Saving Private Bob - A piloting challenge

[dnbattley]

Following on from @Missingno200's excellent discovery regarding the existence and functionality of scenarios, I am pleased to present my first challenge using this format.

From the in-game description: Bob was conducting a manoeuvring test of a new Lander while on attachment to Scenario Station when disaster struck: a gravitational anomaly hit both station and lander, nudging both into a sub-orbital trajectory. Worse, Bob's lander can was severely damaged: losing both autopilot control and one of his RCS thrusters. Fortunately, Valentina was visiting the station on a resupply run, and has room to bring Bob, as well as the station's resident scientist, Bill, back to Kerbin. Bob must limp home on limited resources to meet up with Bill and Valentina, and all three need to return home safely.

Your mission is to guide Bob back to Kerbin. Mission Control additionally ask if you can try to save the station, and also land near the VAB if possible, for cost-saving purposes.

Usage: Download the .sfs file from the link below and place it in your Kerbal Space Program/saves/scenarios folder. The mission is the accessible from the "scenarios" menu option, under "Saving Private Bob (Hard Piloting Test)".

Fair warning: this is a hard, but doable piloting challenge, with Bob's piloting skill set low meaning that SAS cannot be enabled. Worse, the single RCS thruster is off-centre, so care must be taken. You have access to the map and IVA, but cannot quicksave/load, nor EVA.

https://www.dropbox.com/s/aak9ydlvzvnjw4j/Saving Private Bob.sfs?dl=0

Edited May 11, 2019 by dnbattley
updated link

[vyznev]

Looks like you have some Making History parts on the station.  

I do actually own the DLC, I just don't normally play with it installed. Let me reinstall it and try again...

(Also, why is Bill in the lander instead of Bob...?)

Edited May 11, 2019 by vyznev

[dnbattley]

All good catches. Let me adjust and update.

[vyznev]

Found some more issues... apparently switching vessels is supposed to be disabled in the scenario, but the "Cycle through active ships" hotkeys (left and right square bracket by default, although I have them rebound since I'm using a non-US keyboard) still work. Which screwed up my first attempt: I managed to get the lander nice and close to the station, then switched to the station to turn it to face the lander, then tried to switch back... but ended up switching to the RCS thruster debris instead. And the thruster had dropped below 70 km at that point, so I couldn't switch back because KSP won't let you switch vessels while in the atmosphere. 

[dnbattley]

1 hour ago, vyznev said:

Found some more issues... apparently switching vessels is supposed to be disabled in the scenario, but the "Cycle through active ships" hotkeys (left and right square bracket by default, although I have them rebound since I'm using a non-US keyboard) still work. Which screwed up my first attempt: I managed to get the lander nice and close to the station, then switched to the station to turn it to face the lander, then tried to switch back... but ended up switching to the RCS thruster debris instead. And the thruster had dropped below 70 km at that point, so I couldn't switch back because KSP won't let you switch vessels while in the atmosphere. 

Thanks... cycling is deliberately allowed, even though changing via map menu isn't, as otherwise there is a chance of getting "stuck" with the wrong ship when you decouple the landing craft from the station.

The atmosphere (plus daylight) provide an urgency to the mission

Anyway... file is updated on dropbox link. Shouldn't need DLC any more. These files are very fiddly: if you d/l the file again you will probably need to delete the "Saving Private Bob" folder (which is created inside the scenario folder when you run it for the first time) before running the new version of the file to ensure the start state is forced to be updated.

 

Here is my slideshow of the challenge: just to prove it is possible!

https://imgur.com/a/Ls88YZS

Edited May 11, 2019 by dnbattley

[vyznev]

3 hours ago, dnbattley said:

Here is my slideshow of the challenge: just to prove it is possible!

...and here's my video: 

It's kind of long, but only the first half contains anything particularly interesting — the rest is just me waiting a full orbit at 4x warp for a shot at landing near KSC (and still ending up on the other side of the mountains ).

3 hours ago, dnbattley said:

Thanks... cycling is deliberately allowed, even though changing via map menu isn't, as otherwise there is a chance of getting "stuck" with the wrong ship when you decouple the landing craft from the station.

I do appreciate that. I was just grumbling about the fact that it's still possible to get stuck "piloting" the cast-off thruster quad, since that will enter the atmosphere and if you switch to it after that, the game won't let you switch back.   

(Actually, I feel like there may be something else screwy here: in one of my attempts, IIRC, the game let me switch to the quad even though it was way outside physics range, but then prevented me from switching back because there were "no vessels in range," even though I was still in space. I suspect that might be a bug in KSP; it's just not something most people would normally pay much attention to, since normally you can always switch vessels via the map instead. Anyway, it's not hard to avoid once you know about it, it's just kind of an annoying surprise the first time.)

Anyway, the ability to switch vessels does make this scenario somewhat easier, and I (ab)used it a lot in my video. Not only did it let me rotate the station's docking port to face Bob's craft, but it also allowed me to boost the station into a stable orbit while Bob was coasting towards it, significantly reducing the time pressure for the actual docking.

(On the attempt before I figured that out, I spent quite a while trying to finish the docking inside the upper atmosphere, which was an... interesting experience. The station has a lot more drag than Bob's lander can, so as you get deeper and deeper down, drag will inevitably pull the two vessels apart if you haven't managed to dock them. I might upload the video of that run too, just for the epic struggle of one RCS port against the slowly thickening atmosphere.)

Anyway, cool scenario!  Thanks for making it!

[dnbattley]

28 minutes ago, vyznev said:

Anyway, cool scenario!  Thanks for making it!

Thanks for trying it out - and for helping me debug it!

[vyznev]

1 hour ago, vyznev said:

(On the attempt before I figured that out, I spent quite a while trying to finish the docking inside the upper atmosphere, which was an... interesting experience. The station has a lot more drag than Bob's lander can, so as you get deeper and deeper down, drag will inevitably pull the two vessels apart if you haven't managed to dock them. I might upload the video of that run too, just for the epic struggle of one RCS port against the slowly thickening atmosphere.)

Well, here it is:

If you've already seen the previous video, you can safely skip to around the midpoint of this one, which is where things start going wrong. At first mostly just due to the station wobbling like crazy (tip: disable the reaction wheels on the command pod!), but things really get interesting after the 15 minute mark, when both vessels enter the atmosphere.

(Also, if you're wondering what the heck happens at the end, I was trying to ditch the station and dock Val's ship directly with Bob's. But I screwed up and accidentally decoupled the capsule when I was trying to turn on the engine. Oops. )

[Missingno200]

Nice work! I'm definitely going to use the knowledge used here to make my own, harder version of the "Gilly and back with 3 parts" challenge.