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The next step in the process is to add one or more data sources A data source represents a connection to one or more sources of data for the cube Often, there is a single data source, which points to the star schema as was described in the previous section The star schema is supposed to the single source of information for the cube, so it makes sense that this would be the only connection In some cases, however, customers may have multiple data sources, and these sources might store their data in different formats For example, some of the data may be in SQL Server with additional data in Microsoft Access and Oracle There are many options when it comes to setting up data sources, including the specific provider to use and the different types of security These issues are beyond the scope of this particular book, although security will be revisited in 8 For the rest of this discussion, there will be a single data source that has been set up to a relational data warehouse hosted in SQL Server

Originally the Iridium proposal was for 77 satellites, but Motorola amended this number after the World Administrative Radio Council meeting in the spring of 1992

14-3

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The original concept was to use seven polar orbits with eleven satellites in each This would provide worldwide coverage, much similar to an orange slice concept

The ammo box was destined to receive all the electronics It took time to determine the arrangement of all the items inside the limited space Inside the ammo case are the Vantec speed controller, the radio and its battery pack, two Futaba servos driving standard microswitches to switch the weapons systems, and three relays for the weapons systems two for the arm mechanism and one for the saw motors An evening of careful planning and trial-and-error assembly found the configuration that worked best They all fit, albeit in a densely packed configuration Between the axle and the rear of the box are the batteries two high-rate-discharge Yuasa MPH1-12 batteries that can supply 100 amps or more They were chosen for their high discharge rate, something many gel cell batteries are incapable of, as it was needed to run the saw motors Quality varies widely among gel cell manufacturers The Yuasas ran $26 each not inexpensive, but battery quality is an area where you can t afford to scrimp Everything was fitted in and tested; the robot was driven around as a mechanical ammo box to be certain the design worked The axle through the center of the robot, the gearbox, and the wheels help to brace the batteries in place The motors are held in place by hose clamps over PVC pipe It may not have looked pretty, but the parts were inexpensive, effective, and easily obtainable Most of this robot s parts were obtained from scrap yards, hardware stores, scavenged materials, and a surplus catalog or two Although work on the basic drive box was completed and initial testing showed the design to be a solid one, there was still much more work to be done

With the market ripe for a global communications system, and the lead in getting the service up and running, how did Iridium fail One can only speculate, but the cost of launching Iridium was over $5 billion (US) and the project was nearly a year late Moreover, during launch, several factors plagued Iridium (lost satellites, explosions, and failed launches), putting significant financial strain on the operating budget When Iridium became available, the initial costs were touted as being $5 7 (US) per minute for an international call In 1992 when the model was created, this price may have been realistic However, in the time it took to get off the ground, the costs for dial-up voice communications plummeted No one was willing to pay the prices asked by Iridium A better price may have been one I predicted in 1995 stating that they will have to charge from $1 3 (US) per minute That may have been one of the total downfalls for the Iridium network Moreover, the handset price was too high, ranging upwards of $3,000 each This does not mean that they cannot come back and reestablish themselves as the leader in the LEO industry, but there are many providers right on their heels (such as GlobalStar and Teledesic) These companies and their networks are aggressively chasing behind Iridium and plan to offer the broadband communications services initially when they open their doors Iridium felt that they could do this later, possibly because of their lead in establishing the market niche