RadHazard

A useful thing to note about radiators in this mod is that both upgraded and non-upgraded radiators will dissipate exactly the same amount of heat at the same temperature. The only difference is the upgraded radiators have higher temperature caps and thus can dissipate a LOT more heat when at their maximum temperature. The Waste Heat Management page has some formulas you can use when using electrical generators, so that you can determine how many radiators you need in order to achieve the efficiency you want. If your solar panels are closing, you don't have enough radiators on your ship to dissipate all the waste heat. Since you are close to the sun, your solar panels generate a lot more heat than they do near Kerbin. I believe they generate half as much waste heat as power, so if you are getting 500 kW out of the solar panels you need enough radiators to dissipate at least 250 kw. You can click on the transmitter to determine how much electricity you are generating in total, which should help you determine how many radiators you need. To Fractal: Since you already hook into solar panels to cause them to generate waste heat, how hard would it be to convert them to producing Megajoules? I know in a lot of cases they would be mostly useless, but one good use case I thought of would be building a microwave-transmitting solar satellite with a plasma engine. You could launch it from Kerbin by receiving power from LKO nuclear satellites, and then swap to solar power when you get near the sun in order to circularize. Since you changed it so megajoule-producing parts fill up electric charge before anything else, there's no longer any downside to swapping, as far as I can tell.

I used a DT-Vista to get three satellites into low kerbol orbit in one mission. That engine is absolutely insane with it's Isp as long as you stick to 1/2 or 1/3 throttle. I can't think of any other missions with such a high dV requirement, which is where it really shines. For fusion reactors, it'd be great if you could have a mission dedicated to producing the different fuels for it (deutrium, tritium, and helium-3). Additionally, it would be good if you could showcase the different fuel modes and how they vary in effectiveness (D/T for thermal rockets, D/He-3 for fuel-efficient electricity, Pure He-3 for more electricity). You could also have another plasma engine mission, as a fusion reactor running pure He-3 and powering a xenon-burning plasma engine is probably the first self-sufficient plasma craft you can make that has a decent level of thrust.

A bigger NERVA would be nice to keep part count down and to help with asthetics, but you should be able to use LV-N clusters to get the same effect. If your space stations are that large, most of your mass is going to be payload and fuel anyway. 29 LV-Ns and 415 tons of fuel would get you 5000m/s of dV at around 0.2 TWR, assuming your stations mass in at around 400 tons (based on your description of 10 orange tanks of fuel + 1 orange tank's worth of other stuff). 29 LV-Ns is only 65.25 tons, which is featherweight in comparison to the total ship mass of about 880 tons. IF you use the larger and slightly better engine you mentioned (9.5 t, 300 kN, and I assume the same 800 s ISP), you can get the same dV and TWR with 6 engines and 405 tons of fuel. That gives you a total mass of 860 tons, only a 20-ton savings.

Thermal turbojets artificially lower the ISP of intake air to something around 200 - 300 s. This is hand-waved as integrated turbomachinery compressing the intake air and results in much higher thrusts when using intake air/atmosphere compared to any other propellant. Pure liquid fuels is almost the exact opposite, having much higher ISP but also much lower thrust. You'll want to use LFO instead as it offers about 3x the thrust of liquid fuel with about 0.6x the ISP. Also note that your thrust will increase as you go higher in the atmosphere and your engine's ISP increases. You can get 12 kN out of a fusion rocket at high altitudes using pure liquid and 46 kN using LFO. If that's still not enough to circularize, you'll probably need to strap on some smaller booster rockets to help you get into space. You can turn those off once you get into space and fly around using only the high-ISP thermal rocket. It's likely because your waste heat levels are rising and thus your generator's efficiency is dropping. If your generators and radiators aren't upgraded, you might not have enough radiators to cool off your reactors when running at full power, meaning they'll eventually overheat. It's a bit cheaty, but if you swap away from the satellite while the transmitter is on, it will stay frozen in the state it last was and will continue to produce that much power without gaining any more waste heat until it is loaded again. 10 huge unupgraded radiators is enough to dissipate the entirety of the 3000 MW of power the unupgraded 3.75m reactor produces. I'm fairly certain you can get away with 9 since some of that thermal power will become electricity instead of waste heat, but 8 is pushing it. Regardless, you aren't likely to get any good efficiencies out of these unless you spam radiators or you unlock the generator upgrade. The Waste Heat Management page on the wiki can help you figure out how many radiators to stick on your rocket.

If you like, I have a tool I wrote in java to do exactly this sort of math. The link is in my signature. You input the minimum TWR, minimum ∆v, and weight of the payload, and it spits the amount of fuel you will need for each type of engine, along with the minimum number of engines to achieve your stated TWR. It uses vacuum Isp for all the engines, but you can use the custom engine function to input the atmospheric Isp if you want to design a lifter.

Using physical time warp shouldn't be too bad as long as you don't have some 500+ part monstrosity. I had several 20-minute circularization burns I had to do (I was placing solar satellites in low solar orbit for KSPI microwave transmission), and my decently-sized ship (It had 3 ~20 part satellites stuck to it, and it had about ~30 parts itself) was fine for the most part at 3x warp. I couldn't use 4x as the docking port would get squished and cause it to start to drift sideways, but 3x was more than enough to make it bearable.

Try it with Xenon, you will get twice the thrust and half the ISP. Try using the 62.5 cm thruster as well. The only difference between the sizes is their weight and the maximum amount of power they can use. You won't cap the 62.5 cm one using only nuclear power, so that saves you 0.833 tons of weight. It's not much, but it can make a difference for your small ships. But yeah, it takes a lot of power to get usable levels of thrust from plasma. It takes 820 megawatts to match the LV-N's thrust using Xenon, after accounting for the power you lose from xenon's 69% efficiency. That's more power than what you can get out of any unupgraded fission reactor/generator combo.

Hmm... you're right. I looked it up and the costs were rather surprising. Beryllium was $930 per kg and Flourine was $1900 per kg. At those prices, it'd probably be cheaper to stuff dollar bills into the fuel tanks. I did already know about the dangers of handling fluorine, but I didn't expect it to be so damn expensive. Maybe Chlorine Trifluoride would be cheaper?

I use liquid boosters for my lifters. If my boosters need a boost I strap SRBs to them. They're easier than setting up proper asparagus stages for when I just need some extra kick. I also find them useful when using KSP interstellar, as the engines in that mod have less thrust thrust when they're in the atmosphere. I use them to push my thermal rockets high enough to where their own thrust becomes enough to lift themselves.

This is dependent on what you have unlocked. If all you have unlocked are basic nuclear reactors and generators, the best you can do is a large space tug with a 0.1 TWR (using a 3.75m Thorium Reactor + generator and xenon fuel, before any payload is attached). It's fairly useless unless you wanted to send a large nuclear reactor and generator combo somewhere for whatever reason. It would require a lot of patience though. If you go ahead and get fusion power, that same tug would have a 0.4 TWR and could actually work as a tug. At that point, you could also build a small fusion-powered plasma craft, which would have a decent TWR using xenon. The unfortunate truth is that plasma engines are almost useless until you either get microwave transmission or fusion power. You can't get useful amounts of thrust out of them if you have to lug around an unupgraded fission reactor to power them.

Your radiators are not upgraded. The huge radiators only dissipate 300 MW each, and the upgraded reactor produces 9000 MW at full power. Your unupgraded generator will turn at least 70% of that into waste heat. If you want to operate an upgraded 3.75m reactor in space with unupgraded radiators, you will need a minimum of 9 huge radiators, which are only enough to dissipate the heat produced by the reactor at 30%.

The wiki is the best place to find information on the mod. For microwave transceivers, the relevant page is here: Microwave Power Trasceivers

Is your reactor overheating? The reactor will automatically shut down if waste heat levels go over 95%. This can be solved by adding more radiators. If that's not the case, it sounds like a bug and you should write up a report, as I haven't heard of the reactors automatically shutting off for anything other than overheating or running out of fuel. Fuel crossfeed and fuel lines are both unnecessary for fuel pods. As long as the fuel is somewhere on the same vessel, the kerbal can use it to refuel the reactor.

Fission reactors have to be refueled manually. You have to shut down the reactor, wait for it to cool, and then use a kerbal on EVA to right click and select the "refuel" option. This option should be available as long as you have enough fuel of the correct type and the reactor isn't completely full of actinides.

I was bored, so I did some more work on the wiki. Since lots of people are asking what the purpose of unupgraded fission reactors are, I wrote up a small paragraph about the strengths and weaknesses of low-tech nukes on the reactor page, in addition to the expanded information I added. I also touched up some other pages.

Yes, the scoring table is updated. Yup, and that's half of the challenge! (the other is building and piloting a lander with a giant six ton engine)

Given the number of people asking about waste heat, I went and updated the radiator page on the wiki. I don't know the exact formulas for radiator temp or generator efficiency, so if someone else knows them them it'd be great if you could update the page with the actual formulas.

There is an option in the .cfg file to disable waste heat, but it will disable waste heat for the entire mod. I don't think it's possible to disable it just for solar panels anymore.

The smaller reactors are not very viable as thermal rockets before you upgrade them. Their primary use at a low tech level is either powering thermal turbojets or generating a large amount of electricity. The 2.5m and 3.75m unupgraded reactors have superior T/W with LFO over stock LV-Ns, although they are larger and heavier and have a lower ISP. The 3.75m can even match the LV-N in T/W using pure liquid fuel, which gives you superior ISP (915s vs 800s). These numbers are all considering Uranium-powered reactors. If you swap to Thorium, your performance is even better, although not enough to make the 1.25m viable. Basically, if you want to use the low-tech reactors on a ship, you need to build big. You might as well stick a science lab (for reprocessing) on your ship and run thorium, which gives you even better performance for only a slight additional weight.

At the moment, nothing. It's just flavor. In a future update there might be hazards to it, as well as countermeasures. How high does your waste heat get? There was a change to the waste heat mechanics in the most recent version. Your radiators' temperatures are now dependent on the level of waste heat, meaning the more waste heat your ship accumulates, the hotter the radiators get and the more heat they radiate. This means that in almost all setups, waste heat will now go up at least a little bit before stabilizing at some value. If your station has only a single 62.5cm reactor and all those radiators, you shouldn't have to worry about overheating, as it should stabilize just fine.

I like the idea presented in this story. I'm pretty sure the Project NAILSPIKE part is total bunk, but the shuttle tweaks mentioned sounded pretty convincing. As I'm not a rocket scientist myself, I can't vouch for the accuracy of the science, but if it's anywhere close to correct it sounds great (if you don't mind a little hazardous exhaust )

Exactly this. This craft has 13km/s dV and a TWR of 2.35 using a lithium-fueled plasma engine. It's powered by 3 2.5m nukes in Kerbin orbit and a 3.75m nuke landed at KSC. All of those reactor/generators are upgraded, but there's nothing stopping you from using un-upgraded versions. In fact, you could just put a relay constellation in orbit and build a ground station with like 5-10 3.75m nukes to power your LKO ships with impunity. You wouldn't even need to worry about reprocessing because you could just recover and relaunch the ground station. Yes, you'll have a difficult time doing a circularization burn when you fly interplanetary, but using aerobraking or packing a backup thermal rocket would fix that just fine. Self-sufficient plasma ship are tough to do at low tech levels, but with a bit of creativity the plasma engines themselves aren't useless.

Not even planet-eating robots can withstand a black hole.

Nope, sorry. Separations are allowed, but only for separating stages, not for propulsion. Rockomax really wants to push their Mainsales (okay, you can shoot me for that one ) I could make a note by anyone's entry that doesn't use the thrust limiter. I'm not sure how to easily it would be to verify this, though. You have to bring all the fuel with you in a single craft. You can assemble that craft in LKO using multiple launches and docking, but once you leave Kerbin's SoI you are only allowed to use what you bring on that craft. Laythe's score, along with all the other moons of Jool, come from the fact that it takes ~2000 m/s to intercept Jool, plus some dV to intercept them once you hit Joolean orbit. I may have overestimated the amount of dV it will take to intercept them, however. As for Moho's score, it's already higher than Laythe and Vall's score for landing. Returning is a bit different. Laythe is much tougher to take off from due to the atmosphere and the gravity, but looking at it again, Vall definitely shouldn't have such a high return value. I'll look into adjusting the point values. As for Eeloo, if I'm not mistaken it takes more dV to intercept and land on all the moons of Jool than it does to get to Eeloo, making it a more difficult challenge. EDIT: Okay, I looked at and adjusted the scores of the planets. The biggest change is that Jool's moons are mostly worth a lot less now. I seem to have tacked on an extra 250 points (~2500 m/s) to most of the return scores for the moons for reason I cannot even fathom. I assume a ~3000m/s return burn + however much it costs to liftoff the planet. Some of the other scores are also adjusted. Full list: - Moho return increased by 100 points (underestimated liftoff dV) - Duna return increased by 50 points (underestimated liftoff dV) - Ike landing decreased by 50 points (overestimated intercept dV), return decreased by 10 points (rounded to nearest 50 like the other scores) - All Jool's moons landing decreased by 100 points (overestimated intercept dV). - Laythe return decreased by 50 points (overestimated liftoff dV) - Vall return decreased by 150 points (vastly overestimated liftoff dV) - Tylo return decreased by 250 points (I don't even know) - Bop return cost decreased by 250 points (again, I don't even know) - Pol landing decreased by additional 50 points (overestimated landing costs), return decreased by 250 points (My brain was broken when I made these scores up, apparently)

I don't know about going that far. It doesn't make sense to me that a hybrid engine designed for spaceplanes would work better than dedicated turbojets designed for aircraft, or dedicated rockets designed for spacecraft. Otherwise we'll end up with people sticking RAPIERs on high-altitude jets that are never intended to leave the atmosphere, which seems silly. The cost would be one factor in balancing it, but I feel like it would be better to find a sweet spot where 1 RAPIER is better than 1 turbojet AND 1 aerospike, but is inferior to just a single turbojet OR a single aerospike. EDIT: This would actually be a good way of hitting that sweet spot. Make 1 RAPIER perform exactly the same as a turbojet in airbreathing mode, and exactly the same as an aerospike in rocket mode. Then, make the weight of the RAPIER more than either a turbojet or an aerospike alone, but less than both of them together.