BOUNDARY(71)

Even after the start of CAD/CAM in the late part of the twentieth century, the designs still had to be built multiple times and tested physically for a number of purposes. The computers back then simply weren't capable of modeling the full range of complex interactions the real world would throw at a device in a high-stress environment. That applied twice-over to spacecraft, which would have no safe harbor, no "side of the road" to pull over to, and which would be entering and exiting Earth's atmosphere under the greatest "environmental stress" imaginable. There was insufficient experience in the design of multiple types of space-suitable devices, in the assembly of spaceworthy habitats and vehicles, and related problems to permit the designers to make any useful assumptions.



In the past two decades, however, things had changed. Just as an old-style CAD/CAM package had permitted one person to equal the design production of a dozen or more old-style designers, modern CDM (Computer Design and Modeling) packages made one person trained in their use equal to a department of old CAD/CAM users, plus an entire testing lab. The modern CDM packages integrated modeling software equally advanced from its predecessors like MATLAB—capable of modeling and testing a designed part to a degree never before possible. Components were automatically checked for their capability to endure the stresses inherent in the design intent, while the designer continued the main design work based on broad conceptual designs. The specifics could be modified at will, and the entire design reworked to fit new specifications, all in a small fraction of the time earlier generations would have needed. With the firm empirical knowledge derived from thirty years of the International Space Station and its successors in orbit, such CDM packages now routinely produced new satellite designs, new living modules, and so on for space use in mere days—designs that worked.



Ken's hand reached out, tracing the ghostly outline of Nike. The main ship's body was one and a half times as long as her fully-opened span—about fourteen hundred feet. From slightly forward of the halfway point, a great wheellike ring encircled the ship, glittering with hints of both metal and transparent windows.



"That's the habitat area, of course," Ken said, pointing. "Do you realize how huge this thing is? I mean, good God, it must be nearly three thousand feet around!"



"We certainly do. And we'll all be discussing the logistics with everyone later. It can be done, though, with the priority that the government's put on it. The size is pretty much necessary, to give us room to operate in as well as to give us the gravity we need. We may be living in Nike for a year or more."



Jackie circled one area of the hab ring and a separate view zoomed up. As it did so, the ring seemed to fragment into multiple identical segments with the profile of a sort of squarish croissant pastry that was being slightly bent in the middle.



"The main structural elements here, and in the main body, are standardized units that lock together. The internals can be customized almost limitlessly around a set of standardized modular connection points. You'll have hallway sections that basically have nothing but empty space, and habitable sections that are in the center of a bunch of supplies like water which help with shielding. The same, as a rule, with labs, dining or rec areas—and all of them based on the same support and maintenance structure. The main body has its own standardized assembly parts. This allows us to crank out a lot of the ship from a relatively few assembly designs, then fill it up with what we need. The fuel areas, of course, are basically subdivided tanks."



Ken nodded, continuing his visual tour. To the rear of Nike, six great blocky assemblies, arranged in a pentagonal rosette with the sixth in the center, ended in the unmistakable vents of nuclear rockets. Front and back ended in smooth curves, the forward end coming to a graceful point. Colored areas indicated windows and sensor mountings.



"You've streamlined things along the front to back contours," Ken remarked absently. "Why? She's not going into atmosphere."



"Are you objecting to her appearance, Major?" Gupta's voice was slightly nettled. "Can an engineer not also have some appreciation of aesthetics?"



"Oh, no, no, not at all. She's beautiful. It's just . . ."



Gupta accepted Ken's backpedaling with a gracious nod. "Still, it cannot be argued that there is effort involved in such design and manufacture. Perhaps making the ship less streamlined would be cheaper and more swift. Yet, there are other considerations."



He nodded once more, to tell Jackie to continue. Gupta liked to distribute explanations among all his engineers, rather than be the sole source of information.