totm january 2020 Community Caveman Jool 5 mission

[Jacke]

2 hours ago, Rakaydos said:

It was in the state that I received, and was already causing problems after docking until I changed which core controlled mike.

DELTA doesn't appear to be affected by it.  When I undocked DELTA in my flight, it starts with SAS off and toggleable.  I just checked it again from my submitted latest.sfs and DELTA still behaves that way.

Using the updated latest.sfs, I just test undocked the other 4 cores from MIKE (the 3 vacuum landers docked at the rear and the first one docked to the front).  After undocking, they have SAS off and SAS is toggleable.

But the KILOLIMA 2nd stage was affected by it.  After I undocked it, it was as MIKE, with SAS active, showing lite but greyed out, and not toggleable.

When I redocked DELTA with the KILO tank, its SAS was on.  When I docked the 2nd stage, its SAS was off.  I don't know if that is repeatable.

Edited September 26, 2019 by Jacke

[ManEatingApe]

14 hours ago, Jacke said:

This SAS locked-on thing might be a disaster waiting to happen.  It's inherited by parts of MIKE that undock.  I can imagine this screwing up at least the LAYTHE craft.

Don't know what caused it, but it was already in the state of MIKE on the LATEST I received.  Just confirmed that to be sure.

@Jacke Thanks for bringing this to the attention of the community! That strange SAS "zombie" state is indeed concerning.

Did some digging into the save file.

UT = 579247.5307921588
This is the offset in seconds from day 1. Dividing by 3600 then by 6, gives 26.81 days which agrees with what is displayed in the game UI.

Looking under the ACTIONGROUPS section of the MIKE craft file, show something strange.
Some craft have entries, such as:

SAS = True, 301136.616637823
The 2nd parameter looks like a timestamp format similar to UT. In this case it is less than the current save file UT.

MIKE's entry is:
SAS = True, 2344797.46947679
This timestamp is greater than the current UT, in this case an instant during day 109.

Sure enough there's a correlation - any craft with a timestamp greater than current UT displays the "zombie" SAS indicator.
You can see this in your screenshots as the craft displays a negative MET.

I time-warped past day 110 and after that SAS displayed and acted normally. I then un-docked every craft to verify that they also acted normally.
So we're in the clear here - I'll time-warp to this position when flying the next mission and we can keep an eye on things in case it re-occurs.
No idea how this happened, must be a Kraken sabotage attempt.

Thanks for the deftly delivered double-docking contribution, I've merged your changes and tagged them as "v15".
Everybody please pull the latest changes.

I'm up next to fly either a KILO or LIMA mission.
If anyone would like to take the final remaining assembly slot, please let me know!

Edited September 26, 2019 by ManEatingApe

[Jacke]

Thanks for tracking down the source of the SAS locking, @ManEatingApe.

Considering we likely have to wait for a launch window but also would like to hit the first one, if that's before day 109, perhaps a manual edit of the .sfs file to fix the offending timestamp should be tested.

In other news....

This time, I created a branch of my own forked master to receive my changed files and to originate the pull request back to @ManEatingApe's master.

https://help.github.com/en/articles/creating-and-deleting-branches-within-your-repository

After the pull request was accepted, I deleted my branch, then attempted a different way to integrate the master's commits into my fork.

https://stackoverflow.com/questions/20984802/how-can-i-keep-my-fork-in-sync-without-adding-a-separate-remote/21131381#21131381

Alas, GitHub's interface doesn't have the proper tool, a git push, so I did it the other way in that link.

Results: my fork was now the same as @ManEatingApe's.  But damned GitHub still had the damning and incorrect words "1 commit ahead of master".

Final results: I just deleted my fork and forked again from the master.  Again.  Sigh.

[dvader]

1 hour ago, ManEatingApe said:

Did some digging into the save file.

.....

I'm up next to fly either a KILO or LIMA mission.
If anyone would like to take the final remaining assembly slot, please let me know!

Well done with the debugging!

If you want to try launching LIMA, go for an L shaped ascent. Straight up until the first stage runs out and then sideways. The rocket will flip over if you try to do anything in low atmo. I can do it if it sounds fishy. It is a very dumb rocket

 

 

 

[IncongruousGoat]

4 hours ago, ManEatingApe said:

If anyone would like to take the final remaining assembly slot, please let me know!

I'll take the last slot, if no one else desperately wants it.

[Muetdhiver]

Kudos on the debugging !

Nice to see that we're nearly done with the assembly. This is looking good. 

The real hard part of ladder riding will start soon

 

 

[ManEatingApe]

21 hours ago, dvader said:

If you want to try launching LIMA, go for an L shaped ascent. Straight up until the first stage runs out and then sideways. The rocket will flip over if you try to do anything in low atmo.

Followed your instructions - straight up then sideways. Worked perfectly and LIMA rendezvoused with MIKE with 200 m/s remaining.

Docking with MIKE was much trickier due the perpendicular docking ports and the tendency of the wings to collide with the existing FOXTROT and KILOLIMA fuel tanks. Took 3 attempts but finally got a decent docking making good use of DELTA's RCS thrusters to nudge it gently into position.

Snapshot of MIKE with LIMA attached and DELTA moved to a spare docking port.

I then had a little fun de-orbiting the upper section of MIKE by "headbutting" with the FOXTROT tug (the 2 craft are not docked).
The front section of the upper staged somehow survived the crash landing and was recovered.

Additionally:

• De-orbited or deleted remaining debris
• Time-warped to day 110 to fix SAS glitch
• Rejected contracts that were cluttering the map view

Latest version is merged as "v16". Everybody please pull the latest changes.

@IncongruousGoat Over to you for the final KILO mission!

 

Edited September 27, 2019 by ManEatingApe

[Jacke]

7 hours ago, ManEatingApe said:

I then had a little fun de-orbiting the upper section of MIKE by "headbutting" with the FOXTROT tug (the 2 craft are not docked).

The front section of the upper staged somehow survived the crash landing and was recovered.

When I deorbitted the 2nd stage of the KILOLIMA, it survived reentry (even with SAS stuck on) and slowed down to just above 70m/s before impact.  All of it was destroyed, but I can believe the larger upper part of MIKE had something survive.

[ManEatingApe]

We have a badge!

I've uploaded the badge in a variety of sizes to the repository and also included an Imgur link.

[Muetdhiver]

That is one beautifull badge. Way above my art skills XD

I have my NCD duna mission close to arrival, so it will provide a good final check for the Nav tool in real conditions.

If I see things correctly, we only miss our passenger now. Shall we time warp to the Jool window and then send the Kerbal up (who do we send by the way) ?

[ManEatingApe]

8 hours ago, Muetdhiver said:

That is one beautifull badge. Way above my art skills XD

Thanks, well above mine too - I outsourced it to a friend!

8 hours ago, Muetdhiver said:

I have my NCD duna mission close to arrival, so it will provide a good final check for the Nav tool in real conditions.

If I see things correctly, we only miss our passenger now. Shall we time warp to the Jool window and then send the Kerbal up (who do we send by the way) ?

There is still KILO mission to be attached. @IncongruousGoat has volunteered to fly it.


@Muetdhiver @IncongruousGoat @dvader @Pds314 @Jacke @Rakaydos and all other contributors, can you please post links of your albums and videos in this thread.
I'm going to collect all the links into the OP, so that we can assemble a complete mission album once finished!

Edited September 30, 2019 by ManEatingApe

[Rakaydos]

Ugh, documentation. This is the reason I don't actually have a Cavemen badge.

[ManEatingApe]

16 minutes ago, Rakaydos said:

This is the reason I don't actually have a Cavemen badge.

Then I have some good news for you
Anyone who has contributed a craft or mission segment to the repository is eligible for the shiny new badge linked above.

8 hours ago, Muetdhiver said:

....and then send the Kerbal up (who do we send by the way) ?

Great question! Since we're using probe cores to do the heavy lifting, we don't necessarily need an actual pilot.
Survey link to vote on which Kerbal should fly the mission.

Edited September 30, 2019 by ManEatingApe

[IncongruousGoat]

@ManEatingApe I... haven't really been extensively documenting my launches so far. I figured that rendezvous and docking was a common enough thing that it would be fine.

Should I go back and re-do them?

UPDATE: KILO has been launched and docked to MIKE. With screenshots this time! Link here: https://imgur.com/a/hU6aFug
I also made some changes to the KILO launch vehicle to give it better TWR at launch (basically, I swapped the fins out for a fairing and used the extra parts for a pair of spark engines/nosecones on the booster).
A PR has been made with the changes.

Edited October 1, 2019 by IncongruousGoat

[ManEatingApe]

7 hours ago, IncongruousGoat said:

I... haven't really been extensively documenting my launches so far. I figured that rendezvous and docking was a common enough thing that it would be fine.

Should I go back and re-do them?

What we have so far is fine  A screenshot or two per assembly mission is enough and we don't need each and every mission, just enough to show progress.

When flying the Jool missions we should include reasonable challenge detail, for example the maneuvers and rendezvouses will be quite interesting.

7 hours ago, IncongruousGoat said:

UPDATE: KILO has been launched and docked to MIKE. With screenshots this time! Link here: https://imgur.com/a/hU6aFug
I also made some changes to the KILO launch vehicle to give it better TWR at launch (basically, I swapped the fins out for a fairing and used the extra parts for a pair of spark engines/nosecones on the booster).
A PR has been made with the changes.

Thanks for the PR and the album! Merged changes and tagged them as "v17".
Everybody please pull the latest changes.

Jeb won the pilot poll, just ahead of Valentina by 3 votes to 2.

@Muetdhiver Exciting news, you're up next, to start the mission to Jool!
The objective is to get MIKE (and Jeb!) into high Jool orbit, after that we can decide who wants to fly the other missions.

Edited October 1, 2019 by ManEatingApe

[Muetdhiver]

Okay

Here is what I will do :

0) Check the Duna arrival in the NCD run. If okay, proceed with 1). If not, check the procedure again. Also, add a new function for precision burns using the fuel gauge rather than the displayed DV. that way I can get to 0.1 m/s accuracy.

1) Check if MIKE inclination is really zero (compared to Mun orbital plane). Correct if necessary (turns out that small inclination will give a few m/s in normal/anti-normal and create errors in the thousands of kilometers)

2) Warp to launch window minus one day.

3) Get Jeb up there and rendez-vous. Since personal RCS fuel comes at at premium, I will try to do it at physics warp.

4) Ejection burn and navigation shenanigans. Correction burn, using precise burns based on the fuel gauge. Then propagate the new orbit and check numbers. Do a second Lambert porkchop to check for residual corrections.

5) Wait till getting into Jool SOI.

6) The plan is to get into high elliptical orbit and correct the inclination for as cheap as possible by trying to put the node as close to AP as possible. Then pass on the save with the craft high in the orbit (i.e. close to AP). Then the next persons separate the landers and do the different orbital insertions manoeuvres. I suppose we can do those manoeuvres without a Nav Tool (I could try to pull of something, but it would be rather imprecise).

I will try to be frugal with the RCS fuel, but each correction burn will cost us a bit.

 

Everyone happy with the plan ?

Edited October 1, 2019 by Muetdhiver

[IncongruousGoat]

4 hours ago, Muetdhiver said:

Everyone happy with the plan ?

For step 3 (and all future ship-Kerbal rendezvous) I think it makes more sense to rendezvous MIKE with Jeb and not the other way around, considering just how much jetpack RCS fuel a Kerbal burns doing anything. I'm sure our resident expert ladder rider @dvader has more to say on the matter, since he's the one who pioneered long-distance ladder trips in the first place.

Oh, and you should probably add a note to jettison the docking tug somewhere around step 1 or step 4, because otherwise we'll forget and end up dragging that thing all the way to Jool. I know I'd forget, anyways.

Other than that it looks good to me.

 

[Muetdhiver]

26 minutes ago, IncongruousGoat said:

For step 3 (and all future ship-Kerbal rendezvous) I think it makes more sense to rendezvous MIKE with Jeb and not the other way around, considering just how much jetpack RCS fuel a Kerbal burns doing anything. I'm sure our resident expert ladder rider @dvader has more to say on the matter, since he's the one who pioneered long-distance ladder trips in the first place.

Oh, and you should probably add a note to jettison the docking tug somewhere around step 1 or step 4, because otherwise we'll forget and end up dragging that thing all the way to Jool. I know I'd forget, anyways.

Other than that it looks good to me.

 

Indeed !

Moving Mike is to catch Jeb is a good idea. I can always do the inclination correction afterward.

(I did four full ladder missions to Mun and Minmus, and LKO rendez-vous still costs me about 0.3 RCS fuel at best)

About the Jool transfer correction burn : moving mike would be an interesting idea, however it must be done with the utmost care since if the orbit changes (net thrust is not zero) then the Jool encounter will be changed. However, as long as it's done in a clean way (i.e. precise burn, coast, then precise equal retro-burn, it would be okay in principle.) If the burns is small in terms of DV, given Mike's mass and mass ratios, we can probably assume linearity and just use the fuel gauge to do just that. (i.e. burn 1.5 unit of fuel pro-target, coast, burn 1.5 unit of fuel anti-target.) The introduced error should be acceptable if the coast distance is no more than say 100km.

Once in the jool system, moving Mike to pick up Jeb makes a lot more sense than using RCS fuel. In fact this should be pretty much be the guidline for all rendez-vous : use craft's fuel, not Jeb's whenever possible.

Edited October 1, 2019 by Muetdhiver

[ManEatingApe]

On 10/1/2019 at 10:47 AM, Muetdhiver said:

Everyone happy with the plan ?

Sounds good to me!

[Jacke]

I'd like to see the plan again with @IncongruousGoat's changes incorporated.

On 10/1/2019 at 8:37 AM, IncongruousGoat said:

For step 3 (and all future ship-Kerbal rendezvous) I think it makes more sense to rendezvous MIKE with Jeb and not the other way around, considering just how much jetpack RCS fuel a Kerbal burns doing anything. I'm sure our resident expert ladder rider @dvader has more to say on the matter, since he's the one who pioneered long-distance ladder trips in the first place.

Oh, and you should probably add a note to jettison the docking tug somewhere around step 1 or step 4, because otherwise we'll forget and end up dragging that thing all the way to Jool. I know I'd forget, anyways.

Other than that it looks good to me.

 

[dvader]

On 10/1/2019 at 4:37 PM, IncongruousGoat said:

For step 3 (and all future ship-Kerbal rendezvous) I think it makes more sense to rendezvous MIKE with Jeb and not the other way around, considering just how much jetpack RCS fuel a Kerbal burns doing anything. I'm sure our resident expert ladder rider @dvader has more to say on the matter, since he's the one who pioneered long-distance ladder trips in the first place.

 

It is a bit like playing baseball. There is a decent zero RCS retrieval at 4:20 below. The basic idea is to go for a collision course with the Kerbal and then rotate the craft to hit him with the pod at the right time (assuming the pod is not close to the center of mass).  You can let the Kerbal "slide" along the craft and then hit him just when he passes the pod. It helped  to click "Aim from here" on the Kerbal occasionally to watch his trajectory. At the very last minute, you switch to the Kerbal and grab the ladder. Going slow is essential.

Spoiler

 

 

@Muetdhiver Why would it be impractical to move MIKE for the Jool corrections? Can't you do the calculations after the rendezvous? (Sorry if I'm missing something obvious, I've been otherwise occupied again and haven't been very active lately. I would have voted for Bob!)

[Muetdhiver]

In order to account correctly for MIKE's kerbal catchup manoeuvres I would have to know the net DV values for all three vector components, then solve the lambert problem as planed. This is not impossible but probably quite difficult.

However, one can do the burns and note the fuel use each time. Collect the kerbal and the perform the same burns in reverse. That way the error on arrival should be about the distance crossed to pick up Jeb. Aka : not that much. 

Call me lazy but if this causes a 200km error it's fine IMO. 

I have to think about a bit more. It could be useful to note the pro-target angles on the nav ball as an insurance policy in case of mishaps.

 

Edited October 4, 2019 by Muetdhiver

[Muetdhiver]

Quick update : I have launched a Lima-Taxi variant with Jeb, and did the approach to 1km. I lost one of the spark due to a collision with the ladder trolley, so it was a tad more challenging than expected ^^

Spoiler

I also added some code for small burns and I am trying to put everything in a short video as it's more convenient than a pile of screenshots. (This will be my first, so it might take a while)

Anyone has a good suggestion for basic free video editing software ?

Edited October 6, 2019 by Muetdhiver
Typo bonzana

[Muetdhiver]

Status report : collecting Jeb with MIKE is a pain, but I'm getting the hang of it.

More seriously : I did the ejection burn, but I overcooked the burn a bit (about 30 m/s from the looks of things). Since the TWR is "not great", I had to do the burn in two passes, which complicate things.

That implied a Jeb drop and Pickup between burn one and two.

Next step is doing a retro burn to uncook a bit the ejection burn, then proceed as plan with the correction burn calculation and stuff.

 

[Muetdhiver]

Smooth ride so far !

I have found a way to keep Jeb drift to a minimum (~50m for 100 days) and the correction burn seems on the money. I decided to not retro burn the excess DV, since I was not really sure about it.

Picking up Jeb before second part of the ejection burn.

Correction burn calculation. Results : 31.68 m/s... seems I was on the money with my estimate.

If all goes to plan, Jeb will reach Jool this evening. I have some screens for an album and quite a bit of video to montage.