Orbiter-Forum [General Question] Understanding TransX Escape plan
 Register Blogs Orbinauts List Social Groups FAQ Projects Mark Forums Read

 General Questions & Help General & Advanced Orbiter flight questions, Orbiter installation questions, to all other help topics here.

 03-22-2019, 01:50 PM #1 Nikogori Donator Understanding TransX Escape plan I've been writing orbiter tutorial for Japanese players for a few years. Now I'm thinking about giving more detailed explanation for TransX Escape plan. The problem is, there are not so many orbiter players in Japan... no one would correct me even if I made a mistake. Here is my explanation for TransX Escape plan. Please tell me if there's anything wrong. In Eject plan you can create interplanetary transfer orbit. How do we get to this transfer orbit from Earth? In this image below, red line shows the direction towards the transfer orbit from Earth. Blue curved line is a hyperbolic orbit which is parallel with transfer orbit. (Green circle is parking orbit) Red line and blue curved line are not the same but the difference is negligible compared with huge distance towards the target planet. We live in 3-dimensional space. Therefore we can rotate this hyperbolic orbit around red line. Actually there are infinitely many possible hyperbolic orbits. You can go in the desired direction from above, below and both sides of the planet. This means there's always one hyperbolic orbit passing over your launch site. If you use TransX, you can find it using Ej Orientation (Eject Orientation) function in Escape plan.
 03-22-2019, 05:21 PM #2 Ripley Tutorial translator Some years ago, THE TransX Gurus (flytandem, dgatsoulis and blixel) shared some preciously interesting infos... https://www.orbiter-forum.com/showth...96&postcount=1
 Thanked by:
 03-22-2019, 05:32 PM #3 Ajaja Orbinaut It's good. I wish I had such explanation when I tried to use TransX first time Quote: Originally Posted by Nikogori  In this image below, red line shows the direction towards the transfer orbit from Earth. They call it "outgoing asymptote direction" in NASA Quote: Originally Posted by Nikogori  This means there's always one hyperbolic orbit passing over your launch site. I think, there are two hyperbolic orbit passing over the launch site, but taking into account the planet rotation one is always more preferable than other.
 Thanked by:
 03-22-2019, 09:11 PM #4 Ajaja Orbinaut BTW, it's very easy to create illustrations for those hyperbolas with GMAT: Code: ```Create Spacecraft DefaultSC; GMAT DefaultSC.DateFormat = TAIModJulian; GMAT DefaultSC.Epoch = '21545'; GMAT DefaultSC.CoordinateSystem = EarthMJ2000Ec; GMAT DefaultSC.DisplayStateType = OutgoingAsymptote; GMAT DefaultSC.OutgoingRadPer = 7100; GMAT DefaultSC.OutgoingC3Energy = 100; GMAT DefaultSC.OutgoingRHA = 90; GMAT DefaultSC.OutgoingDHA = 0; GMAT DefaultSC.OutgoingBVAZI = 360; GMAT DefaultSC.TA = 360; Create ForceModel DefaultProp_ForceModel; GMAT DefaultProp_ForceModel.CentralBody = Earth; GMAT DefaultProp_ForceModel.PointMasses = {Earth, Jupiter, Luna, Sun}; Create Propagator DefaultProp; GMAT DefaultProp.FM = DefaultProp_ForceModel; GMAT DefaultProp.Type = RungeKutta89; Create OrbitView DefaultOrbitView; GMAT DefaultOrbitView.Add = {DefaultSC, Earth}; GMAT DefaultOrbitView.CoordinateSystem = EarthMJ2000Eq; GMAT DefaultOrbitView.DrawObject = [ true true ]; GMAT DefaultOrbitView.ViewPointReference = Earth; GMAT DefaultOrbitView.ViewPointVector = [ 100000 10000 0 ]; GMAT DefaultOrbitView.ViewDirection = Earth; GMAT DefaultOrbitView.ViewUpCoordinateSystem = EarthMJ2000Eq; GMAT DefaultOrbitView.ViewUpAxis = Z; GMAT DefaultOrbitView.EnableStars = Off; Create Variable I; BeginMissionSequence; For I = 0:30:330; GMAT DefaultSC.EarthMJ2000Ec.OutgoingBVAZI = I; Propagate BackProp DefaultProp(DefaultSC) {DefaultSC.ElapsedDays = -3}; Propagate DefaultProp(DefaultSC) {DefaultSC.ElapsedDays = 6}; Propagate BackProp DefaultProp(DefaultSC) {DefaultSC.ElapsedDays = -3}; EndFor;``` Attached Thumbnails
 Thanked by:
 03-23-2019, 02:08 AM #5 Nikogori Donator Quote: Originally Posted by Ripley  Some years ago, THE TransX Gurus (flytandem, dgatsoulis and blixel) shared some preciously interesting infos... https://www.orbiter-forum.com/showth...96&postcount=1 Test1.avi - YouTube Thank you! Actually I remember I read this thread a few years ago. I learned a lot from those videos and articles by flytandem, dgatsoulis and blixel. Maybe I should include link to these materials in my tutorial. Quote: Originally Posted by Ajaja  They call it "outgoing asymptote direction" in NASA I didn't know the "red line" has such a fancy name. Thank you! Now I need to find Japanese translation of "outgoing asymptote direction"... Quote: Originally Posted by Ajaja  I think, there are two hyperbolic orbit passing over the launch site, but taking into account the planet rotation one is always more preferable than other. Ah yes! There are always two hyperbolic orbits (one is prograde and the other is retrograde). How didn't I notice this? It's obvious in the 3rd image... Thank you so much. Quote: Originally Posted by Ajaja  BTW, it's very easy to create illustrations for those hyperbolas with GMAT: Thank you. I'm using Geogebra to draw these diagrams but that GMAT illustration looks cool! I guess I need to learn how to use it.

 Posting Rules BB code is On Smilies are On [IMG] code is On HTML code is Off You may not post new threads You may not post replies You may not post attachments You may not edit your posts
 Forum Jump User Control Panel Private Messages Subscriptions Who's Online Search Forums Forums Home Orbiter-Forum.com     Announcements     Meets & Greets Orbiter Space Flight Simulator     Orbiter Web Forum         OFMM         Orbiter Forum Space Station         Simpit Forum     General Questions & Help     MFD Questions & Help     Hardware & Software Help     Tutorials & Challenges     Orbiter SDK     Orbiter Visualization Project     Orbiter Beta » Orbiter Project Orbiter Addons     OrbitHangar Addons & Comments     Addons     Addon Development     Addon Requests     Addon Support & Bugs         Addon Developer Forums             Project Apollo - NASSP     Orbiter Lua Scripting Far Side of the Moon     Spaceflight News     Math & Physics     Astronomy & the Night Sky     Backyard Rocketry     Brighton Lounge     International Forum

All times are GMT. The time now is 04:48 PM.