Finally got around to using IMFD :)

[TachyonDriver]

All I can say is, it really is rather good! It got that lumbering old brick of a freighter (Clydesdale) out from LEO to a Lunar orbit. Why Clydesdale? Well, its RCS isn't that powerful, it's a bit slow to accelerate, but it has quite a lot of fuel. To quote Refuel MFD, its fuel tank is COLOSSAL :thumbup: I figured if IMFD can handle that, then it'll handle almost anything in the Orbiter simverse.

I've still got quite a bit to learn, but thanks to the videos from David Courtney featuring dgatsoulis, I felt inspired to sit down and give it a go. I must have done something wrong on the moon -Earth trip.. I missed the Earth.. and its SOI :rofl: :facepalm:

I'm going to try and get to Mars and back - that's the sort of journeys space freighters undertake.

There may be some out there who are against using the technology and insist on manually chasing the transfer orbit using Transfer MFD and patched trajectories, but IIRC, I've only hit Mars orbit from Earth once, way, way back (another occasion I did actually hit the planet.. It was messy!)

 

[TMac3000]

I used to be a loyal TransX'er, because I just couldn't understand IMFD. But once I figured what all those strange-looking numbers meant, and that it could orient your craft and burn the engines automatically, I defected:lol: Flying a real spacecraft is mostly automatic anyway--you just enter some numbers and hit a button (but you still have to know how to fly manually if something goes wrong). Basically, spacecraft are not so much flown, as programmed. IMFD portrays that extremely well.

Now I am running Orbiter in Linux, and using OGLA, which for the moment means no IMFD Fortunately, I discovered some TransX tutorials, also by the awesome David Courtney (does he have an OF account?), and they have inspired me to give TransX another run.

But again, I agree, IMFD is a replacement for most autopilots

 

[boogabooga]

David Courtney = Blixel

(Sorry if I outed you, but I don't think it is a secret)

Latest version of TransX has module messaging with BurnTime MFD, plus some attitude hold feature. Sort of the IMFDification of TransX :lol:

Really, the indispensable feature of IMFD is the map. Learn to use the map to your benefit.

 

[TachyonDriver]

David Courtney = Blixel

Beat me to it

 

[Tommy]

There's also the IMFD full manual and playbacks available at orbit hanger. This includes a fairly simple process to set up target intercept that can get you pretty much anywhere you want to go.

 

[Astro SG Wise]

I used to be a loyal TransX'er, because I just couldn't understand IMFD. But once I figured what all those strange-looking numbers meant, and that it could orient your craft and burn the engines automatically, I defected:lol:

Really! No way! I have only gotten to the moon twice with TransX and never made it back. So, can IMFD automatically bring me to Mars?

 

[TachyonDriver]

It seems that way - I've yet to watch the tutorial videos: Earth to Mars...

 

[TMac3000]

Really! No way! I have only gotten to the moon twice with TransX and never made it back. So, can IMFD automatically bring me to Mars?

Not exactly. Like I said, it can orient your ship and burn the engines automatically, according to the information you enter. But like any computer, you have to know what to tell it. That was the hard part for me

 

[Astro SG Wise]

Got it. I was wondering if it truly was that automatic, why there was so much to read. I was always trying to make a Mars stack, and I hope I have the time to learn it!

 

[Delta glider]

IMFD 4.2 is slightly easier than IMFD 5.3 (IMFD 5.5 seems to have a few bugs with the map program) but I use IMFD 5.3 because I know how to slingshot and aerosling with it. IMFD has less numbers you have to input though than TransX.

 

[Ripley]

In a nutshell, after selecting your target, IMFD already gives you a flyable solution, which maybe is far from optimised and largely inefficient, but flyable nonetheless.
TransX, after selecting a target, just shows you a plan which must be optimized by inputting every component (date, prograde, etc) before being flyable.

Have a look at the Training with Dimitris videos by Blixel and Dgatsoulis for a good explanation on IMFD (after digging in Tommy's Full Manual, that is...)

[ame="http://www.youtube.com/watch?v=btiYvWy-QeM"]Orbiter 2010 - [Part 1] IMFD Training with Dimitris - Earth to Moon - YouTube[/ame]

 

[Delta glider]

Well once I just targeted the moon and got a (nearly) optimized plan of only 2.9 km/s of DV.

 

[TachyonDriver]

imfd doesn't care about how little fuel your craft has to play with so you have to play around with the numbers to get the least delta-v, but as Ripley said, if IMFD can give you a solution, it will, & damn the fuel or time cost, just punch the AB button It's good to try and understand some of what's going on though :blink:

---------- Post added at 08:36 PM ---------- Previous post was at 12:07 PM ----------

IMFD also doesn't care about what's in the way either:

I had an Arrow freighter full of ore bags for shipment from the Moon to Mars. I took off from the Lunar Mining Complex into a stable Lunar orbit. I then had IMFD give me a solution to Mars and hang the expense - delta V was around 26k plus!! I didn't check the alignment of the celestial bodies and just punched autoburn. Once out of lunar SOI, I went for the Course option with Orbit insert selected for Mars. I just wanted to see if it could target Mars complete with misalignment & bad inclination.

Time warped out only to have Orbiter automatically shut of time warp because of a beeping alarm on the ship - Hull Temp was going over 500 degrees! In fact I think it got to about 539 :focus:

This is a screenshot taken after I'd slingshotted around the Sun, too close for comfort.

I thought the mission was a fail complete with the toasted remains of a beautiful Arrow, but once the hull temp began to reduce I knew I'd got away with it.

I was going to Mars OK, but doing a screaming flyby at 13k m/s, aiming for the default base approach periapsis altitude of 120k. Managed to get the orbit circularised at 175k. Only has 41% fuel left in the tanks!

Expensive trip, but IMFD can do a lot for you

 

[Loru]

Well. IMFD rarely cares about celestial objects in your way. There were many reports of hitting the Moon while performing Earth - Mars Hohmann's transfers.

 

[C3PO]

Well. IMFD rarely cares about celestial objects in your way. There were many reports of hitting the Moon while performing Earth - Mars Hohmann's transfers.

Doesn't the map mode catch those?

 

[Delta glider]

Yeah, in intercept mode, but you have to set the reference to the moon AND it's not likely you will be using intercept as you leave earth. You could guess that you would hit the moon but it is difficult.

---------- Post added at 07:49 AM ---------- Previous post was at 07:47 AM ----------

If you set the reference to the moon, you could see if you will collide-not unless you do my style transfers (you leave earth, only to return to earth to then sling to mars)

 

[MikeB]

There's also the IMFD full manual and playbacks available at orbit hanger. This includes a fairly simple process to set up target intercept that can get you pretty much anywhere you want to go.

Note that the IMFD Full Manual is now available on OrbiterWiki, and the scenario files can be downloaded from there as well: http://www.orbiterwiki.org/wiki/IMFD_Manual

The manual hasn't been updated for a long time, so anyone with IMFD skills should feel free to edit the manual or provide updated scenarios.

---------- Post added at 09:02 AM ---------- Previous post was at 08:53 AM ----------

Have a look at the Training with Dimitris videos by Blixel and Dgatsoulis for a good explanation on IMFD (after digging in Tommy's Full Manual, that is...)

Thanks, Ripley, for the link to Dgatsoulis/Blixel's tutorial. Note that OrbiterWiki has an index to all (maybe only most?) of Blixel's Orbiter videos (tutorials as well as sightseeing and just thinking-out-loud): http://www.orbiterwiki.org/wiki/David_Courtney_YouTube_Index

It's hard to keep up with him, so feel free to update the index yourself if you spot something missing.

 

[Tommy]

Note that the IMFD Full Manual is now available on OrbiterWiki, and the scenario files can be downloaded from there as well: <a href="http://www.orbiterwiki.org/wiki/IMFD_Manual" target="_blank">http://www.orbiterwiki.org/wiki/IMFD_Manual</a><br />
<br />
The manual hasn't been updated for a long time, so anyone with IMFD skills should feel free to edit the manual or provide updated scenarios.<font color="Red"><br />
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<font size="1">---------- Post added at 09:02 AM ---------- Previous post was at 08:53 AM ----------</font><br />
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<br />
Thanks, Ripley, for the link to Dgatsoulis/Blixel's tutorial. Note that OrbiterWiki has an index to all (maybe only most?) of Blixel's Orbiter videos (tutorials as well as sightseeing and just thinking-out-loud): <a href="http://www.orbiterwiki.org/wiki/David_Courtney_YouTube_Index" target="_blank">http://www.orbiterwiki.org/wiki/David_Courtney_YouTube_Index</a><br />
<br />
It's hard to keep up with him, so feel free to update the index yourself if you spot something missing.

<br />
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I wasn't aware that they had put the full manual on the wiki, thanks for the tip. I've been wanting to do some work on that for a long time but I don't have the .doc, just a PDF, and I haven't heard from Mark lately so I haven't been able to edit it. It will be nice to be able to fix the errors in the target intercept offsetting and in the slingshot tutorials. If I can get my computer repaired or replaced I will have two or three new additions for that, including setting up a free return lunar trajectory using target intercept and offsetting, one using tangential transfer for a Mars trip, and one that shows how to make more efficient course corrections and planted approaches using either target intercept offsetting or Delta-V. All of them include a manual with screenshots and a flight recording.

 

[MikeB]

I wasn't aware that they had put the full manual on the wiki.

Yep, Mark gave me permission to post the latest edition (early 2009) edition of "The IMFD Full Manual", specifically so that it can be edited in small chunks. It would be great if you could help with updates.

Also, Bruce Irving and Mark Paton gave permission for posting the unpublished (because not quite finished) 2010 edition of "Go Play In Space" on OrbiterWiki: http://www.orbiterwiki.org/wiki/Go_Play_In_Space

Both of these works are so large that updating them in their entirety is too much of a task for volunteers. The wiki format lets any of us improve them in manageable pieces.

I put both documents under an umbrella page that I call "Rocket Science For Amateurs", with the hope that additional tutorial information for the Orbiter community can be referenced from one place. TransX anyone?
http://www.orbiterwiki.org/wiki/Rocket_Science_For_Amateurs

 

[Astro SG Wise]

I had a little bit of time yesterday, and I read the fast steps to object intercept, but I never made it to the moon. It didn't work :beathead:. I guess I'm going to have to take much more time on this one!