MaxFenig

I've built a couple of worthy launchers which are not direct copies of real LV, from early 10 tons to 200 tons - all in my RP-1 Career. Rockets of the World-inspired schematics poster and specs: Cerberus Medium LV - 10+ tons to LEO, Proton-based (3.8% Payload Fraction) Cerberus Heavy LV - 20+tons to LEO, Proton-based (4% Payload Fraction) Lowfyr LV - 40+tons to LEO, NK engine-based (man-rated, 5.2% Payload Fraction) Deus LV - 200 tons to LEO, Energia-based (man-rated, 7.1% Payload Fraction) Pretty happy with all of them, they all hit a sweet spot in career mode and have flown tons of times (except Deus which I am still waiting for the first production to finish). Not sure what the next step is - I know I will use Deus for many mission, first it will launch my 30 ton Lunar Station, then a manned Venus flyby and also for Mars, plus a sample-return mission to Saturn (12 ton to Saturn). I might need an even heavier one after that for my Mars station and base, but I like to keep cost, tooling and Launch Pad requirements sane - I just moved to 8m diameter with the Deus. It also as "cheap" (168 + rollout vs 185 millions), lighter (2,600 tons vs 2,970 tons), smaller (86 vs 111 meters) and more powerful than Saturn V (200 vs 140 tons to LEO). Reddit post and full imgur gallery:

I think the challenge lacks an important aspect - we can make inefficient design with cheap part with very very little payload or no payload at all since only the total weight is taken into account - that does not make it a usable launch vehicle tho. You can game it and add tons of weight with cheap parts/lead ballast that increases the weight more than the cost, to fill leftover thrust from your over-sized engines. I think it should be, or add it as a extra challenge: Funds / LEO Payload In KG (periapsis >= 140km) Otherwise it's just the heaviest rocket that can reach leo with the lowest cost possible.