totm january 2020 Community Caveman Jool 5 mission

[IncongruousGoat]

5 hours ago, ManEatingApe said:

What does everyone think?

I like it. The fewer caveman transfers/intercepts we have to do, the better.

[dvader]

19 hours ago, ManEatingApe said:

 

• LIMA and KILO together with extra fuel attached -> low Laythe orbit

What does everyone think?

Yes. That is the way to go. As long as  you get into orbit I wouldnt worry too much about aerobraking down to LLO since you can be as careful as needed and go for a PE of 49 km if necessary. I tested the aerobraking at 48km and it only took two orbits to get to LLO. But, the spaceplane is very light with a huge surface area so it is probably worse with KILO attached.

19 hours ago, ManEatingApe said:

Thank you for the contribution! You're definitely pushing the frontiers of ladder technology.

• There was an invalid part error when I loaded the craft from the save file. It seemed to be just the loadmeta file. My copy of KSP auto-updated it and now it appears OK, but it would be good if you could double-check that the craft file is still as intended.
• Let's add a 2nd docking port to the craft. This will allow the orbital construction drone to "grab" the craft then dock it with MIKE in LKO.
  Alternatively another solution is to add the capability for the craft to dock itself to MIKE (this would require 1 fewer orbital rendezvous)
• Do include your launch vehicle - we'll have to get your lander to LKO somehow!

• Yeah, I got that invalid part message several times. It disappeared after saving but reappeared much later. There must have been some crap left in memory. I hope it is gone now.
• Hmmm... The launcher had maxed out the part count but there is a FL-A10 adapter I could remove. The extra docking port would have to be placed on the radial decoupler. I'll give it a try.
• Sure. The rocket flips around in mid air but lets just say that is by design...

As for ladder technology, let me add my latest results to further the knowledge of mankind. There IS a difference between mounting the ladder sideways or parallel to the craft. I thought I was just imagining things but then I tried staging without touching the controls afterwards. When the ladder was mounted parallel to the craft, the torque made it start tilting upwards at about 175 m/s, but when it was mounted sideways it didn't. I can't see any significant difference in drag vectors though so I don't understand what is going on. The terminal velocity for the space plane is also lower (about 100m/s vs 130m/s). This matches my experience that I've had more issues and worse result with the parallel ladders even though I still can't understand why. I typically get about 1950 m/s with parallel ladder but 2050 m/s with sideways. Not a big difference but an annoying one. Oh, and both are good enough for Laythe... so I'm not sure why I'm doing this.

Spoiler

 

 

[Muetdhiver]

I should be able to do a full on-pad assembly test of MIKE along with a launch test.

One thing that has been bothering me is the dV budget required on the mothership. I think that adding an extra 3T of fuel fo use in the Jools system is 100% necessary (so that we can deliver 2x TANGO with ease to low Tylo orbit)

The way I see it, MIKE should be packing about 3K dV. So, that would mean 2K for the ejection, 200 for the correction burn(s), 200 for high eliptical Jool orbit. That leaves about 600 for use & safety, which is enough for a Tylo intercept.

2x TANGO + 3T of fuel to low Tylo orbit as planned will work fine as a 3T tank should provide in the ballpark of 1600 dV with 2x TANGO attached.

My concern is for the delivery of KILO+LIMA to Laythe. A possibility could be to use the reamining MIKE fuel once all the 3xTANGO and the extra 3T of fuel are detached. This is about 9 Tons of payload, so once it's dropped off, we would recover a bit of dV from the reduced dry mass (assuming 200 m/s remaining before drop, we would go back up to about 400). We could also attempt a grav assist from Tylo to boost Pe from low Jool orbit to Laythe orbit (since we have to get close to it anyway), but that will not be an easy task to pull off (esp. in caveman), but it would save about 500 dV.

If I see things correctly the most economical (and risky) option is

Equip KILO with fuel for the return + a bit of margin, dock it to MIKE after payload delivery (3xTANGO + 3T fuel) at an Ap matching Tylo's orbit. Compute (??)/Devine a grav assist to lift Pe to Laythe orbit. Correct the resulting orvit with MIKE remaining fuel, then enter in Laythe high E orbit. Aerobrake gently over many passes. Done.

Less risky : beef up KILO with more fuel. That might require in beefing up MIKE's fuel too... so... not that great.

An other potential issue I see with the Mothership is that we'll have FUEL+LIMA+KILO docked inline with Jr ports, that might create issues from Wienerli oscillations during the ejection burn (it was a major problem during my caveman Jool mission, I could not burn higher than 0.2-0.3 TWR)

To answer @ManEatingApe questions : I can't move the 3 ports because they are the ports for the 2.5tank that get the thing into orbit. I used good'ol paint to annotate.

Edited September 2, 2019 by Muetdhiver

[ManEatingApe]

10 hours ago, dvader said:

As for ladder technology, let me add my latest results to further the knowledge of mankind. There IS a difference between mounting the ladder sideways or parallel to the craft...

Nice research! Really taking things to the next rung  (sorry I couldn't resist)

Seriously though, great findings. I would never have though that ladder orientation makes such as difference.

6 hours ago, Muetdhiver said:

I should be able to do a full on-pad assembly test of MIKE along with a launch test...

Looking forward to this! Good dV breakdown of the mothership mission.

6 hours ago, Muetdhiver said:

If I see things correctly the most economical (and risky) option is

Equip KILO with fuel for the return + a bit of margin, dock it to MIKE after payload delivery (3xTANGO + 3T fuel) at an Ap matching Tylo's orbit. Compute (??)/Devine a grav assist to lift Pe to Laythe orbit. Correct the resulting orvit with MIKE remaining fuel, then enter in Laythe high E orbit. Aerobrake gently over many passes. Done.

Less risky : beef up KILO with more fuel. That might require in beefing up MIKE's fuel too... so... not that great.

I'm in favor of the 2nd option, as gravity assists without conics are a gamble.

We only have 3 x 3 ton drop tanks attached to MIKE at the moment.
It wouldn't be too much extra effort to add another 3 for a grand total of 18 tons of extra fuel (in addition to the 12 tons in MIKE) to compensate for the extra mass.

Plus as @dvader mentioned, we only need to get KILO+LIMA to Laythe high orbit on propulsion, very gentle braking passes can nibble away at the orbit from there.

6 hours ago, Muetdhiver said:

To answer @ManEatingApe questions : I can't move the 3 ports because they are the ports for the 2.5tank that get the thing into orbit. I used good'ol paint to annotate.

Thanks for the answers. Also TIL Wienerli

@Pds314 Do you have any designs (even preliminary ones) you'd like to share? This will help plan integrating KILO with MIKE.

Edited September 2, 2019 by ManEatingApe

[Pds314]

Just a sec. I'm gonna post the designs.

[Pds314]

Both are WIP, and I couldn't figure out what was wrong with my Github account so... Here are the launchers and reentry/return stage. KILO with quite a bit of fuel. ~500 more Delta-V than is needed for a Kerbin intercept, although I didn't actually get a Kerbin intercept. because TFW no patched conics.
The Atmospheric entry module.
https://kerbalx.com/pds314/Atmospheric-module-LV


Orbital construction drone:
https://kerbalx.com/pds314/Orbital-construction-worker-LV

Edited September 2, 2019 by Pds314

[ManEatingApe]

30 minutes ago, Pds314 said:

Both are WIP, and I couldn't figure out what was wrong with my Github account so... Here are the launchers and reentry/return stage. KILO with quite a bit of fuel. ~500 more Delta-V than is needed for a Kerbin intercept, although I didn't actually get a Kerbin intercept. because TFW no patched conics.
The Atmospheric entry module.
https://kerbalx.com/pds314/Atmospheric-module-LV


Orbital construction drone:
https://kerbalx.com/pds314/Orbital-construction-worker-LV

Thanks for the contribution! I pushed the craft file to the repository on your behalf.

Notes:

• The construction drone didn't have a designation, so it's now DELTA (for drone).
• The "HitpointTracker" module from "BDArmoury" was in the craft files. It seems to be removed when I re-saved the craft files.
• Renamed "Atmospheric-module-LV" to "KILO"
• Renamed "Orbital-construction-worker-LV" to "DELTA"

Everyone please pull the latest changes.

[Pds314]

@IncongruousGoat How is TANGO supposed to actually like.... land? 

TANGO vs my Tylo Lander


TANGO how it must have to land vs my Tylo lander how it has to land:

TANGO orbital return stage vs my Tylo Lander orbital return stage:

[Muetdhiver]

MIKE test complete !

TBH, this rocket is a pile of junk, and a major pain to assemble....

Spoiler

I seem many flying turds but this one takes the cake.

Gravity turn not before 25km, if the boosters undock get messed up, save & load. Aim for Ap 120, or at the very least 110, or you'll fall back down.

Just enough fuel to get in LKO with the payload.

Spoiler

Complete lemon, but does the job anyway.

TBH I would not mind if I could not have to redo it XD

how can we do to use my save so that we don't repeat the exercice ? I'll put everything in the repo in any case tomorrow.

Edited September 2, 2019 by Muetdhiver

[ManEatingApe]

17 minutes ago, Muetdhiver said:

MIKE test complete !

Excellent work, things are starting to come together nicely!
Getting 15 tons to LKO intact is a major achievement.

17 minutes ago, Muetdhiver said:

TBH, this rocket is a pile of junk, and a major pain to assemble.

I think it looks quite neat.
Nice touch making the top and bottom central parts more rigid by using the side boosters.

I'd love to see some more photos of your assembly if you have them. For example, how you mounted the top central piece onto the bottom core.

Edited September 2, 2019 by ManEatingApe

[Pds314]

Also what is CHARLIE good for if KILO has that functionality?

[ManEatingApe]

15 minutes ago, Pds314 said:

Also what is CHARLIE good for if KILO has that functionality?

In my opinion having 2 different designs provides flexibility, by allowing each design to focus on 1 particular task and do it well.

For example, if we need to we could easily increase the mass of KILO delivered into LKO by leaving out the pod (and Kerbal drag).
This would provide more dV during the Jool return journey.

You're correct that CHARLIE may not strictly be necessary as KILO can double-job, but I feel there's no harm in having options

Edited September 2, 2019 by ManEatingApe

[IncongruousGoat]

@Pds314 The descent "stage" (they're just drop tanks) has 2200 m/s delta-V, which is almost but not quite enough to land on Tylo. The lander is designed to ditch the drop tanks during descent and land on the two remaining Baguette tanks.

[Pds314]

1 hour ago, IncongruousGoat said:

@Pds314 The descent "stage" (they're just drop tanks) has 2200 m/s delta-V, which is almost but not quite enough to land on Tylo. The lander is designed to ditch the drop tanks during descent and land on the two remaining Baguette tanks.

Ah. I see. I guess that saves the 150 kg and 3 parts of legs that something like mine has attached to its drop tank ring.

Edited September 3, 2019 by Pds314

[Muetdhiver]

7 hours ago, ManEatingApe said:

Excellent work, things are starting to come together nicely!
Getting 15 tons to LKO intact is a major achievement.

I think it looks quite neat.
Nice touch making the top and bottom central parts more rigid by using the side boosters.

I'd love to see some more photos of your assembly if you have them. For example, how you mounted the top central piece onto the bottom core.

I have assembly pictures. Quite a few, since I had to try the assembly 3 darn times before getting it to work XD

For the top tank it's a really simple trick : launch the bottom part & park it on the crawlerway. Then launch the upper part (held by clamps). Roll beneath it, couple by detaching the upper part from the clamps.

In principle you could build a rather high stack that way, and it's mch easier than docking lateral boosters. The problem it gets all wobbly. And yeah, the side boosters help a lot wrt to rigidity, but detaching them is bug prone.

One thing I realised is that only having reliants for the boosters is not that great. My TWR at launch was really poor, and the poodle is only used above 10km. With making history one could make bobcat based 1.875m boosters that would have way more TWR and control authority.

The neatest trick in all of this is using fairings truss as structural elements : lightweight and very rigid, they are just perfect. I was able to put more fuel in the boosters that way. It's becoming one of my favorite Caveman part along with the magical 1.25 payload bay.

I have started an NCD run a while ago with MH, but between on-pad assembly and the new nav tools, I will certainly go back to it since it opens up new possibilities (I got demotivated upon reaching the "Minmus science farming" stage, as I was not too keen on grinding my way through NCD, but now I could try to go early interplanetary with way less margins, i.e. before Jr ports.)

[ManEatingApe]

20 hours ago, Muetdhiver said:

TBH I would not mind if I could not have to redo it XD

how can we do to use my save so that we don't repeat the exercice ? I'll put everything in the repo in any case tomorrow.

Just saw this now!

I've added a new "Mission Mutex" section at the bottom of the OP.
This is the name of participant currently flying a mission along with a brief description of the mission.
To prevent save game conflicts I'll only merge latest.sfs files from the current holder of the mutex and you should make sure to have the latest version of the save file before acquiring the mutex.

@Muetdhiver You are now the mutex holder, so please submit a PR updating latest.sfs along with your craft files.
Additionally, stash your assembly photos somewhere - we'll use them as part of the official mission album.

There's also a "Mission Queue" list to acquire the mutex. PM me to be added to the list along with a description of which part of the mission plan you want to fly.
I'm happy to tweak the mission plan if necessary, but let's have that conversation in public.

For example: We never decided on the orbit for MIKE during assembly. I'm proposing to send up a DELTA drone and move it to 80km x 80km at 0° inclination.
What do folks think?

Edited September 3, 2019 by ManEatingApe

[Muetdhiver]

TBH with MIKE I was only concerned with getting it in orbit. At the moment it is 80x120 but it has a bit of manoeuvre fuel left. 80x80 might be possible. 

I have an imgur album with the pics. It's my SOP for all missions.

I will try to make the pull request as soon as possible.

Next step will be adding the fuel with the four tenders I suppose.

Who's up ?

[ManEatingApe]

51 minutes ago, Muetdhiver said:

TBH with MIKE I was only concerned with getting it in orbit. At the moment it is 80x120 but it has a bit of manoeuvre fuel left. 80x80 might be possible. 

I have an imgur album with the pics. It's my SOP for all missions.

I will try to make the pull request as soon as possible.

Next step will be adding the fuel with the four tenders I suppose.

Who's up ?

Good thinking!
Suppose I should test my own design... I'll fly 1 FOXTROT fuel run.

Right now the queue looks like:

1.  @??? Move MIKE to 80km x 80k orbit (or whatever we decide)
2. @ManEatingApe Dock 1 x FOXTROT with MIKE
3. ???

In other news I've reached out to a graphic designer acquaintance to design a badge. Anyone who merges a craft design or flies a mission segment will be eligible.

Would anyone else like to fly a fuel run?
@JAFO @Jacke @The Dunatian @IncongruousGoat @dvader @joshudson @Pds314 @tfantonsen

or any other takers?

Edited September 3, 2019 by ManEatingApe

[Muetdhiver]

So I created a pull request. It's a bit of mess because I'm a complete github noob.

I'll let you check it

MIKE is in 70x120 and has 78 m/s dV of manoeuvre fuel left.

=> Badge : Jool 5 Badge with a trilobite or caveman instead of the kerbal ?

[Pds314]

15 minutes ago, Muetdhiver said:

So I created a pull request. It's a bit of mess because I'm a complete github noob.

I'll let you check it

MIKE is in 70x120 and has 78 m/s dV of manoeuvre fuel left.

=> Badge : Jool 5 Badge with a trilobite or caveman instead of the kerbal ?

Not at my PC right now but what's the argument of peripasis relative to KSC?

Edited September 3, 2019 by Pds314

[ManEatingApe]

19 minutes ago, Muetdhiver said:

So I created a pull request. It's a bit of mess because I'm a complete github noob.

Your PR is fine
I have seen much much worse from seasoned software professionals.
Left some minor feedback, once addressed then we can merge.

5 minutes ago, Pds314 said:

Not at my PC right now but what's the argument of peripasis relative to KSC?

Next mission should be to circularize MIKE's orbit (in order to make rendevous easier) so this should become moot. You could take it on if you want?

[Pds314]

12 minutes ago, ManEatingApe said:

Your PR is fine
I have seen much much worse from seasoned software professionals.
Left some minor feedback, once addressed then we can merge.

Next mission should be to circularize MIKE's orbit (in order to make rendevous easier) so this should become moot. You could take it on if you want?

Should we circularize it with its own fuel? FOXTROT? DELTA? Again not at my PC right now so I can't do it yet. DELTA also only has like 80 or 120 units of LFO or something so even though it has a nice efficient Terrier it might burn a lot of that. Although it can use the upper stage drop tank right until it needs a docking port.

Edited September 3, 2019 by Pds314

[ManEatingApe]

7 minutes ago, Pds314 said:

Should we circularize it with its own fuel? FOXTROT? DELTA? Again not at my PC right now so I can't do it yet.

There's 78 m/s left in a still attached upper stage. This may be enough to circularize to an 80 km x 80 km orbit (be as precise as possible)

If not, then send up a DELTA and use it as a tug. We have to conserve the precious full fuel tanks in the bottom part for the mission proper.

Edited September 3, 2019 by ManEatingApe

[Mr. Peabody]

1 hour ago, ManEatingApe said:

In other news I've reached out to a graphic designer acquaintance to design a badge. Anyone who merges a craft design or flies a mission segment will be eligible.

Would anyone else like to fly a fuel run?

If the hair makes the man, the badge makes the challenge.

I'd love to try a fuel mission, but I'm afraid it would be beyond my current time constraints.

[dvader]

I've updated LIMA to the final version. Only minor changes this time. Added a docking port (on the radial decoupler on the belly), rotated the ladder to sideways and added a launcher rocket.

I've tested the full rescue mission with the final version (from Laythe orbit) and it works well. I seem to get at ~300m/s left in orbit depending unless I screw something up. I've provided a video here for those interested and to remember the flight parameters:

Spoiler

 

 

On 9/2/2019 at 7:45 PM, ManEatingApe said:

Nice research! Really taking things to the next rung  (sorry I couldn't resist)

Seriously though, great findings. I would never have though that ladder orientation makes such as difference.

Filming a Kerbal on a ladder (twice) just so I can compare screenshots of the drag vectors really makes me question my own hobbies I still don't really believe the results though. I still expect it to be due to some other effect or just random chance but it really seems to matter.