6 ms·

You can try docking yourself at https://iss-sim.spacex.com https://iss-sim.spacex.com

• ericol 6y ago
  Took me 3 tries to do it; my bad was not carefully reading the instructions.
  • cbhl 6y ago
    First three times I tried doing it by eye and ended up hopelessly lost. Needed to pull out my trigonometry to figure out how to line up the capsule to get the Y/Z aligned...
    • yellowapple 6y ago
      I got it on the first try, but only because I've got 600+ hours of Kerbal Space Program under my belt (where docking is much harder when you consider that docking in KSP entails actually getting to the target and doing it with imbalanced RCS thrusters that I placed on the craft willy-nilly; SpaceX's online docking sim was a breeze in comparison). Trick was to get rotation aligned first, then worry about translation. And yeah, might as well ignore visual; just went by the numbers.
      • stoneman24 6y ago
        I had a terrible first attempt. Then discovered the same procedure, sort the rotation to 0, then minimise the translation and finally approach the dock. Head down And concentrate on the numbers. I didn’t have the KSP experience to fall back on. I wish they had added a timer as I am now trying for my fastest time.
        • yellowapple 6y ago
          Yeah, the live stream mentioned the ability to switch between coarse and fine controls, and that ability would be invaluable for a speed run.
          • nickez 6y ago
            You can do that by clicking in the middle of the controls.
            • yellowapple 6y ago
              Well shit. That would've been useful to know. Time for some speed-running!
      • mortehu 6y ago
        If you do rotation then translation, you're either going to waste fuel or time. Just aim for the target and get within 20 meters before doing any of that, and the amount of translation you'll have to do is minimal. It's like traveling on the hypotenuse instead of the other two sides of a right triangle.
        • yellowapple 6y ago
          Rotating before translating should have little to no impact on fuel consumption. You still have to do the same amount of translation no matter how the craft is oriented. That means the same amount of energy, and thus the same amount of fuel. It took a little bit more time, but at the timeframes typical of orbital docking it's negligible. In my first-try-success attempt, I was doing all translations at once, not something silly like lining up the numbers one at a time (that won't work well anyway, due to the differences in orbit between yourself and the docking target). That is: moving toward the ISS while simultaneously moving up/down and left/right to line up, and thus moving along the hypotenuse. And by the way, this seems to be the exact approach Crew Dragon Endeavour took, judging by what I saw in the livestream early Sunday morning. They were already lined up rotationally before starting the final docking approach.
          • mortehu 6y ago
            Yes, you're right. You can of course travel on the hypotenuse even if you're not oriented along it. I was probably stuck in some fixed front wheel thinking. I would think it's a lot easier to get the the proportion of lateral speed exactly right if you're aimed along the hypotenuse though.
            • yellowapple 6y ago
              True. Still, if you wanted to get really exact about it, you could surely work it out mathematically (i.e. by making sure your velocity components are proportional to your distance components). So for example, with the simulator loaded up in a tab right now, after lining up the rotation, I'm seeing: X | 200.0 m Y | 12.0 m Z | 30.0 m So if I then apply an X thrust of 20 m/s, Y thrust of 1.2 m/s, and Z thrust of 3.0 m/s, then I should travel along the hypotenuse and reach the docking port in 10 seconds. Likewise, a thrust of X=2,Y=0.12,Z=0.3 would get me there in 100 seconds (and X=200,Y=12,Z=30 would get me there in an insane single second). Of course, some corrections will be necessary along the way to account for small differences between my orbit and the target orbit (which is more relevant the longer it takes for you to get to the target), and the velocity change ain't instantaneous so I'll need to adjust for that, too (making 10s or 1s runs kinda implausible with the current interface, unless perhaps I do some kind of browser-level scripting to click the buttons and read the numbers). Crucially, this makes it feasible for a computer to do automatically (though automated docking tends to stop shy of actually docking from what I understand, instead using CanadArm to grab the craft and put it on the dock). You're right that aiming along the hypotenuse makes this a little bit easier to eyeball, but it also makes it a bit harder in other respects since now you'll have to adjust both rotation and translation along the way to stay along that slightly-curving hypotenuse.
    • gpm 6y ago
      There's a really simple strategy to this. One at a time move pitch, yaw, and roll to zero (with 0 velocity). Before touching any translation buttons. Never touch the pitch yaw and roll buttons again. Start moving x, y, and z translation to zero using transnational thrusters. Make sure you zero out y and z before you get close to zeroing out x.
      • flixic 6y ago
        Using this strategy docking is much, much easier than trying to follow hexagons.
        • deleted 6y ago
          [deleted]
      • dlgeek 6y ago
        And make sure you lower your closing rate before X gets to 0. (But yes, this is the strategy I used)
  • ozim 6y ago
    Am I kind of weird? Did it first time without reading anything just looking at numbers on the HUD. Maybe a bit of common sense?
• Jaruzel 6y ago
  Except that the real Dragon capsule has automated docking. The on-board computer does it.