General Question How realistic is Orbiter?

[block o butter]

So how realistic is this simulator? I am finding a simulator to research and test on my project (particularly science fair:thumbup Is it realistic enough to be reliable with data gatherings?... Like can I actually apply my findings to real life? All I'm doing is performing re-entries and landing with Atlantis (because it's the most realistic shuttle I can find). Is this just for nerds like me to pass time as a game, or a legitimate researching and simulation engine?

 

[C3PO]

Reentries are probably the least realistic part of Orbiter mainly because add-on developers don't find it worth the effort. You could make a realistic winged/lifting-body craft for Orbiter but the result would be something that would be nearly impossible to fly manually, or would have to be (almost) fully automated like real space craft. Only the most hard-core simmers (like me :lol would enjoy reentering such a vehicle.

For realism capsules is probably the best option. Hyper-sonic flight is not like dusting crops. :thumbup:

Welcome aboard!

 

[TMac3000]

The Dragon capsule is probably the most realistic real-tech item--the XR-series probably gives you the best idea of what SSTO flight would be like.

 

[boogabooga]

Actually, quite realistic, once you get into space. (aerodynamics is sort of a weak spot) Orbiter is sort of a hybrid between serious and leisure. Actually, this has been discussed already today:

http://www.orbiter-forum.com/showthread.php?t=35243

The physics behind Orbiter are quite real. Also, Orbiter does model some fairly advanced phenomena such as non-spherical gravity,micro drag, gravity gradients, and solar radiation pressure. It just may not quite be accurate as professional software. Orbiter has to compromise a little bit on pure accuracy because it must also have beautiful 3D graphics and be in real time.

If you are a real-world professional and tens of millions of dollars and your job is on the line, you aren't going to necessarily rely on Orbiter results. I'm sure it would be just fine for a high school level project, though.

See for example GMAT for something more "serious" but free. Then you start moving into expensive software like STK Astrogator or FreeFlyer. The professional programs will have better accuracy plus optimization tools, etc. The "graphics" usually aren't as good, though. Even GMAT does not model the atmosphere below ~100 km.

 

[statickid]

If you are a real-world professional and tens of millions of dollars and your job is on the line, you aren't going to necessarily rely on Orbiter results. I'm sure it would be just fine for a high school level project, though.

On the other hand I've heard of several occasions where these same professionals have used orbiter as a visual aid for mission briefings or as animation.

 

[Ripley]

Some ESA videos made good use of Orbiter :thumbup:

 

[Urwumpe]

On the other hand I've heard of several occasions where these same professionals have used orbiter as a visual aid for mission briefings or as animation.

Yeah, that's one strength of Orbiter, especially with good assets and skilled developers, it looks much better in real time, than many blood-less ray-tracing renderings .

 

[Jumper_001]

Certainly with the callback functions for coefficient of lift and coefficient of drag, re-entry aerodynamics could be as complicated as the add-on developer desires (or not).

 

[boogabooga]

Certainly with the callback functions for coefficient of lift and coefficient of drag, re-entry aerodynamics could be as complicated as the add-on developer desires (or not).

I'm skeptical.

I've just learning the sdk, but one issue I see right away is Orbiter AFAIK is assuming a constant gamma (ratio of specific heats) for an atmosphere. Gamma actually has temperature and species dependencies that come into play, especially during re-entry.

I don't know if there is a work-around, but just having call-backs to aerodynamic coefficients is not good enough if they are not handled correctly by the core.

 

[NukeET]

Some ESA videos made good use of Orbiter :thumbup:

Which ones? :blink:

 

[Ripley]

This one for example, which credits:

Special Thanks to:
...
Martin Schweiger (for use of his Orbiter software: http://orbit.medphys.ucl.ac.uk)
...