sevenperforce

Here's my submission. Part count is 117 without the launch transport and erection mechanism, but 88 of that is payload, so the actual part count is 29, which certainly qualifies as "big dumb booster". It definitely looks like the Sea Dragon, though it's obviously not quite that big, because I don't use mods. I used a 12x3.75 meter fairing, so that was the limit on vehicle diameter. In order to keep it looking realistic, I couldn't make it any bigger, so this is a Sea Dragon Mini. The main engines are all gimbal-locked and there are no active reaction wheels. RCS is disabled on the way up. The only reaction control is four Swivels set up as Vernier thrusters. Payload is an orange tank blanketed in RCS tanks and thrusters, with the attached Mark 2 capsule. The tank can be delivered to your standard space station or fuel depot; the capsule then returns independently and lands. I don't have mods to allow for part persistence, but if you want me to throw a probe core and some chutes on the first stage to demonstrate that it can be recovered, I will.

Dumb news coverage: Uh, no. Most of SpaceX's missions have gone to GTO, not LEO. And a satellite in GTO does not appear stationary; a satellite in GEO appears stationary. The reason the launch is expendable is because they are sending a particularly heavy bird to GTO. But what do you expect?

So, in other words...build a really ridiculously large TSTO that can lift a 10x3.75m fairing, and figure out a way to get it to launch from the water? mmmmkay. Coming up.

If you're talking about airbreathing NERVAs, there's always Project Pluto.

For certain trajectories, the tug can take a free-return trajectory back and then aerobrake/aerocapture.

Naked eye. I happened to glance up at the sky and saw a weird triangular glow shooting across the sky at ridiculous speeds. The object was huge, too; from my working knowledge of orbital mechanics, I would have said it was either 10 km across in orbit, or a few hundred feet across at an altitude of 10,000 feet or less. I watched it for as long as it took to move across the sky, which was about 15 seconds. As it moved, I noticed that it changed shape, which clued me in that it was a projection rather than an actual object. Of course, its size and speed made me sure it wasn't a real object. The shape change was due to the slow rotation of the rocket body. I spotted a small glowing speck (the actual rocket body) traveling in lockstep with the projection; that was when I realized it was a reflection. The two merged about 20 degrees above the horizon. I glanced to the other side of the sky and saw the crescent moon (I think I said full moon before; I meant crescent) and realized that's what was being reflected.

All right, here you go! I like this entry a lot. It's super easy to control once you get the hang of it, it has a nice TWR and lots of fuel, and it's very versatile. Messy if you don't know how to control it, though. I don't think I'm going to get high high scores on this, but it's definitely a lot of fun to fly! Images are in no particular order and I didn't have time to annotate them all. Maybe sometime this weekend. It's 100% stock, with no tweakscaling. I used long radial ramp intakes for the forward section, which gave it a nice Star Wars profile and helps immensely with jet efficiency during acceleration. The mass is perfectly balanced between two fuel tanks that drain evenly, with the central engine providing about 0.98 gees at "launch" so it is extremely responsive and controllable. I just set the throttle to 100% and I right-click the tail engine and use tweakables to adjust its throttle. It's SO much fun to fly. I'm happy to post the craft file if anyone wants it. It has six Sepratrons for an extra speed boost; I set the staging so you use them one at a time. Engaging them all at once allows you to just barely go supersonic, if you're high enough and use a shallow dive. I've taken it up to 8.5 km and brought it back down; not exactly sure what the service ceiling really is. I'm pretty sure I could go exoatmospheric but I haven't tested that yet. This is my first time (other than the jetpack challenge) working with jet engines; I only got the full KSP a few days ago. The low responsiveness of jet engines is annoying, but I got used to it. One of the tricks is to use the high level of control authority (provided by several reaction wheels) to alter pitch heavily during flight. I pretty much keep the central engine at max the whole time and alter speed and altitude using pitch and the tweakable on the rear engine. It climbs pretty well at up to 20 degrees, though it tends to slow down past that. The rear fins are solely to provide prograde stability; they contribute no lift whatsoever. I gave them a very very small amount of control authority; you can very easily rip this craft apart or send it into an unrecoverable spin if you aren't careful. Turning at speed is very challenging; you need to use roll, pitch, and yaw in tandem or you'll end up either not turning at all, or spinning wildly. Most of the time I control from the probe core hidden between the central intake and the central engine. Setting this to "Radial Out" provides complete stability, though if your fuel tanks are full you need to keep an eye on things so you don't lose altitude and crash. In this setting, roll is yaw and yaw is roll, so compensate accordingly. If you control from the Kerbal in the command seat, you can use prograde SAS to great effect; you can climb super high this way without any manual control input. I don't think it's possible to circumnavigate Kerbin in this, but if anyone wants the craft file to try, be my guest! Scoring: I did this more for aesthetics than for scoring, but whatever score I get I'll be happy with. I know I completed Eye of the Needle, Jet Ski, and Boom!. If you want to assess the Lazy Robot for my use of a probe core for control, that's fine; I could have used a docking port for the same effect, though. I think I currently hold title to West Koast Kustom for pure brilliance in design aesthetics, but that's not entirely up to me.

I'm building one, but using a probe core just to make it more controllable -- hope that's okay. It's clipped away where it can't be seen.

What you likey saw was the a flare from a geostationary satellite. Five or six years ago I recall seeing several similar occurrences while looking towards the constellation Leo in late spring. These short (lasting mere seconds) bright flashes usually about the same time; around 11:30 PM local time and occurred in the same place in the sky. These flashes looked nothing like shooting stars nor of satellites flying overhead. Flybys exhibit a gradual change in the magnitude as a spacecraft passes by; ranging from several seconds to sometime several minutes. But the flashes were extremely brief. Having also seen Iridium Flares before I knew these flashes were not quite the same; as Iridium Flares do have noticable motion to them; where as these aforementioned flashes were seemingly fixed. At the time I was unaware geostationary satellite flares occurred. Thus much like you I thought I was witnessing a star flaring up or some other naturally occurring process rather than a man-made one. Weirdest thing I ever saw was an old rocket body in an elliptical orbit reflecting the image of the full moon onto a low-lying mostly-transparent cloud layer. I could have sworn it was a UFO.

Another issue is the propellant density. If you take an engine capable of running on multiple propellants (like an NTR or some variable-mixture tripropellant engines), increasing the density of the propellants while maintaining the same fuel flow increases thrust and decreases specific impulse. Hypergolic fuels are much higher-density than hydrocarbon fuels, and nitrogen tetraoxide is slightly higher-density than LOX, IIRC.

Okay, so....I do believe this qualifies. Flew for a total of about 15 minutes, but 13:05 is the highest value on the screenshot.

Yeah, upgrading the pad is definitely an improvement!

Yeah, I did a challenge almost identical to this a while back, but I believe I specified an 18-tonne pad limit. I'll see what I can do.

A dual-thrust-axis, atmospheric VTOL upper stage. It's a rather complicated problem, because you need to be balanced for ascent, but you also have to be aerodynamically balanced for entry, descent, and landing along an alternate axis. Getting center of mass and center of pressure correct is a big challenge.

A recent trade dispute (arising from an unfortunate misunderstanding wherein pinecones were mislabeled as pineapples and shipped to the Kerbalhouse Correspondents Dinner) has led to a ban on importing numerous products, including critical aerospace hardware. Among those items no longer available are parachutes, circular heat shields, and wheels. But the Kerbonauts still need to service the Space Station. To do so, they'll need to build an upper stage capable of re-entering and landing on its own. Jeb has decided he is tired of suicide burns, so he insists on a dual-thrust-axis lander. Your mission is to build a manned reusable integrated upper stage vehicle that can re-enter and land on auxiliary thrusters in a horizontal attitude (example here) at the KSC. The vehicle must reach orbit (presumably being launched by an initial stage of your own design), performing its own final circularization, then re-enter and land (on land) without losing any parts. All entries must be stock. Scoring is based on part count; the fewer parts you have in your vehicle, the better. EDIT: After a dizzyingly successful entry by @qzgy, it was pointed out by @MaxL_1023 that reaction wheels make this challenge all too easy. So, reworking the scoring table to make this more interesting. Scoring is based on payload into orbit and back down (pretend you're taking crew and/or cargo up to a space station and then returning). A kerbal counts as 0.1 tonnes; cargo mass counts as, well, cargo mass. You cannot count unburned fuel as cargo. Multipliers: No reaction wheels: x2 No reaction wheels or RCS (use only control surfaces and gimbaling): x3 Good luck!

Okay, that is what I assumed. So...whoever plays this mission for the longest wins? There needs to be a limit, like "you can only go to Minmus once" or "all the ore needs to come back in a single ship".

Dark, man. Very dark.

I did it Apollo Style...on my VERY FIRST FLIGHT! A little explanation: I've been playing the Demo for about a year, and I've flown some pretty cool missions, but I've never been able to do an Apollo-style LOR because the demo doesn't have docking ports. Anyway, I finally got the full game. So, I decided: why not replicate Apollo 11 on my very first flight in the full game? Ambitious, true, but I think I'm up to the challenge. Not too shabby for the very first flight in-game.

I did it Apollo Style...on my VERY FIRST FLIGHT! A little explanation: I've been playing the Demo for about a year, and I've flown some pretty cool missions, but I've never been able to do an Apollo-style LOR because the demo doesn't have docking ports. Anyway, I finally got the full game. So, I decided: why not replicate Apollo 11 on my very first flight in the full game? Ambitious, true, but I think I'm up to the challenge. With no further ado: Scoring: Single-stack ascent, LOR, manual piloting, BYOR: +30 3-man Mission +10 2-man Lander +10 2-stage Lander (leave the decent-engine on the Mun) +20 Launch escape system in place? +10 Lander stored behind the CM during ascent +20 Lander tucked away behind some kind of fairing? +5 Free return trajectory to the Mun +10 Flawless landing (no parts broke off, Neil Armstrong is watching you!) +10 After succesfull Mun landing dock CM and MM in munar orbit (no swapping ships without docking them first) +10 MM disposed by crashing it into the Mun (remove Kerbal first!) +5 Plant flag on the Mun (no cumulative, i.e. two flags don't get you 6 points) +3 TOTAL: Now, I really think I deserve a 100-point bonus for this literally being my very first flight in KSP, but that's not up to me!

I'm wondering -- do you have to bring the ore back to Kerbin for it to count? Your post never actually says that the ore needs to be recovered, only collected. Also, what limitations are there to prevent someone from just running the same mission over and over again to grind for ore, if multiple launches are possible?

The boosters have to essentially be SSTOs, though, which is problematic. With a smaller payload bay, an internal tank, and crossfeed, you could really get some good performance. Even better if you use methalox and make the wings wet.

I'm not sure if I am understanding you correctly or not, but one thing to note is that the dry mass must be excess; you can't say that a manned crew cabin or an occupied storage container is "dry mass". Now, if you are bringing an empty cabin or an empty storage container to represent your dry mass, that works just fine. A very good approach for getting your consumables there would be to add parts with liquid fuel storage. Liquid fuel can't be used by rocket engines, so it is a nice compact way to get that dry mass. If I was being a little more realistic I'd specify the need for some large-volume module to act as a transfer hab for astronaut space, but that would get messy. Once you've demonstrated reuse, you can carry the fuel you would need with crossfeed disabled.

Get the Kerbals there any way you want, but remember that you need to pack enough dry mass (in whatever form you'd like) for each leg of the trip, as I outlined above. Spaceplanes and inflatable heat shields are perfectly fine! But you can't land horizontally on Duna; that's a bit too unrealistic. So even if you use a spaceplane, it would need to land vertically, somehow. And you can't reuse inflatable heat shields, so that cuts into your score a bit. On reuse -- you don't have to actually reuse everything; you just need to demonstrate reuse. For example, if someone went the ITS route with a RTLS booster launching a persistent second stage, you'd only need to perform the RTLS once, though you'd need to reserve the same amount of propellant on all subsequent launches. That should save you some time.

If desired, we can do two leaderboards: one with RSS and one without. But this is more about mission configuration than getting everything perfect.

You're absolutely right, on all of your points. I'm not actually trying to solve for the minimum cost of getting to Mars; obviously it is easier to get to Duna in KSP than it is to get to Mars IRL. Of course, the engine TWRs and fuel tank fractions in KSP are a lot more punishing, but not enough to make up for it. But this challenge is more about finding a mission configuration and architecture that will permit the lowest overall cost, once things like consumables are factored in. Hope that makes sense.