thus spreading the Windows vs. Java war to the automobile market. § 5.3.2.5 Additional products and services At the Unwired Universe conference in San Jose, California, in 1999, many experts had concluded that there was no way that terrestrially based solutions can handle the traffic demand. These predictions were made:
We can probably expand this list considerably. Let's start with a general discussion of internet applications. internet Phone is not being used much because of limitations in internet bandwidth, and that's just voice, not video. The same goes for internet Radio, and especially internet video applications such as videoconferencing and sports. The advertising and services market for internet radio and video applications is potentially enormous, as a content provider can reach a much larger audience rather than be dependent upon the local channels. Some large entities are already developing these applications even though the current internet bandwidth cannot support it, due to their conviction that it will come about and they want to get the market. (IP also doesn't fit many of these applications well, except as the last gatewayed segment, which the technology supply end of the market has also been adapting to.) There are quite a number of societal and environmental benefits which can be provided by the communications platforms. Already, endangered species are being tracked using satellites and devices attached to the animals. (Smaller devices would be nicer.) Parolled prisoners could be tracked similarly, thereby reducing crime. Wireless communications systems can have a panic button to notify authorities of the location of a crime taking place or another emergency. Services provided to defense, police and hospital services can be offered in bulk contracts. Weather monitoring by distributed sensors becomes more feasible. Basically, any vendor who has an information technology service or product can set up a compact presence anywhere without needing to arrange a phone line, and with server-based systems will not need to drag along a PC but just a mobile multimedia device. Many in the industry think that entertainment will be the main driver of much higher bandwidth. For examples of what's to come, and if you have a very high bandwidth connection, see the Warner Bros. Entertainment site called Entertaindom at http://www.entertaindom.com or the BigVideo section of tunes.com § 5.3.3 Why optical fiber, other land lines and local cellular won't undercut satellites Optical fiber and land lines will always be competitive for local communications and for backbone links. However, they are not competitive outside urban concentrations. They also miss the demand for wireless, mobile communications. Local cellular transponders will be competitive in urban areas, but they are fraught with obstruction problems. Outside of urban areas, the cost effectiveness and coverage diminish for high speed pipes all the way to the end users' dwellings. This is not the case for satellite constellations which are by their very nature global. From a theoretical point of view, it seems inefficient to have a large number of omni-directional ground-based transponders all over the world to deal with obstructions on the surface of the Earth, when we can just buy into one overhead satellite constellation. From a practical business point of view, whoever builds a cost-efficient satellite network will take over markets in all countries, not just their own region, due to the global coverage of very low orbit satellite constellations by their very nature. Notably, one of the biggest pains of mobile phone users has been travelling, whereby they have bought into a local cellular service somewhere but they can't use their cellular phone in other regions because of lack of agreements between the ground-based cellular phone companies. However, by switching to satellites, what can the ground-based competition do? (...Even if they have a monopoly with the corrupt local authorities?) The authorities of any country would be hard pressed to deny their citizens access to both entertainment and useful services by satellite providers, and to deny access to these markets by any service provider anywhere. But why complain? Import and export of services and goods can be a two way street and leveller of the playing field. The revolution of communications has not ended, and indeed the revolution is stepping up to another level. What emerging standard is UMTS, or Universal Mobile Telecommunications Systems, which in the long term is expected to transmit data at speeds of 2 megabits per second, which makes hard-wired ISDN look like a snail's pace, and especially 56 kilobits per second modems. Indeed, the question today is whether the emerging wireless systems will make the land based systems unnecessary for many subscribers. The limit will be coverage. For both landline and ground-based transponders. The market for satellite based services is clear and present. Now for a market that's really not. There has also been a frequent re-run of a claim that the electricity distribution lines provided by our power utilities could also provide a wired network for internet communications. The answer is: Yes but no. The main barrier is that electrical power distribution utilizes transformers, which by their fundamental nature do not propagate the high frequency signals required for high speed communications -- only extremely low frequency AC 50-60 Hz). You can use the power outlets inside your house, but you cannot communicate outside your house because not much of a broadband signal will go through the transformer that links the power from the utility company to your home. (The power lines outside your home operate at much higher voltages, and the transformer steps down the voltage.) The power companies have other kinds of devices on their lines which cause problems, which varies from country to country, and locality to locality. Also, the wires are unshielded and untwisted, which means they lose the signal over the "backbone" while picking up noise from all directions on the power lines which are like giant antennas. However, you can get a slow, isolated LAN inside your house. Most products on the market offer 200 kbps to 1 mbps, and some new ones offer 2.5 mbps. That can save costs and carpentry work for laying regular LAN cable between PC's in the home. However, it's still too slow for corporate networking. Nortel (Northern Telecom) and Norweb Communications, the latter a part of United Utilities, has been working for years on providing voice and data services over power lines. The first step is a device that they sell to bypass the transformer, which a technician skilled with high voltage wires can install. This gets you to their local substation. From this substation, they must provide a separate, conventional telecommunications link, e.g., fiber optic or satellite dish. You can not connect to your office down the highway by only their power lines. You connect to their substation's new link. They have never claimed that you can communicate far by power lines, only that you can use the last segments of the power lines to reach a conventional telecommunications link which one of their partners will be happy to sell you (and maybe sell you internet service, too). It's a way for the power companies to try to get in on the internet business, in a limited way, and dependent on other, conventional partners. This partnership has an experimental setup in Manchester, England to provide a 1 mbps connection to each dwelling (school or home or small office). England is one of the best markets because there is typically one transformer per 100 to 300 homes (vs. per 4 to 10 homes in the US), and the local phone companies in England are expensive for internet calls because they charge users per minute on the phone (vs. countries which charge a flat rate per call or per month). However, after some high profile press on this initial setup in 1997, I've seen nothing more, and heard they had a lot of problems. Power lines are unlikely to compete in most places with existing standard telephone company wires for still another wired network, and are quite unlikely to compete with a multinational, wireless, global service provider. § 5.3.3.2 Flying antenna complexes (HALE - High Altitute, Long Endurance Platforms)? This concept is for high-flying antenna complexes to serve cities, solving many of the obstruction problems caused by ground-based transponders, and reducing the number of transponders needed to give thorough ground coverage. These complexes can be winged aircraft or dirigibles. The challenge is that these antenna complexes must fly for long periods of time at altitudes above storms, reliably, and have power for both the communications platforms and flying. Maintaining aerodynamics with a cost-effective antenna complex is another challenge. Very high wind speeds are common in the upper atmosphere, so dirigibles will be significantly challenged in stationkeeping. How much you can pack into a HALE platform is arguable. In comparison, satellites stay up with little effort (a little stationkeeping thrust once in a while), and you can build up these transponder platforms as big as you want without losing their "flight" capabilities or operating expenses. Flying antenna complexes can serve very localized markets, but not global markets. Since they can go up about 30 km, they will be competitive for unobstructed cellular communications for a fair sized cone area compared to a satellite at around 250 km altitude, and can serve concentrated market areas in a complimentary way to satellites -- with local telephone companies relaying local traffic to the HALE platform and internet traffic beyond to satellites. Their appeal as a relay to satellites exists as long as a broadband global satellite constellation does not exist, which in turn is the case until space infrastructure comes around to build transponder platforms for such a constellation. § 5.3.4 Lower orbits vs. higher orbits Most people are aware of satellites that stay permanently in one part of the sky, e.g., so that you can point your TV satellite dish towards them. Unfortunately, those satellites are in the geostationary 24-hour orbit, 36,000 km (22,500 miles) above Earth. Right now, you need a stationary satellite dish to communicate with a geostationary satellite. They're not cheap and they need to be pointed precisely.
(Mobile phone users, as of 1999, essentially buy into a local company's ground-based cellular network which has a central uplink to the geostationary satellite for international calls.) One solution is to move the satellites into lower orbits, but any satellite not in geosynchronous orbit will move across the sky and around the world, so that multiple satellites are needed to cover a given area. No longer one satellite. The lower the satellite orbit, the more satellites you need, due to the horizon and surface obstructions. The low Earth orbit satellites themselves relay signals between each other in addition to relaying to and from the ground. For example, if you're in Thailand and want to connect to an internet link in the USA, the signal may hop from the ground to the satellite over Thailand at the moment, then between half a dozen satellites hugging low Earth orbit until it reaches the satellite above the internet site in the USA, and then down to the internet site on the ground. This is faster than bouncing signals up to geostationary orbit and its circumference. However, the satellites in low Earth orbit could easily spend far more of their communications capacity relaying information between satellites as between the ground and the satellites. One disadvantage of geostationary satellites is that it takes one fourth of a second for the signal to travel up to geostationary orbit and back down. While this is a minor nuisance for most users, it is a significant problem for some kinds of users (e.g., certain high speed computer networking such as finance systems, teleconferencing, and eventually the technology of televideo teleoperated surgery). With low Earth orbit satellites, this time can usually be cut to less than a tenth of a second, and in most cases on the same side of the world it can be cut to hundredths of a second with fast routing and gatewaying equipment. Most low orbit satellite constellations are at altitudes of less than 1500 km (900 miles). The altitude is based on such factors as horizon/obstruction, number of satellites budgeted for the constellation, satellite power budget, and stationkeeping fuel. Due to the strength of market demand, there has been an explosion in development of satellites destined for low Earth orbit (LEO) constellations. Even the most conservative analyses make a strong statement that we will be launching more material into space in the next 5 years than we have launched in the 40 years since Russia launched the first satellite ever, Sputnik. A huge jump in launch capacity will be necessary, and the launch industry is responding with new rocket startup ventures and ramped up production of old rockets. This is a huge new market, and the competition has only started as the market has not matured or proven itself enough for the vast majority of conservative investors. It's also likely that the amount of orbital junk and debris will also increase dramatically (including from failed, exploded rocket stages), and with it the need for more shielding, especially of manned space facilities. Further, unlike satellites in high geostationary orbit, satellites in low Earth orbit will eventually come crashing down to Earth. Those placed into orbit successfully will have a lifetime of about 10 years. After that, they will run out of stationkeeping propellant. They either need to be resupplied with stationkeeping propellant (and probably retrofitted with a new engine to use asteroidal fuel) or picked up and scrapped. Otherwise, who knows where they will come crashing down from the sky, including potentially in the middle of a metropolitan area, at considerable liability to the owner. If their stationkeeping rockets fail, they will come crashing down prematurely and out of control. This is not a trivial issue. Thus, it's a market for orbital infrastructure. A local taxi service in space fueled by asteroidal propellants can handle decaying satellites anywhere. As mentioned above, the number of satellites going into low Earth orbit will be multiplying like never before. We need to plan ahead, as it will take several years to get to the point where services based on asteroidal materials will come to fruition. It has been pointed out before that assembly of satellites in orbit could reduce the costs of satellites. One reason is that it reduces the risk of damage during launch, and hence of work in preventative design and testing. Satellites assembled in orbit by a couple of technicians could be tested thoroughly before deployment. The satellites could have geometries that would be infeasible to launch in compact form and deployed automatically in space. Once assembled in space and thoroughly tested, they can be deployed into the proper orbit by a low thrust interorbital vehicle such as a solar steam rocket, rather than a conventional high thrust chemical rocket upper stage. The CEO of Skycorp, Dennis Wingo, is trying to arrange space on the upcoming International Space Station for this purpose. He estimates that this process could save about 80% of the costs of producing satellites, which he figures would be roughly 50% of total costs, and is targetting the satellite constellation makers. These figures are for 100% Earth launched parts and have not considered using asteroidal resources yet. § 5.3.6 Currently proposed satellite constellations None of the satellite systems currently under development will put the present land-based phone companies out of business. They will be challenged enough to supply services directly to users of mobile handheld devices (without a large groundbased transmitter and receiver), using their small satellites, at prices affordable to a large enough part of the market. The vast majority of the satellite systems currently under development work with the existing communications infrastructure rather than transcend it, e.g., with links to local cellular relay systems. Most of the satellite system creators are first trying to sell to the gateway providers such as local phone companies (both landline and mobile) and internet service providers. They are competing with the AT&T, MCI, Sprint, British Telecom, Telstra, etc., providers in selling high speed links to local resellers. Here are some of the tradeoffs:
The total communications market is currently about $650 billion, and that is projected to double in 10 years, mainly due to data communications. The following are some of the emerging satellite constellations which will be handling that expanded bandwidth as well as offering new services as an edge on the competition. For most of them I have the vital technical specifications. (For comparisons on speed, note that most modems today operate at between 28 kbps and 56 kbps.) Notably, while I have the estimated size and cost of the ground terminal for many of them (analogous to the cost of buying a modem), I do not have the prices for the monthly service subscription fees (analogous to subscribing to your local internet service provider) which will be determined largely by market conditions at the time they come online, and indeed will usually be determined by the local resellers of the service. Thus, the costs to users is murky, and the costs quoted below must be taken in context. Indeed, if a local reseller gateways the link to a local cellular phone or internet service provider, then you don't pay for any special equipment. The following is a result of research of plans as of mid-1998, some of which are subject to change, and thus some of the information may be incorrect. For precise and accurate information, you must go ask the vendor yourself. I make no guarantees that the following is correct. The low earth orbit constellations:
A hybrid geostationary and low orbit network:
Newly emerging geostationary satellite constellations:
Medium orbit constellations (who don't have to worry about their satellites crashing to Earth in 10 years):
And finally, an odd one in terms of orbit:
Notably, there are tradeoffs in satellite altitude. The higher the altitude, the greater the land coverage (in view of the satellite) and the further apart the satellites can be for seeing each other and relaying signals without the Earth's horizon getting in the way. However, the higher the satellite, the more technically challenging it is in terms of signal strength and focusing for two-way communications with ground users. Also, the lower the satellite, the more sensitive it is to orbital perturbations by the Moon and Sun because such perturbations make the satellite dip into more dense fringes of the upper atmosphere, slow it down and reduce its lifetime in orbit. Thus, the need for stationkeeping fuel propellants puts a practical limit on the lowest orbit. Another problem that has arisen from time to time, and will only get worse, is interference between satellites because they are too close to each other and operating on similar frequencies. Lawsuits have already flown due to satellites interfering with each other. Two solutions are larger antennas to focus transmissions and receptions to smaller footprints, and platforms to mount multiple satellites operating at different, compatible frequencies, ans so satellites can communicate with each other by optical fibers rather than radio transmitters. Large antennas would also allow satellites and platforms operating at the same frequency to be closer to each other, due to the better focusing. This would relieve problems of running out of available signal frequencies for new satellites. Many companies have moved to higher frequency transmissions for two reasons: you can achieve higher rates of data transmission on higher frequency signals, and there are fewer people using higher frequency bandwidths so that there is less potential for conflict. The problem with higher frequency signals is that they are absorbed more by the atmosphere, especially by rain, which causes fading and even complete loss of signal. In fact, some people expect that Teledesic will have occasional problems with its signals due to weather. The only solution is to compensate with higher transmission power. But that means a bigger power plant on the satellite (or else more power beamed to the satellite -- see the PERMANENT section on wireless transmission of electric power). The latest band to be developed is the Ka-band (also known in slang as the "future multimedia satellite band"), which uses wavelengths of between one and 1.5 centimeters. There are about 50 proposed Ka-band satellites requiring approximately 170 geostationary orbit locations. Most of these are for national or regional based systems. As Scientific American (April 1998) put it, "The choice of Ka-band is driven largely by the absence of a suitable alternative; recent developments have made it almost impossible to secure orbital locations for satellites that would operate in other bands without interfereing with neighboring satellites." But the Ka-band signal is significantly attenuated by rain, as experienced by experimental satellites. The Teledesic constellation needs so many satellites because the transmission cone is relatively narrow to the service area of each satellite, due to rain fading at wider angles. Proliferation of satellites is one of the strategies to circumvent rain attenuation problems. Despite the rain attenuation problems with the Ka-band, companies have already filed for licenses from the FCC for building systems operating at still shorter wavelengths -- the Q/V band of six to eight millimeters. After Hughes and Motorola filed, at least 14 additional system had been proposed as of early 1998, including a total of 400 satellites at an investment cost of around $40 billion. Yet, the Q/V band is significantly attenuated by the atmosphere even in clear weather, e.g., by a factor of three to four along paths as low as 20 degrees above the horizon during clear weather. The only solution will be larger satellite antennas to collect weaker signals, and higher powered transmissions. There are pressures coming from everywhere to find new frequencies which can be punched through the atmosphere in order to circumvent frequency congestion, as well as efforts to find ways to re-use the same frequency by smaller beams to prevent interference. As reported in the Ka-band Report at http://www.spotbeam.com/mansum.htm:
It's a notable rumor in the journalistic medium starting in September 1999 that Teledesic is looking into the potential of acquiring the assets of bankrupt Iridium or ICO Global Communications in order to get an early entry into this market, based on quoted statements by Teledesic co-CEO Bill Owens, spokesman Roger Nyhus, and key industry analysts. I've been asked what is my favorite of the future satellite constellations. My favorite of them all is overwhelmingly Teledesic. Founded by the practical visionary Craig McCaw who made his fortune in cellular phones, and who brought in Bill Gates and AT&T Wireless Services as coinvestors, this satellite constellation will provide the best service of any satellite based network under development today. It's interesting to read the interview with Teledesic President Russell Daggatt by Upside Media Inc. at http://upside.master.com/texis/mvm/story?id=34712c1674. Related PERMANENT sections: PERMANENT has a related commentary article on communication satellite systems entitled The Next Space Race -- by Multinationals
PERMANENT has a section on larger power sources and wireless transmission of electric power for satellites.
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