totm january 2020 Community Caveman Jool 5 mission

[Pds314]

If the current plan is to have KILO fly itself and LIMA into position around Laythe and use the nose as a docking port anyway, I'm gonna give it a lighter nose and add fuel reserves to the nose so it can be used like a drop tank.

Edited September 4, 2019 by Pds314

[Pds314]

Okay... KILO ULTRALIGHT PLUS.
It is now back up to 2968 kg (2938 if you get rid of the engine docking port) to Jool intercept, but it has a drop tank with 1306 m/s Delta-V and a docking port. I checked the Delta-V with LIMA attached and... well, it's not great. LIMA will need some fuel to go up with it I think. Also this version has to sacrifice having an integrated pod to put a Kerbal in so the Kerbal will have to ride up on something else if we use it.... or create a rather comical Kerbal ladder truck.

Edited September 4, 2019 by Pds314

[Pds314]

Speaking of which, did someone order a Kerbal ladder truck?
 

New Electric Car. 60 - 0 feet high in 1.9 seconds if you fall off it. 0-60 in quite a while longer (go behind it and hold F)

Edited September 4, 2019 by Pds314

[Mr. Peabody]

@ManEatingApe, I'm not entirely sure how to award badges for this challenge attempt. Is it an actual Caveman run, (ie. all necessary parts have to be researched and funds collected before the Jool mission) or is it a Jool 5 with Caveman tech?

[ManEatingApe]

42 minutes ago, The Dunatian said:

@ManEatingApe, I'm not entirely sure how to award badges for this challenge attempt. Is it an actual Caveman run, (ie. all necessary parts have to be researched and funds collected before the Jool mission) or is it a Jool 5 with Caveman tech?

It's definitely in the "Jool 5 with Caveman tech" or "Inspired by Caveman" category.

Specifically 2 Caveman rules have been breached:

• Cheat menu used to provide funds, tech and experience.
• Debug menu used to set orbit for craft testing

So I couldn't in good conscience call it an official Caveman attempt, but definitely Caveman-like

 

[Muetdhiver]

I think this is really a jool5 with caveman tech and should be counted as such.

We can always mention it in the caveman thread as an achievement thing like the trilobite is at the moment.

 

Edited September 4, 2019 by Muetdhiver

[ManEatingApe]

Wow, so much great discussion and thank you to all the mission volunteers!

I'm currently working with @Pds314 to get their changes merged, and the mission queue currently looks like (OP is updated):

1.  @ManEatingApe 1 x FOXTROT dock with MIKE
2. @IncongruousGoat 1 x FOXTROT dock with MIKE
3. @Jacke 1 x FOXTROT dock with MIKE

Regarding LIMA and KILO, I think it's important to consider "packing" or how we arrange craft on MIKE for balance and stability.
There are 6 x radial docking ports on the side and 4 on the front (1 in the center and 3 on the edge).
I suggest that we:

• Make mass of (LIMA + extra fuel) ≈ KILO ≈ FOXTROT payload ≈ 3.3 tons
• Dock LIMA, KILO and 1 x FOXTROT to the front of MIKE
• As these 3 items will have roughly the same mass, they will be roughtly balanced (hopefully within the gimbal tolerance of the poodle)
•  @dvader and @Pds314 this supports your ideas of flying LIMA + KILO + extra fuel to Laythe orbit
• Arrange drop tanks, TANGO, BRAVO and VICTOR around the 6 radial docking ports

Here is a picture of the proposal:

Note that I've included 3 extra drop tanks to give the mothership a total dV of ~ 3,100 m/s.

What does everyone think?

Edited September 4, 2019 by ManEatingApe

[Muetdhiver]

I think it's an interesting idea that needs testing (?). If the balance is not right, we'll have quite a mess.

Jr Ports are very flimsy things.

In any case it's better than piling them on top of each other '^^

[Jacke]

14 hours ago, Muetdhiver said:

Just be aware that MIKE alone has no probe core (saves weight, and we'll have plenty of those on bord anyway).

Then we'd better be very careful about the "Control from here" setting to avoid control issues.  If there's a probe core oriented vertically, it would likely be the best choice.

[ManEatingApe]

1 hour ago, Muetdhiver said:

I think it's an interesting idea that needs testing (?). If the balance is not right, we'll have quite a mess.

Jr Ports are very flimsy things.

In any case it's better than piling them on top of each other '^^

1 hour ago, Jacke said:

Then we'd better be very careful about the "Control from here" setting to avoid control issues.  If there's a probe core oriented vertically, it would likely be the best choice.

I used the debug menu to place the hacked together craft from my previous post into LKO.
Control point was set to LIMA probe core.

Results were very promising:

• As expected the docking ports are a noodly nightmare
• However the craft was surprisingly controllable and even had a good rate of response with all the reactions wheels from the various landers contributing together.
• I ran the Poodle at full throttle until all tanks were empty, staging along the way
• MIKE remained stable when full, during burn and when empty.

Edited September 4, 2019 by ManEatingApe

[Pds314]

Do we have a tested LIMA launch vehicle yet?

Edited September 4, 2019 by Pds314

[ManEatingApe]

23 minutes ago, Pds314 said:

Do we have a tested LIMA launch vehicle yet?

We do! @dvader has tested the design extremely thoroughly (see video in the spoiler on their post on page 5) and has merged it into the repo, along with a launch vehicle.

Edited September 4, 2019 by ManEatingApe

[ManEatingApe]

@Pds314 I've merged your latest save file. Thanks for the lovely circular orbit!
Everyone please pull the latest update "v7"

I will be AFK (away from Kerbal) for the next 24 hours, so I sent myself to the back of line.
@IncongruousGoat You are now the mutex holder.

Some tips on flying FOXTROT to orbit:

• Launch craft, set throttle to full and SAS on.
• Yes, the probe core is upside down! This is intentional
• Wait 10 seconds for craft to stabilize, as initial launch angle is critical
• Trigger 1st stage, do nothing except open a PAW to monitor fuel in lower tanks
• Craft will begin a gentle gravity turn automatically with no control input needed
• Stage 2nd stage once lower tanks are empty
• Continue to chill out until AP is 80km, then cut throttle
• There should be just enough fuel left to circularize normally
• Undock payload with small robot tug. Probe core is now facing the right way
• Dock with MIKE using the ~160 m/s dV remaining
   

[dvader]

@Pds314 Nice work on the slimmed KILO!

I've calculated dV for KILO+LIMA+extra fuel (KLIMA) and it seems like more than enough. Total weight is about 6.5

Stage    dV
KILO Stage 2    3138
KILO Stage 1    1226
KILO+LIMA    831

831 should be enough to get into LLO with some trickery and 4300 is more than enough to reach Kerbin. I did a quick check in a sandbox and it seems like do not need more than 1050 dV to get an intercept with Kerbin from Laythe even if we aim poorly (plus some extra for adjustments to actually intercept). I don't know what the reentry speed would be but we could use propulsive braking to get down to the survivable 4500 m/s. If I'm right about the return , I think we could slim down KLIMA a lot more by removing 1-2 fuel tanks. Please double check all my calculations and especially the Laythe return cost. I was in a hurry.

@The Dunatian I'd be happy with an honorable mention,  rogues gallery or such. It is more of a proof of concept than a proper attempt (infinite funding, no science grind, more than one player)

 

[dvader]

I've checked my calculations again (but haven't tried it in game). All calculations are under ideal conditions with no inclination, perfect ejections and perfect hits.

From LLO 50 km we need 1072 m/s to reach Kerbins orbit (best case). The atmospheric reentry speed then 4.2 km/s which is within the survivable margin of KILO without a heat shield. I can't remember typical in-game speeds but I think it is usually more than that by quite a bit.

If we put a 45 Lq tank on KILOs return stage we get about 1875 dV which could be enough for adjustments and imperfections. Another 90 Lq on KILOs second stage (below the nose cone) would be enough to get KLIMA into laythe orbit (~900 dV) and we don't even need the extra fuel tanks. This would get KLIMA down to just 4t total.

If I get the time, I'll test a return trip with caveman tools and a max budget of 1875 dV from LLO but it seems at least plausible.

[IncongruousGoat]

FOXTROT 1 has been launched & docked with MIKE. I also used a tiny bit of the remaining launch dV on MIKE to circularize the orbit to 80.3x80.3 km, to make rendezvousing with it even easier.

@ManEatingApe pthread_mutex_unlock(mission_mutex). Also, seriously, nice job with the FOXTROT LV. That's the smoothest pre-calibrated gravity turn I've seen in a long time.

As a general administrative note, feel free to enqueue me for one of the TANGO/VICTOR/BRAVO launches, with the caveat that I might have to be bumped down the queue since I'm going to be out of commission until Monday.

[Muetdhiver]

15 hours ago, dvader said:

I've checked my calculations again (but haven't tried it in game). All calculations are under ideal conditions with no inclination, perfect ejections and perfect hits.

From LLO 50 km we need 1072 m/s to reach Kerbins orbit (best case). The atmospheric reentry speed then 4.2 km/s which is within the survivable margin of KILO without a heat shield. I can't remember typical in-game speeds but I think it is usually more than that by quite a bit.

If we put a 45 Lq tank on KILOs return stage we get about 1875 dV which could be enough for adjustments and imperfections. Another 90 Lq on KILOs second stage (below the nose cone) would be enough to get KLIMA into laythe orbit (~900 dV) and we don't even need the extra fuel tanks. This would get KLIMA down to just 4t total.

If I get the time, I'll test a return trip with caveman tools and a max budget of 1875 dV from LLO but it seems at least plausible.

That sounds great. We can do a deep space manoeuvre to correct the trajectory. 1875 dV should be more than enough.

We'll have to be carefull to not stumble upon Vall or Tylo on our way to the exit though.

[ManEatingApe]

14 hours ago, IncongruousGoat said:

FOXTROT 1 has been launched & docked with MIKE. I also used a tiny bit of the remaining launch dV on MIKE to circularize the orbit to 80.3x80.3 km, to make rendezvousing with it even easier...

...As a general administrative note, feel free to enqueue me for one of the TANGO/VICTOR/BRAVO launches, with the caveat that I might have to be bumped down the queue since I'm going to be out of commission until Monday.

Great! I've re-added you to the mission queue at the end.

14 hours ago, IncongruousGoat said:

pthread_mutex_unlock(mission_mutex)

0

@Jacke You are now the mission mutex holder. Pull the latest version of the repo "v8" and have fun!
 

On 9/5/2019 at 4:03 PM, dvader said:

I've calculated dV for KILO+LIMA+extra fuel (KLIMA) and it seems like more than enough. Total weight is about 6.5

Stage    dV
KILO Stage 2    3138
KILO Stage 1    1226
KILO+LIMA    831

831 should be enough to get into LLO with some trickery and 4300 is more than enough to reach Kerbin. I did a quick check in a sandbox and it seems like do not need more than 1050 dV to get an intercept with Kerbin from Laythe even if we aim poorly (plus some extra for adjustments to actually intercept). I don't know what the reentry speed would be but we could use propulsive braking to get down to the survivable 4500 m/s. If I'm right about the return , I think we could slim down KLIMA a lot more by removing 1-2 fuel tanks. Please double check all my calculations and especially the Laythe return cost. I was in a hurry.

Nice work on the calculations. I feel if we follow your plan and use @Pds314's latest design e.g.

• Design an fuel package for LIMA to bring the total weight up to ~3.3 tons
• Update KILO to the "Ultralight Plus" design

then we will achieve 3 objectives:

• Achieve balance for "packing" onto the mothership
• Provide enough dV to use for combined LIMA+KILO Laythe insertion
• Leave plentiful dV remaining for KILO (over and above the bare minimum) that will make the return journey easier

@dvader Could you open a PR with the fuel package for LIMA?
Depending on how you want to de-orbit, it could include an engine plus a little fuel so that LIMA can de-orbit on its own, or just fuel in which case KILO+LIMA would lower PE below Laythe's atmosphere but then boost back up again after detaching LIMA.

@Pds314 Could you open a PR updating KILO to your "Ultralight Plus" design?

Edited September 6, 2019 by ManEatingApe

[Pds314]

11 hours ago, ManEatingApe said:

 

@Pds314 Could you open a PR updating KILO to your "Ultralight Plus" design?

I thought I already did that???

[ManEatingApe]

3 hours ago, Pds314 said:

I thought I already did that???

I wasn't able to use your previous PR directly as some other files were inadvertently included. This would be a new PR containing only the updated KILO design.

Alternatively if you prefer, I can cherry-pick across the "Kilo Ultralight Plus" design from your previous PR, rename it to "KIlo", and commit it on your behalf.

Edited September 7, 2019 by ManEatingApe

[Pds314]

2 hours ago, ManEatingApe said:

I wasn't able to use your previous PR directly as some other files were inadvertently included. This would be a new PR containing only the updated KILO design.

Alternatively if you prefer, I can cherry-pick across the "Kilo Ultralight Plus" design from your previous PR, rename it to "KIlo", and commit it on your behalf.

I guess I could, but it is basically literally the same craft. So if you want you can commit it on my behalf.

Edited September 7, 2019 by Pds314

[Pds314]

On 9/5/2019 at 8:03 AM, dvader said:

@Pds314 Nice work on the slimmed KILO!

I've calculated dV for KILO+LIMA+extra fuel (KLIMA) and it seems like more than enough. Total weight is about 6.5

Stage    dV
KILO Stage 2    3138
KILO Stage 1    1226
KILO+LIMA    831

831 should be enough to get into LLO with some trickery and 4300 is more than enough to reach Kerbin. I did a quick check in a sandbox and it seems like do not need more than 1050 dV to get an intercept with Kerbin from Laythe even if we aim poorly (plus some extra for adjustments to actually intercept). I don't know what the reentry speed would be but we could use propulsive braking to get down to the survivable 4500 m/s. If I'm right about the return , I think we could slim down KLIMA a lot more by removing 1-2 fuel tanks. Please double check all my calculations and especially the Laythe return cost. I was in a hurry.

@The Dunatian I'd be happy with an honorable mention,  rogues gallery or such. It is more of a proof of concept than a proper attempt (infinite funding, no science grind, more than one player)

 

1050 to get from Laythe to Kerbin??? What route? Is it direct escape? Diving at Jool and then direct escape? Vis viva for the latter says getting out of Jool SOI should take like 1900 m/s?

If this is true, KILO's 3500 m/s final stage design delta-v is WAY overkill. Not just a bit overkill but "go back to Kerbin with enough fuel to come back to Laythe again" overkill.

 

Also your Delta-V numbers look about 300 and 100 m/s too low compared with ingsme UI. The stages have 1300 and 3550 or so.

 

I don't have time to test it right now but I will definitely look if just throwing it directly from Laythe to Kerbin can be done in 1050 Delta-V. If so I may opt for a much smaller return rocket and just use most of the KILO mass as a fuel reserve. Especially if I can change the engine to something else like an ant or a pair of ants (don't worry, the drop tank can still have a spark for KILO+LIMA to use). I can very well see return to Kerbin mass being around 500 kg. Meaning 2800 kg to play around with of possible orbital maneuvering and other hardware. And perhaps saving weight by not having a decoupler.

Edited September 7, 2019 by Pds314

[Muetdhiver]

Yes vis viva gives 1800 from Laythe orbit around Jool, however this is not the right number.

The thing is that an hyperbolic excess velocity of 1.8km/s out of Laythe does not require 1.8km/s dv from  low Laythe orbit. Back if the envelope says 900 to 1000 range, so 1050 seems right.

Hev = sqrt(V0^2 - Vesc^2)

 

Edited September 7, 2019 by Muetdhiver

[dvader]

8 hours ago, Pds314 said:

1050 to get from Laythe to Kerbin??? What route? Is it direct escape?

Yes, direct escape. It was much lower than what I expected as well so I expected some calculation error to pop up somewhere. But, now I've tested it and it was almost spot on . I started with perhaps 1900dV at 63km LLO and burnt 1072 dV when Laythe was roughly in the right place. I actually burnt too much and overshot Kerbins orbit so I had to do some corrections once around Kerbol. I intentionally missed Kerbin the first time around and did a orbit correction to hit the second time (which failed). I paid a bit more attention to the second orbit correction and hit Kerbin with 600 m/s left. Not spot on though so I had to burn a lot to actually hit the atmosphere. The reentry speed was about 4.2km/s and well below your tested safety limit. (I did not have a Kerbal on a ladder but had added 90kg of antennas to make up for it).

I used orbital energy for my calculations. Basically an excel sheets with one row for each change in SoI, assuming either prograde or retrograde exits relative to the body etc. Here's a screenshot of the ejection angles from Laythe and Jool.

 

Spoiler

 

But, if @ManEatingApe has already planned for 2x3t crafts then I guess it is best to go with that so MIKES balance doesn't shift. More fuel is always better than less fuel. The KILO return crafts would get an even more impressive dV with an Ant though It is a very light and capable design.

[Pds314]

7 minutes ago, dvader said:

Yes, direct escape. It was much lower than what I expected as well so I expected some calculation error to pop up somewhere. But, now I've tested it and it was almost spot on . I started with perhaps 1900dV at 63km LLO and burnt 1072 dV when Laythe was roughly in the right place. I actually burnt too much and overshot Kerbins orbit so I had to do some corrections once around Kerbol. I intentionally missed Kerbin the first time around and did a orbit correction to hit the second time (which failed). I paid a bit more attention to the second orbit correction and hit Kerbin with 600 m/s left. Not spot on though so I had to burn a lot to actually hit the atmosphere. The reentry speed was about 4.2km/s and well below your tested safety limit. (I did not have a Kerbal on a ladder but had added 90kg of antennas to make up for it).

I used orbital energy for my calculations. Basically an excel sheets with one row for each change in SoI, assuming either prograde or retrograde exits relative to the body etc. Here's a screenshot of the ejection angles from Laythe and Jool.

 

  Hide contents

 

But, if @ManEatingApe has already planned for 2x3t crafts then I guess it is best to go with that so MIKES balance doesn't shift. More fuel is always better than less fuel. The KILO return crafts would get an even more impressive dV with an Ant though It is a very light and capable design.

Nice. I think I can give it 2 tonnes of fuel in the drop tank and just have an Oscar-B and an ant to get home.