Getting to Mars

[dcsmokey]

Is there a way to get to Mars in the Deltaglider without using Transx or the other one people use - can't even think of the name since my head exploded about an hour ago.

Look, I'm a smart guy - but i cannot get to mars with either of these two MFDs. I've read every tutorial, done everything step by step, but i cannot do anything but go to the moon and back - and i do that using the Align, and Transfer MFDs - and i have a crazier method to get back to Earth using only the Orbit MFD.

So please, someone, help me get to Mars at least.

Thanks

 

[Woo482]

to this Forum. I dont think you would be able to reach Mars with out TransX

 

[EJ316]

Yeah it'll be pretty hard to do without TransX but it's not impossible. I guess you just use the same method as the one you used to get to the moon, but having said that I now realise you probably won't be able to get anywhere near enough to be captured.

What problems do you have with the TransX tutorials and such?

 

[cjp]

Is there a way to get to Mars in the Deltaglider without using Transx or the other one people use - can't even think of the name since my head exploded about an hour ago.

Look, I'm a smart guy - but i cannot get to mars with either of these two MFDs. I've read every tutorial, done everything step by step, but i cannot do anything but go to the moon and back - and i do that using the Align, and Transfer MFDs - and i have a crazier method to get back to Earth using only the Orbit MFD.

So please, someone, help me get to Mars at least.

Thanks

Trying to get to Mars without TransX sounds a bit like trying to fly without wings. Maybe not impossible, but unusual, and probably complicated.

But first of all: which tutorials did you use, and where did you get stuck? I learned TransX through its manual ("Manual for TransX V3.0 MFD"), but maybe there are better tutorials.

My flight to Mars usually looks like this:

Step A: planning

1. Start at earth surface
2. Make the Hohmann transfer planning in TransX MFD. Bring the target orbit closer than 1Gm to Mars.
3. Rotate the orbital plane in the first stage of the plan to get a launch heading close to 90 degrees (may require some days of time acceleration to find the optimum)
4. Wait on the surface (time acceleration) until a few days before the departure date

Step B: departure

1. Fine-tune the orbital plane in the first stage of the plan
2. Wait until the indicated launch heading in TransX is close to 90 degrees
3. Switch to Surface and Orbit MFD and launch into circular LEO (Low Earth Orbit)
4. Switch back to TransX, set the PeD to the radius of the current orbit, and fine-tune the orbital plane to match the current plane as closely as possible
5. Do an orbital change burn to match the current plane to the orbital plane in TransX as closely as possible
6. Wait until you are a bit before the earth departure burn point (maybe 10 degrees, or about 150 seconds, depending on the delta-v and the vehicle)
7. Start the ejection burn
8. The most accurate indication of when to stop the burn is the second stage of the plan in TransX, where the yellow dashed line should match the planned orbit. Here, it is also visible whether you should steer a bit more to the left or to the right during the burn.
9. After the ejection burn, wait until TransX indicates we've left earth.

Step C: interplanetary space

1. This is all about course corrections. I usually do the first one right after leaving earth, a second one about halfway, and two or three more when I feel I need them.
2. Each course correction is done with Manoevre mode. Try planning a burn with as little delta-v as possible that brings your path as close to Mars as possible.
3. Early corrections cost less fuel, but it makes no sense to make them very accurate. The closer you get to Mars, the more accurate you want to be.

Step D: arriving

1. Enable Orbit MFD to see how large Mars' gravity contribution is. And don't forget to reduce time acceleration.
2. Actually, we don't need TransX anymore from this point on.

 

[EJ316]

If you print of the above tutorial and know the buttons to use in TransX, this is pretty much foolproof. I'll admit I'm not great with it, and usually I'm pretty far away from my target planet, but it just takes practice I guess.

Good Luck!

 

[flytandem]

Don't sweat not understanding TransX or IMFD. I just about went bonkers trying to get TransX. I eventually did get it, but I have never spent the time to learn IMFD yet.

Yes you can drive all around the solar system simply with Transfer and Align and Orbit. It's somewhat wasteful in fuel but it works. The reason it's wasteful is that it gives somewhat false readings of the end result and has a low resultion so you will have to do a few mid course corrections while transferring between planets.

Method:
try the deltaglider Mk IV in orbit scenario.
-after scenario starts, turn prograde and burn until you have an orbit that will -escape Earth and then perhaps add another 1000 m/s so you escape quicker.
-advance time until your orbit around the sun shows the sun influence above .80 (the number in the lower center in Orbit MFD)
-Now you can use Transfer to set up a hypothetical burn to target Mars.
-After that burn look at Align MFD and burn to get the alignment so a node is ballpark visually somewhere near where you will intercept Mars.
-Advance time until you are about 2/3rds the way to Mars and use orbit reference Mars. Manually set the Orbit HUD reference (control R) to Mars and turn to prograde direction. Use the LIN up/down and side/side to reduce the Pe to hit Mars. It'll keep wandering because you are still being affected by the sun more than Mars.
-Advance to 1/3 of what distance is left and do another correction same as above and this time consider how close to the surface and the inclination so you can arrive with an aerobrake.

I used the above method my first few days with orbiter. It worked to find my way to every planet and moon in the base package but did require unlimited fuel to go planet to planet with an orbit insert at each. It allowed me to get a good feel for the motions involved which gave a good understanding to begin using TransX to fine tune the burns which in turn allowed turning off unlimited fuel. And life just got better and better.

cjp, Since I'm here, I am wondering what you mean in your tutorial by...

Step B: departure

1. Fine-tune the orbital plane in the first stage of the plan
2. Wait until the indicated launch heading in TransX is close to 90 degrees

 

[dcsmokey]

Thanks for all the suggestions - I'll try them all

I'll tell you this, I've been flying Orbiter since early 2004 - that's how bad I am lol still haven't reached Mars in all that time lol

 

[Jarvitä]

Just use IMFD, it has a far more intuitive interface. It can't do slingshots and more complex burns, but it can get you to Mars just the same.

 

[Linguofreak]

A pair of questions:

1. What part of the process with TransX is tripping you up?

2. What parts of the interface don't you understand?

There's alot of overlap between the two questions, but one or the other might be easier to answer, so I'm asking them both.

 

[dcsmokey]

Well, first from reading these posts, I discovered you HAVE to be on Earth when you start the TransX process. Let me retry the process and see where I get.

I've never gotten past setting up the ejection burn. Once I burn I just go and go and nothing is changing on the MFD to tell me what to do next.

I got to Mars once, about a week ago, but i think now it was a fluke as i can't recreate what I did. LOL

 

[Linguofreak]

Well, first from reading these posts, I discovered you HAVE to be on Earth when you start the TransX process. Let me retry the process and see where I get.

Actually you don't have to be on Earth. I've flown from LEO to Mars using TransX many times.

I've never gotten past setting up the ejection burn. Once I burn I just go and go and nothing is changing on the MFD to tell me what to do next.

I got to Mars once, about a week ago, but i think now it was a fluke as i can't recreate what I did. LOL

If you got to Mars once, you've probably made other flyby's that weren't close enough for you to realize that you'd gotten so close, but that were very close compared to the distance between planets. It seems like you need to learn how to tell when you need to make a course correction, and how to do one.


-----Post Added-----

Each course correction is done with Manoevre mode. Try planning a burn with as little delta-v as possible that brings your path as close to Mars as possible.

Actually I don't use manouver mode for course corrections. It always drove me batty trying to figure it out when I was learning to use TransX. What I do is just to set "Intercept with" to "focus" (or use encounter MFD), orient myself prograde, hit killrot to turn off the prograde AP (I find that with the DG trying to use translation thrusters with an autopilot on tends to cause undesireable rotations), and then start playing with my translation thrusters. I'll make a couple short burns on each axis and see which one causes the closest approach distance to change the fastest. I'll burn on that axis in whichever direction causes the closest approach distance to go down until the closest approach distance stops going down. Then I'll choose another axis and repeat the process until I'm satisfied with the closest approach distance. Maybe not the most efficient use of RCS fuel, but it works. I've since learned to use maneuver mode for other things, where I find that it really helps, but I still don't use it for course corrections. It's just so easy to do them by feel.

 

[cjp]

cjp, Since I'm here, I am wondering what you mean in your tutorial by...

Step B: departure

1. Fine-tune the orbital plane in the first stage of the plan
2. Wait until the indicated launch heading in TransX is close to 90 degrees

1. You've already set up a nice orbital plane in the planning, but that was several simulation-months ago, so maybe it isn't entirely accurate anymore. Basically, you just redo the last step of the planning, but you use the result of the planning as a starting point. In other words: fine-tuning. OTOH, I think you can usually get away with not doing this step.
2. There's only one point in a 24-hour period where the launch heading in TransX MFD indicator says 90 degrees. This is when your launch base is inside the planned orbital plane. You should wait for this moment, and then launch with a heading of 90 degrees. If somehow the indicator never becomes 90 degrees (but e.g. flips from 87 degrees to 93 degrees), launch into the heading indicated by TransX when it's closest to 90 degrees.

We're doing this 90 degree thing for fuel efficiency only, so if you want to practice navigation, you can make life a bit easier by using a DG with unlimited fuel. Then, any launch heading will do, as long as it's the one indicated by TransX.

Actually I don't use manouver mode for course corrections. It always drove me batty trying to figure it out when I was learning to use TransX. What I do is [..] start playing with my translation thrusters. [..] It's just so easy to do them by feel.

Using Maneuver mode is very similar to 'trying all linear RCS thrusters'. The only difference is you're now experimenting with planned burns instead of actual burns, so it saves some fuel. The prograde / outward / change plane directions in TransX are equivalent to the three linear RCS directions.
Usually, I have a second TransX opened in the other MFD window, set to the last (approach) stage of the plan, to have a detailed view of how close I will get to Mars.

My experience is that prograde changes work best when you're far away from Mars, while outward and plane change directions work best when you're closer to Mars (say, less than 1/4 orbit).

Another tip: try flying to Jupiter with TransX first. My experience is that reaching Jupiter accurately is a lot easier, and often hardly requires course corrections. Use this to develop your skills and accuracy, and then try to go to Mars.

A final tip: TransX is supposed to give you a map that tells you when you're about to reach Mars. When you're close, open Orbit MFD in the other MFD window, and set its REF to Mars. You're more familiar to Orbit MFD, so you can use it this way to see how close you actually are to Mars.

If you really don't mind to cheat, and have unlimited fuel, you can just do a retrograde burn when Orbit MFD tells you you've reached the closest point to Mars. Reduce all speed w.r.t. Mars. and then point the nose towards Mars and accelerate towards it. You probably need to repeat this several times, especially if you're initially far away from Mars. In the end, it will get you as close to Mars as you want. Don't forget to brace for impact.

 

[flytandem]

1. You've already set up a nice orbital plane in the planning, but that was several simulation-months ago, so maybe it isn't entirely accurate anymore. Basically, you just redo the last step of the planning, but you use the result of the planning as a starting point. In other words: fine-tuning. OTOH, I think you can usually get away with not doing this step.

So then it's your description of the planning that seems unclear. Could you elaborate on exactly what one does to set up a nice orbital plane. The way I do it is more involved than just swinging the orbital plane around. Perhaps you have found a way that is an easier method.

 

[HiPotOk1978]

I have always liked Interplanetary MFD (IMFD) cause it seems more simple to me. I am planning on creating a scenario and a recording and a PDF to describe the function of IMFD to fly to Mars, flying around Jupiter space.. Matter of fact, I think I will do this now...

 

[dcsmokey]

Bless you

 

[T.Neo]

I just tried to fly to Mars with the MRO addon. I rewound after missing a correction manouver, which went fine, but, afterwards, Orbiter froze up and CTDed. I guess that's the Probe punishing me for my non-adherance to realism.

 

[cjp]

So then it's your description of the planning that seems unclear. Could you elaborate on exactly what one does to set up a nice orbital plane. The way I do it is more involved than just swinging the orbital plane around. Perhaps you have found a way that is an easier method.

I think the variable is called "Ej. Orientation" in TransX. This is the only variable that needs to be changed to change the orbital plane around the earth of the eject stage of the plan. The goal is to allow a 90 degree launch heading; usually there is only a single moment in a day that allows for this. So, during a day, you pick several moments, and on each moment you vary Ej. Orientation to try to get a 90 degree launch heading. With a bit of practice, you'll find the right combination of orbital plane and launch time of the day.

 

[flytandem]

Yes the Eject Orientation is the name of the adjustment. This is a white (or gray) line. It represents the axis of intersect between your orbit, (if you fell through the earth from your current surface location), and the orbit of the planned eject direction.

What I think is unclear to many is that this white line needs to be swung around over you for the launch heading to have any validity. I think a good change to TransX would be to have the launch heading value either disappear or turn red when the line is not close to your position. It should then appear or turn green when you have the white line near you. In essence then the launch heading would only appear when you are starting out at a node and therefore in plane with the planned parking orbit.

The launch decision (choosing when to launch and what heading) is then to keep the line over you by adjustments of the Ej Orientation, as you warp ahead at 100 or maybe 1000 for short bursts, and as you do this keep glancing at the launch heading. As it approaches a full easterly heading (090) then slow to real time and launch to the heading indicated.

Sometimes it never allows a full 90 easterly heading. And there would in theory on rare occasion be the opportunity to be at a location on the Earth where you could launch any direction you like and it would be correct. Ever noticed how you sometimes can adjust the "Ej. Or'" and over a large adjustment range the line sits over you and only for a short range of adjustment it swings the white line a full 180.

There would actually be 2 times a day when a most easterly heading is available since the line can be swung a full 360 degrees of choice. You can place either end of the white line over you. Each end will have 1 opportunity per day to be most easterly.

A good idea is to have in the MFD refresh rate set to .01 second so TransX responds rapidly to adjustments.

 

[dcsmokey]

So I tried IMFD and the following suggestion:

This is for going to the moon
1. First you get a Deltaglider IV with unlimited fuel docked to the ISS.
2. Then open up IMFD
3. Press menu
4. Press Course
5. Press set on orbit eject
6. Press target
7. Type moon (press enter on your keyboard after this)
8. Press the PG button on the left
9. Press AB completely on the right bottom
10. wait untill the countdown has finished and your engines stop
11. Repeat step 9 a few times during the travel
For going to mars this is exactly the same except for this
1. Between 3 and 4 press orbit eject
2. In orbit eject press PG
3. Press AB
4. Open orbit MFD on your other screen and wait untill the G at the bottom has lowered to 0.49
5. Repeat 4/5/6/7(instead of moon, mars ofcourse)8/9/10/11


Even this doesn't work for me - I tried going to the moon first and it crashed me into Earth during the intial burn.

Maybe I'm just a Moon guy and the planets are for others lol


-----Post Added-----


OK, I tried the above method again, and making some adjustments on how I did a few things, I made it to the moon, with little difficulty. Of course, the moon, that's easy

Off to try Mars now.

 

[Woo482]

Mars works if you follow that but last time I tried the Orbit Eject program I crashed so it Might be better to do that part you self