SaturnianBlue

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  • Interests A young person who enjoys space-related things, especially spacecraft. I have a small interest in early 20th century warships, and has picked up an interest in writing from the KSP forums. I also draw quite a bit.

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  1. Finished writing up the Colonizing Dres chapter, and I've stated some work on the Jool chapter as well. Here's two of the pictures from some mining craft designs I built for the chapter. The first iteration, used small TWR reactors on Liquid Ammonia and an onboard ISRU refinery. Upgraded version, with a pebble bed nuclear rocket, radiators, and storage for regolith.
  2. Chapter 13: Other Propulsion Systems In this chapter, I cover the rockets that don’t fit in the three categories of propulsion I laid out earlier. These designs are very different, ranging from chemical to antimatter. For that reason, I’ve split this chapter into subsections. Chemical Most of the engines featured in the stock game fall into the category of this. Either by burning solid, liquid, or a combination of such fuels, they can achieve very high thrusts and can be used in space and the atmosphere. However, they are incredibly inefficient, and can certainly explode. It's not intended to be an SLS, but it sure ended up looking like one. However, they are the best option currently working in real life (and in-game) to lift payloads into space. Chances are that the first colony ships will have to be lifted into orbit by such rockets. Even in the future they could still be useful, since they aren’t particularly radioactive and can be fairly cheap. This would make them quite ideal for landers, since they can keep the surrounding area fairly safe, and missiles, as they provide the thrust necessary without being too bulky. Small scout vessels and drones would also benefit, especially if their excursions are in the timescales of hours, rather than days, where electrical thrusters could help. Using an NTR like this would be rather unsafe to any kerbals nearby... HA-1 Aluminium Hybrid Rocket How It Works This is a hybrid rocket, which means that it uses a combination of solid and liquid fuel, burned in a chemical reaction. Why Use It? This rocket is greatly appealing for operations on the Mun, where aluminum oxide (alumina) is plentiful, and provides plenty of thrust for getting into orbit. This would mean that the operation of such rockets will be cheaper, so transportation from the surface to orbit will be fairly cheap even without mass drivers. Why Not? The efficiency of these engines is very low, at only 285 secs. This would prevent they use in interplanetary space. What Should It Be For? Such low efficiency will mean that such rockets will be mainly for surface-to-orbit operations on planetary bodies with plenty of Alumina. Such craft could easily drop resources off at Kerbostationary orbit to aid the construction of early space colonies. In Testing By the way, some of the Liquid Oxygen is part of the payload. Since this engine is rather inefficient, I decided to send it on a route it would be more likely to take—from the Mun, to Kerbostationary, and back. I have designed this test vessel to carry 180 tons of payload, with a booster stage with 2,350 m/s of delta-V. With it’s powerful engine, it takes off the Mun's surface very easily and enters orbit, where it soon heads for a Kerbostationary orbit. It arrives there with ease, and it presumably drops off it’s payload and takes on new ones, without refueling. The landing however, was quite difficult. Had I placed some large landing legs and RCS thrusters, the ship may have had significantly less trouble. However, I had to resort to killing the horizontal velocity, and falling straight down. Even this was not perfect, and usually resulted in the vessel tipping, though most of the ship and the payload would survive and could probably be repaired. Any landing you can walk away from... When? As a chemical rocket, it can be built with current technology. Provided enough infrastructure exists for reducing alumina into the component elements, such rockets could see wide use around the Mun and the Kerbin system in general, even with the introduction of mass drivers, as they can slow down at the other end of the trip, and can launch from remote settlements as well. In A Story Being a chemical rocket, it is quite a dangerous and certainly has the potential to explode. However, these rockets are throttleable and restartable, which gives them a big advantage over the especially volatile solid rocket boosters.That said, things can go explosively wrong with this kind of rocket. With a rocket like this, you have a chance to have a rather intense liftoff sequence, especially compared to a slow burning ion drive, for example. Lasers Laser-Thermal Rocket This rocket absorbs beamed power from an external laser source, converting it into heat that is applied to the propellant. Why Use it? No onboard reactor is needed to heat the propellant, reducing the mass of the vehicle significantly. This means that the vessel can carry more, or have a higher acceleration. This type of rocket also works in the atmosphere, unlike many designs covered in this series so far. This allows them to be used for lifter rockets, which is easily achievable if a big enough laser is around to provide thrust. Why Not? This design is limited by the fact that a laser must be capable of sending the beam to the rocket, whether it is relayed or not, and this would likely necessitate the use of multiple stations to relay or transmit the power. Probably a bit more than needed, but still... The part in KSP is also incapable of receiving power from above or below, so for a launcher a laser platform has to be built somewhere along the flight path. Thankfully, the Old Airfield island is an excellent location. The laser thermal rocket is not suited for interplanetary travel, never reaching more than about 1000 seconds of specific impulse. This is because the heat exchangers would melt at a certain temperature. Perhaps a fair analogue would be the solid core NTR, which has a similar Isp and is also limited from materials melting. In Testing The thrust changes all the time, which makes judging a gravity turn quite difficult. The test rocket is a large lifter stage, with several giant power stations off the coast of the KSC. The payload weighs 563 tons, and the liquid methane fuel that the rocket runs off totals in at 457 tons. Immediately after takeoff the thrust is immense—up to 5 G's of acceleration, and even more later on! I throttle down, since it would be rather inefficient to burn so much. The ship has to be in range of the power stations, so either the ship should attempt orbit immediately, or a power station should be available when you circularize. I went for the first option, and deployed the target into orbit with fuel to spare for a landing. However, the receivers didn’t seem to give thrust to the vessel, so it was stuck in orbit. When? This design is quite simple and provided the infrastructure can be built, they would make excellent lifter stages that would be quite buildable now. Though not the most efficient engine, it is well suited for lifting into orbit. The lasers would require massive amounts of power, but if something like fusion is created and produces massive amounts of power, then all is well. What Should It Be For? They would allow for more effective SSTOs, reduced cost, and increased payload thanks to their higher specific impulse. They would also be useful with around planets, as the lasers do not have to aim very far, and their beam is not spread out, leading to a decent way to get around rather cheaply and without nuclear rockets. A vertically launching SSTO, but it lands horizontally! In A Story Any rocket that is powered by laser thermal rockets is at the mercy of the ones controlling the laser, which could certainly go wrong, anything from simply redirecting the beam when a ship is about to land, to the laser getting pointed at the ship itself, though safety measures are hopefully installed to prevent this. Ablative Laser Nozzle How It Works A group of pulsed lasers heats a solid propellant (in the game’s case, PVC), creating a plasma that generates thrust for the ship. Why Use It? Ablative Laser Nozzles have a higher specific impulse in-game of about 1400, though even higher specific impulses should be physically possible. The engine can also provide high thrust levels, making it quite useful for high-g uses. A much more reasonably sized power station. Why Not? Like the laser thermal rocket, this needs lasers, and from a specific direction as well. In KSP-I you can get more by deploying receiver parts, but those don’t work as well in the atmosphere, especially since they create drag. In Testing At liftoff, the thrust isn’t at it’s maximum, so I strap some SRBs on the side of the rocket to get into orbit. The payload masses in at 105,000 kilograms. The liftoff has to be mostly vertical in the early phase of the launch, as the thrust from the lasers decrease if aimed horizontally too early. Once separated, the ablative nozzle finally thrusts with a TWR of >1. It reaches orbit just fine, and the payload is detached. The small SRBS are located if I cannot get into orbit immediately. Without its payload, the ship decelerates very nicely as it approaches the KSC for a landing, only to have the thrust cut in the final phase of descent. The stage crashes into the ocean. This issue can be prevented with high thrust rocket engines or parachutes, but rockets add considerable weight and the parachutes tend to be rather inaccurate (though I already was at that point). This landing was not one you could come away from... What Should It Be For? This is actually contains delta-V for a trip to other planets, but only really for a slightly-faster-than-Hohmann trajectory. The Ablative Laser Nozzle should be well suited, like the laser thermal rocket, for travel inside planetary systems and for liftoff, as well as the high-thrust engine for interplanetary craft. However they would perform poorly in this regard if a power station is not located at the other end of the trip. They can be scaled quite small, so they could be the powerhouse behind powerful, high-thrust probes and missiles, though in the case of a missile, it would be easily compromised if the laser was damaged—besides, why not just use the laser as a weapon? From a worldbuilding view (I don’t think you can do this in-game) lasers can be used to push around asteroids and space debris in the same style, by heating the surfaces of these objects till they either enter the right orbit or re-enter the atmosphere (hopefully the space debris, not the asteroids). When? As a propulsion source this also seems to be quite near-future, which is quite good considering non-rocket launcher systems would likely take over further in the future. Use In a Story Considering the laser can heat a propellant into a plasma, this also implies that the laser as a destructive weapon. Additionally, the spacecraft’s propellant could be ablated unevenly, causing the ship to flip if more force is exerted on one side. Antimatter Antimatter-Initiated Nuclear Pulse Propulsion How It Works Typically, nuclear pulse propulsion is limited by the fact that nuclear devices cannot have a yield of 1/100 kilotons, the explosion of which fuels a fusion explosion. The fusion fuel tends to be less expensive and radioactive, making bigger bombs more efficient. However, large bombs cannot be used on small ships. The antimatter-initiated version attempts to solve this by injecting small amounts of antimatter into the fission fuel, which annihilate and makes achieving fusion far easier. The stats on the engine are quite similar to the ICAN-II concept. Why Use It? The Antimatter Initiated (or Catalyzed) engine provides a solid specific impulse of 12,000 seconds, which is quite comparable to the lowest thrust setting on the Tokamak, while providing far more thrust for its weight. Why Not? The specific impulse of the vessel cannot be increased for lower thrust, unlike many other designs that utilize the magnetic nozzle. The helium-3 used as the fusion fuel is very expensive, though hardly as expensive as the next issue... Probably the biggest problem involved with this design is the use of antimatter, which is extremely expensive and difficult to store. Additionally, the very reason antimatter is used is also the most dangerous part—granted, the amount of antimatter used in this is miniscule, but if it reacts with matter, there won’t be any fuel left… I wouldn't click that... The annihilation of matter and antimatter produces gamma-rays, which are quite dangerous to any crew onboard. In Testing The test ship ended up being very big, with 1160 tons of liquid hydrogen fuel, and a payload of 1308 tons. Fully fueled, the vessel carries 61,700 m/s of delta-V and accelerates at a fair 0.39 m/s2 with a thrust of 1,100 kilonewtons. Though the acceleration isn’t ideal, it’s still enough to leave orbit and use up half the fuel in a few days. The vessel coasts for the remainder of the trip, before braking to ensure a capture at Jool 106 days later. Judging the ideal entry isn’t easy, but watching the time to periapsis during a braking burn is helpful—if it’s increasing, the ship should probably wait a while. Once in orbit, the thrust is more than enough for moving around the Jool system. This does mean it could be used in-system, though it would be quite wasteful to spend valuable antimatter where a nuclear engine would work just as well. When? Such a spacecraft would require the storage of considerable quantities of antimatter for extended periods of time, something that is far from reach currently. However, the rest of the engine would be easier to build, since the antimatter makes fusion easier to achieve. This design would probably be one of the first antimatter using engines put into service. What Should It Be For? The high Isp would make it well suited for interplanetary travel, like most of the fusion engines. The use of antimatter would probably prevent it from becoming dominant, but if antimatter becomes relatively cheap, then it has a rather good shot at it, though the VISTA may spoil such hopes, since the thrust would be somewhat better. In A Story Shooting antimatter into the reaction chamber could risk damaging the reaction chamber wall, and the storage of antimatter must be especially concerning if anyone’s onboard. If the containment starts to go wrong, I don’t think anyone would want to be the one fixing it (which is why robots are quite helpful, and also make stories a bit boring…) Antimatter Plasma Core A future with significant stockpiles of antimatter may have this—the antimatter plasma core engine. Antimatter is injected into a stream of reaction mass (usually liquid hydrogen), which is heated into a plasma. Why Use It? The plasma core engine is generally listed as having a specific impulse in the hundred thousands, but the KSP-I version can go higher, presumably with more equal amounts of antimatter and matter than the plasma core, which still uses relatively little. The number it can reach? 20 Million—a significant fraction of C. That is of course with absurdly low thrust, but this can always be changed for higher thrust. Disadvantages Any ship using this will have to store fairly significant amounts of expensive antimatter for long periods of time, which in itself is already difficult. The highlighted portion is the 2.5 meter wide reactor—the radiators need to be this big to disperse its heat! The reactor generates enormous amounts of waste heat, so it requires a huge amount of radiators—so much so, that a plurality if not a majority of the dry mass would be dedicated for that purpose! Not even the torchship fusion drives can compare to that! In Testing When I mean covered in radiators, I mean it—even with a small 3.125 meter wide reactor, easily over 100 tons of radiators were dedicated to the ship, and the amount of antimatter that needed storage (on the order of kilograms) meant a container weighing in at 250 tons! In the end it needed far less, but it still consumed ½ of it! The engine takes time to get up to speed, which is why I had to reduce the amount of hydrogen carried compared to the antimatter-catalyzed vessel—it would never be able to consume it on a short trip to Jool. At peak thrust it produced a relatively meager 791 kilonewtons, producing an acceleration of 0.36 m/s2 with an Isp of 200,000. Since the thrust power is consistent, the plasma core can put out 100 times that Isp, at a mere 1/100th of the thrust. Obviously this has no use in interplanetary space, so I use the much higher thrust. The vessel achieves around 150 km/s at top speed, thrusting the whole way to Jool, which it reached on the 47th day. It swung towards Vall, but missed. With so much delta-V, the ship simply burned to re-intercept Vall, where it slowed with a small 200 m/s maneuver. When? As far as I know, this is probably the most advanced thruster in KSP-Interstellar Extended. Considering the need for kilograms of antimatter to be contained, this shouldn’t be altogether surprising. What Should It Be For Their exhaust velocity would make them good starship engines, but it probably wouldn’t work as a departure engine, since the thrust is quite low, especially in the low thrust mode where it’s quite special. Perhaps they’d work as a “cruise engine” to add speed to the vehicle during the whole trip to the target, but the weight of the radiators might make this somewhat ineffective. A "small" interstellar ship For interplanetary uses, this engine is simply not for it—perhaps between the inner planets and the very outer planets (like Neidon, in the Outer Planets Mod), but the Kerbstein drive and possibly even the Daedalus would be better suited, since they don’t require huge radiators and though the Daedalus uses helium-3, even that is cheaper than antimatter. In A Story In the case that the magnetic bottles storing antimatter fail, the antimatter will drift into the walls before reacting and causing a spectacular explosion. If the antimatter is simply shot into space with no matter to react with it, they pose a threat to any nearby spacecraft, which could suffer significant damage when hit. End of Chapter XIII Thanks For Reading! Next: Mixing Propulsion Systems if you haven't read it, and Colonizing Dres if you've read them all!
  3. Antimatter Plasma Core ship in orbit around Vall just 48 days after departure from kerbostationary orbit!
  4. Definitely true for chemical engines—not sure about more advanced ones like fusion though. I suppose you could get around the issue of needing reactors by using mostly missiles and kinetic weapons, though of course the former can be shot down and the latter takes rather noticeable amounts of time to reach the target. As for delta-V, ships could just carry drop tanks with them, and drop them—they might make the ship vulnerable, but they would probably be used for an intercept burn only. Having multiple engine bells would also make the ship more redundant, which would be very important in combat, where the ships would be unable to repair quickly enough. As for lasers, couldn't the ships just mount two or more?
  5. I suppose that people can't help but think in terrestrial analogues, where bigger generally means less maneuverable. For that matter, why would it have terrible delta-V? I had an idea for a group of ships that would piggy-back aboard a large supply ship, and would use higher thrust but possibly lower Isp engines. They'd be fairly expendable and could attack larger ships, before retiring to the supply ship and restocking. The main problem I can see with this is the huge dependence on the supply ship.
  6. Just curious: Are there any craft you'd like to test/mess around with from the chapters? I'd be glad to share them. As for the next propulsion chapter, it's coming along steadily. I've also worked a bit on the Dres chapter as well, though it's certainly a short one.
  7. Thanks! I suppose that makes sense - you don't have to keep the thing running all the time. I read your blog a lot, it's quite helpful in writing some of these chapters!
  8. Chapter 4: Fusion Propulsion Now we come to fusion propulsion—a truly powerful form of travel. Magneto Inertial Fusion \ I have a feeling the ships get longer every chapter... How It Works Rings of Lithium are injected into the chamber, then crushed with powerful electromagnets around fusion fuel, which ignites and shoots out of a magnetic nozzle at high speed. These pulses occur every few seconds. Why Use It? Compared to many of the designs that will be covered in this chapter, this propulsion system does not need massive amounts of radiators, thanks to the fact that the exhaust carries the waste heat away. Why Not? For a fusion drive, this design has a rather low exhaust velocity, therefore having an Isp of 4452 seconds. Additionally, it provides fairly little thrust for its weight. In Testing This vessel comes in at around 1000 tons fully loaded with a 300 tons of cargo and about 450 tons of Lithium propellant. The version of the magneto inertial fusion drive is upscaled to around 100 tons, and produces only about 950 kilonewtons of thrust. The vessel had to burn for about 3 hours for a burn of around 12 km/s. It took 209 days to reach Jool, and after another long thrusting, I managed to reach orbit with a rather thin fuel margin. I decided to wait 9 days before attempting to orbit Vall, which I succeeded, but only barely—not only did I nearly collide with Vall, I used up all the fuel to enter orbit. What Should It Be For? The Magneto Inertial Fusion engine would provide an alternative to the open cycle gas core engine, as the engine involves less radiation, are simpler, and probably harder to maintain. Additionally, they would be more likely to be used to travel between lithium-rich planetary systems, due to the fuel used. However, I do not believe they would be particularly dominant, as they don’t perform as well as other engines. When? The Magneto Inertial Fusion engine can be built rather easily with current technology, though that design is low thrust. That said, higher thrust levels can be achieved with relatively little steps for technology. Out of the fusion designs covered, this is the most feasible, having the least problems that need to be solved—with the engines available in-game, this would likely be the first. Use In a Story While I haven’t found much on how these can cause a convenient engine failure for a story, I think that the Lithium rings could misfire and be smashed by the magnets without the fusion fuel, and possibly damage the engine with the debris. A demand for more lithium might arise from the creation of such an engine, encouraging new mining operations, Tokamak Fusion Rocket How It Works A Tokamak uses magnetic fields to confine a plasma in a torus, and the basis for many fusion reactor designs. This rocket uses that for propulsion by heating up hydrogen as well as the fusion products and directing it out of the spacecraft with a magnetic nozzle. However, it is more efficient to simply use the fusion products, though this comes with less thrust. The Stellerator is a rather similar type of reactor, and performs similarly. Why Use It? With the plasma nozzle part, the Tokamak rocket achieves an impressive specific impulse of 7513 seconds—on par with the MPD using something like Helium. However, with the magnetic nozzle part, a far higher specific impulse of around one million seconds can be achieved, though with less thrust without the “afterburner” that the additional reaction mass provides. Why Not? The engine has rather low thrust; despite a 90 ton reactor, my test ship would only manage around 800 kilonewtons of thrust. This is still far more than the electric propulsion ships, and the ship can still burn on short time scales. Though of course not modelled in-game, the engine would be rather radioactive, especially with Deuterium-Tritium fusion, where many lethal neutrons are released. In Testing I based this new ship partially off of the Discovery II, a NASA concept of the Discovery from 2001: A Space Odyssey that would actually work, using a Tokamak just like this one! With the plasma nozzle, the ship accelerated at only 0.86 m/s even with a giant reactor, so I installed the Better Time Warp mod to make the Kerbin departure burn happen quickly. For the 17,000 m/s burn that took several hours to complete, this was very helpful. After 160 days, the thousand ton ship arrived at Jool, and began the process of slowing down. I didn’t reach Vall as I approached, but I was able to do so on the next orbit, and the Tokamak did provide enough thrust to make the course corrections bearable. After a quick Tylo flyby, the ship arrived at Vall with a large 900 M/s burn with over 2,000 m/s left in the tanks. With a magnetic nozzle design not unlike the Discovery II, the thrust was about half of the plasma nozzle, but the magnetic nozzle allows time warp during acceleration, so it was rather bearable. After leaving Kerbin, I burned with the lower thrust modes with Isp around 500,000, and just before crossing Dres, I flip and start burning the other way. This proved to be quite early with the higher thrust, yet I still arrived at Jool just 95 days in the mission and entered Vall immediately. Provided I took a riskier route, I think the Tokamak can reach Jool in 70 days. "I'm sorry Dave, but I'm afraid I can't do that" When? The achievability of this design depends on whether nuclear fusion is feasible, among other things like making magnetic nozzles work. Though I tend to dislike putting a date on these, I think the general consensus is that a fusion rocket like this is “late 21st century-era” technology. Though the reactor can power electric drives during transit, the engine itself can replace them, since it can burn at low thrust for an extended period of time. What Should It Be For? These ships would replace most of the vessels that use one engine for high thrust, and another for higher exhaust velocity, since the Tokamak can do both at the same time. Provided more advanced engines are not introduced, they will likely dominate interplanetary travel. I don’t think they’d be very effective on in-system transit, considering the low delta-V requirements, which mostly negates their advantage, and they would be poorly built for landing or takeoff. Use In a Story With a fusion rocket, the time scales of travel are lessened a lot, so there’s probably a lot less “downtime” for the story as the kerbals do not need to spend many Muns traveling to the outer planets. With powerful magnetic fields inside the rocket, having several on a single ship would be a very dangerous idea, and the direction of very hot propellant could be disrupted, causing an explosion. VISTA (Vehicle of Interplanetary Space Transport Application) How It Works This powerful fusion engine works by shooting out pellets of deuterium and tritium surrounded by propellant, which are then zapped by an array of powerful lasers, compressing the pellet till nuclear fusion is initiated. The propellant is then directed by magnetic coils and accelerated to high speed. Why Use It? The VISTA provides thrust comparable to the above engines (not much), but in return has much higher specific impulse at the top thrust, 15678, while being much lighter. The thrust can be lowered to reach 27144, though this does reduce thrust. For reference, the actual concept design only puts out about 240 kilonewtons while being considerably heavier. Why Not? The VISTA fusion rocket happens to use Deuterium-Tritium fusion, which puts out a lot of waste neutron radiation and will kill nearby kerbals. In fact, the VISTA concept was cone shaped to reduce the radiation exposure. The bit depicted by the KSP part is actually far bigger in real life, at over 100 meters wide! Roughly something like this—a flying saucer of sorts. In Testing The VISTA cannot thrust during on-rails time warp, so again the Better Time Warp mod steps in. Without it, I probably wouldn’t have bothered, since the departure burn of 57 km/s took 4 days! With that, the ship skipped across the solar system and only 59 days later it arrived in Jool’s SOI, where I immediately began burning to slow down for a slightly shorter burn, thanks to the lowered mass. After 3 days of semi-continuous burning, the ship is captured by Jool. After a small correction burn and an orbit later, I arrive at Vall with a short burn in a mere 72 days with enough delta-V to make it back to Kerbin, though much slower. When? As @MatterBeam made aware of, pulsed fusion designs like these would be easier to develop, since the fusion only has to be sustained for very brief periods at a time, not continuously. Of course, the VISTA is very powerful compared to the Tokamak, so for balancing purposes, one might want to keep the thrust of these quite low in the beginning when they are initially invented. Use In a Story For an example, a warship is attempting to get away, so the thrust is increased by adding more propellant; this only prevents the fusion pellets from igniting, and they fail. Another scenario: the ship is in the middle of a big turn, and the lasers cannot adjust to this when the fuel pellets are shot through, causing them to miss, or fly off. "It's goin' as far as it can go, Captain!" What Should It Be For? It’s in the name of the vehicle—interplanetary space transport! Since it’s so expensive, I think it would be mainly put on routes to the outer planets (of various mods), where shorter travel time can always be used, and the colonization of said areas would be completed much quicker. However, their efficiency wouldn’t be good enough for interstellar applications. As the VISTA becomes more and more frequent, they should become cheaper and cheaper, and they may even see use in warships in its higher thrust mode, though a space admiral must pay close attention to not irradiate one of his own ships. However, their use as the primary high-speed ship may eventually be replaced by the following engines... TORCHSHIPS These are the Really, Really, Really powerful engines—able to accelerate at a considerable fraction of one G, while being extremely efficient. Some of these engines can point right at the target, flip, then slow down, practically traveling in a straight line in a brachistochrone trajectory. Project Daedalus Fusion Engine How It Works The Daedalus fusion engine is the one of the most efficient engines available in KSP-Interstellar Extended. A form of nuclear pulse propulsion, the engine uses tiny pellets of deuterium and helium-3 that are bombarded with electron beams and effectively explode like small nuclear bombs. The plasma that results from this is directed by a magnetic nozzle. Why Use It? Finally, a ship is capable of constant thrust throughout the journey! Not only does this allow the ship to achieve incredible speeds, the ship can provide gravity purely by the force of its engine, with no need for huge centrifuges. The Daedalus fusion engine has a specific impulse of one million, while providing hundreds of kilonewtons of thrust! The engine acts as a powerful transmitter, so those very far away can communicate. Why Not? The problem with the Daedalus fusion engine is its fuel—helium-3 and deuterium makes for a fusion reaction with less neutron radiation, but helium-3 is extremely rare. Even Moho or the Mun, which would likely have helium-3 might not have enough; mining at Jool or some other gas giant may be required, and leaving the atmospheres of gas giants is very difficult, and the methods of cheaper methods like launch loops may be initially too expensive. Additionally, the high specific impulse of the Daedalus might be just too high for interplanetary use—the engine just doesn’t have the time to use all its fuel at times! In Testing I chose to increase the cargo from 300 tons to 475, and the whole thing weighed just 658 tons wet, because only 41 tons of fuel pellets were needed for a delta-V of 631 km/s! The acceleration at departure was a fairly low 0.95 m/s. It still proved to be more than enough to leave Kerbin, and would be still provide some useful amount of gravity. As I expected, the ship was more than enough to conduct a constant thrust brachistochrone trajectory, attaining a speed of 250 km/s before flipping around and slowing down for an arrival at the Joolian system 30 days after departing from Kerbin! Now that I think about it, I probably should've just burned straight at Vall if I wanted to get there! The ship has so much delta-V it wouldn't make a difference! When? This is a highly advanced fusion drive, which probably won’t come along till after the VISTA. Even if it can be built, the use of helium-3 may discourage its development, and even then it doesn’t guarantee that they would be very common, unlike the VISTA. What Should It Be For? As helium-3 is rather rare without mining the gas giants or scraping massive quantities of it from fusion reactors, they would best be used sparingly, like on a starship, which was the purpose of the Project Daedalus concept by the British Interplanetary Society, that would allow a ship to fly past Barnard’s star in only 50 years. Later, I got the ship up to 0.06 C—I could go even faster, but for some reason the ship wouldn't want to! Even my replica is a little small compared to the real thing! The high Isp should allow a ship to reach several percent of light speed, making sure any star systems are in reach for colonization. Almost a thousand passengers onboard! Provided this kerbal future has access to plentiful helium-3, then now the doors to ultra-fast transport are opened. Needing to catch a business trip on Duna from Kerbin in a week? Fear no longer, the Space Concorde’s got you covered! Well, if it doesn’t become unprofitable... Use In a Story The methods of failure are probably quite similar to the VISTA—involving lasers and fuel pellets. For a potential scenario—perhaps the lasers are hijacked just before a starship begins slowing down to orbit a star with no help for light years! The Kerbstein Drive How It Works The fusion drive based off the ones seen in the book series and TV show The Expanse. Having read the first three books, they mention fuel pellets—implying a form of inertial confinement fusion like those covered above. The version of the drive in KSP-Interstellar seems to be based off the MCRN Tachi/Rocinanate’s stats. A quick little replica of the Tachi Rocinante! It can get up to 2 Gees, though the thrust tails off very quickly. Why Use It? The Kerbstein drive has half the efficiency of the Daedalus fusion engine, but also uses lithium hydride, which is almost certainly more abundant than helium-3, which makes it potentially cheaper and thus better suited for interplanetary travel. It is also somewhat lighter and smaller than the Daedalus, with higher thrust as well. Why Not? However, it takes significantly more power to run, and cannot be scaled below 5 meters in diameter. Additionally, it has a tendency to overheat when pushed at its highest thrust. In Testing The function that allows acceleration during timewarp only seems to allow a certain amount. Therefore, I upped the amount of the amount of cargo to 787 tons to make full use of the engine’s thrust. In the end, it still wasn’t enough, and I had to limit thrust. The ability to accelerate quickly puts this engine in the advantage over the Daedalus, and now the engine can actually make full use of a larger fuel reserve of 316 tons. It should come as no surprise that this engine shot to Jool in 14 days. With such short travel times, it soon becomes a waste to wait for gravity assists to get around Jool! What Should It Be For? If the Kerbstein drive really is as apparently cheap as the Epstein drive seems to be in The Expanse, with every large ship using it, then this would open up interplanetary travel to most people! Even if it is expensive, they would finally give a solution for a high thrust, high efficiency drive, making warships equipped with these drives both powerful in combat and very quick to respond. When? I’m not sure if the Daedalus or Kerbstein would be created first, but the proton-Lithium fusion of a Kerbstein drive would be harder to achieve, so that may make it come later. In any case, this is a very powerful engine that would take a long time to arise. The Orion Drive “old Boom-Boom” How It Works Considering the radiation blasted out by the open-cycle gas core and many of the fusion drives, perhaps it’s no surprise that this powerful engine is also quite dangerous… Because it’s propelled by nuclear bombs… The spacecraft is mounted on a thick pusher plate and small shaped nuclear bombs are shot through the center of the plate and detonated to push the ship forward. An occupied ship would be equipped with shock absorbers to suppress the jolt of the ship. Though fission or fusion bombs can be used, I figured that it would fit here with many other… Extreme designs, so to speak. Two updated mods provide Orion drives— the TD edition and the USI one. Why Use It? Was it really worth it? The Orion drive provides massive amounts of thrust, and can easily accelerate at over one G, even reaching levels that are dangerous to any crew on board taking off from planets with lots of gravity… Sure, they are nuclear bombs, but small ones, so the damage will be fairly limited. Why Not? The Orion drive isn’t as efficient as many of the other designs, though it’s rather hard to find solid numbers. Additionally, the ride would be rather uncomfortable, even with shock absorbers, with nuclear bombs releasing their energy in a very brief amount of time. What Should It Be For? Uchuu Senkan Orion! Seriously, an actual design had an Orion drive powered ship strapped with naval guns, nuclear missiles, point defense guns, and Casaba Howitzers that would direct the energy of a nuke into a tiny angle! These would likely be the first torchships, and would probably be the powerhouse of the first starships as well. Thanks to the high acceleration, they would be good launchers, but poor atmospheric landers, since the vehicle would fly into it’s own nuclear fireball… The acceleration would be welcomed on a naval capital ship that needs to accelerate quickly to dodge enemies. When? The Orion drive can be built with current technology, though the incentive to build such an engine is rather low at the moment. However, as space becomes more developed, a high payload capacity vessel may be welcome. In Testing For the tests, I used the TD edition Orion drive with the 15 kiloton nukes! The ship carried a payload of 475 tons, and it accelerated at 85 Gs! The game lagged a lot, and without an accurate delta-V reading, I had to guess how much I had. Thanks to the killer (literally…) acceleration, I reached upwards of 150 km/s in just an hour! Even though this isn’t as high as the other engines, because the burn was so short, it spent less time at low speed. The vessel arrived at Jool in 22 days, and I almost got into orbit, but was short by about 20 km/s. However, arrival at Jool in 25 days is perfectly possible, and travel to Eve at its closest might be as short as 5! Use In a Story Since the Orion drive can be built with today (and yesterday’s) technology, it opens a storytelling opportunity where the Orion drive was actually built and used to colonize space. The pulse units can detonate too close and vaporize much of the pusher plate, or veer off to the side and create an asymmetrical force that flips the ship. If a malicious faction gets their hands on an Orion drive-propelled vessel, whether it crashes, is hijacked, or something else, they have plenty of opportunity to cause great destruction if they can repurpose the pulse units… Summary Fusion engines do not come around until later, but when they do, such designs are extremely powerful, and excel at providing both high thrust and high efficiency. Thanks for Reading! Next: "Other" propulsion methods and the Colonizing Dres chapter!
  9. War spacecraft would probably be pretty pointy to deflect enemy shells and increase the effective armor thickness. I don't know if it would work for particularly high velocity weapons, but maybe for conventional guns strapped on drones they would definitely work.I'd imagine most of the armament would be forward-mounted to increase protection and firepower at once. Missiles would also be pointed shaped so that oncoming fire would get deflected.
  10. Very nice! As for the slow performance of your computer, it might have to do with the part count of the submarine or maybe the graphics mods you're using—I encountered this issue a lot when I made my naval ships, since they came it at around 800-1100 parts.
  11. Today I finished the Magneto Inertial Fusion and VISTA engines!
  12. Remember the Cant! I drew the Canterbury from The Expanse with pencil and pen/marker. The pencil went pretty well as usual, but I think the pens took away some of the detail that the drawing had. That said, I haven't used the pens in a while.
  13. My Tokamak rocket design arriving at Jool and its many Muns after just 160 days of travel.
  14. Version: KSP OSX 1.3 (Uncertain if 32bit or 64 bit) Mod List: Like some other reports, KSP is about at the end of the loading, when it crashes. A few mods seem to cause this, and a few examples seem to include BDArmory (but not Baha Turret), SM Armory (with SM Industries), and Modular Kolonization System (MKS). The above are the mods that DO seem to work, though adding any of the ones I just listed makes the game crash. I assume it isn't related to memory, because if I remove a big folder like the BoulderCo from Andromeda: Daydream and add BDA, it still crashes. Link to the Player.log