Armchair Rocket Scientist

I'm guessing the RL10 and the Descent Propulsion System from the Apollo lunar module. The thrusters on Curiousity's skycrane appear to throttle pretty deeply too: http://en.wikipedia.org/wiki/Mars_Science_Laboratory#Powered_descent

I didn't do this exact design, but I did once try to make an Air Launch to Orbit vehicle. Let me tell you, it's hard. First of all, your 1st stage has to be flyable with or without a huge rocket sitting on top of it, and has to be flyable in a wide range of conditions ranging from sea level and subsonic to Kerbin's upper stratosphere at mach 3+. This means that your Center of Mass, Center of Lift, Center of Thrust, and Center of Drag have to be aligned in all those conditions. In addition, your second stage appears to need to be flyable on its own. Your second stage is even worse off, as it will have to deal with asymmetric thrust with no air to make control surfaces work. Anyway, in stock or FAR KSP, your idea should probably work fine without the kick stage: if you can get up to 1000 m/s and 20 km on your first stage, a single rocket-powered stage should be plenty to get you into orbit. However, your payload fraction will probably be lower than that of a well-designed SSTO, and possibly even harder to build. If you can get your first stage up to hypersonic speeds (1700+ m/s), you might be able to push the payload into a high enough suborbital trajectory that your second stage can use a nuclear engine. For reference, here's what I built: It does technically work, but it needs two B9 VTOL engines in the tail to keep the nose up at high altitude despite my best efforts to balance it. Its payload fraction is only 15%. There are SSTOs out there with payload fractions of 30%. Anyway, a good source of advice might be the people who build shuttles. After all, an air-launched rocket is kinda like a shuttle in reverse if you think about it.

I can't do it with my computer, but I'm sure someone will deorbit an asteroid... and then launch it back into orbit again. Bonus points for doing so on Tylo or Eve.

I'm not sure it would work very well to have the command seat as a root part; it's a chair. Nothing structural can attach to it any more than to an RCS block. As for "controls properly," do you mean giving it torque? Once again, it's a chair with some joysticks, there's no real place for reaction wheels, and there aren't any situations I can think of where you couldn't just add a probe core or reaction wheel. I definitely agree that it should be possible to add crew in the VAB though. It would make testing rovers much less obnoxious. We don't have to make our kerbals walk from the Astronaut Complex to the launch pad, do we? For those saying it's overpowered, I agree with a major qualification: it's only overpowered because we don't have life support or proper aerodynamics yet. When a kerbal in an EVA suit can't survive more than a day, or when the airflow rips him out of his seat belt when you try to launch from Kerbin, it should be fine. Even then, the EVA seat might be viable for some lander ascent stages.

Venus can't form oceans unless water is introduced from somewhere else. Water vapor in a planet's upper atmosphere can be split into hydrogen and oxygen by high-energy radiation. Because the hydrogen is so lightweight, it may be moving fast enough to escape the planet's gravity. This means that over geologic time, planets that can easily retain water vapor will lose water from their atmospheres. The only reason Earth doesn't lose its water is because it has an atmospheric cold trap: basically, Earth's stratosphere is so cold that the water vapor freezes out and doesn't reach the exosphere. When Venus's original oceans boiled, the resulting water vapor was lost to space. Its current atmosphere is pretty much bone dry.

We already tried that. It didn't work.

Well, if NH Hohmann transferred to Pluto, you'd be in your 60s by the time the pictures came back, assuming the probe was even still working. And then you'd need a lot of dV to get into Pluto orbit, and almost as much to get into an orbit within the Kuiper Belt. If you did enter a kuiper belt orbit, it could be another 50 years before you encountered another really interesting object. New Horizons is pretty light by interplanetary probe standards, and launched on the heaviest Atlas V variant, so I don't think it would have been possible to get much more dV out of it. To perform a Pluto mission that didn't end in solar escape in a reasonable timeframe would be HARD. I don't know the exact dV requirements, but I would guess that with chemical propulsion only, you'd need a launcher on the scale of Saturn V or SLS to deliver a reasonable payload. With any other propulsion, you'd probably need a nuclear reactor, either for a NTR or to power some kind of electric engine. Either way, it would be an extremely ambitious mission for a very small target. With the same budget, you could probably put a submarine on Europa, a Curiosity-sized rover (or boat) on Titan, or a permanently flying airplane or balloon on Venus or Titan. If I wanted to study a KBO in detail, I'd probably go for Triton. Neptune seems like a more interesting secondary target than Triton, and I think because of Neptunes greater mass you wouldn't need as large an orbital insertion.

Let's start with the three basic resources in TAC Life Support: Snacks/Rubbish (rubbish includes things like snack wrappers, broken board game pieces, toenail clippings, etc). Water/Wastewater (wastewater includes water from laundry, washing, etc). Oxygen/CO2. Our initial life support model is as follows: Kerbals consume snacks, water, and oxygen, and produce rubbish, wastewater, and CO2, at a fixed rate. In addition, command modules (and inhabitable parts like the hitchhiker) consume electricity at a fixed rate regardless of the amount of crew in them, representing climate control, lights, running video games, etc. EVA suits contain a fixed amount of snacks, water, oxygen, and electricity. Of course, converter parts are available as well; Air Scrubber: CO2 + Electricity -> Oxygen + Rubbish Water Recycler: Wastewater + Electricity -> Water Hydroponics Farm: Rubbish + CO2 + Electricity (sunlight) -> Snacks + Oxygen. The problem is, even a basic capsule or EVA suit will be equipped with an air scrubber, so there isn't even a point to tracking CO2 and Oxygen: just include running air scrubbers in the capsule's electricity requirements. So, all we really need are: Kerbals: Food + Water -> Rubbish + WasteWater Command Modules: Electricity. Water Recycler: Wastewater + Electricity -> Water Hydroponics Farm: Rubbish + Electricity (sunlight) -> Snacks + Oxygen. (plants use water, but most of that ends up being lost via transpiration and reclaimed by water recycling equipment). The water recycler and hydroponics farm would be heavy, power-hungry, and potential have conversion losses. Now, before people complain that this will make career mode too hard before solar panels, I don't think electricity should be the limiting factor in career mode. The fourth satellite ever launched had solar panels: http://en.wikipedia.org/wiki/Vanguard_I. Placing them so late in the tech tree is silly. Besides, operating your 20-kerbal space station with 4 of the fixed solar panels is ridiculous anyway.

All right, I can see several possible issues. 1. The B9 turbojets have a higher air-fuel ratio than stock, and from what I've heard they also have a worse thrust-velocity curve. I don't know how using FAR affects this, but it's possible that's making it harder to reach high speeds on jets. 2. 35 degrees is a pretty steep ascent profile. In general, you want to flatten out your trajectory at high altitudes and build up as much horizontal speed as possible on the jets. How fast are you going when you switch to rockets? 3. You appear to be using the big white radial engines. These are garbage. Change them for 2 LV-T45s, or if you can control your vehicle fine without thrust vectoring LV-T30s or aerospikes. You'll be getting a 50-70s boost in ISP (at 30 km engines are pretty much at vacuum isp) for at most an extra 0.3 tons.

Can we see a picture of your payload? That mass sounds like it should be within the reach of a 7 x 2.5m asparagus stager.

I guess my post was a little confusing and Hodo thought I was trying to enter the B9 plane into the challenge. I added some clarification. Anyway, takeoff speed is about 80 m/s and top speed at 100 m is about 100 m/s.

This bit here is an amusing background anecdote about how building huge aircraft in stock is harder than I though. Well, I already have an aircraft that can carry 2 orange tanks to 20 km and 800 m/s. While it's terrible at its original goal of being an Air Launch to Orbit mothership (18 tons in orbit with a 120 ton launch mass is worse than an SSTO), it can carry heavy underslung cargo quite well. This is not the story of that plane. Unfortunately, that plane is made mostly of B9 parts, so it doesn't qualify for this challenge. So I built a new plane along the same lines, figuring that it wouldn't be too different. I was subsequently reminded why B9 is worth the memory: building anything big with the stock wing parts is an enormous pain. This is my actual entry. Unfortunately, I didn't get a screenshot of touchdown/landing roll, as I was too busy trying not to crash. Also note the background appearance of the Sleigh from http://forum.kerbalspaceprogram.com/threads/62728-The-Santa-Substitute-Challenge!?p=874674&viewfull=1#post874674 This bit is my saying how making a large aircraft stock made me very happy that I have the mods I'm about to mention when I'm not doing a challenge.This challenge attempt is dedicated to B9 and Procedural Wings. They make my life not hell.

That doesn't look too far off the scale of the largest landing legs in KSP (and the LEM is the largest vehicle ever to land anywhere besides Earth). The tiny legs are really just for probes (or manned vehicles without pressurized cabins), and the larger ones work well with a one-man lander or something on the scale of a Dragon spacecraft. That being said, I wouldn't mind some bigger landing legs - maybe Falcon 9/Grasshopper sized (and long enough to extend past a Mainsail's nozzle).

You know what? I'll join this (the flame war, not the challenge). A: I have to agree with Kashua, this is a perfectly valid means of completing the challenge, if not as efficient as some other methods. It doesn't really even count as a "spirit of the challenge" violation, since there doesn't seem to be any spirit of the challenge besides: " B: Basically, you openly admitted to making a challenge just to prove a point / spite the other side in a debate over a mod. This isn't particularly mature, and is likely to rub people the wrong way. C: The vast majority of challenges posted here do not require mods. When they do, they only require mods that are relevant to the challenge. Example: http://forum.kerbalspaceprogram.com/threads/58068-kOS-The-Automated-Mission-Challenge requires kOS because the entire purpose of the challenge is to accomplish the coolest mission you can using kOS. http://forum.kerbalspaceprogram.com/threads/64506-Solar-Electric-Airplane-Speed-Challenge requires Firespitter because the whole point of the challenge is going fast using Firespitter propellers. The purpose of this challenge is to launch an awkward payload into an orbit. NovaPunch and ProcFairings are not critical to the challenge; I doubt it would take you more than 15 minutes to rebuild your craft stock. It's silly to expect people to install unnecessary mods just for one challenge, especially with memory-eaters like NovaPunch. While Kasuha's second post was a bit excessive, this is a completely inappropriate way to respond to criticism. You've also pretty much guaranteed that nobody will take your challenge with that attitude. Take this as constructive criticism: insulting everyone who disagrees with you is a fast way to earn a bad reputation. EDIT: For the record, I didn't see your post sal_vager. Should I leave this up?

It would be interesting to have a "Sample Return Canister" part that could store a set number of experiments, similar to http://en.wikipedia.org/wiki/Luna_16.

There are a lot of problems with sending a cubesat to Uranus. 1: The only reason Juno is bothering to use solar panels out at Jupiter is because there's a shortage of Plutionium-238. Otherwise, they'd use RTGs. Now consider the fact that there's less than 10% as much sunlight at Uranus as at Jupiter. Basically, you need RTGs. 2: Instrumentation designed to work on a cubesat in LEO for 1 year won't necessarily work in interplanetary space for 20+ years. 3: You're gonna need a lot of power. At launch, the Voyager probes generated 470 W, Cassini 880, and New Horizons 228. I'm guessing a large part part of that is because you need a big antenna to transmit a useful amount of data all the way to Earth. If you're using an ion drive, that requires even more power. 4: Uranus takes a lot of dV to reach. A hohmann transfer might be doable with a small probe like New Horizons, but the journey to Uranus would take 17 years. Most likely any mission would involve at the very least a gravity assist from Jupiter, and possibly flybys of Earth and Venus as well, similar to Cassini. To reduce the transit time to something practical like 10 years, the probe would need to take a trajectory which caused it to encounter Uranus at very high speeds. This means a big orbital insertion burn, and not much time to do it. Ion engines would likely not be suitable for such a mission. Therefore, you need relatively large tanks of monopropellant. All told, it would probably be difficult to go much smaller than New Horizons for a Uranus mission; a probe of that size could probably be launched on an Atlas, Ariane 5, Proton, or similar vehicle. However, by the time we're actually ready for a mission like that, F9H and Angara 7 will almost certainly be operational.

An aerodynamically shaped jet-boosted rocket would probably still work, but like in stock it would be less efficient than a plane due to gravity losses. Something like Cupcake's dropships would probably have a lot of drag at supersonic speeds, and potentially be uncontrollable.

Doesn't that mean you're carrying around dead weight in empty fuel tanks? Why not just build your plane with the amount of fuel and oxidizer needed to carry the payload you want to the orbit you want?

The problem is you can't strut together two ships that you just docked in orbit, unless you're using one of the mods Sovek suggested. OP, I don't know if Kerbal Joint reinforcement stiffens docking ports, but it might. Also, try downloading a docking alignment mod to help with multiple docking.

What about a piston pump?

That's a completely different problem, called the Infiniglide glitch. Basically, it's caused by stock KSP aerodynamics being bad at life.

Is the heating model compatible with Deadly Reentry? Because this sounds like something that could work really well combined with Realism Overhaul, or even end up as a required mod for it someday. I assume support for ramjets, scramjets, and precoolers works well with this too?

I can think of 2 basic ways of handling micrometeoroids in KSP: 1. The game procedurally generates and tracks every single piece of debris. Even on rails, these will bog down your computer, and they'll come within physics load radius all the time, making the lag even worse. 2. The game approximately calculates how much debris is in a region of space, then calculates the odds of a collision, and has a random chance of spawning an object of random size and velocity and firing it at your ship. So basically, random failures, AKA the subject that attracts flame wars like ladders attract the Kraken. So no, I seriously doubt we'll see anything like that; there just isn't a practical way to implement it.

That payload is about 100 tons (give or take extra for RCS, reaction wheels, probe cores, girders, etc). With a payload fraction of 15% for an asparagus-staged rocket, you should have a launch mass of about 750 t. Six mainsail-powered boosters and a core with 4 LV-T45s and 8 LV-T30s should lift that comfortably. For equal fuel on each stack, give each 2 orange tanks and one of the smallest 2.5m tanks on the bottom. Now add struts as necessary. If you want it serial-staged, you'll probably need 900-1000 tons of rocket: 9 mainsails in the first stage would be a good choice for getting it off the pad. Now might be a good time to read up on construction techniques for large vehicles, such as thrust plates. In addition, if you don't have a fast computer (or even if you do) you should consider downloading Kerbal Joint Reinforcement. On large vehicles, probably the biggest contributor to CPU-melting part counts is the huge number of struts required.

Your SSTO itself doesn't need to be long range. Unless you're going to Laythe, your wings and jet engines are dead weight once you reach LKO. Use your SSTO to launch stuff like nuclear-powered transfer stages, fuel tanks, habitation modules, and landers into LKO, and build your spacecraft there. If you are going to Laythe, there aren't good landing spots for your giant interplanetary SSTO anyway; build a smaller SSTO with STOL or even VTOL capability and get it to Laythe orbit with the heavy nuclear transfer stage.