[jkot]

I had look at source code, it seems like very inaccurate approximation, real planet position could be a few degrees different.

You can get 10' accuracy with a few kilobytes of polynomials. Some astronomical (and astrological) programs use polynomials a few megabytes big. JPL ephems are 1 to 100 gigabytes.

[mikeash]

You raise an interesting question. Does accuracy matter for something like this? Would a more accurate version be better...?

[jkot]

Yes! NASA does deployments based on planet positions:-)

Even normal deployment based on time of day, or time since sunrise depends on planets positions. Center of gravity of solar system is not inside the Sun but OUTSIDE. Sunrise and sunset times depends on Jupiter, Saturn and other planets.

Also Moon and Sun brings tidal waves...

[pfortuny]

Of course. The fact that it has not worked until now is that all the calculations were wrong!

[peterwwillis]

As most people who've used commercial deployment systems will tell you, accuracy does not appear to matter.