So where do we all think SID orbits? I just received my copy of the UFO tech manual today and I looked up SID.

According to the book SID orbits opposite of the moon in an orbit 12,500 miles up. This way it is always covering the area that the Moonbase tracking systems can't see.

Nice in theroy but in fact this is a clear violation of orbital mechanics. In order to stay opposite of the moon, SID would have to be parked at the L3 libration point 240,000 miles up. This orbit is unstable by nature and the satellite would have to expend quite a bit of parking fuel to maintain that orbit. It's like trying to balance a baseball on an upside down bowl. It can be done but it's not easy! I did this in Soul Mates, as SID 3 is parked there in the story. It was equipped with larger fuel tanks and a special station keeping system and required refueling once a year.

The orbit the book describes would most likley have a period between 10 and 12 hours, rather than 27.3 days.

The one thing they did get right is the fact that a large booster (like the Saturn V) would be needed to reach SID for a repair or refueling mission.

In my storylines I always parked SID at the L5 libration point. It's a very stable orbit and it allows SID to accomplish the same thing as as being parked at L3 without the technical problems.

There is a great article on wikipedea about the libration points.

Hi,



Which is why I really only take what's onscreen as canon. Then at least I only have to explain away errors made by director and continuity girl, and not by hindsight writers 

Physics are of the essence. Yep.

I see Louise paid attention to my essay on techno-babble! Don't explain it if you don't have to! sniggering again

It must be nice to have someone to talk with about all this good stuff! I'm jealous!