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Mats_J

Why 90

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HiWhen you select any of the prograde, retrograde, normal or antinormal attitudes with the ShuttleAtlantis it always rolls over to a 90

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Orbiter does that with the other ships too. Hopefully, the autopilot will become configurable in a future version. I would also like it to be able to maintain "cargo bay down" even with the DeltaGlider so that I can see the surface better while using the nice panels.Peter http://bfu.avsim.net/sigpics/PeterR.gifBFU Forums ModeratorRenegade/Seawolf Design Group (RSDG)"Orbiter: The sky's no longer the limit"[table border=2 cellpadding=0 cellspacing=1][tr][td][table border=0 cellpadding=8 cellspacing=0][tr][td bgcolor=#6f0000]http://bfu.avsim.net/sigpics/logo75t.gif[/td][td align="center" bgcolor=#FFFFF6]Bush Flying Unlimited"At home in the wild"Looking for adventure? Come join us! * [link:bfu.avsim.net|Web Site] * [link:www.cafepress.com/bfu,bfu2,bfu3,bfu4|BFU Store] * [link:bfu.avsim.net/join.htm]Join!][/td][/tr][/table][/td][/tr][/table

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Ah thanks Peter,So it is a little flaw in the attitude controller? Glad it's just a simulation! ;-)Regards,

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This is pure speculation, but here is my theory:I think it's because nearly all spacecraft are symmetrical if you look at it from directly above, but quite alot arent symmetrical when virewed from the side (centre of gravity). You'll notice some of the spacecrafts has an tendency to roll when you yaw. This comes into play when you are doing a pro (or retro) burn and you adjust inclination at same time as you will vary from the prograde course. If you were level and your rcs thrusters weren't placed exactly according to center of gravity you'll roll alittle and you would have one mor dimension to take of as you are adjusting your heading. This does also make it possible to use a two axis joystick to control a burn. Another reason could be the thrusers might not be of the same size (effect) in all directions, you might have stronger and better thrusters for controlling pitch as this is the most demanding control axis (during descent and particulary ascent), you'll have better heading control if you use the pitch thrusters. The autopilot is common to most of the spacecrafts, so thats probably why it applies to most of the spacecrafts.

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It's not a flaw, per se, or a fancy implementation of thermodynamics that I'm aware of. Riding with your head pointing north and your seat pointing south may have been why 90-degrees was chosen rather than some other angle but I believe that the current operation is just a case of the autopilot system being simple in its current state. There have been discussions about ship-specific autopilot parameters and such. Every version of Orbiter gets better so it's just a matter of time. :-)Peter http://bfu.avsim.net/sigpics/PeterR.gifBFU Forums ModeratorRenegade/Seawolf Design Group (RSDG)

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