I agree with kevinvr who said, "I agree with Oceanic, wish I had seen it a few moths ago, but then again I did learn a lot by making my own mistakes." Like kevinvr, I feel like I learned a lot by making my own mistakes. So maybe it's a good thing that I didn't watch this video until now.
But I just wanted to say what many others in this forum have said before me. But it's worth repeating. Great job on this tutorial. I say that with absolute sincerity!
I've done a bit of work with video, so I can appreciate how much effort goes into this kind of thing.
The audio quality of this video is outstanding. It sounds like you were definitely using a mic and were mindful enough to eliminate any background noise. (No TV's blaring, no dogs barking, no kids screaming, etc...) The audio is nice and clear.
The video quality is very good. I understand how much disk space and "bandwidth" video takes at high resolutions, so I understand why this was kept at 640x480. (Plus it was recorded a couple of years ago ... which I believe was before youtube even offered HD.)
The production quality was top notch! The way you broke the video up into logical segments and added additional images to help clarify your points ... that kind of thing is incredibly useful. You definitely have some production skills. (I've seen some other videos on your youtube channel ... great stuff.)
Something that I think is worth mentioning ... I don't think there is anything about your instructions that requires the DG IV is there? (Other than the autopilot take off.) The reason I mention that is because I had actually avoided your video up to this point because I assumed you were using some technique that could only be done in the DG IV. And since I don't use the DG IV (and don't want to use it
[yet]), I figured I couldn't learn anything from your video.
But I decided to watch it anyway today ... and the main thing I noticed was that everything you did (other than the autopilot take off) can be done in the regular Delta-glider. Right?
As a relative newbie to Orbiter, I don't want to clutter my system with additional spacecrafts and MFD add-ons. I want to learn the standard MFD's first and stick to the standard spacecrafts.
I read in another forum post how there are a lot of add-ons that can make Orbiter completely unstable. Whatever the guy was talking about, the people who responded suggested that he disable all his MFD add-ons and try again.
So ... I don't know what's safe and what isn't, so I'm just sticking to the defaults. It seems to me the defaults will always get the most attention from the developers, so I'd rather learn that stuff than learn about some add-on that may become obsolete with the next release because the developer of such and such add-on isn't actively involved with Orbiter any more. Know what I mean?
9:20 (Synchronize orbit)
This section was really useful to me. I had already read (somewhere) about docking with the ISS on the sunlit side of the planet. But the information I read didn't explain *how* to make sure you will dock with the ISS on the sunlit side of the planet.
So up to this point, I have been using my existing apoapsis and periapsis points as the reference points for determinging which side to dock on. By existing
points, I mean - whatever my apoapsis and periapsis happened to be at the point after I achieved orbit and stabilized my perigee.
For example, if my periapsis happened to be on the dark side of the planet, then I would choose the apoapsis as my rendezvous point. And if the apoapsis happened to be on the dark side, then I would use the periapsis as my rendezvous point.
I never put any thought into making
my apoapsis be the rendezvous point right after sunrise. That was an excellent tip that I picked up from watching your video! (Learn something new every day.)
The problem with my method (of relying on wherever my apogee/perigee just happened to be) was if I needed to make a large burn to bring DTmin down to zero, I could potentially lower my periapsis down so far that it would be in the earth's atmosphere. (Like you mention in the video at around 17:55)
To work around that
problem, I would fast forward time for as many revolutions as was necessary to bring my Delta-glider closer to the ISS so that my DTmin adjustment would be minimal.
That, of course, is very sloppy and time consuming.
I also found that when I would make my burn to bring DTmin down to zero, my apoapsis and periapsis would often "flip" on me. For example, if I was burning at perigee to bring apogee down a little so that DTmin would be closer to zero, it would often be the case that my burn would last so long that my apogee would end up lower than my current perigee ... so they would "flip."
That wasn't too much of a problem really ... (other than being confusing) ... but I would then have to change the Sync Orbit MFD from Sh-apoapsis to Sh-periapsis.
The whole thing just felt very sloppy and imprecise. I have (only recently) been able to catch up and dock with the ISS/Mir/another vessel ... but the procedure has felt dirty. Your video has given me a great bit of insight. I can't wait to get into Orbiter and try this out.
One thing I found interesting about your video was at about 17:05, you mention that you don't know if you're going to need the main engines or the retro engines. I have had that problem too but just assumed it was my own lack of knowledge. Surely there is a scientific way to know which way to burn to bring DTmin down to 0? Surely it isn't just trial and error?
Finally, what is all that extra stuff at the end of your tutorial?? It looks like you have a person remove an object from the ship and transfer it to the ISS? Can you really do that with Orbiter?? I've never seen any options for taking a space walk. If Orbiter can do that ... OMG ... how freaking awesome is this program???
I'm discovering new things I can do all the time. Like the Shuttle-A ... I just learned that it has some kind of payload thing. I don't know how to use it yet, but it sounds like a really fun simulation to take a payload to the moon and drop it off.
---------- Post added at 11:57 PM ---------- Previous post was at 07:42 PM ----------
I didn't have time to watch the whole tutorial, but if you zoomed the map just a bit more, you'd notice that you had actually passed the launch window
The key is to launch a bit before the orbital plane passes our launch site.
Hmm... I didn't know this. I thought the launch window was when the target object (the ISS, Mir, whatever), was along the same longitudinal line as the launch site? So ... launching from Cape Canaveral, I thought you were supposed to launch when the ISS was along the 80 degree West longitudinal line. Basically as close to "over head" as possible.
But if I'm understanding what you said here, you are saying you want to launch when the orbital plane line is crossing over the launch site.
Is there a way to calculate this more scientifically. Using terms like "a bit before" doesn't seem very accurate. What is "a bit" exactly? A dozen pixels on the Map MFD? A centimeter on the Map MFD?
With the precision that all the other MFD's offer, I'm thinking there must be a more precise way of figuring out when to launch to rendezvous with an orbiting target like the ISS. (Please don't say TransX. Fingers crossed.)