To reach other planets, i use TransX.
It is much easier than it looks, it is just like a de-orbiting and re-entry a question of pracice.
An example, i'll use the XR-2 and i want to get to Mars.
By default, the XR-2 has only a fuel capacity to get to ISS or at most the Moon.
So before getting a Mars trip, we need to use bigger reserves.
You need to edit the XR-2 properties in the file named
XR2RavenstarPrefs.cfg
located in the config folder of your Orbiter directory.
so in this file (each entries are described), look for
MainFuelISP=2and change it to
MainFuelISP=5that the explanation said to be enough for a trip to Mars.
Now the XR serie simulate oxygen being consummed by the crew, and Mars is not exactly close enough for a default setting (by default the XR-2 has enough oxygen for 14 days)
So change
LOXLoadout=1into
LOXLoadout=7enough oxygen to spend 3 years in space (should take much less to get to Mars)
Of course, after those changes your XR-2 will be a -very- lot heavier, so don't attempt a re-entry with your fuel and O2 cargo load at their fullest
In the Orbiter launcher, in the module tab make sure transX is activated (it is not by default)
Load the "Docked at ISS" scenario from the XR-2 entries.
By default in this scenario the XR-2 is not full of fuel and O2, so you need to fill them.
It's good you're docked at ISS because you can get fuel from the station.
Open the Fuel Hatch and the LOX Hatch
Once they're open, click on the external supply line button corresponding to MAIN, APU and LOX.
Once they're full they unclick themselves.
Now close the Fuel and LOX hatches
Undock from ISS
Put the APU online, close the Nose Cone and bring the APU offline again.
Use the Align Plane MFD
Press TGT -> Celestial Bodies -> More Celestial Bodies and select Mars
Wait until you (P in the MFD) are +/- coming near position DN use the to Orbit Normal+ autopilot, and when "ENGAGE THRUST ORBIT NORMAL +" flashing indicator happen, just burn, you'll see RInc being lowered.
When KILL THRUST appear again, stop burning.
Wait until you're going for position AN , use Orbit Normal - autopilot, wait until "ENGAGE THRUST ORBIT NORMAL -" appear and BURN.
Etc...etc.. until you get the RInc as close as possible to 0 (remember you can use the Translation RCS numpad6 and numpad9 to fine tune), it will mean you're now moving in Orbit while being on the same orbital plane as Mars.
Now use the TransX MFD
By default we're on Stage 1.
There's no target at the Select Target Planets/Moons
Click on the button ++ to the right until Escape is selected, the stage 1 of our Mars travel will be to actually escape Earth Orbit.
Once done, click on the button FWD to bring us to Stage 2.
Again by default nothing is selected, so click ++ until Mars is displayed.
the inner blue circle is Earth Orbit
the outer blue circle is Mars Orbit
Click the VW button to change the "Select Target Planets/Moons" to Eject Date
click Var to browse until you have Prograde Vel (velocity) in which we'll setup our prograde autopilot planning
By clicking ++ we add some prograde speed in the plan and with -- we lower it.
The increments are set to "Coarse" for tuning , we can lower the size of the increments by ADJ+ or ADJ- button for finer tuning, but for the prograde plan, let it to Coarse.
I increase until my planned trajectory (the yellow growing circle) cut Mars orbit.
It happens there :
Notice the Cl. App (rough) at 7.43G , it means that at this trajectory, our closest approach would throw us at 7.43 millions of kilometers from it !
Ouch, not really close we would just be lost so far from Mars it would not be very funny.
But notice that we have set only the prograde speed, meaning that's for immediate departure, something that would be rather silly considering where is Mars.
Now press VAR until you are on Eject Date.
Press ++ to change our eject date for the future until you see the Cl. App. decreasing.
Do not get too much more than Coarse increment.
At some point the Cl. App would increase again, get back (-- key) at your lowest Cl. App. and increase the increment from Coarse to Medium or Fine, we need to find the best date possible for the closest encounter.
For my best eject date for my plan, i found it to be there :
It would throw us at +/- 4 millions of kilometers from Mars, that's better, if we like being lost in space.
So continue to increase the date until your yellow bar catch the white bar. A bit like that :
Go back to Prograde Vel and again make it so the Cl. App got lowered, fine tune the result for best Cl. App.
Not bad, we're at 836.000 km from Mars.
Now press Var until you see "Ch Plane Vel." and fine tune to lower the Cl. App. again.
Not too bad, we're closer, 320.000 km
Play again with the prograde/eject date/ch plane vel to make the lowest Cl. App possible.
In the end a very good 21000 km from Mars (very close) for my eject date that will be
MJD 52029.1081 and we're currently at MJD 51984.7563
MJD is for Modified Julian Day
According to this website
http://heasarc.gsfc.nasa.gov/cgi-bin/Tools/xTime/xTime.plit means my current day is 16 March 2001
And the eject date for my planning will be 30 April 2001
Well, good that Orbiter comes with accelerated time
Note it's important to know that this is only the plan, reality will be different, and that's why we'll certainly a correction once or twice during the travel to Mars.
Press FWD to see the Stage 3 of our plan, in the center it's Mars and in green our planned trajectory :
Now remove any autopilot (high accelerated time + autopilot is an extremely bad idea in Orbiter) and max accelerate time until you're reaching MJD 52028, be very very very carefull to not miss and overshoot MJD 52029 or you'll be very sorry.
Now look at your Stage 3 in the TransX MFD , press BCK 2 times to get back to Stage 1
Notice the "Begin Burn" that the count until we should start burning like crazy.
Important, remember the word prograde we have used so far, it because when you will start your escape burn, you will need to be in PROGRADE autopilot.
When you will have burned well enough, the Stage1 MFD will change, you can't miss it , you're not in Orbit anymore
Note the planned trajectory in yellow, and the real one in green, that's already a bit different isn't it, and it will get worse (and so will need corrections)
Click FWD to see Stage 2, again in yellow the plan and in green our real.
That's rather big as a difference. But don't worry (too much).
Wait and wait and ... when you far from Earth, the Stage 1 MFD will change into this automatically :
So we'll miss Mars by 89 millions of kilometers, Robsoie you're the worst pilot ever !
But that's great as it's time for our first correction.
Press VW until you see "Manoeuvre Mode" that is OFF, click on ++ to set it to ON
Press VAR until you see the familiar Prograde Vel , press VAR again until you see Man. Date
Click ++ a bit to set a date for a few hours ahead, so you have time to setup the remnant of your correction planning.
We're at 52038 (9 May), so let's put this to 52039 (10 May) with a very fine tunning when pressing ++
Press VAR (or -VR) until you get back to Prograde Vel and use ++ until you get the closest approach at its lowest
Not bad, missing Mars from 89 millions of km , we get to 1.7 millions of miss.
Press VAR and get to Ch Plane Vel and fine tune to lower this number.
Play again with , don't hesitate to increase a bit the date of our maneouver, if it help to lower the distance we'll get , but keep enough time for setting up your correction.
You can play with Outward Vel too.
After making what i could, my correction plan
38000 kilometers, that's very good (remember plan and reality may not be the same anyways, we will very certainly a correction in mid flight.
Now press VW until you see this :
With the Rotation RCS (and the give some slight press of a Rotation RCS following immediately by a Killrot to help you fine tuning), put the crosshair roughly in the middle of it.
Notice the "Begin Burn" to help us now when we will start burning again to make the correction.
Do not engage any autopilot now and wait until you're ready to burn.
IMPORTANT, before burning make sure the crosshair will be roughly at the center, it will have drifted while you're waiting.
The goal during this burn will be to lower the "Delta V" to ideally 0
When you're done, press VW until you're back at the prograde/plane vel change and press VAR until you see Manoeuver ON, turn it to OFF by pressing ++
My correction was very good as it put me at 340.000 kilometers from Mars, far from the 38.000 planned, but the next correction in mid flight will certainly make it much much better.
Time to sleep, be sure you've got no autopilot engaged and go to Max acceleration time and wait a while, look at the MFD to see when you're +/- at mid flight.
And set the Manoeuver again to ON and do the exact same as we just did for another correction, because the estimated closest approach will never cease to increase due to the various gravity force applied on us by the whole cosmic floaters
In the end of the flight, don't hesitate to make another correction before Mars.
At the end of my 2nd correction( i waited only for a few days, far far from the mid flight, after i turn Manoeuver to oo, i'm planned to 66.000 km from Mars, not the best possible, but that's much better than before (you can press FWD to see Stage 3 and look where your Orbit lead you in comparison to Mars)
See this point :
Yes it's Mars.
The encounter is planned at MJD 52345 (12 March 2002) and we're at MJD 52074 (14 June 2001), so back to max acceleration, follow your trajectory and the Mars one (you can see the Earth orbit too) until your encounter to decide when to do correction and when to wait.
Important again, never use any autopilot during a max acceleration time.
After my last correction, not too far from Mars, i'm flying good with a +/- close approach of 15000 kilometers.
Time to keep on Stage 3 when you're close to Mars (look at your planned encounter date and your current date)
You'll have to use the Retrograde Autopilot and burn to build the orbit once you're in position.
Sadly it's where the game crashed on me, guess the XR2 built-in checks, scripts and functions do not like max acceleration and planets proximities and can conflicts with Orbiter own checks, scripts and functions.
It's not the first time the XR2 crash on me, even the very recent latest version from a few days ago, in such conditions.
I should have used the more stable stock Deltaglider for this little tutorial, less built-in functions but never crashed anywhere.
But in Stage 3 you should be able to see your approach to Mars, and once near, go into retrograde position and burn until you have finished building an orbit.
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Topic: Orbiter (free space flight simulator) (Read 49978 times)