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

[Popestar]

2 hours ago, Superfluous J said:

I don't know the details because I've never done it, but a Kerbal on a ladder climbing against something that blocks them (say the starter strut) puts a force on the craft. Which means you can get to orbit for free, with an EVA'd Kerbal to boot.

That explains why its banned.  Thanks!

[Mr. Peabody]

2 hours ago, Popestar said:

Quick question:  what's a ladder drive?  Saw it mentioned in the first post, and I realized I have no clue what that is.

 

[JAFO]

12 hours ago, JAFO said:

Assuming that even still works. It was a very old bug. May have been fixed by now.

Nope. I was wrong.

According to evi1wombat, who made the video @Mr. Peabody posted above, it still works in v1.10!

Edited November 29, 2020 by JAFO

[Popestar]

I just watched that video.  That's just sick.  Takes away all the fun from the game to cheat like that.  I mean, it's fun the first time you do it...maybe the second.  If you have one of those saves where you cheat to test stuff out, I guess it's ok.  But that's just wrong and against the spirit of the game.

FYI, I'm still working on this career.  At this point, however, the going is getting slow.  90 science points per tech tree node, and I need 8 more nodes to finish the challenge.  720 more science points to go, and earning the science is getting harder and harder now.  But I'm going to finish this, primarily because I want that shiny badge in my signature!

[JAFO]

55 minutes ago, Popestar said:

FYI, I'm still working on this career.  At this point, however, the going is getting slow.  90 science points per tech tree node, and I need 8 more nodes to finish the challenge.  720 more science points to go, and earning the science is getting harder and harder now.  But I'm going to finish this, primarily because I want that shiny badge in my signature!

Good to hear! So what's the next mission going to be?

[Popestar]

17 minutes ago, JAFO said:

Good to hear! So what's the next mission going to be?

I've got a few more contracts to get science points, but the next actual mission will be to dock more fuselage parts to the station.  You know, so that it looks like they are intersecting the main fuselage in the middle.  Then I want to get some antenna on it and then command pods.

It's a lot that I want to do, but that's kind of the point if this challenge, right?

[fourfa]

Still running NCD-level + reverts.  I had good success with ladder rides on Mun flyby.  Scaled up to ladder rides to Minmus, with juuuuust enough dV to drop into elliptical orbit.  But Bill, after years of next to no missions or accomplishments, decides...

to be the first Kerbal* to set foot on another world

 

 

* [in this save]

 

 

(now I hope I can get him back)

Edited December 2, 2020 by fourfa

[Popestar]

So I'm sitting at 81 science points, with at least 1 biome on Kerbin to get points from.  I am going to get the next 9 points from contracts, and then I'll focus on the space station.  I tried using a couple designs I found here at the forums to get to the Mun, but I just can't make a go of it without the station, so that's my next focus.

However, I have a question!  What should be the next tech tree node i open?  I have Miniaturization and Electrics, but I'm not sure what will help me the most.  Any thoughts what I should do?

[IncongruousGoat]

2 hours ago, Popestar said:

So I'm sitting at 81 science points, with at least 1 biome on Kerbin to get points from.  I am going to get the next 9 points from contracts, and then I'll focus on the space station.  I tried using a couple designs I found here at the forums to get to the Mun, but I just can't make a go of it without the station, so that's my next focus.

However, I have a question!  What should be the next tech tree node i open?  I have Miniaturization and Electrics, but I'm not sure what will help me the most.  Any thoughts what I should do?

Advanced Construction, for fairings. After that the best choice is probably Propulsion Systems, for good probe and lander engines & tanks, but you need fairings to take full advantage of those.

[Popestar]

So I was able to complete a few more contracts, and in the process of doing so land Valentina on the Northern Ice Shelf.  Did the science-y thing up there, and earned enough Science Points to unlock Advanced Construction!  3 down, 7 to go.  With Advanced Construction out of the way, I am now going to work on the docking tutorials; the fairings will allow me to haul pieces for larger ship construction up to the Venture space station and then launch from there to the Mun and Minmus.  Which will allow me to then gain more science points, and get more nodes unlocked, and build bigger ships in orbit...you get the idea.

I'm having, though, a bit of an issue still getting into Orbit and having dV left over to do other stuff.  My flying skills leave something to be desired, but I'm still just for some reason not "getting it".  I do the gravity turn, starting at 70 degrees when I'm at 50 m/s, then turning over to 45 degrees once my altitude reaches ~25k, always watching my TWR and making sure it's closer to 1 than it is to 2.  But for some reason I'm just burning fuel way too quickly it seems.  Anybody have any advice, other than "just keep practicing"?  Is there something I might be missing here that I should pay more attention to?

[fourfa]

On 12/4/2020 at 5:39 PM, Popestar said:

I do the gravity turn, starting at 70 degrees when I'm at 50 m/s, then turning over to 45 degrees once my altitude reaches ~25k, always watching my TWR and making sure it's closer to 1 than it is to 2.  But for some reason I'm just burning fuel way too quickly it seems.  Anybody have any advice, other than "just keep practicing"?  Is there something I might be missing here that I should pay more attention to?

This sounds rather steep.  Let's assume you're flying the standard caveman 12T single-Reliant booster, 6T single-Terrier payload/spacecraft.  6 tons being the mass that gets you 1.0 TWR at staging (which is just enough to keep the second-stage apoapsis moving away from you at all times on the following launch trajectory).  And no draggy leading-edge mismatches in part diameter (i.e. no probe core right on top of a 1.25m tank with no adapter).

What works for me is: straight up until 75m/s.  Start the turn with about a 10° turn east, getting just to the edge of the prograde circle.  Keep nudging it steadily east; the steering is never going to be hands-off for the whole flight.  Halfway to the 45° mark at 4-5km.  Hit 45° at ~10km.  Keep steering toward the horizon but never outside the prograde circle on the first stage.  Watch the TWR and start to throttle back as needed towards the end of the first stage.  Don't worry about flames or reentry effects (a proper gravity turn will have plenty of both).

Stage and throttle to max.  At this point you should watch and guess about your time to apopasis - watching apo in the lower left corner (click the purple square) make sure it's increasing at the same or greater rate as your current altitude.  If the apo is moving away in a hurry, turn harder towards the horizon to slow it down (this is better than throttling).  If you're starting to get close to apo, turn upward away from the horizon to boost it momentarily.  I find I'm halfway between 45° and horizon by 25-30km, and fully flat on the horizon at ~50km and nearly at orbital speed.  Keep the throttle at max until your apo is above 70km - max throttle gets you going faster down lower where it's most efficient; use your pitch above horizon to control your vertical speed instead.  Once the apo is in space, throttle down to fine tune to 80km (or your desired final altitude).  At this point you should have a fairly long coast to apo, make sure you're staying prograde (have to steer it by hand on probes). 

That's it.  If it's a smaller probe things can be different - throttling more, turning a little harder.  But in my game there's very little that needs to be more complex than one Reliant, one Terrier, and decent aerodynamics.

 

Bill jetpacked to orbit from Minmus surface but neither he nor the spacecraft had enough dV to match orbits.  Sent a rescue mission with a single empty Mk1 seat and full RCS, picked up Bill, docked with Jeb, staged away Jeb's dead propulsion module, and burned for Kerbin with plenty to spare.  And forgot to get a screenshot

[Popestar]

So I'm having a bit of an issue with the docking tutorial.  I get to the part where it says to get within 15k of the target and then throttle full at retrograde until relative velocity is ~50 m/s.  I hover over the ship and throttle full, but I'm running out of fuel before I reach the target velocity.  Any advice here?  I dont expect this to be easy, but I must be missing something on this tutorial, right?

Posted here as this directly relates to my caveman challenge career.

[Popestar]

So, while waiting for an answer on the docking tutorial question above, I decided to continue on with the Caveman Challenge, doing what I could.  Which today involved a Munar fly-by!  First, the Explorer I rocket in the VAB.

Spoiler

The build of Explorer I, from the top down":

• Mk16 Parachute
• Mk12-R Radial Mount Drogue Chute (2)
• Mk1 Command Pod
• 2Hot Thermometer
• PresMat Barometer
• Mystery Goo Container
• Heat Shield 1.25m
• TS-06 Stack Separator
• FL-T200 Liquid Fuel Tank
• FL-T400 Liquid Fuel Tank
• LV-909 Terrier Liquid Fuel Engine
• TS-06 Stack Separator
• FL-T400 Liquid Fuel Engine (5)
• LV-T30 Reliant Liquid Fuel Engine
• Basic Fin (4)

17.885 tons, 21 parts, and she cost 9497 funds.  I might have to go back and see what the recovery cost was; this one might actually work for the Lowest Cost to Orbit/Mun challenge as well.

**Goes back into KSP and checks the logs for recovery funds...**

Nope, no log file to show that.  Not to mention that I think the cheapskate challenge involves landing on the Mun and returning, which I haven't done yet.  Oh well!

A shot of Explorer I in orbit, with the first stage long gone.

And a shot of Explorer I as she passes by the Mun.  I wish I would have gotten a better shot here; I was so excited to have done the fly-by without the help of maneuver nodes that I just grabbed a screen shot.  Eyeballing where things are is not all it's cracked up to be.  But, thankfully, I have been paying attention, so I can kind of see where I should be aiming in Kerbin's SOI.

Thanks to this trip and gathering some science data - as well as hitting a whole bunch of World Firsts milestones AND completing the Mun Fly-By contract, I was able to hoard a whole bunch of science points.  Spent 90 to pick up Fuel Systems, which means I'm now at 4/10.  The interesting thing about Explorer I is that the Engineer's data there shows the ship with monopropellant still in the command pod.  Yeah, I forgot to remove it.  Which means I might have to put her back up in space, this time with no monopropellant, remove the existing science gadgets (thermometer, barometer, mystery goo container), and add the science junior.  Might have to also remove 2 of the fins to get under the 18 ton limit; I'll have to play around with the design. 

All told, I love that this challenge is pushing me to think about how to actually fly instead of just setting a node and letting it rip.  Or just saying "Moar Boosters".  Anyhow, that's my report for today.  I will probably have more to say about the Mun tomorrow!

Edited December 9, 2020 by Popestar

[Popestar]

So I was able to shave enough weight off this thing and add the SC-9001 Science Junior, and my weight came in at exactly 18.0000 tons.  I put Jeb in the command pod, sent her to the launch pad, and successfully intercepted the Mun so I could get some sweet science points.  Unfortunately, the SC-9001 is about as heat resistant as a snowball, and the thing blew up on re-entry.  Multiple times.  I tried multiple times to get this thing back to the surface, and it blew up.  In most cases, the command pod also ignited, which tells me that my re-entry is too fast.

Is there a way to slow down during re-entry?  The last time I tried, I noticed my speed coming in was like 3 km/s, which is far higher than what you see even in the above screen shot of Explorer I by the Mun.  I am pretty sure that the Mun acted as a gravity assist when I got close enough to it, but how to slow down?  I can get to Ap and do the retrograde burn to set the Pe to something in the neighborhood of 40k, but I'm just going too fast.

Help?

[fourfa]

It’s really hard to get the Science Junior to re-enter (just look at its temperature max in the VAB).  It’s a lot easier to use the Experiment Storage Unit to pull the data, toss the Science Junior, and re-enter with the box.

[Popestar]

So, how do I add the Storage Unit to a rocket and have it not blow up?  I can't seem to figure out how to add it to Seat 0's inventory, and leaving it outside the command pod you'd think it'd explode upon re-entry as well?

Anyhow, I did some orbital science gathering in high over Kerbin (at about 7000 km), and I earned enough to pick up Propulsion Systems.  That gives me 5/10 on tier 5, which means I'm halfway home!  Got a couple of contracts related to the Mun, one of which is to orbit and return.  Trying to squeeze more out of this rocket design so I can do that, but gosh darned it all if fuel ain't heavy!  I'm just slightly over the max weight, but I know I need that third fuel tank on the second stage in order to orbit and return (currently have an FL-T400 and an FL-T200; would like to put an FL-T100 on there as well so I can make sure to have enough fuel).

[fourfa]

3 hours ago, Popestar said:

leaving it outside the command pod you'd think it'd explode upon re-entry as well?

The best predictor of how a part will fare through reentry is its 'max temp rating,' visible when you right click items in the VAB/SPH selection menus.  You will find your answers there.

(P.S. it's an attachable part, it's not at all involved in the seat inventory system)

[IncongruousGoat]

3 hours ago, Popestar said:

So, how do I add the Storage Unit to a rocket and have it not blow up?  I can't seem to figure out how to add it to Seat 0's inventory, and leaving it outside the command pod you'd think it'd explode upon re-entry as well?

The surefire thing to do here is to put it (and any other small science you bring along) inside a service bay. Those have a really high heat tolerance, to the point of working as substitute heat shield, and as a bonus work as a great airbrake if you open the bay doors. You still need a parachute to land safely, but the airbrake effect is nice for those times when the capsule ends up pointed the wrong way during descent.

[Popestar]

1 hour ago, IncongruousGoat said:

The surefire thing to do here is to put it (and any other small science you bring along) inside a service bay. Those have a really high heat tolerance, to the point of working as substitute heat shield, and as a bonus work as a great airbrake if you open the bay doors. You still need a parachute to land safely, but the airbrake effect is nice for those times when the capsule ends up pointed the wrong way during descent.

That won't  work due to part and weight limitations.  Guess I just forgo the science junior.  

[Popestar]

Ok, so I know it's possible to orbit the Mun and return with the 12 ton/6 ton rocket...but the mechanics of doing so are eluding me.  I can get into a stable Kerbin orbit, and I can do Munar fly-bys and then land on Kerbin (or, well, what substitutes for landing, sans the skyward-reaching flames upon impact).  I've even been able to do a fly-by of the Mun at ~10km (Munar Pe).  But orbiting and returning...I am nearly out of fuel by the time I set the orbit, and have just enough to reach escape velocity of the Mun, but never on a trajectory anywhere close to Kerbin, let alone in a path where I would actually intersect the blue ball.  And this is with a retrograde burn at Munar Pe until a basic orbit (with a pretty high Ap) is reached.  Like, just long enough to set the orbit.

So why is this important?  Well, I'm asking for tips and tricks on how to pull this off.  I've done about all I can to shave weight off the rocket so I can add an FL-T100 to the upper stage to give me enough fuel, but I'm coming in at just over 18 tons.  No monopropellant, no science gadgets, no fins, smallest stack separators, pea re-entry module.  And I'm just barely over.  But I know it's possible with the original rocket design - I've seen posts where people claim they've done it.  Heck, I've seen posts where people claim they've landed and returned.  But this eludes me.

What am I missing?  What tips should I be taking into account when doing this?  Am I burning too much fuel to get into LKO, and if so, how do I correct that?  I'm using the advice given earlier (10 degree pitch at 75 m/s...ish; 20 degree pitch at ~4-5 km; 45 degree pitch at ~20km, stage when I have to and full throttle; cut the engines when Ap is ~71km, horizontal pitch and full throttle when ~25 seconds way from Ap, trying to keep time to Ap between 10 and 20 seconds; cutting engine when Pe of orbit reaches ~71km).  At least, that's what I got out of the advice.  I'm sure I could definitely use practice to improve all that and get more efficient.  But what am I missing?  Munar orbit and return has to be achievable here, right?

[Muetdhiver]

On 12/10/2020 at 5:36 AM, Popestar said:

That won't  work due to part and weight limitations.  Guess I just forgo the science junior.  

Note that if you have a service bay, drogue chutes are not needed. Just open the doors and you'll bleed speed real quick. 

If you aim at a water body l found that you may be able to recover the terrier stage.

This type of recovery is possible from a mun return, but the reentry window is very small. 

For caveman docking : youyou need to launch a bit before the target flies over the LAX, and aim an orbit that shares Pe but has Ap a tad higher than the target if it is behind you. (Or a tad lower if before you, swapping Pe and Ap above)

Then, trim relative inclination. After that look at the distance between the craft in the map and look at how much it shrinks with each orbit. Then adjust Pe or Ap to get a close encounter, select target then kill relative velocity (which should be low).

The enjoy the docking

Edited December 12, 2020 by Muetdhiver

[fourfa]

Well that trajectory is (again) pretty different from the advice that's been given here.  45 degrees at 20km is going to be inefficient.  Rather than repeat myself ad infinitum I'll move on to other tricks

One: there's no need to circularize at Mun - if you just want to grab science and trigger achievements, your Ap can be pretty high (just inside Mun SOI, trial and error to figure this out) and Pe just below the "space low over Mun" threshold altitude (under spoiler tag)

Spoiler

(60km)

Two: When ejecting from Mun orbit the standard single-burn advice is to cancel out the Mun's orbital speed around Kerbin; ie burn on the side of Mun that's leading in its orbit, so your Ap increases on the trailing side.  In other words when you transfer from Mun SOI back to Kerbin SOI, you have relatively little sideways motion, and fall almost straight down with a very low Kerbin Pe.  With abundant fuel, patched conics and maneuver nodes (not allowed here) you can easily plan a single burn of ~280m/s that lands you at a safe atmospheric re-entry.

Without that it's a lot of guesswork, and when you get it wrong (you will; we all will) the correction burn performed around Mun's orbital height is relatively expensive, and you'll likely run out of fuel before getting the Pe down to Kerbin atmosphere.

The other option is to burn for prograde ejection on the trailing side of Mun, raising the Ap on the leading side.  Then when you exit to Kerbin SOI, your Ap may be extremely high (perhaps as high as Minmus), and Pe still nowhere near atmosphere.  Counterintuitively, this is a good thing!  It takes longer but when you orbit all the way around to that high Ap, you will find that adjustments to Pe are MUCH cheaper than they are from Mun height.  Often this will be enough to get you home.  Be aware, though, that reentry will be at higher speed and much care is needed on proper Pe choice - nothing wrong with setting it high and taking a few laps to slow down.

But don't despair, you're right that this is pretty hard.  Orbiting Minmus is far easier.  Properly orbiting Mun and returning probably isn't possible without the Terrier (I assume you have this already) and it helps a lot to have Advanced Rocketry and Fuel Systems unlocked to free up part count.  Landing on Mun and returning with a probe is certainly possible (though it implies a good relay network), many examples in this thread and earlier ones.  Landing and returning alive with a single-launch crewed pod is not.  I'd love to be proved wrong though!

In my late-NCD run I've only just gotten crew on Mun with a lander-can-based ship; the pilot then waits for rescue in medium Mun orbit.  That requires Fuel Systems (to reduce part count), Advanced Construction (for fairings as the lander can has absurd drag on launch without them), Advanced Flight Control (lander can and RCS for rescue craft), Miniaturization (docking ports), Electrics (probe core to enable sending an empty rescue pod). That's more than halfway through the final tech tier, so yeah, it's hard.

 

While I'm here I'm fairly proud of the long-range Kerbin science plane I came up with on this run.  Can bring every experiment to every biome on Kerbin with just Aviation and Basic Science nodes:

https://kerbalx.com/fourfa/The-Long-Ranger

 

Edited December 11, 2020 by fourfa
typo

[Popestar]

@fourfa

That's a typo on my part; it is at ~10km (probably more like 12; I don't want to push too hard on the turn and end up flipping).

I have to go back and look at the nodes I've unlocked, but I'm pretty sure I am missing Heavy Rocketry.  Fuel Systems I have, so I'll have to check out the tonnage and fuel requirements that come with the upgraded tanks to see if I can free up any space.  I actually looked at trying to use the Spark engine...but man does that thing have lousy thrust in a vacuum.  20?  Seriously?  I could push faster than that.  But I am at 5/10 nodes on that last tier; I'm thinking a fly-by of Minmus might help push me closer.  But I'd really like to get a close fly-by of the Mun first to pick up those nice science points.

I'm not worried about this being hard; I expected it to be.  It wouldn't be a challenge if it wasn't. 

[fourfa]

The Spark has plenty of thrust to land and take off on Mun actually, and it can be slightly more efficient overall due to its lower mass.  But it's not enough to work as a Kerbin launch upper stage, so usually it ends up overall more efficient to hang on to a single Terrier for launch and all stages of flight at Mun despite how overpowered it is

[Popestar]

So I can get the fuel I need by using the OKTO and a pair of solar panels, but upon launch the rockets pitches west uncontrollably.  Even if I hold down S, it continues pitching west and I cannot stop it.  Happens at about 1km and doesn't stop.  Anybody know why this happens, and what to do to correct it?  I've got 4 basic fins at the bottom of the rocket, and when I use a command pod with a Kerbal it doesn't do this.

thoughts?