The KSP Caveman Challenge 1.3.x - 1.10.x [re-booted]

[Muetdhiver]

Done !

Now. The Crunchy bits.

My initial plan was Mun Sling, Kerbin-Kerbin Sling and then Jool. Turns out that Mun slings are near impossible to setup well enough and are not worth the trouble. As for K-K slings, it's completly doable in caveman, so long as one des not care about angle of arrival (which controls the sling direction...) Turns out K-K sling with a tangent at Pe 2yr orbit is only good for braking

So, I decided to rolls back and do a "direct" transfer. Burn for 2000 DV, as well as possible (i.e. so that the hyperbola sticks to Prograde w.r.t the kerbol centric orbit). I had to correct the AP and inclination to get the AP touching Jool orbit. Then I waited. And missed Jool by 345.76 days (vessel too early). Since jool orbit is 4845.44 days, adding the advance we get that in 5191.20 days after passing AP, the vessel must be at AP again or miss Jool. Using T = 2*Pi*sqrt(A0^3/Mu) where A0 is the semi-major axis and Mu = GM (grav cst * mass of kerbol) along with the knowledge of the period of our orbit once we get to AP again (period was 2363.04 dy), we can compute the period we need for the next orbit to get Jool. Since now we have 5191.20 - 2363.04 = 2828.16 dy, we have to slow our orbit (i.e. raise our PE) such that we get there at the right time. The new A0 is simply A0_new = (A0)*((2828.16 / 2363.04)^2)^(1/3). Substracting AP to 2*A0_new we get our new PE of 24099896873 m. The burn is quite costly, be we have packed quite some fuel for the trip. More than 7.7K overall. We get a perfect encounter, and we have (if my math are right) 4.85K Dv left, minus the retro burn.

Spoiler

Rather tricky burn with a docking procedure in the middle to drop the half empty tanks that where determined to be the best to drop off first to lower the dry mass. Before that we had some fuel in the first booster stage adding about 200 m/s of DV.

Orbit after 2K DV burn with eyeball guidance. Not too bad. Three plane changes to fully remove inclination (makes things easy for caveman orbital mechanics)

Now that is a close encounter. Too close XD

Setting up 245 km PE for a caputre burn. No Aerocapture this time... though it would be quite a feat. Science is already tasty, and I get gravy : Jool exploration mission.

Retro burn. Not to strong, PA is past Bop / Pol. We'll use gravity assists for "improving" the orbit (whatever that means) and getting more science from flybys (hopefully). It's also at this point that I discover a fuel cache : all the oscar B's where locked out

Next part will be Jool system exploration while keeping an eye on DV for the return...

Edited June 8, 2018 by Muetdhiver

[Muetdhiver]

Jool5 lite and Dodging Tylo.

I thought getting to jool was the hard part. Then I remembered : both Tylo and Laythe can mess you up bad. Bad braking : Jool dive. Bad Sling : say hello to eeloo on your way out. OTOH, good slings will save us fuel. Maybe. Here is how I planed to dodge bad encounters : measure orbital period of the ship, and divide it by the moons orbital periods. If it's something like integer,  half or quarter, they will be placed in predictable fashion. Since I want to still visit them, all I got to do is plan gor gentle encounters by shifting the fractions away from nice ratios. I got lucky on the first orbit, no encounter. I use this to keep Tylo pined while trying to arrange for nice (read high altitude) encounter with laythe. However I can't manage Valls at the same time.

Spoiler

Surprise Valls. The encounter is high altitude and more or less a good braking. I have to reboost PE though I use the oportunity do dip in Jool atmosphere for extra Icy Mint science.

The Laythe encounter has to be replaned, but it's just more maths. Things do work out but the Sling is still stronger than I expected. AP is shifted, but also lifted to the edge of Jool SOI. Not far enough from Laythe I guess. Still, one big one is done. To avoid further trouble I raise PE beyond Laythe. On the way back I meed Valls again. That rock. Bracking on the way down is not good, but it's really a nudge, pushing us below Laythe. I push it up again. Costly but worth it. That way we only have Tylo to deal with. And well, surprise Valls.

Spoiler

Beautifull Laythe. Very nice place to explorer with better gear. We'll just flyby on our way to nearly god knows where. We'll avoid the damn place after that. Too dangerous.

The Tylo encounter is planed carefull to push us (hopefully) a bit toward Pol and roundify our orbit a bit.

Spoiler

Tylo the dreaded at a very safe distance. We get a nice boost out of it, plus science.

Using the last fuel of the big tank plus the 4 full oscar B's to lift us up to Pol level and correct inclination.

Getting to Pol costs all the remaining fuel from the drop tank. We know are running with 3.9K DV in the tanks. Pol is easy to land on. No problems here. No lucky greenolith this time.

Spoiler

Slopes. Slopes everywhere. After a bit of terrier skiing we stabilize. Science time. Then back before the battery runs dry.

At this point I still have a lot of DV left. I decide to not play safely and try to do a Bop landing. I have 3.4K DV, and I think 2K will be enough for the return. 1.4K should be more than enough for Bop. I don't correct inclination this time, so the encounter is a bit trickier to get. Still, that quite a bit of DV saved.

Spoiler

The 5th Rock. Jool5 lite (very lite) completed. Now. To get home.

After Bop and more science, time for going hope. Fuel is more than enough it seems. I burn hard but come out above Duna. More Fuel. PE to Kerbin - ish. Then ritual inclination correction. Then the now usual AP correction to catch Kerbin.

Spoiler

Going home. At long last. Well, we'll get there in a few years. A decade maybe ?

This was a very challenging serie. I did some some previous Jool expedition in 3.2x with heavy hardware, so I had an idea of how bad Tylo and Laythe would be. What I did not expect is how difficult it is to avoid them without patched conics...

The overall trip took 40 years in game. Time for Valentina to head for the retirement home now. Btw. The service bay handles kerbin aerocapture from jool like a boss. Did get very red though.

Anyway. This will mark the end of this Caveman run for me. I will return to 3.2x caveman evolved, although I'll do it Gael. I hope that the trick to do interplanetary transfer was clear enough and usefull to other brave cavemens . Interplanetary is  much more fun than biome farming. And Special thanks to ManEatingApe for the lawn built rockets ideas. It was fun and challenging. And a bit frustrating too

Edited June 9, 2018 by Muetdhiver

[ManEatingApe]

10 hours ago, Muetdhiver said:

Jool5 lite and Dodging Tylo.

Fantastic! Bop and Pol landings plus 3 flybys is a great achievement - you've set a new bar for Caveman interplanetary shenanigans!

Edited June 10, 2018 by ManEatingApe

[MinimalMinmus]

Now that's what I call a lvel 2 trilobite!

(Ichtyosaur?)

(And an even more hypothetical level 3 would be Mosasaurus?)

[Muetdhiver]

More like Eukaryote level XD.

It was loads if fun and a very good challenge. I would be very, very impressed by a caveman landing on all jool's moons. 

I'm not 100% certain it's possible due to the wobblyness of such a ship... and the assembly process is a bit too crazy for me.

Edited June 10, 2018 by Muetdhiver

[JAFO]

11 hours ago, Muetdhiver said:

Jool5 lite and Dodging Tylo.

Never underestimate a determined caveman!

Congratulations on a truly stunning achievement, @Muetdhiver!

[Rakaydos]

Ok, so if I havnt missed something, this module has both the wet TWR and the DV rating to go from the surface of Tylo to a low tylo orbit.

The part count requires a build-a-rocket to get it into orbit. Kerbin ground tests says the TWR=1 at about 2 tons, which accounting for atmospheric thrust of the primary engine(16 vs 20) and Tylo's lighter gravity, gives it a tylo TWR just over 1 after it ditches the landing shocks. The Ant engines have a bigger atmo/vac performance gap than the primary engine, so the TWR should be semi reasonable. Gravity losses may still kill the idea, but I dont have hyperedit to conduct simulations.

[IncongruousGoat]

It's finally done. Ladies and gentlemen, Nanocrystalline Diamond has officially been completed.

Mission thread is here:

It took over 7 in-game years and nearly 2 IRL months to complete, but it's done. Let it be known. The challenge is possible.

I wish the best of luck to anyone else who undertakes this.

Edited June 10, 2018 by IncongruousGoat

[Rakaydos]

Assembily was finniky, but I put the tylo lifter into orbit for some DV testing.

I ran into some fuel flow bugs (the tank the fairing was attached to wanted to drain last), but with tanks opened manually per stage, the lifter was able to achieve approximately 2560 DV above orbital velocity. That should give me 350 DV for gravity losses on tylo... at least once I sort out the fuel flow bug.

[JAFO]

13 hours ago, IncongruousGoat said:

It's finally done. Ladies and gentlemen, Nanocrystalline Diamond has officially been completed.

Well done!

As it says in a certain well-known song, "Look at that caveman go!"

 

[JAFO]

13 hours ago, Rakaydos said:

I put the tylo lifter into orbit for some DV testing.

I ran into some fuel flow bugs (the tank the fairing was attached to wanted to drain last), but with tanks opened manually per stage, the lifter was able to achieve approximately 2560 DV above orbital velocity. That should give me 350 DV for gravity losses on tylo... at least once I sort out the fuel flow bug.

While I've nothing against empirical testing, surely it would have been easier to just calculate dV and TWR whilst in the VAB? 

[Rakaydos]

Rocket math isnt my strong suit.

1 hour ago, JAFO said:

While I've nothing against empirical testing, surely it would have been easier to just calculate dV and TWR whilst in the VAB? 

 

[Muetdhiver]

Rocket math is pretty much a neccessity for interplanetary caveman. Otherwise you have no idea if you are on budget or not and efficient transfer burns (i.e. using Oberth as much as possible) are not really possible. (You must know if you have to abort, because an interplanetary rescue mission in caveman is going to be a crapshot once out of a planetary SOI)

It becomes even worse for orbital assembly where tanks may or may not get there 100% full.

DV = LN(m_wet/m_dry) * 9.81 * ISP is all you need. put it in an xls sheet and let it do the math for you. (LN : natural log), wet mass : mass with fuel of the stage. dry mass : mass without the fuel of the stage.

Thumb rules :

• If 1/3 is fuel mass : 4x ISP
• If 1/2 is fuel mass : 7x ISP
• If 2/3 is fuel mass : 11x ISP

I hope this helps ^^ And best of luck with Tylo. You will need at least 3K DV to get down and 2.5K up. Going with 6K is probably a good idea.

One concern I have with your craft is that the capsule cannot reenter kerbin atmosphere and survive from a Jool transfer. You will need at least a 125 service bay for that. Remember that you can't transfer your crew, so the capsule has to be used for everything (and this implies that the chute and the science box have to be there too... wich pushes dry mass up).

Edited June 12, 2018 by Muetdhiver

[Superfluous J]

I know it's not Kosher and doesn't actually count, but I did this in the Snarkiverse, and it was really fun. I posted the first of 3 parts here.

[JAFO]

Just now, 5thHorseman said:

I know it's not Kosher and doesn't actually count, but I did this in the Snarkiverse, and it was really fun. I posted the first of 3 parts here.

Woohoo! I've been waiting for this! 

5 minutes ago, 5thHorseman said:

I posted the first of 3 parts here.

Do you still intend to do the video with commentary?

Re "Rolly 1". I see a second design flaw there.. if that thing loses its balance, it's not going anywhere either! A bold idea, for sure.. but maybe too bold.

Looking at the first part, it occurs to me that the highly eccentric Mun orbit simplifies the job of getting to the Mun somewhat.. I'm looking forward to learning more about your later difficulties.

[Superfluous J]

37 minutes ago, JAFO said:

Woohoo! I've been waiting for this! 

Do you still intend to do the video with commentary?

Re "Rolly 1". I see a second design flaw there.. if that thing loses its balance, it's not going anywhere either! A bold idea, for sure.. but maybe too bold.

Looking at the first part, it occurs to me that the highly eccentric Mun orbit simplifies the job of getting to the Mun somewhat.. I'm looking forward to learning more about your later difficulties.

It makes getting there easier, but getting into orbit - and any specific orbit, is a bit trickier, as you'll learn in PART 2!

And no, no video commentary. I may post the videos themselves but it may not be that good with no talking. Maybe I'll try to add some music and the text from the reddit posts as captions or something.

And Rolly 1 was interestingly stable. Though maybe it'd have been less stable on the direction it should have rolled if I'd turned the trusses sideways so they were rolling along their short ends. I've made so many of these over the years and never like them once I'm done with them, and then make a new one that I'm just as unhappy with.

Part 3 (the final caveman part) will be up tonight or tomorrow.

[JAFO]

3 hours ago, 5thHorseman said:

PART 2

Hmm.. interesting. About a year ago, I did some experiments to see how just powerful a comms network it was practical for cavemen to construct (turns out in a stock system, it's simply not practical at all), and I think a setup capable of permitting control of drones around Snarki-Dres MAY just be feasible. I might put some time into experimenting with that.

[Muetdhiver]

36 minutes ago, JAFO said:

Hmm.. interesting. About a year ago, I did some experiments to see how just powerful a comms network it was practical for cavemen to construct (turns out in a stock system, it's simply not practical at all), and I think a setup capable of permitting control of drones around Snarki-Dres MAY just be feasible. I might put some time into experimenting with that.

Indeed. In my caveman evolved play in 3.2X / SETI I uses the woomerang site as a giant cluster of antenas to overcome the horrible l1 tracking stations. I was able to get to duna that way, though I had to lauch a relay probe behind the first one.

Though in vanilla one only has access to the HG-5, So I'm unsure of how far such a sheme can stretch...

Snarkverse does sound like fun. Will try it.

[Rakaydos]

8 hours ago, Muetdhiver said:

Rocket math is pretty much a neccessity for interplanetary caveman. Otherwise you have no idea if you are on budget or not and efficient transfer burns (i.e. using Oberth as much as possible) are not really possible. (You must know if you have to abort, because an interplanetary rescue mission in caveman is going to be a crapshot once out of a planetary SOI)

It becomes even worse for orbital assembly where tanks may or may not get there 100% full.

DV = LN(m_wet/m_dry) * 9.81 * ISP is all you need. put it in an xls sheet and let it do the math for you. (LN : natural log), wet mass : mass with fuel of the stage. dry mass : mass without the fuel of the stage.

Thumb rules :

• If 1/3 is fuel mass : 4x ISP
• If 1/2 is fuel mass : 7x ISP
• If 2/3 is fuel mass : 11x ISP

I hope this helps ^^ And best of luck with Tylo. You will need at least 3K DV to get down and 2.5K up. Going with 6K is probably a good idea.

One concern I have with your craft is that the capsule cannot reenter kerbin atmosphere and survive from a Jool transfer. You will need at least a 125 service bay for that. Remember that you can't transfer your crew, so the capsule has to be used for everything (and this implies that the chute and the science box have to be there too... wich pushes dry mass up).

You'll note that I'm throwing together designs and doing empirical testing of DV ratings, rather than taking a calculator to it. I'm referencing those numbers against DV charts. My orbial assemily technique sacrifices module size for a guarntee of full fuel loads for the component- residual fuel in the booster is used for docking and discarded.

I missed not being able to transfer crew in caveman- that would have been a nasty suprise, as I was optimizing my design for airless lift from tylo. I do have a docking port, so I may be able to get away with a "recovery package" I attach to the capsule before it comes home. (Service bay, parachutes, extra battery for SAS), though I dont think I can spare the mass for any science beyond crew reports.

[Superfluous J]

9 hours ago, JAFO said:

Hmm.. interesting. About a year ago, I did some experiments to see how just powerful a comms network it was practical for cavemen to construct (turns out in a stock system, it's simply not practical at all), and I think a setup capable of permitting control of drones around Snarki-Dres MAY just be feasible. I might put some time into experimenting with that.

I wasn't aware that there were any relay dishes in stock at Caveman levels. I may have tried it. Or do you mean just throwing a bunch of them on a probe core to make a better ground station than the ground stations?

Anyway, Part 3 is up. I've completed it, and am moving on to Caveman Evolved.

[Rakaydos]

1 hour ago, 5thHorseman said:

I wasn't aware that there were any relay dishes in stock at Caveman levels.

https://wiki.kerbalspaceprogram.com/wiki/HG-5_High_Gain_Antenna

[JAFO]

6 hours ago, 5thHorseman said:

I wasn't aware that there were any relay dishes in stock at Caveman levels. I may have tried it. Or do you mean just throwing a bunch of them on a probe core to make a better ground station than the ground stations?

The only relay antenna available to Cavemen is the HG-5. It's just a matter of stacking enough of them onto a single craft to extend the range out far enough to be useful. I found that with L3 tracking stations, a cluster of 88 HG-5s orbiting Eve gave an 11% signal at Eve when Eve was at closest approach to Kerbin (so for 90% of its orbit, Eve was still out of range, and Duna was just never gonna happen). I estimate that to do the same thing with L1 tracking would need something on the order of 500-1000 HG-5s, so it really wasn't feasible.

Snarki-Dres, on the other hand, is a lot closer to Kerbin than Eve at closest approach, so it may just be within the bounds of possibility.

Edited June 13, 2018 by JAFO
Wrote 'Kerbin' where I meant 'Eve'.. oops

[Superfluous J]

What a fool I am. I thought that just because it was listed as a direct antenna and didn't show the relay stats that it wasn't a relay antenna. Now I know how people feel when they can't find the Materials Bay to complete satellite contracts.

[JAFO]

On 6/13/2018 at 3:51 PM, 5thHorseman said:

What a fool I am. I thought that just because it was listed as a direct antenna and didn't show the relay stats that it wasn't a relay antenna. Now I know how people feel when they can't find the Materials Bay to complete satellite contracts.

Hey.. That's more a failing on the KSP devs part, than yours.. 

In other news, I've been playing around with relay clusters at Snarki-Dres, with L1 Tracking Stations. Turns out to be VERY feasible.

HG-5 Antenna Clusters @ Snarki-Dres

Number of HG-5 Antennas	Signal Strength Percentage
1	0%
2	4%
3	15%
4	25%
5	32%
6	38%
7	43%
8	47%
16	65%
24	73%
32	77%
40	81%
48	83%
56	85%
64	86%
72	87%
80	88%

 

 

 

 

 

 

 

 

 

 

 

 

 

 

As the formula for antenna-stacking would suggest, the law of diminishing returns starts kicking in after a while, but it's clear that a Snarki-Dres-probe with 8-16 HG-5s on board should have no trouble staying in contact with Kerbin.

Putting 2 or 3 16-24 HG-5 cluster-satellites around Snarki-Dres ought to be fairly easy to arrange as well.

Edited June 14, 2018 by JAFO
Added additional low-antenna-count data

[JAFO]

6 hours ago, 5thHorseman said:

Anyway, Part 3 is up.

Oh boy.. talk about a comedy of errors! Gave me some good laughs.

I feel your pain, but.