When it began designing the International Space Station, NASA quickly realized it must have an integrated analysis tool for its system-level design studies. Station assembly would require at least 15 space shuttle flights to deliver all the hardware to orbit, which meant in essence that they would have to analyze 15 separate spacecraft. (The number of flights soon grew to 17, then 20, and, by the time the first components were actually launched, 44 flights.) All of these analyses would have to be performed for every overall configuration considered (Power Tower, Dual Keel, etc.) NASA engineers had a suite of separate programs to perform all the necessary analyses, but they saw that they could never be sure that all the programs were using the same models and conditions unless they were somehow integrated. They saw that SDRC® I-deas®; offered the model building capabilities they needed, plus the graphical interface and database capabilities which their codes lacked and asked us to integrate their codes with ours. Since their codes were known collectively as I-deas®, for Interactive Design Evaluation of Advanced Spacecraft, and ours was called I-deas®, the integrated product was called Ideas² as illustrated in Figure 1.

Figure 1. ATA developed Ideas² for system-level analysis of the international space station.

Before we began writing code, or even writing a specification for the code, we actually performed a typical series of analyses so that we would understand directly what the eventual users of Ideas² would need. (One of the benefits of working with ATA is that we are all engineers, so we can do the actual engineering work when we have to.) What evolved is shown in Figure 2. Where the most useful thing to do was to tailor or extend the standard I-deas® capabilities, we were able to do that through I-deas® Open Architecture™ tools. In other cases, we wrote special programs to read the data from I-deas® and interpret it correctly to generate the input data needed by each of the spacecraft analysis programs. We modified those programs so they could get data directly from I-deas®'s built-in relational database and store their results back into it, using its Application Programmer's Interface. In the end, users could define all geometric data as a single model in the tailored solid modeler, automatically move that to the database, define nongeometric conditions such as orbit parameters and solar activity levels directly in the database, run the analyses, and plot the results from the database. All of this had a common user interface and was presented to the user as a single application. The database provided complete traceability of the geometric configuration and the other conditions. In this way, Ideas² made the latest models available to all concerned engineers and guaranteed that when different analytical disciplines presented their results, they could be sure they were all talking about the same models. Ideas² made it possible to evaluate a new station concept in weeks, where it had taken months to do it before.

Figure 2. ATA wrote custom interfaces or tailored I-deas®, as necessary.

Ideas² also gave the various NASA codes (Figure 3) wider exposure than they might otherwise have had. Not only were all of the programs used at all of the NASA centers involved, but they were also used at Boeing, Lockheed (now LockheedMartin), and McDonnell Douglas (now part of Boeing) in their space station activities. From 1986 through 1992, Ideas² was the primary analysis tool used to prepare all eight major task force studies and design reviews for the station.

Figure 3. ATA wrote custom interfaces or tailored I-deas®, as necessary.