bayesian_acolyte

Hit me with a Stratzenblitz. I would greatly prefer a challenge with a significant minimization component (mass/time/etc.) rather than something like a megastructure or 1000 kerbal colony. I'm happy to install a planet pack if the wheel so dictates. My current mods are just better time warp, mechjeb, and maneuver node splitter. I haven't played in 2.5 years and this seems like a great way to scrape off some rust before KSP 2. There's a chance I'm biting off more than I can chew, but at least it should be interesting.

Here are some I've had fun with, although they aren't great fits with your no-revert style: You can't accept any contracts or set admin strategies. The only way to get funds is world first bonuses. Double gravity for all bodies (be warned this messes with orbital mechanics, also more of a setting than self-imposed). Limit the total number of launches allowed. If you want an extreme challenge, it's possible to complete either of the above careers in just 3 launches. Start your career on a more difficult body like Eve, or do RSS with stock parts (requires mods, but you can leave everything else unchanged).

I've completed the challenge on the 3rd launch by landing on the Jool 5 plus Eeloo and Dres. ~20 image report: ~100 image report: https://imgur.com/a/nsUdX59 I've thought about doing extra missions for more points but decided to just post what I've got so far. Hopefully it's alright if I extend on this career later.

I made it to Eeloo and back:

I made a table of interplanetary phase angles for 2G. Standard disclaimer, these assume no inclination or eccentricity and are only partially tested. See here if you aren't sure how to use this info.

I've completed 2 launches so far on a 2G default settings career. I've only used mods to automate science sampling, improve time warp, or add information. Launch 1: upper atmosphere Launch 2: Minmus biome hopping plus Sun and Mun orbits

I'm not sure. The TWR was mostly between 10 and 15. In the video it maxes out the G force meter at 15 a few different times on the ascent, but the max G force was likely on the rather abrupt landing.

I don't think it was off at all. I never actually ran any of the maneuver nodes, instead checking all around the window and assuming that it would show if there was an encounter like it did in that screenshot. But I just ran a 2G Mun/Minmus mission and this wasn't the case. It showed the first Minmus encounter via node, but later it refused to show a Mun encounter despite there being one. After writing the above paragraph I just went and tested it. The +14.4 degree phase angle I calculated to Eve appears to be correct. However in testing this I encountered another issue: to get to Eve, we eject retrograde to Kerbin, but are still following a similar prograde path around the sun. But our path around the sun is now faster than Kerbin because we are on 2G speed while it's on 1G, so after leaving Kerbin's SOI we run into it again and then leave and re-enter in a never ending cycle. I was able to get around this by using very high time warp with the better time warp mod, and it just skipped over the SOI.

I believe my time is 2:34 /2 = 1:17 if we use the "under 2 m/s" definition of "landed".

I haven't had time to do a full investigation but there are some weird things going on with interplanetary transfers with increased gravity enabled. First, all the normal tools don't work like Alex Moon's planner and Mechjeb. This is somewhat to be expected, increased gravity increases orbital speeds, which changes the timing and DV of everything. The nice thing should be that despite window timing changing, the required phase angle should be exactly the same (it just happens on a different date), because the transfer orbit and the angular velocity of the target planet increase by the exact same factor and effectively cancel out. However the odd thing is that despite Kerbin's listed orbital speed appropriately changing when the gravity is changed, it appears to move at the same speed, with one rotation around the sun taking exactly one year. I next tried to run the phase angle math using the modified gravity value for the transfer orbit (because craft still move faster with more gravity), and the default gravity value for the target/origin orbits (because planets apparently don't), but when I tried to set a node to implement that value by holding a protractor up to the screen I still couldn't get an intercept with Eve. That's as far as I got. Complicating matters is the fact that the "closest approach" markers seem to be worthless with increased gravity, making it impossible to visually fine tune maneuvers to get an encounter. For example this is what things looks like with a Mun encounter extremely close to happening: And here is what it looks like with the maneuver node moved just a few seconds so there is an encounter: It's impossible to tell that the 1st image is very close to an encounter, with the "closest approach" markers being wrong in every way. When the encounter is achieved, the visual is still bugged and a bit confusing. Anyone understand what is going on here? These problems really amplify the difficulty of this challenge.

I finished a stock RSS career about 6 weeks ago with the added restriction of no contracts:

While we are clarifying rules, forgive me if there is a standard convention for this as I've never done a payload challenge, but what exactly counts as payload? Can any of the following parts be counted as payload if they assist in getting to orbit: engines, fuel tanks, command modules, SAS, fairings? Does the payload have to separate?

It used a bit over 1km/s worth of fuel, but the efficiency was only something like 60% converting that into orbital speed because of the low TWR (<0.25). The whole LVN stage was like 11.5 km/s dV so it was only using the start of it. I was maximizing for cost and post-LEO dV, so I only wanted to use one LVN, and that was about as much as I could pull off using it on the ascent with the TWR so low. If I was maximizing for launch weight instead of cost, I might try to add more engines and use them for more of the ascent, but not sure it would make much positive difference because of the low TWR.

It's not that bad. In that link I posted earlier I launched ~25 tons to LEO with 5 twin boars, 6 kickbacks, 2 poodles, and a NERV, at less than 200k cost and ~900 tons. Using drop tanks/asparagus helps, especially for TWR in later early stages. Like @moar ssto was saying about TWR, I was starting around 1.6 and going up to ~3.5 before I started dropping boars. I haven't tried to scale it up to deliver 20t to GEO but I'd guess it's possible to do under 1500 tons and 300k cost (not easily). Not sure how FAR or that parts mod mandated by the OP might affect things though. In my experience using higher average TWR designs lowered the cost (to a point at least).

Here's a rocket that can deliver a 5.5 ton satellite payload to LKO for under 5k net funds:

Happy to see this challenge still so active! Here's a new entry with 4183 dV in orbit:

I hope this challenge takes off. It might be tough to get people to participate though, especially with requiring such a specific group of mods. I might DL these mods and whip up something later, but I'm not sure I want to be the first. In the mean time, you might be interested in some of the relatively low cost and low tech launchers I built for my RSS career with all stock parts and no contracts. For example on the last mission I planted a flag on every moon of Jupiter and Saturn with under 400k launch cost with this ship: You can read more about it here:

I was hoping to have the first kickback entry, but Mystified beat me to the punch while my video was converting to fast motion. I'll settle for cheapest (for now). Introducing the Steely Glint at 8151 initial cost:

I did an all round trips career run in 5:00:29. This was done under the speedrun rules at https://www.speedrun.com/ksp#All_Round_Trips which are a bit different than those in the OP, especially the planting flags rules. So I understand that this doesn't count for the leaderboard in the OP. The biggest difference from previous submissions in this category were using a pretty low tech level and only doing 4 orbital launches.

They were the default textures when I downloaded RSS. This was my first time playing RSS and I think they did an excellent job overall, especially for a free mod.

The ascent profile is important. Before the whiplash cuts out you want an AP at least 50 km and ideally more like 60 km (70+ km also works but is less efficient), and you also want a surface speed of around 1500 m/s at 20km. It's mostly about getting the right ascent angle early on which can take trial and error. The wing attachment angle is also very important here; I'm not sure it's possible to get this ascent profile with wings that are attached straight on, and if they are tilted too much you can't get enough speed, so that might be your problem. Here is the craft file (you probably want to add more fuel though, the margins are slim): https://kerbalx.com/Bayesian_Acolyte/Nervous-Energy-4 IIRC you want to flip at like 43 km for a 60 km AP. There is less drag if you flip using yaw from the side (as opposed to flipping with pitch). You may want to rock the opposite way a bit first to make the turn more forceful and quicker. Having it stick on retrograde can be a bit tricky, especially if you are flipping at a lower altitude, so try to time some counter-rotation.

Nervous Energy 4: 4809 initial cost - 4668 recovery = 141 mission cost

Nice work @sevenperforce, but two can play at that game. Introducing Little Rascal 3 with an initial price tag of 1578.

Little Rascal 2: 2003 initial cost

Nervous Energy 3: 5079 - 4929 = 150 cost