Now that the second data release (DR-2) of the GAIA star catalog is available, we are working on incorporating it into SkySafari Pro.
The "standard" SkySafari Pro will include GAIA stars to G magnitude 15. This is a modest increase in the number of stars (from 29 to about 33 million) that ship in SkySafari Pro by default.
The big whopper will come in the GAIA extension, which will replace the UCAC5 extension in-app purchase. This will be a free replacement for the UCAC5 extension - if you already purchased the UCAC5 extension, you won't have to buy the GAIA DR2 extension separately. The new GAIA DR-2 extension will include stars from G magnitude 15.0 to 17.0. That's a total of about 120 million stars, as opposed to the ~80 million currently present in the UCAC5 extension. The file size of the GAIA extension will be 2.24 gigabytes, as opposed to 1.45 gigabytes.
Beyond this, we are thinking we'll move to a "streaming" architecture, where even more of the GAIA catalog is loaded on demand, in bits and pieces, across the internet, as you pan around the sky. The entire 1.7-billion-star GAIA catalog would occupy a file more than 30 gigabytes in size. We just don't think that's practical, even in this day and age. But we can certainly stream it as you need it.
We'd like to get your thoughts on whether we should just jump to a streaming architecture, right now, and don't bother with a 2.24GB downloadable "extension". Is 2.24 GB simply too big of a file? Do people really want this many stars downloaded to their mobile device? Flame away!