First successful dock

[Lucy]

I'd put this off for quite a while because everything I'd read about docking suggested it was a rather complicated procedure. Up until now, I'd been to the moon and managed two or three successful VTOL landings at Brighton Beach.

However, I downloaded the XR2 this morning and thought I'd give it a spin. The default scenarios were all about the ISS, so I picked the first one, started off landed at KSC, launched into the ISS's orbit, did the necessary plane change (orbit insertion wasn't exactly accurate) and then sat about for a few minutes working out the sync orbit MFD. It seemed to function like I read in Go Play In Space, so I did what I thought I should and hit the T.

I damn nearly hit the ISS in the end. After slowing down and sorting out relative velocities, the docking itself was a lot more simple than I thought. A little fiddly, especially up close, but a grand sense of achievement as the range callouts turned to "contact" and the "capture and hard dock" was announced.

Much fun. I don't know why I put it off so long.

 

[TSPenguin]

Congratulations!

I too think that the difficulty for docking is overstated. If you can get there in the first place, you should be able to keep your nose pointed to their dock. Very much like nose picking

 

[Nemoricus]

Indeed. Docking in and of itself is no great challenge. Getting to that point can be much more interesting.

To the Moon in 24 Hours is a good example. Doing it requires you to dock the PTM to the LANTR booster in preparation for the lunar transfer, plan a transfer orbit that brings you close to the inclination of the lunar station, perform the transfer with midcourse corrections, insert into lunar orbit, rendezvous with the lunar station, dock the LANTR to the station, dock the PTM to the lander, and then land on the moon.

If you accomplish all that, it's probably safe to say that you're pretty good at Orbiter. I can do everything up to the lunar landing. I haven't worked up the nerve to try.

 

[ar81]

I had problems to land, because there is no autopilot to keep your nose pointing inward when using the lander in TTM24. Landing was for me a matter of trial and error, because AerobrakeMFD does not work on the moon.

Also, docking backwards with the rocket was a bit annoying.

 

[Usquanigo]

Indeed. Docking in and of itself is no great challenge. Getting to that point can be much more interesting.

It is still damn good fun though. And it's much more interesting with Non-Spherical Gravity Sources and Gravity Gradient Torque turned on too.

Then you have the Dragonfly. If you are just starting out building a station say, and have 2 single containers there, latching onto the first is easy, but then you have more mass to move around, which slows everything down and modifies the fulcrum point a bit. Then you have to take that and try to hook up with a smaller, somewhat tumbling mass.

Docking is docking, so it's not like it's learning a new skill, but it does increase the difficulty quite a bit, and you feel great when you connect them.

 

[Lucy]

I had a look at the Dragonfly a while ago.

Not a beginner's vehicle? Seems like whatever I did I managed to set off about three different alarms by doing it. Each time.

Another thing for me to learn. Best part of this sim, not only did I learn how to dock with ISS in full, including syncing and everything, but I learned how and why it works too.

To prove this, I have just done it again. Except this time I didn't come quite so near on my sync. ~100m is pretty worrying at 100x.

 

[TMac3000]

Excellent job! Docking without autopilot (did you use autopilot?) can be a bit of a pain. I have to go in at about .07 m/s over the last 50 meters to keep the cursors from wandering too much.

 

[Lucy]

No, no autopilot. I think I did the last 40-50m at 0.5(ish) for that very reason.

I also found myself cursing that the ctrl to dampen the RCS is not a toggle. I kept forgetting to press it and shooting a lot further than I meant to.

 

[Nemoricus]

The XR2 doesn't have an autopilot. As far as I know, only the Delta Glider IV has an actual docking autopilot.

And only the XR5 Vanguard and Dragonfly have a toggle to permanently dampen the thrusters and it's not quite the same thing. Still, it would be nice to have such a toggle. Ctrl-thruster should still require to hold the Ctrl button down to get those effects so that you can apply low thrust without constantly having to toggle it on and off.

In other news, I finally worked up the nerve to actually land on the Moon. It certainly wasn't a perfect landing (I overshot by about a kilometer and came in rather high, about four kilometers up), but I landed within one meter of the designated landing site, at -.34 m/s vertical speed, and with over 48% fuel left in the tanks. I'd call it a success. My first landing could have been far worse than that.

I did have a brief moment where I was looking at the altimeter reading a constant four meters above the surface and wondering why it wasn't going down. Then I realised, "Oh, yeah. Touchdown." It was a nice feeling.

 

[Lucy]

I know that feeling all too well. First time I landed on the moon I tried to "flare" the DGIV I was flying with the hover thrusters, to make a nice, elegant, smooth descent. However, I didn't realise that at about 2.4m alt, when I was starting to add hov thrust, I was actually down on the pad already. So I went back up and had to land twice.

I've also had some fun trying to work out why the RCS was firing randomly and continually until I turned off the Horizon Level autopilot and it stopped.

Much fun. Next trick is docking a heavy XR5 to see if I can tell the difference. And I may hunt out that dampening toggle mentioned while I'm at it - I agree that having both works best. I also look forward to coming underneath the ISS and docking the other way, though with the thruster mod change I doubt it'll be so different.

Anyway. I'd talk more but I got a launch window in like thirty minutes, and my co-pilot gets annoyed when she has to do all the preflight.

 

[Nemoricus]

In the panel view of the XR5, from the main panel, hit Ctrl-up twice. That's the docking camera. There's a button on that panel which switches the XR5's RCS control scheme from normal to docking mode. This rearranges your controls so that it feels like you're docking a nose-mounted dock. It also reduces RCS thrust by 40% to allow for finer attitude and translational control.

Good luck.

 

[Lucy]

Worked out pretty much the same, in the end, though the final approach was of course different because I wanted to be "underneath" the docking port rather than pointed at it.

I tried to re-entry the XR5 after I did this. It didn't go well.

 

[ar81]

Try Rendezvous MFD. It makes your interception of space station easier when you are in radar range.