Earth to Mars.. Sun keeps sucking up my ship!!!

[caningo]

Hello everyone,

I've been playing Orbiter for like a week or two now and I am trying my first trip to Mars. :lol:

I am using as reference Ch. 6 of Go Fly in Space and have the latest version of IMFD (5.1m).

This is what I do:

1) Course Program
a) tgt mars
b) select Off-Plane Intercept
c) adjust arrival MJD until oV is minimized

2) Surface Launch
a) synchronize with Course program
b) wait until Bad plane msg goes away and take off to attain an orbit of 150km.

** I usually don't let Rinc be 0.00 deg, maybe like 0.2 deg or something. Don't know if it makes a difference or not.

3) Orbit-Eject
a) synchronize with Course program
b) wait for BT to get aroiund 60s and press AB.
c) wait for have a nice voyage message.

4) Course Program
a) Src -> self

5) Map Program
a) Ref -> mars
b) Cnt -> self
c) Disp PG & SOI

After this, the tutorial instructs you to time warp until you reach the midpoint of your trajectory. There you are supposed to make a correction.

BUT...

When I time warp to the mid-point my trajectory seems to veer into the sun, as if it were sucking up my ship... I'm halfway to mars but my trajectory intercepts mercury's orbit for example.

So I really don't know what it is, and the tutorial doesn't seem to have that problem.

Does anyone have an idea of what it might be?

Is the realism settings? I have non-spherical gravity sources and gravity-gradient torque activated.

Thanks for all your help.

 

[ar81]

I would suggest you to download IMFD 4.2.1 and use this tutorial
[ame="http://www.orbithangar.com/searchid.php?ID=3403"]Tutorial: Concepts for Interplanetary MFD 4.2.1[/ame]

IMFD 5.1x is still under construction.

The tutorial explains you what you are doing and why, so you are not just pressing buttons, but you could be able to decide what to do.

Interplanetary travel requires you to master concepts used to rendezvous and dock a space station in orbit, so if you haven't done that I would advise to try docking first.

 

[polaris149Tiberius]

Cool!

Cool!

I am doing the same flight. I think you will want to note that flying to mars is something NASA has done reciently with the Pheonix mission. It was a great success and it includes a landing on Mars.
If you want some information on thier flight you can find it here.
It has a window of launch. I dont know if this will help your current flight but I am trying to fly the mission from the window Pheonix took.

This window should be an optimum window for getting to Mars with the least ammount of energy needed.

That said, I dont use the surface launch program. I use Orbit Eject after getting into orbit.

So, I find my window using scenario editor. ( I have found a window on UT Jun 13th 20:30:00 2001 which is a day when the earth is closest to Mars) (You can find other windows using IMFD Map. You want a day, month, year when your close to Mars to launch)
Then launch in an eastern launch (this uses the earth's rotation as a sort of catapult), get into an LEO at whatever altitude.
Then I set the IMFD Cours Intercept program to find the target Mars.
Offset Disabled
Now here is where it gets tricky. I calculated in GET what a 9 month flight would be and it comes to about 6480 hours.(24h /1 day X 30 days X 9 months = 6480 hours. But setting this GET has an increadible Tot dV of about 14k so what I did was advance the Tin GET to when the PeA of my flight reaches a point where Mars is at its periapsis to earth. This came to about GET 10979:05:55 which gave a dV tot of about 15k
Thats alot of dV but its alot less than if we were to launch for a GET arrival of 6480 hours.
Bring up LMFD and share it with RMFD and then set the type of ejection to Course. You should see the earth and a purple curved line. You can set AB if your in an orbit heading easterly. I dont know if the DG can make it on the fuel it has left after launch but again I am just checking this out too.
Halfway there you can do a plane approach burn.
I dont know if this will help but this is how I do it.

 

[polaris149Tiberius]

Why IMFD 4.2.1?

Why IMFD 4.2.1?

ar81, I dont think IMFD 5.1m is still under construction. There was 1 bug last month and it has been fixed. IMFD 5.1m has more functionallity than 4.2.1 and is more user friendly in my opinion. Your tutorial is awesome by the way but, couldnt you make a tutorial for the latest version of IMFD? 5.1m? That is what the poster of this thread wanted and it is the latest stable version.

If noone else will do it I suppose I could eventually. I will have to master a Mars flight and then test it extensively but I suppose this is what more and more people are interested in.
I have been using IMFD 5.1m to do all sorts of things since its release last month and it is plenty stable.

IMFD 5.1m works like a charm. Tutorials for legacy versions of IMFD will eventually prove to be obsolete as well. There may come a time when IMFD 4.2.1 is not available and we will be stuck with older tutorials that dont work for the current versions of IMFD.

I will only publish tutorials for the latest versions of addons because I have seen all too many times that authors cant keep older versions available to the public.
Ill work on a tutorial for the latest and greatest version of IMFD for those of us that are interested in using it as soon as I can.

 

[Urwumpe]

I also have no problems with 5.1 since the g release. It had often been even too effective.

 

[toodoo213]

another pioneer anomaly lol?

 

[toodoo213]

which version of IMFD are u using?

 

[TeddyJohn]

I use this method. http://solo.dc3.com/orbiter/video/EuropaToCallisto/
It works well for me to get to any planet. I am currently using IMFD 5.1h.
I also use TransX to find my Closest Approach and eject date.

 

[polaris149Tiberius]

I use this method. http://solo.dc3.com/orbiter/video/EuropaToCallisto/
It works well for me to get to any planet. I am currently using IMFD 5.1h.
I also use TransX to find my Closest Approach and eject date.

I have used these scenarios too.
TeddyJohn, could you explain how you decide what your interception time is (GET) to get to Mars. The EuropaToCallisto scenarios show how to set up IMFD to get to Callisto, but the transfer time is much greater to go to Mars. How do you figure your coast time for Earth to Mars? Or do you just use IMFD's recommended TIn GET?

Thanks in advance.

 

[TeddyJohn]

I have used these scenarios too.
TeddyJohn, could you explain how you decide what your interception time is (GET) to get to Mars. The EuropaToCallisto scenarios show how to set up IMFD to get to Callisto, but the transfer time is much greater to go to Mars. How do you figure your coast time for Earth to Mars? Or do you just use IMFD's recommended TIn GET?

Thanks in advance.

Once I have set my eject date with scenario editor, I align planes and open IMFD. Under configuration, I change GET to MJD. Then set course (I use source plane transfer because it requires the least amount of delta v. Once outside SOI and when dv has reached it's minimum, just hit AutoBurn. At node (watch Tn) do another AutoBurn (be sure Prep PlC is highlighted) . The rest is IMFD procedure. (planet approach,orbit insert)

 

[polaris149Tiberius]

Yes but...

Yes but...

I have seen the video too. This is exactly what the proceedure tells you to do. But, why switch the date timming to MJD from GET? The are equivilants to eachother. What doest this step do for us?

I left mine as GET and then I was able to set the GET intercept time to exactly 9 months which NASA claims is thier manned mission Mission Elapsed Time (or MET) GET I think is about the same as MET.
Can somone here shed some light on why the tutorial says to use MJD instead of GET?
And,...
What is the difference between MET and GET?
Thanks in advance.

 

[TeddyJohn]

Timer StartMJD

specifies the start date of the GET

timer. If the date is not valid GET feature will be​

automatically disabled. This is the METHOD I use regardless of the scenario or ship. I let IMFD calculate the transfer.

​

 

[caningo]

I'm back

Hi everyone,

It's been a long time I haven't responded to this thread. Been kinda busy with summer school and other things. :study:

I finally got to do some orbiteering yesterday and I redid the flight from earth to mars. The problem turned out to be that I wasn't using the off-axis mode when i did my orbit eject burn from earth. This somehow totally screwed up my trajectory and contributed to my ship getting attracted by the sun.

Another thing that helped was doing frequent MCC burns. This way the path didn't screw up and end up taking me somewhere else!

Now that the mars trip is done, I am focusing on doing earth to moon, moon to earth trips. I am however having some issues with the IMFD here. Please check out my newest thread with regards to this.

For all those that helped me here and suggested thank you very much!

I would suggest you to download IMFD 4.2.1 and use this tutorial
http://www.orbithangar.com/searchid.php?ID=3403

IMFD 5.1x is still under construction.

The tutorial explains you what you are doing and why, so you are not just pressing buttons, but you could be able to decide what to do.

Interplanetary travel requires you to master concepts used to rendezvous and dock a space station in orbit, so if you haven't done that I would advise to try docking first.

Ar81 gracias un millón por esta tutoría tuya! It really helped me a lot in understanding IMFD better and why I am doing the things I do when I enter values and press buttons. I keep using it for reference every now and then.

Cool!

I am doing the same flight. I think you will want to note that flying to mars is something NASA has done reciently with the Pheonix mission. It was a great success and it includes a landing on Mars.
If you want some information on thier flight you can find it here.
It has a window of launch. I dont know if this will help your current flight but I am trying to fly the mission from the window Pheonix took.

This window should be an optimum window for getting to Mars with the least ammount of energy needed.

That said, I dont use the surface launch program. I use Orbit Eject after getting into orbit.

So, I find my window using scenario editor. ( I have found a window on UT Jun 13th 20:30:00 2001 which is a day when the earth is closest to Mars) (You can find other windows using IMFD Map. You want a day, month, year when your close to Mars to launch)
Then launch in an eastern launch (this uses the earth's rotation as a sort of catapult), get into an LEO at whatever altitude.
Then I set the IMFD Cours Intercept program to find the target Mars.
Offset Disabled
Now here is where it gets tricky. I calculated in GET what a 9 month flight would be and it comes to about 6480 hours.(24h /1 day X 30 days X 9 months = 6480 hours. But setting this GET has an increadible Tot dV of about 14k so what I did was advance the Tin GET to when the PeA of my flight reaches a point where Mars is at its periapsis to earth. This came to about GET 10979:05:55 which gave a dV tot of about 15k
Thats alot of dV but its alot less than if we were to launch for a GET arrival of 6480 hours.
Bring up LMFD and share it with RMFD and then set the type of ejection to Course. You should see the earth and a purple curved line. You can set AB if your in an orbit heading easterly. I dont know if the DG can make it on the fuel it has left after launch but again I am just checking this out too.
Halfway there you can do a plane approach burn.
I dont know if this will help but this is how I do it.

Polaris, I tried your method and it worked. The drawback to this however is the longer time it takes to reach Mars.... but not something that can't be overcome with a little time acceleration!

CANINGO :hotcool: