Celestia Forums

I just loaded Jack Higgins MER cruise phase package (Which worked Great!)
Try going out of the plane of the Solar System and turning orbit rendering on after selecting the MER-a-2 : . You get a big nice letter D. Don't think this is a major problem, but could confuse some people.

There are several problems with Celestia's current rendering of non-periodic orbits.

First, Celestia assumes that the orbit is closed, and draws a segment connecting the beginning and end points. That's why the MER trajectory looks like a "D". A "quick fix" for this problem might be possible by changing the code to omit the closing segment if the distance between the beginning and end points is large (e.g. compared to the distance between the first or last two points).

The second problem is that Celestia draws its orbits from the object's position at the current time forward (depending on when you turn orbits on). It would be better if open orbits were drawn from beginning to end.

Also, the number of samples per orbit is fixed, which causes long trajectories to appear segmented.

Cassini provides a good example of these last two problems. (MER's orbit is rather boring in comparison to Cassini, BTW.)

Another problem with Cassini is that once it enters orbit around Saturn, you might like to see its path displayed as a Saturn-centric orbit, like the orbits of the other satellites. But I'm not sure how this would be combined effectively with the heliocentric segments.

Finally (although this one is minor), orbits are always drawn behind the planets.

Speaking of Cassini, we're now less than a year away from its arrival at the Saturn system. If all goes well, the spacecraft will make a close flyby of Saturn's outer moon Phoebe on June 11.

- Hank