I followed that link and found a awesome astronautics simulator, unfortunately on the DirectX domain.
I agree users wanting such a simulation should try Orbiter instead on wasting efforts in changing the purpose of Celestia. Both examples are impressive enough to please the most demanding users, but following so similar trends (forums included), I wondered why not some sort of cross links could be stablished between one and the other. I wrote Martin Schweiger on that idea, and got that kind and enthusiastic reply (I should ask Martin permission to quote him, but I hope he will not be upset by that):
"On Celestia, needless to say, I am very impressed.
I think some sort of loose collaboration for the mutual benefit of both
simulators would be a very good idea. I guess you are not suggesting to
actually merge them into a single project. I think the aims of the two
simulators are quite different, so they should be perfectly able to
coexist alongside each other.
I'll be happy to sign up to the Celestia board, although generally my
own message board keeps me more than busy.
Likewise, any contributions from the Celestia community to the Orbiter
development will be very welcome. Martin Schweiger"
Orbiter could, from my point of view, address the needs of the Celestia community for Astronautics simulation, and provide Celestia tools for gravitational simulation or texture issues in return. I encourage all Celestia and Orbiter fans to join efforts to keep both platforms mutually independent but building on each other strenghts.