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OrbiterSim | FAQ | Acronyms | Add-ons | Screen Shots | Orbiter Tutorials Direct Flight Method of Interplanetary Travel I've set out to do futuristic flights more realistically. I realize flying my soup up ships from Earth to Mars within a few hours would in reality squash my flesh like a bug on the windshield. But manned flights to Mars or outer planets in microgravity is not sensible. I know we have Men and Women on the ISS for months at a time. Yet what we have learned is that physiologically we are not meant to live this way. Also I don't see us coasting our way to the outer planets in hibernation sleeping off the years. This is not at all sensible either. So I don't believe futuristic manned flights are going to be fuel efficient ones. I foresee them to be constant acceleration flights rather then constant velocity flights. So now I can fly a futuristic and realistic flight from Earth to Moon in less then four hours. A trip from Earth to Mars can be accomplished in just over a weeks time. This was using a constant acceleration of 9.8 m/s/s ( 1 G ). A very comfortable way to travel since everyone can walk around the ship with their feet firmly planted on the floor. Therefore I use the direct flight method. This gets men to locations around the solar system in a reasonable amount of time while supporting life functions at 1G. Very comfortable way to travel. Way to do it Download the Attitude MFD. This MFD will point your ship to any target in the solar system. So lets say I'm at Mars and I set my Attitude MFD to Io, one of Jupiter's moons. I would then launch from Mars and once I'm out of the atmosphere, pitch and yaw toward Io using the Attitude MFD. With the Surface MFD up on the other side I will begin a constant thrust of 9.8 m/s/s. At this point everyone on board ship can unbuckle and continue normal living. I would then take note of the distance to Io display in the MFD. Lets say its 500AU. Fly the ship to less then half that distance say 275AU. You will be increasing speed the whole time. Note: The Attitude MFD displays AU with very large numbers. It may be the dicimal place is off in this MFD. You can check these numbers against the TransX MFD to verify. Everyone buckle up we are about to cut engines and have a few moments of weightlessness while we turn the ship around. Yaw to 180, or just fire retro thrust to 9.8 m/s/s. You may notice that the surface MFD doesn't always know what the reference is out in space so I use my main engine thrust gage at the top left corner of the HUD. This is the gage right below the fuel gage and wouldn't you know it, this displays acceleration in m/s/s. Now we will be decreasing our speed for the second half of the journey. Only I want to arrive at a relative stop some 50AU out( by Attitude MFD display ). Now some time has passed since I left Mars and Io isn't where it was anymore. Note: I am hoping someone will build a direct flight MFD that will calculate where a planet will be after a certain time lapse. Then we can point to where it will be in time just like we do with Transfer MFD. The 50AU gives me a buffer to repoint and make a correction flight without blowing past my target. Flying from Earth to Moon only take 4 hours very little correction is needed. Also Earth to Mars takes only a little over a week so only a small correction is needed here. ------------------------- The mathematical formulae for figuring out travel times at 1 gee of acceleration (and deceleration is this. T = time in hours O.K. at 50AU I would reset the pitch and yaw to Io and finish my trip. Make sure you slow your ship down in time. You may find yourself blowing past the target planet with not enough energy to stop. Remember you don't want to plaster everyone against the ship wall at 5 Gees for hours on end trying to stop that puppy. If you do pass up your target and are not able to slow down in time you could join the ranks of "LOST IN SPACE" One more thing the Attitude MFD shows the relative velocity to target. This is very handy but is not the right place to look if you want to come to a complete stop in space. To come to a halt use the retograde autopilot " ]" and fire until it turns prograde. Be careful not to let the autopilot around, so turn it off once oriented. Once I'm near my target I use the Orbit MFD to help me get pulled in. Now for those of you who want to slip into orbit when approaching a planet/moon. I use the Orbit MFD when coming upon a planet. Hopefully you come close enough that your ship is in the planets 'Sphere of Influence', SOI. You can tell by looking at your HUD in Orbit mode. It will read [Sun] if the sun is still the major body or [PlanetX] if planetX is. You may manually select by using Ctrl R and typing the planet name in. Now with the target planet as the major influence and selected in the HUD you are ready to begin. Use the retrograde autopilot to turn away from your direction of travel and thrust towards it. This will slow your craft down to enter the proper orbit velocity. Lets say your craft has a velocity of 25k and orbit velocity is around 7k (such as it is in Low Earth Orbit) this may take some time. If your craft is traveling to fast you may leave the planet SOI before you can be capture by it. So try to slow your approach to manageable speeds in advance. When your craft gets close to orbit velocity you will notice the green line in the Orbit MFD turn elliptical. Keep thrusting until you get a circular orbit. At this point you want to watch your PeD, you could get to close and smack right into the planet. The thing to do is cut engines turn prograde and make sure the target velocity vector indicator isn't pointed right at the planet surface. You now can make fine adjustments to get the PeD to where ever you want it. This technique needs to be improved upon, but this is how I do it for now. I'm sure the more I do this the I'll find more accurate methods and tools. Good bye waiting for months to get anywhere. Related Links: OrbiterSim | FAQ | Acronyms | Add-ons | Screen Shots | Orbiter Tutorials
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