Earth to Mars, Transfer MFD vs Trans X

[Kevin James]

Alright, I've been at this for about 2 weeks now and I have a few questions:

How do I get to Mars from Earth?

I've followed all the the various rules in the manual(s), all the various tutorials (Manual for TransX 3.0, Deep
Space/Interplanetary flight) to no avail.  

My best effort is passing within 500M of Mars, only to watch it sail by.  I've done all the low Earth orbit, trans lunar
stuff...but deep space navigation seems to be beyond my mental capabilities.  As my parents spent all that money on
my college education (and not to mention my employer), I find that a bit disturbing.

I guess what I'm asking is if I'm the only one having these problems...I've attempted Duncan's tutorials to the letter
only to find some relevant piece of information missing.  Is there something at the conceptual level I'm missing?

PRIMARY ISSUES: TransX
-----------------
When do I start the ejection burn?
Why does TransX allow me to select MJD's that have passed?
Why does the documentation call the views by number (view 1, 2 or 3)...and what does that mean in english?
Escape plan variables?  In theory I understand what is being attempted, but how does it manifest in the sim?
Manoevre Mode?  What the h*ll is this?

PRIMARY ISSUES: Transfer MFD
---------------------
Why is there no change in DV once  you begin the burn, for any target other than the moon?  I read the bit
about "changing the src to ship" prior but that seems to destroy my value for DV?
Can you use Transfer MFD to get from the moon to the earth?

If you use the default orbiter instruments for an earth to mars trip (http://www.orbitermars.co.uk/oldindex.htm), why
can I not duplicate the results from the enclosed scenario? (http://www.orbitermars.co.uk/beforego.htm)

Sorry if I'm a bit...abrupt, just getting frustrated.

Blacknight

[DocHoliday]

Heh, I'm not to big on TransX either

Try Interplanetary MFD instead. It's a slightly less complicated that TransX (with all it's stages and all), but can also
do less. But for Mars it is probably more convenient

On TransferMFD. Make sure you set your REFerence to Sun and TARget to Mars. Maybe that's the reason for the
problem.

Hehe, don't worry, you'll get the hang of it. It's just that interplanetary flying is a little bit of art too

[Simonpro_2]

The problem with using imfd as an introduction to transx is the fact that you get used to imfd and end up not wanting
to use transx, which gives you real headaches when you come to plan difficult flights

I would suggest downloading every transx tutorial in sight and just trying as hard as you can to get to mars, you'll
get there

And dont use transfermfd for getting to mars, managing to do it using transfer mfd is big and clever (:p) but it isnt
worth the hasstle, TBH.

[DocHoliday]

I know That's why I still can't use TransX properly even though in theory I know what should be done..

You really should write a tutorial on the subject

[Simonpro_2]

Hehe, got about 1e403 other things to do, but if i get sufficiently bored waiting around in airports then ill give it a
go :p

[Kevin James]

Just for the record guys...I did get to Mars using TransX

I'm experiementing with IMFD now and find it an interesting concept, but sometimes get some odd results.  Is there
any *better/additional* documentation for IMFD?

[AphelionHellion]

Yay, I finally did it!!!!
Flew the DGIII from Earth to Mars with TransX, and even though my ejection burn timing was off, TransX has that very
handy closest approach stat which made corrections easy.
I got in close enough that I was able to slip right into a 3-orbit-aerobrake, too, using the IMFD aerobrake program.
Now that's what I call fun

I still have no idea what half that transX stuff does, but at least I can use it
Of course I had to print out about 30 or so pages worth of tutorials to crack it, but hey, we can always grow more
trees



Post Edited ( 07-27-04 11:33 )

[AphelionHellion]

Hmm - one thing I might add to this discussion as a warning to new TransXers: You might not want to be TOO
accurate in some cases; particularly when leaving your computer for awhile.  

Just now I used transX to get from Callisto to Io. It worked great! In fact I smacked right into Io at about 5 kilometers
per second I honestly don't think I could have been off perfect-center by more than 6 klicks.
Using the default transfer MFD I'd wind up a couple megameters away at periapsis and from there you have plenty of
time to lower your orbit around the target planet... In this case I diverted my attention for a few minutes and by the
time I realized what was happening I only had a few hundred miles to slow down from that speed. Needless to say I
didn't make it
And this was the Shuttle A2, so it appropriately enough broke into pieces

[DocHoliday]

heheh, sounds like you guys will soon become local experts on the subject. I haven't actually flown Orbiter in days
now so I hint a short tutorial once you get around it. More of a checklist so us lazy guys can get into the game too..

[Pierre_le]

i did succesful trips to mars using native transferMFD & syncMFD & alignMFD & burntimeMFD
set up your intersection in transfer, write down your Dv (about 3000m.s-1) and switch to self source ("x"), or just look
at the little line rotating around earth & actual velocity in orbitMFD. your ship head perpendicular to this line.
start burn before the eject point until Dv reach 0, or v=initial_v+Dv . wait for escape earth g field. switch to syncMFD
and correct your course to intersect mars with a Dt min near 0s (it start to fluctuate a bit during rest of the travel but
dont care). you should burn a little prograde and +90° on your right to proceed.

dont forget to check orbit plane alignment at every step. it must be 0.00°