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Old 02-01-2011, 11:16 PM   #31
cessnapilot
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Originally Posted by dgatsoulis View Post
 
You mean something like this? YouTube - TESARACT 12 09 2009
Yup... That's it... Before the days of Google, though, you were on your on. But it's still hard to think about it in the 4th dimension.
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Old 02-01-2011, 11:41 PM   #32
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Originally Posted by flytandem View Post
 I wonder if you are doing the maneuver at the correct time (date). Please do something like what you describe and make a save and post the scenario.
Ok, here it is. I think I see what's wrong. It's the negative plane change, which would certainly flip the orbit as I explained earlier. When planning, I usually add a small amount of prograde first, then I adjust plane change to move closer to the yellow lines, then I move on to date and outward velocity to get everything lined up to the plane change. I'm beginning to see this isn't such a good idea and transx doesn't take the planet into account. I've attached the screenshot where you can clearly see the retrograde direction transx puts this in, and you see also that I have a good fairly close encounter with Mars with this setup.

Click image for larger version

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Here, notice the that the maneuver mode target is centered, but my orientation is nearly all retrograde. I've never had it that close. Usually, it orients me around 300 degrees or so. In this case, I'm at 191. And crap...It's never suggested that much DV. Most of the time, it's between 7k and 10k.

Here are the settings for this scenario.

DGIV in Orbit Scenario

Transx parameters
Eject date: 52020.8928
Prograde: 1,405
Outward: 806.8
Plane Change: -8,815
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Old 02-02-2011, 12:33 AM   #33
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Originally Posted by cessnapilot View Post
 Not necessarily impossible, but as you said, inefficient, and in my opinion, a royal pain in the rear.
I don't know about inefficiency, but I actually found really difficult to keep centered the cross of the burn. Using the standard prograde autopilot, the cross was not centered, revealing that Trans-X was using an additional inward component, maybe due to sun gravity calculation. However the autopilot worked the same (just for moon, I dunno about other planets, I'm a beginner).

And for the tesseract... Gosh, that is just a 3D projection (or shadow) of a 4D cube, we can't really see the hypercube, but I would really like...
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Old 02-02-2011, 01:07 AM   #34
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Originally Posted by orbekler View Post
 I don't know about inefficiency, but I actually found really difficult to keep centered the cross of the burn. Using the standard prograde autopilot, the cross was not centered, revealing that Trans-X was using an additional inward component, maybe due to sun gravity calculation. However the autopilot worked the same (just for moon, I dunno about other planets, I'm a beginner).

And for the tesseract... Gosh, that is just a 3D projection (or shadow) of a 4D cube, we can't really see the hypercube, but I would really like...
I too have noticed that the crosshairs are never centered even when burning purely prograde.

As for the tesseract, it caused me many sleepless nights. And still does when I revisit it.

---------- Post added at 01:07 AM ---------- Previous post was at 01:01 AM ----------

Quote:
Originally Posted by cessnapilot View Post
 And crap...It's never suggested that much DV. Most of the time, it's between 7k and 10k.5
FlyTandem,

I just realized why the DV was so high. I inadvertently plugged the Encounter DV from stage 2 into stage 1 during the maneuver portion.

In some of your videos, you set up the plan in stage 2, then you look at the Delta V in stage 1. Then you enable maneuver mode in stage one and plug that number in, which is what I do. I also set the date in the stage 1 maneuver to match that of the date in the stage 2 plan. Should I also enter the values for outward velocity and plane change, or am I correct in assuming that the DV calculation read from stage 1 after planning accounts for that? That number is different than the number in the stage 2 plan, so that's why I'm assuming it does account for it.
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Old 02-02-2011, 04:04 AM   #35
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Quote:
Originally Posted by cessnapilot View Post
 I too have noticed that the crosshairs are never centered even when burning purely prograde.

As for the tesseract, it caused me many sleepless nights. And still does when I revisit it.

---------- Post added at 01:07 AM ---------- Previous post was at 01:01 AM ----------



FlyTandem,

I just realized why the DV was so high. I inadvertently plugged the Encounter DV from stage 2 into stage 1 during the maneuver portion.

In some of your videos, you set up the plan in stage 2, then you look at the Delta V in stage 1. Then you enable maneuver mode in stage one and plug that number in, which is what I do. I also set the date in the stage 1 maneuver to match that of the date in the stage 2 plan. Should I also enter the values for outward velocity and plane change, or am I correct in assuming that the DV calculation read from stage 1 after planning accounts for that? That number is different than the number in the stage 2 plan, so that's why I'm assuming it does account for it.
I was thinking that we are 2 blind men in a dark room. You can't find the door and I can't find you to show you the door. Now I have a glimmer of light.

You said you set the date of the maneuver as being the date from the stage 2 plan. There's the problem.

The plan is very rough when it comes to date. Let's say you have a plan and you get into a nice parking orbit, nicely aligned with the plan. The problem is that as you are doing your orbits you will surely find that yhou are part way around an orbit at the exact time of the planned departure date. This is a reason to set up a maneuver instead of trusting the plan. Especially if the plan is date sensitive. Sometimes they are not too bad to be 45 minutes early or late. But to set up a maneuver then use the date of the plan shows you don't understand the importance of the precision of the maneuver with respect to date.

Here's what you need to do....
As you said you do,... grab the required deltav from Stage 1 for the stage 1 maneuver that you are turning on. Make sure you are aligned well (within .1 degrees of the plan). When you turn on the maneuver and add the required prograde you will now see 2 separate dashed yellow trajectories. One of them is for your plan from stage 2 and the other is for the maneuver you have just set up. Now for date swing the date forward and you'll see the yellow dashed yellow line start rotating around the Earth. Adjust the date forward until it lays perfectly on top of the other yellow dashed line. Use hyper and do short clicks of the mouse to be precise. Then go to stage 2 and make all the velocity values of your plan = zero. When the last velocity value is reset to zero the stage 1 will only show the maneuver trajectory and stage 2 and 3 will now be showing what the maneuver will cause if burned as planned. Now tweak the velocity (prograde) and date (hyper with short clicks) to find the best solution for the trip you are making. The turn to face the x and burn.

In summary, I think you have 2 errors. 1 is using the date of the plan and not making the date according to what the maneuver will show, and the 2nd error is (just guessing since you aren't showing me a full scenario) that you are leaving the plan in place meaning that stage 3 is working from the plan not the maneuver.

---------- Post added at 08:04 PM ---------- Previous post was at 07:46 PM ----------

This is the part of the youtube tutorial that deals with the details explained above
Earth to Mars Part 3:

see from 40 seconds thru about 2:20.
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Old 02-02-2011, 09:20 AM   #36
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Off-Topic:
Quote:
Originally Posted by cessnapilot View Post
 As for the tesseract, it caused me many sleepless nights. And still does when I revisit it.
See this, maybe you'll sleep a bit better:
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Old 02-02-2011, 08:41 PM   #37
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Originally Posted by flytandem View Post
 You can't find the door and I can't find you to show you the door.
Lol.. That reminds me of the Joe Walsch song, "Life's Been Good" - "I go to parties sometimes until 4. It's hard to leave when you can't find the door."



Quote:
Originally Posted by flytandem View Post
 In summary, I think you have 2 errors. 1 is using the date of the plan and not making the date according to what the maneuver will show, and the 2nd error is (just guessing since you aren't showing me a full scenario) that you are leaving the plan in place meaning that stage 3 is working from the plan not the maneuver.
You are correct, sir, in both errors - guilty of both.


Quote:
Originally Posted by flytandem View Post
 Make sure you are aligned well (within .1 degrees of the plan).
Are you talking about the eject orientation function here, or are you talking about a plane alignment burn first? If the former, that was the one we had such a tough time lining up because the planes wouldn't match. I think I got it within 8 degrees relative inclination once with the DG in Orbit scenario.

---------- Post added at 08:41 PM ---------- Previous post was at 08:37 PM ----------

Quote:
Originally Posted by orbekler View Post
 Off-Topic:

See this, maybe you'll sleep a bit better:


Good video! Thanks... Problem is, once I figure that one in my head, something else will pop in to keep me awake - Such is the nature of the insatiable thirst for knowledge.
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Old 02-02-2011, 09:07 PM   #38
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Flytandem, When I plug in the prograde Deltav quantity into the maneuver program, my hypothetical orbit comes up way short. It doesn't even leave Earth's SOI. What is up with that?
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Old 02-02-2011, 09:25 PM   #39
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Originally Posted by Mister Mxyzptlk View Post
 Flytandem, When I plug in the prograde Deltav quantity into the maneuver program, my hypothetical orbit comes up way short. It doesn't even leave Earth's SOI. What is up with that?
Lol... That was one of the original problems I had, which prompted my first post in this thread. But, I'm trying to do it from existing orbit rather than launch. At launch, I have no problems with it based on the way he does it in his videos. Are you trying it from orbit too?
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Old 02-02-2011, 09:39 PM   #40
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Originally Posted by Mister Mxyzptlk View Post
 Flytandem, When I plug in the prograde Deltav quantity into the maneuver program, my hypothetical orbit comes up way short. It doesn't even leave Earth's SOI. What is up with that?
show the scenario text and I'll take a look at what you have.
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Old 02-03-2011, 12:14 AM   #41
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I am such a bonehead! I discovered my error. I was plugging in just the prograde vel. not the total Dv.

Details, details,details!

Last edited by Mister Mxyzptlk; 02-03-2011 at 04:24 AM.
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Old 02-03-2011, 03:22 PM   #42
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Originally Posted by Mister Mxyzptlk View Post
 I am such a bonehead! I discovered my error. I was plugging in just the prograde vel. not the total Dv.

Details, details,details!
that's confusing. if you are trying to set up a maneuver for a prograde burn in stage 1 to overlay and replace the prograde deltav for your eject burn as shown in stage 1 for a plan that is set up in stage 2 then what you said is confusing to me.

---------- Post added 02-03-11 at 07:22 AM ---------- Previous post was 02-02-11 at 09:58 PM ----------

Just thinking about how I used to do just maneuvers in TransX in the first few weeks. Didn't know how to set up plans so I always just did whatever maneuver got me s far to my destination as possible... it's simple but somewhat hit and miss. so with a bit of nostalgia, in a couple of minutes I came up with....

open the stock scenario, dgMk 4 in orbit" in the deltaglider folder.
prograde= 3892.60877755
date= 51982.5631915
may not be the most efficient way but it's not far from it.
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Old 02-03-2011, 03:49 PM   #43
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At this point I am going to digest your earth to mars tuts. I can get wherever I want to go in the solar system, and as I am a returnee (hint: I sent you a CD in the mail), I even have arrived at a trojan as per your trojan tuts and piper's challenge. But, and I have a big but, I am extrmely out of practice, and would like to learn the art of efficiency.
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Old 02-03-2011, 04:16 PM   #44
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Quote:
Originally Posted by Mister Mxyzptlk View Post
 At this point I am going to digest your earth to mars tuts. I can get wherever I want to go in the solar system, and as I am a returnee (hint: I sent you a CD in the mail), I even have arrived at a trojan as per your trojan tuts and piper's challenge. But, and I have a big but, I am extrmely out of practice, and would like to learn the art of efficiency.
I've only received one CD and it was from a very considerate fellow orbiter who helped a poor fellow (me) that had no idea how to assemble a stack of ships (titan rocket or similar). thanks! welcome back.
edit: http://www.orbiter-forum.com/showthr...&postcount=135

Last edited by flytandem; 02-03-2011 at 05:52 PM.
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Old 02-03-2011, 07:54 PM   #45
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Originally Posted by flytandem View Post
 that's confusing. if you are trying to set up a maneuver for a prograde burn in stage 1 to overlay and replace the prograde deltav for your eject burn as shown in stage 1 for a plan that is set up in stage 2 then what you said is confusing to me.

---------- Post added 02-03-11 at 07:22 AM ---------- Previous post was 02-02-11 at 09:58 PM ----------

Just thinking about how I used to do just maneuvers in TransX in the first few weeks. Didn't know how to set up plans so I always just did whatever maneuver got me s far to my destination as possible... it's simple but somewhat hit and miss. so with a bit of nostalgia, in a couple of minutes I came up with....

open the stock scenario, dgMk 4 in orbit" in the deltaglider folder.
prograde= 3892.60877755
date= 51982.5631915
may not be the most efficient way but it's not far from it.
I planned the same way early on - until I watched your videos a few weeks ago. That 51982 date is almost magic. It seems to be a very good date to burn to get to Mars without having to spend 30 minutes creating a plan by tweaking all the parameters.

---------- Post added at 07:54 PM ---------- Previous post was at 07:49 PM ----------

Quote:
Originally Posted by Mister Mxyzptlk View Post
 At this point I am going to digest your earth to mars tuts.
Those Mars tutorials taught me a wealth of information about Transx and its workings. As soon as I conquer this "eject from orbit" issue, I'm gonna try some slingshots.

So far with Tranx, I've visited Mars, Venus, Phobos, Deimos, Jupiter and several of its moons, and Saturn and several of its moons. Oh, and Transx is SO much better than sync orbit when trying to intercept the ISS.
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