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"...In 1961 it took a crisis--the space race--to speed things up. Today we don't have a crisis; we have an opportunity. To seize this opportunity, I'm not proposing a 10-year plan like Apollo; I'm proposing a long-range, continuing commitment. First, for the coming decade, for the 1990s: Space Station Freedom, our critical next step in all our space endeavours. And next, for the new century: Back to the Moon; back to the future. And this time, back to stay. And then a journey into tomorrow, a journey to another planet: a manned mission to Mars...." --George H.W. Bush, 1989 The year is 1992 America has just completed the assembly of Space Station Freedom 3 years have passed since the announcement of 'Project Constellation'. The Constellation program detailed a multi-step program, which involved completing Space Station Freedom, Developing a crewed Lunar vehicle and lander, finally returning Astronauts to the moon, and eventually settling on a location for a Lunar base, a permanent crewed outpost, keeping humanities foothold firmly beyond earth, with an eventual build-up of Mars hardware, ready to land humans on the red planet twenty years down the line. Out of the mess of competing programs, hardware and timeframes, Artemis emerged, a program similar to the early stages of Constellation, consisting of three major components: - Apollo block V, an upgrade to the block IV and the crew return vehicle for Artemis - The Lunar lander, one Hab lander to carry supplies and a living space for the crew, and the other to be a glorified taxi to the surface -A large 5.5m wide TLI stage to send the crew out to the moon, named Pegasus as it gave the Artemis program wings These components would be launched on three separate Saturn Heavy H03 rockets, NASA's biggest and most powerful launcher since the Saturn V My plan with this thread is to recreate the entire Artemis program, along with Orion, and it's Lunar 'Soonbase' The mission list is as follows March 1996 - Artemis 1 September 1996 - Freedom Expedition 32 October 1997 - Pegasus first flight February 1998 - Artemis 2 June 1998 - Artemis 3 November 1998 - Artemis 4A , March 1999 - Artemis 4B & 4C November 1999 - Artemis 5A, July 2000 - Artemis 5B & 5C January 2001 - Artemis 6A, Summer 2001 - Artemis 6B & 6C January 2002 - Artemis 7A, Summer 2002 - Artemis 7B & 7C January 2003 - Artemis 8A, Summer 2003 - Artemis 8B & 8C January 2004 - Artemis 9A, Summer 2004 - Artemis 9B & 9C January 2005 - Artemis 10A, September 2005 - Artemis 10B & 10C January 2006 - Unmanned Saturn M22 explosion July 2006 - Artemis 11A, February 2007 - Artemis 11B & 11C Late 2007 - Orion assembly mission 1 Late 2007 - Orion assembly mission 2 June 2008 - Orion expedition 1 March 2009 - Orion expedition 2 2010 - Orion expedition 3 I hope you all come to enjoy this project as much as I will making it Ad Astra!

"Thus do we reach the stars" Introduction: Hello, and welcome to the "Sic Itur Ad Astra" thread. For the past few weeks, I have been working on my own alternate Apollo program and I've recently gotten to a point where I am confident enough to share my posts here. The main focus of this thread is to have a cohesive collection of mission profiles / reports, lore and screenshots. The Apollo Program begins in 1961 just like in reality and continues on the same path until November 1967 when the crew for Apollo 8 is announced. From there, everything is from my own mind taking inspiration from cancelled missions, TV shows and more. In order to get some of the shots required, I'll be utilising real world images alongside my Kerbal ones which will be more prevalent. Special Thanks: Raccourier for graciously making the patchwork. @Talverd for convincing me to do this and coming up with the name. The Space Shuttle Adventures thread , ISS Adventures thread & the Chasing Dreams thread. All of the mod developers that made this possible. Mission List

Have you guys heard of Hazegrayart? He makes different animations of what could have been, or what could be? Here are some of his videos. He's gotten in trouble in the past, for using real footage, which is really funny, because all of his videos are artificial! He once tried making Nova Rocket, Saturn V's replacement. And he's really good at simulating what Starship will do in the future.

Early crewed Moon landing Nasa proposal Gemini Lander I've just managed to do this early "low-cost" Nasa proposal to a cheap and fast moon landing, since our space program is often running out of money ( big hug to RP-1 team) . Of course, this little thing never flown in reality, was one of the possible applications of the Gemini spacecraft (one design even was planned to a Mars landing!). First, have to launch the landing module, attached to a Centaur stage (2 RL-10 with restart capacity), in LEO. Launch vehicle is the great Titan III-E: first stage 2 solid boosters and LR-87 (burning aerozine/NTO in AJ-9 configuration), second stage is LR-91 (same, AJ-9 too), and last stage is hypergolic Centaur stage , just to finish orbit. Of course we have to launch in the plane of the moon, so waiting, to have right relative inclination. Initial ascent Booters separation, aiming orbit at 250 km: Then LR-91 firing, and finally centaur stage just a bit to finish the work: The Lander is hidden in the fairings, and on top of that, agena probe core/docking port for gemini spacecraft. Now let's launch the crew! The gemini spacecraft have been upgrated with a better service module, providing enough deltav to hopefully come back from moon orbit, and enough life support stuff. Same Launch Vehicle. Crew: Neil Amstrong, Alan Shepard. And launching from Cap Canaveral (same as before) Standing by the launch: Neil and Alan photographs from the launch tower for their respective wives when they will (we hope) come back: Now get in, and launch! Waiting to have the same inclination as our target and an acceptable phase angle to minimize rendez-vous deltav cost. Hmm, all this thrust, glorious. After getting rid of boosters and first stage, centaur is as before finshing orbit: After rendez-vous maneuver, let's dock this! Docked! Now go for the moon: After about 2 days of travel in this tiny spacecraft, and after circularization burn, Neil Amstrong is getting in the Landing Module, leaving Alan Shepard a few hours alone in moon orbit: Undocking, and centaur stage firing its last precious amounts of deltav doing the decceleration burn, after that the lander will be released juuuust to the do final descent, at about 2000 m above the terrain, meaning Neil Amstrong will land with a Centaur stage going to crash.. just under him. What a brutal Nasa idea! Almost, almost, now let's do it smooth (the lander is propelled with 1 or 2 kn engines burning Aerozine/NTO (unthrottable) and have very few life support on it). I made the lander with descent and ascent stage, but not necessary at all, as you can see. And done! Now let's get out quickly of this flying scrap, plant a flag, take one or two pebbles for our scientists, eat a snack on moonar surface, and get back! Good bye moon: Rendez-vous with Gemini, and EVA crew transfer: Now let's go back to our dear old Earth, have to aim the return Pe at 71 km to capture first, and then land, for good ( since the Gemini heatshield will burn up under that, and we don't wan't that). Second and final reentry: Chuutes, chuutes: And gloriously, marvelously, splashed in the Indian Ocean:

Hello! I am between jobs right now and I bought a new computer that can run KSP before my last job ended. I can't afford to buy KSP itself right now, though I will treat myself to it when I get my next job. In the meantime I am a big alternate history fan, and also a fan of space technology and history, and plan to use KSP to model proposed possible alternate history configurations. One interest of mine is whether it might have been possible to repurpose developed Space Transport System technology to make a family of useful launch vehicles with relatively cheap and quick development time, rather than what has been done historically--which was to simply reuse the existing Shuttle fleet until it was deemed superannuated, and then enter an era where the USA had no crewed flight launch ability whatsoever. Over time since the last Shuttle flight, SpaceX in particular and also some competitors in New Space have developed pretty good new launchers and spacecraft and realistically I think these will be America's ticket back into crewed missions in Low Earth Orbit and beyond. However as an alternate history fan I would like to demonstrate some other possibilities we missed out on. My question seems to be an odd one, as I cannot seem to find any online source that details the answer. Bottom line is I want to know, of the three type of dry segments of the historic Shuttle Solid Rocket booster, what were their separate dry masses? My reasons for wanting to know this might require some involved answers but the short version is, I want to be able to estimate how varying the Boosters by -shortening- rather than lengthening them, by removing segments, so we could have three smaller variants with 3, 2 or conceivably even just one segment of solid propellant, to use for smaller expendable or semi-expendable launch systems that would be literally Shuttle Derived in design would have worked out. What I do know is that overall, the historic SRBs each massed 589 metric tonnes fully loaded with propellant, and that propellant massed 502 tonnes, so the six segments--one nose segment, one nozzle segment, and 4 propellant units--massed about 88 tonnes at burnout. It would shed some mass descending but I am only interested in the mass at burnout, not the mass recovered. If all segments were identical in dry mass that would imply each one was 14.3 tonnes, but of course I think the nose and nozzle units each massed more. If we were to make smaller booster units with fewer segments, the nozzle section would have to be redesigned for each possible size, since the mass flow of exhaust gasses is determined by the number of segments. The throat and nozzle would scale down to keep the same expansion ratio, and this means it is lighter and thus easier to move so the gimbaling hydraulic system and its actuators would be smaller in proportion too; conservatively I would guess it scales with 2/3 power of the number of segments, or by area, though it might work out to be closer to linear. So I want to know if anyone already knows for a fact the dry mass of any two of these three elements since then I could compute the third one. That would tell me the burnout mass ratio of a smaller system (or larger though I am not really interested in that). Since the solid fuel segments have little job to do but be strong cylinders that can contain the peak pressure of the grain combustion I suspect they massed remarkably little, say 8 tonnes each, which gives just 32 for the 4 of them and thus the nozzle and nose sections between them would total 56 tonnes, of which about under 2/3 I guess would be the nozzle, for say a 40 tonne nozzle unit (!) and 16 tonne nose unit. If we don't try to recover the boosters but just let them splash, I suppose the nose unit can be lightened more. Well 40 tonnes for the nozzle strikes me as pretty absurdly high, so I hope these aren't close to true figures. But that's my best guess for now. Anyone able to set me straight? I can't just look at SLS's boosters because they aren't really "Shuttle Derived" in that the grains have also been modified, in addition to adding another fuel section. They don't compare directly. I want to know what the classic Shuttle booster mass breakdown was, so I can see what the ratios would be for proper literally Shuttle Derived variants.

Post #1 - April 13th, 2017. DISCLAIMER: This entire thread is intended as a parody of the space race, so please don't take what I say seriously. Kerbin's Geography: 1943 - 1978 (Current): Mod list: Please be advised that I am currently accepting payloads submitted for launch by "private companies." Preferably, payloads must under 15 tons, but the limit is 25. The only mods you can use are MOLE, Tantares (Either LV or spacecraft), TRAILS Plus, Home-Grown Rockets (With the patches for use in 1.2.2), Fuel Tanks Plus, KAS/KIS, and Ven's Stock Revamp. I'm not installing mods just for your payload, because my game already crashes way too much! Payload submission form below: So. Here it is. I've been wanting to do an Eyes Turned Skyward style mission report series, where I'd play a new career mode game, presented in a history book format (Also inspired by this). These mission reports will have multiple different parties launching space vehicles - the USSR and the USA. Yes - It's basically just a career game with a moderately entertaining backstory - but I wanted to do it so here it is: --- Year 1, Day 1. (April 13, 1957) At a remote complex in southern Kazakhstan, a new ICBM is being prepped for launch. But this is no regular ICBM. And it carries no nuclear payload. As trucks and jeeps drive around the missile, ground crew fuel up and prepare the ICBM for takeoff. This missile contains a small satellite, equipped with four long-range antennae and advanced scientific instruments. At T-minus ten minutes to launch, the three large, green metal launch gantries lower themselves away from the rocket, and the ground crew clear the launch zone. TV crews crowd around barriers, blocking any unauthorized personnel from gaining access to Launchpad-G. The rocket has two stages - the first, an FLT-800 fuel tank, with a singular BPT-180 engine, and a TR-18A decoupler to make way for the second stage - an FLT-200 fuel tank and another BPT-180 engine, with four Vernor engines to keep the rocket on course. At zero hour, the entire stack lifts off the pad, the 158 kiloNewtons of thrust more than enough to propel the rocket through the sky. Huge clouds of smoke billow from the engine as it approaches the highest-ever altitude set by an aircraft - 28 kilometres - and easily breaks that altitude record in a mere matter of seconds. At an altitude of thirty kilometres, the first stage cuts-off, and is jettisoned. The craft coasts to apoapsis, the Vernor thrusters aligning it on the correct attitude for the orbital injection. The second stage cuts-off with a mere ten seconds left in the orbital injection, at which point the fairing deploys and the 'Sputnik' satellite completes the burn using its NT-5R engine - an efficient, low-thrust experimental nuclear engine. The engine, also known as the 'Shiba,' has not been perfected, and slowly emits radiation, which would, if exposed to any astronauts for long duration missions - as the USSR would later find out - be lethal. After the satellite had reached orbit, it took readings with its scientific instruments, and broadcasted a continuous message towards Kerbin: Beep, beep, beep, beep... The successful launch of 'Sputnik' prompted the United States of America to respond with their own space program. In the beginning, the task was handed over to the Air Force, which, to put it bluntly, couldn't get to space if they were given a prefabricated rocket with instructions spelled out in block capitals with simple verbs and multiple pictures and diagrams. They were better at designing aircraft. They just couldn't get their heads around the fact that there is no air in space. So it's no surprise that on Year 1, Day 3 (July 21st, 1957), when the US Air Force attempted to launch 'Voyager 1,' the rocket failed to get off the ground. The two strap-on TX-354-3 SRBs and core SCOUT LRB were designed to carry the satellite, 'Voyager-1,' to an Apoapsis above the atmosphere, where the satellite would perform the orbital injection. However, the engineers made the embarrassing mistake of mistaking the vacuum Isp for the Isp at sea level, which wasn't even capable of lifting the rocket a single metre off the ground! The launch had made a mockery of the US Air Force, and the American people lost faith in their country's ability to compete with the USSR, with the failure being nicknamed "Flopnik" by the American press. And so, on Year 1, Day 4 (October 3rd, 1957), the National Advisory Committee for Aeronautics (NACA) became the National Aeronautics and Space Administration (NASA). And NASA's first task was to launch a satellite to compete with the Soviet 'Sputnik' program. The first thing NASA did was haul Wernher Von Kerman out from the Air Force's grasp to become their head rocket engineer. He and the rest of his team happily obliged, and, once work on the KSC (Kerbal Space Centre) was complete, work on the 'Explorer' program began. The facilities at KSC were less advanced than those at Vandenberg Air Force Base, but they were completely NASA-owned, and because NASA was government-funded, it meant that they could decide what to do with their facilities. Construction of the 'Cygnus M-22' rocket began on Year 1, Day 5 (December 19th, 1957). First, the rocket required two DIOSCURI-1 SRBs to provide the necessary boost at launch to raise the Apoapsis. The contract to build and test the boosters was awarded to BDB International, while the first core stage, an FLT-800 fuel tank with a TR-18D stack separator and an MPT-180 engine, was given to LeBeau Space Industries. The upper stage, consisting of another MPT-180 engine and two fuel tanks, one FLT-200 and one FLT-100, was also awarded to LeBeau Space Industries. The payload, the 'Explorer-1' satellite, was to be built and tested by the NASA design teams themselves. And, alas, on Year 1, Day 6 (March 11th, 1958), 'Explorer-1' was ready for launch. It sat on Launchpad-1A at the KSC. Crowds of reporters flocked to the Space Centre, and the local police had to be called in to prevent rambunctious Kerbals from jumping over the barriers and onto the pad! At lift-off, the two SRBs and central LRB ignited, and the rocket ascended towards the heavens on a plume of flame and smoke. Across America, tall tales were told of the launch being felt across the continent. But of course, they were just that - tall tales! At twenty kilometres altitude, the two DIOSCURI-1 SRBs were separated, and the central stage continued until it, too, was jettisoned at forty kilometres. The upper stage completed the orbital injection and raised the orbit of the satellite to a record-breaking altitude of five-hundred kilometres! As the satellite circled Kerbin, it took photographs, and studied ionizing radiation and the temperature of space! A famous image taken by 'Explorer-1,' known as 'the Greenish-Blue Marble.' Summary: USSR successfully launched 'Sputnik' LKO satellite - first artificial satellite - Year 1, Day 1 (April 13, 1957) USA failed to launch 'Voyager-1' LKO satellite - Year 1, Day 3 (July 21st, 1957) USA successfully launched 'Explorer-1' LKO satellite - Year 1, Day 6 (March 11th, 1958)

So I have just started an alternate history project in which the solar system forms very differently from Our Time Line (OTL). What this results in is a very different 19th, 20th and 21st century as space colonization becomes available even to the European Imperial nations. In any case, before I start I just want to check that the alternate solar system I have designed is even possible, taking into account things like orbital physics and planetary climates. So, here's what I have so far: -Sol is the star in the center of the system. Can cause blindness when looked directly at for a long time. For simplicity, it has the same characteristics as in OTL. -Vulcan: (0.071x Earths Mass) Vulcan is the closest planet to the Sun, and is a Lava planet. Due to its closeness to the Sun, it is very hot. Vulcan is close enough to the Sun for more than half of the planet to be molten. It is largely composed of dense Iron, metals, and Iron/Metal Compounds on its sun-facing side, as due to its proximity to the Sun, all of the lighter volatiles and silicates characterizing most planets in the Solar System boiled away, at least on its Sun-facing side. The proximity of the planet to the Sun exerts a lot of gravitational energy on Vulcan, making it tidally locked. Lava oceans cover the Sun-facing side of Vulcan, while (due to heat from the opposite side of the planet moving towards the night side) the night side is dotted with Volcanoes and Lava lakes, puncturing the thin Vulcanian crust. These emit large amounts of Carbon Dioxide and Sulphur into the atmosphere of Vulcan. However, the Sun's powerful solar wind blows away much of the accumulated gases (including silicates and other normally solid material) into space a very high speeds- consequently, from far away, Vulcan looks a little like a comet. This is how it has been visible since ancient times. The night side, however, is relatively cold, (compared to the day side) meaning silicates (and under rare circumstances, ices) are present here. Due to this difference in temperature, the atmosphere can condense, form clouds, and solidify on the night side, forming a silicate 'rain'. However, this is uncommon, as these materials are generally blown away by solar wind before it has a chance to precipitate. Vulcan is somewhat larger than Mercury in OTL, and like Mercury, lacks a proper magnetosphere. [0.45 G] PLANET (12° Inclination) {0.17 AU} -Mercury: (0.055x Earths Mass) Mercury, as in OTL, contains many valuable minerals, being an “iron planet” composed mostly of metallic material. A less eccentric orbit means it is tidally locked. [0.38 G] PLANET (7°) {0.3 AU-0.47 AU} -Venus (Native name Avelia): (0.815x Earths Mass) A habitable planet orbiting at a high inclination in resonance with Earth (avoiding high gravitational interactions with it that would sling it out of its orbit.) It has a (somewhat thick) atmosphere, magnetic field and a surface much different from OTL. Despite being habitable for life, it is a relatively dry desert planet, and lacks large animals, as there is not enough water to support the amount of plants needed by large animal life (aside from its intelligent species, which we will get to later). The surface water available is concentrated in a few small oasises. The surface terrain is composed of flat plains, and high, volcanic plateaus- most of which merged into one large plateau near the equator where Aphrodite Terra is OTL (these form as Venus lacks the water for tectonic plates). The air has a 17% O2 content (with the rest mostly nitrogen), and the surface temperatures average 40-50° C. This makes the planet uninhabitable for unprotected humans in most areas, though the air is breathable for many. Aphrodite Terra contains high concentrations of Uranium-235 for nuclear weaponry, Gold, and Platinum-Group minerals for mining. Venus is also one of the places outside Earth that has intelligent life, which at the time of first contact was a small, feudal, agrarian society. This is strange, as the planet lacks large animals and significant arable land. The intelligent life here is very limited in number due to only having a few areas on Venus with enough water to support them (desert settlements are small and isolated, and look a lot like those on Jakku or Tatooine in the Star Wars series). This also limits their technological advancement, though they love and greatly value the technology they DO see and/or obtain (much like the Manus islanders in OTL). Oh yeah, and the first man to step foot here was Simon Wolf Edmunds, and thus the first base here was called Edmunds' Step. [0.9 G] PLANET (40°) {0.8 AU} -Eros: (0.0000075x Ceres Mass) Venus' only moon, Eros has a very eccentric, somewhat inclined orbit around Venus. It is likely a captured near-Venus asteroid, and being a S-type asteroid, is depleted in volatiles (for refueling), but higher in metals (such as gold), compared to C-type asteroids. Very similar to 433 Eros in OTL. [Negligible G] MOON (10.8° Inclination to Venus’ Inclination) {0.8 AU} -Earth: (1x Earths Mass) Same as IRL. Ignoring the effects of tidal locking, due to storyline purposes, it is a binary to Luna. It also is the home world of the most advanced species in the solar system – according to members of said species. [1.0G] PLANET (0°, in relation to Sun (Constant Format used throughout for objects orbiting the Sun)) {1.0AU} -Luna: (8.13x Moon Mass) Earth’s only large moon. It has a magnetosphere (formed by tidal heating), a biosphere and breathable air. It isn’t tidally locked, so ancient astronomers have been able to see both hemispheres. (Yes, I know this isn’t possible in real life, but I’m keeping it this way for the sake of the storyline). Luna is composed of similar material to Earth in OTL, and can be considered Earth's smaller “brother” or "sister" or "gender-neutral chibi thing" (it is a little smaller than Mars in OTL). Its atmosphere extends much farther above its surface than Earth's due to its low gravity. It also is slightly cooler than Earth due to a thinner, yet still breathable atmosphere. It has intelligent inhabitants, however they are far inferior to most other intelligent species as they were still getting used to ideas like "fire" at the time of first contact in 1946. [0.36 G] PLANET/MOON (0° Inclination, in relation to planet (Constant Format used throughout for objects orbiting another object)) {1.0AU} -Aurora: (Undecided Mass) Moon of Earth, thought to once have been a metal-rich “M-Type Asteroid”, it contains concentrations of platinum-group metals that made it the moon that paved the way for asteroid mining. It is at an inclined, eccentric prograde orbit with Earth-Luna's barycentre- though this orbit is unstable, and the object will likely collide with either Earth or Luna in a few million years due to gravitational interactions between its larger neighbours. Aurora is relatively small, however, it is about the size of 3554 Amun (actually, the two are pretty much the same). It is not tidally locked, however, as Luna's and Earth's gravity are in a “tug of war” with the moon. Aurora is surprisingly sparsely inhabited due to the fact it is used by multiple nations as a testing ground for extremely powerful weapons that shouldn't be experimented with on Earth. [Negligible G] MOON (27°) {1 AU} -Phobos (0.000012x Ceres Mass) and Deimos (0.0000016x Ceres Mass): Now binary trailing Earth Asteroid Trojans. Otherwise, same as IRL. Both have similar compositions, and Phobos lacks the stress stripes caused by its proximity to Mars. A strange “library” containing “monoliths” (Quantum Computers with massive, ultra-long-duration hard drives containing huge amounts of unknown data) has been found here, however- one of the greatest mysteries of the Solar System. Humans are still yet to decipher its data, but as computer technology advances, strides are being made to do so. One theory is that it was from a collapsed ancient civilization, or that it was left behind by its creators for us. [Negligible G] ASTEROIDS (14°) {1 AU} -Comet 109P/Swift-Tuttle: (0.0069x Ceres Mass) First discovered in 1846, Comet Swift-Tuttle is a periodic comet with an orbital period of 133 years. Though this comet's orbit is stable due to a 1:11 orbital resonance with Jupiter, it passes very close to Earth/Luna-in OTL, it will approach 0.03 AU to Earth. In this alternate timeline, its orbit is determined to pass a minimum of (0.0003 AU) to the Earth-Luna system in 1969- dangerously close. As a result, it generates significant scientific study on the comet's orbit, and how to mitigate a potential impact. As 109P in OTL and this timeline have very similar properties, they both have a 26 km nucleus of similar composition- combined with is high-energy orbit, an impact would have 27x greater force than the impactor that cause the Cretaceous-Paleogene Extinction Event. Two manned spacecraft were sent here to push the comet out of the Earth impact corridor, using a Jupiter flyby to match its inclination- named Freedom and Independence. [Negligible G] COMET (113.45°) {0.96 AU-51.23 AU} -Mars (Native name Koppon): (0.12x Earths Mass) Mars is one of the three places outside of Earth with intelligent life and one of the most complex biospheres in the solar system. It has a proper magnetosphere (due to its large moon causing tidal heating in the core) allowing it to retain a breathable atmosphere and a habitable, but relatively cold climate, due to its distance from the Sun and thinner atmosphere- the polar regions to 50°N and 50°S are in a perpetual ice age. Most of the rest of Mars is composed of the Mars equivalent of Tundra, and Boreal Forest. Additionally, the Tharsis Bulge does not exist- due to plate tectonics. Instead, it is a large plain (like the Midwest) with large shield volcanoes and mountains on its western edge. As the Tharsis Bulge pushed Arabia, on the other side of the planet, up, the plains of Arabia are also underwater. Mars' intelligent life was the most technologically advanced other than humanity at the time of first contact, with a technology level only about 50-100 years behind Earth. The fact humanity and the Martians have developed so close to each other chronologically, and the statistical improbability of this, has raised several interesting theories. Its intelligent life was not expected to be killed off by Smallpox and Measles shortly after the first manned landing in 1952, as the difference between species living on Mars and on Earth is so great- despite this, there was a large kill-off after (unknowingly) tainted goods were traded between Mars' intelligent life. Still, this only wiped out about 40% of the population, compared with more than 90% in Australia and the Americas in OTL. Mars is also slightly larger in size, compared to Mars in OTL. As this planet is largely dry, much drier than Earth (due to low amounts of evaporation from its cold climate), it is considered a cold semi-desert planet by some scientists. It is the most Earth-like planet (aside from Luna), but lacks precious minerals and/or resources and animal biodiversity of Earth (due to less O2 produced from the partially-frozen over planet). Its atmosphere is 20% oxygen and 68% nitrogen (the rest mostly noble gases) - breathable. Mars is currently similar in population to Luna, but the recent discovery of large oil and Thorium reserves (which also indicate a vastly expanded biosphere in the past) is bringing that up considerably. [0.38 G] PLANET (1°) {1.3 AU} Bellona (Martian name Eke): (0.011x Moons Mass) Mars' only moon, about the size of Ceres in OTL and based off Ike in KSP. Bellona and Mars' compositions are similar, having formed from the same material. It is almost in hydrostatic equilibrium (but not quite), so it though it looks round at first glance, it is not completely rounded, like Ceres. [0.05 G] MOON (4°) {1.3 AU} Minerva (Native name Nemixis): (8x Earth Mass) The largest rocky planet in the solar system. Its high gravity and large magnetic field (due to active volcanism) have let it develop a large, dense atmosphere, which, though similar to Earth's, is unbreathable due to the high concentrations of CO2 (above the human tolerance of 5mm partial pressure of CO2) to humans, but is perfectly suited to the native life, which is adapted to the conditions. Though there are large concentrations of CO2 on this planet (1% of Atmosphere), it is otherwise similar to Earth's Atmosphere. The Greenhouse effect from CO2 and evaporating water (water planet means more vapor) causes this planet to be habitable, despite its distance from the Sun. Minerva is also one of three places outside of Earth known to have intelligent life, which is not highly advanced (compared to those of Venus, Earth, and Mars), but uses its ability to survive in an atmosphere mostly unsurvivable to humans to its advantage. Minerva is mostly like Laythe in KSP, but with much deeper oceans- as most of the continents are underwater, with only the mountaintops remaining (meaning the land that there is is slanted, and usually not optimal for agriculture). The planet has a very low axial tilt of 1° (though this is thought to have changed significantly over the years, due to a lack of a moon, ranging from a 0-30° axial tilt.) meaning that there are no seasons. This, along with the lack of land, means that civilization is unlikely to advance much farther than basic agriculture without extra help. It contains unusually large concentrations of minerals, such as Silver, Titanium, Zirconium, Gold, and Rare Earths, and the deepest areas, 90 km deep, contain strange, exotic ices, due to their density. (Platinum-Group Metals and Uranium are also available, but at lower concentrations than on Venus.) Of course, extracting these minerals require mining underwater. The atmosphere is very similar to Earth. Minerva also has large reserves of oil and natural gas, due to its oceanic nature. [1.8 G] PLANET (2°) {1.8 AU} Ceres: (0.013x Moons Mass) Same as in OTL, but in a more inclined orbit. Also is surrounded by a very, faint, young ring, thought to be debris from an asteroid impact that took place a few million years ago. [0.04 G] DWARF PLANET (15°) {2.97 AU-2.56 AU} Dres: (0.017x Moons Mass) A Ceres-like protoplanetary object slightly larger than Ceres in OTL. It is similar to Dres in KSP 0.90, with large canyons likely formed when the moon underwent thermal expansion. It has a very eccentric orbit. [0.04 G] DWARF PLANET (5°) {2.5 AU-3.1 AU} Jupiter: (317.8x Earths Mass) A gas giant, Jupiter is also the 2nd largest planet. It is basically the same as in OTL, but with a very different system of moons. [2.528G] PLANET (1.3°) {5.4 AU-4.95 AU} Laythe: (9.3x Moons Mass) The closest moon to Jupiter, Laythe is very similar to its version in KSP (but larger)- an ocean moon. However, due to tidal locking, its vast oceans are pushed to the poles, leaving behind the land in islands clustered near the equator. Unfortunately, Laythe's tides are impressive- due to the gravitational forces from Jupiter and Castillo, these tides have more resemblance to tsunamis on Earth than tides, making the land completely useless! Though the tides hinders complex land life from growing, it has a breathable atmosphere, strong magnetic field (powered by Jupiter's tidal heating of the core) and many diverse aquatic ecosystems. Additionally, Laythe is very volcanically and tectonically active, spewing CO2, which is absorbed by cyanobacteria- however, these cannot support complex life at the surface, due to the lack of sunlight; all life here is deep-water, making use of thermal vents to survive (although many of these vents are in shallow waters). Additionally, the oceans are acidic, due to absorbing large amounts of CO2. Due to the lack of land and Sun, Laythe has an unbreathable atmosphere with a mere 10% oxygen, and composed of mostly nitrogen, with significant amounts of CO2 and Water Vapor. However, the greenhouse gases also makes Laythe an average of 17° Celsius. The moon also lacks a giant impact crater, like Laythe in KSP (as this may have shattered the moon apart). Laythe is between the moons Io and Europa in OTL. Human missions getting here suffer (such as the “MILLER” planetary lander/human precursor sent here, which was quickly consumed by an unexpectedly large swell, or "MILLER2" who's last recorded transmission was "OH **** WHAT THE **** IS THAT SHOOT IT SHOOT IT [indecipherable screaming]!") due to the radiation belts around Jupiter, that Laythe is protected from, but in the middle of(though some still evaporates, as the low gravity means Laythe's atmosphere extends much farther out than Earth's). Though it has large amount of precious minerals mine-able underwater, Laythe has largely been designated a “no-go” zone for human missions- leading to the famous quote, “All these worlds are yours, except Laythe. Attempt no landings there. If you do attempt to land there, you probably deserve whatever happens to you.” [0.37 G] MOON (0°) {5.4 AU-4.95 AU} Castillo: (1.46x Moons Mass) The only other major moon of Jupiter, Castillo is much like OTL. It contains a global ocean under its icy crust and mantle, containing a surprisingly large biosphere. It is a good staging point for a base, being away from Jupiter's radiation belts, (not to mention useful land, and volatiles to fuel ships). It is somewhat closer in to Jupiter than in OTL, allowing the two moons Laythe and Castillo to form a resonance and stabilize their orbits. Unlike in OTL, however, it did get hot enough during formation to be differentiated. Castillo is the most distant body in the solar system with a permanent population as of 2018. [0.12 G] MOON (2°) {5.4 AU-4.95 AU} Saturn: (95.16x Earths Mass) A gas giant. Unlike in OTL, it lacks large, noticeable rings- the processes that formed the larger rings did not take place here (though Saturn still has smaller rings, such as the F-ring). Also, in the planet’s atmosphere there are “gigantic airborne jellyfish monsters”. [1 G] PLANET (2.4°) {9 AU-10 AU} Enceladus: (0.18x Moons Mass) The closest major moon to Saturn, it is about the mass of Pluto in OTL, and has water-ice geysers. Underneath the ice is a global ocean thought to contain complex life getting energy from Enceladus' internal heating, though its study has so far been limited. The geysers are the source of Saturn's E-Ring, and the moon also has cryo-tectonic plates that resurface the moon. Enceladus' ocean also contains large amounts of ammonia, which also acts as an anti-freeze. It also has a more eccentric orbit around Saturn, heating the moon even more, and making its ice layer relatively thin. [0.06 G] MOON (0°) {9 AU-10 AU} Titan (Native name Xanadu): (0.06x Earths Mass) The largest moon of Saturn. Discovered in 1655, it is much larger than OTL Titan, which it is very similar to, and has biologically diverse seas of liquid hydrocarbons. Titan orbits where it does in OTL, and has a hazy atmosphere similar to Titan IRL, but at 2 atm at the surface. Titan is also home to various ecosystems including one intelligent species with medieval technology. Titan is large enough to generate its own (weak) magnetic field, like Ganymede in OTL. [0.22 G] MOON (0.3°) {9 AU-10 AU} Iapetus: (0.02x Moons Mass) One of the few moons that managed to escape Titan, Saturn, and Enceladus' gravitational interactions, Iapetus is the 3rd largest satellite of Saturn, and is the same as in OTL- a large, ellipsoidal, icy moon with a two-tone coloration. [0.02 G] MOON (15.47°) {9 AU-10 AU} Uranus: (14.54x Moons Mass) Similar to OTL. An “ice giant” who has an axis tilted sideways (its moons are also tilted to Uranus' equilateral plane.) However, Uranus (unlike in OTL) also has a large set of young, (less than 500 Million years old) inner rings composed of both ices and dust (thus much darker than Saturn's rings, but are almost as extensive and massive as Saturn’s' rings in OTL- a 'hidden treasure'). These main rings are located within Miranda's orbit, and are formed by a Miranda-sized Uranian Moon that broke up a two Billion years ago after approaching the Roche limit. These rings have stayed in pace due to the existence and formation of 'Shepherd moons' within the ring system. Uranus also has a system of faint, dusty, outer rings (outside the orbit of Miranda) formed by collisions between objects near Uranus. [0.89 G] PLANET (15.47°) {18.3 AU-20.1 AU} Miranda: (0.0009x Moons Mass) Miranda has extreme and varied topography formed by intense geological activity (it looks really cool, go take a look for yourself) and is composed of 75% ice, strangely high. Unlike in OTL, it is geologically active, with cryovolcanoes spewing water ice containing large amounts of ammonia and salts. Its geologic activity is due to tidal interactions with Ariel from its more eccentric orbit (than in OTL). Miranda also has a subsurface ocean containing simple halophies (due to the extreme salt content). It is also the only Uranian Moon that supports life. [0.0044 G] MOON (4.2°) {18.3 AU-20.1 AU} Ariel: (0.018x Moons Mass) Similar to in OTL, Ariel is composed of equal parts ices and rocky material, and is crisscrossed with scarps, and canyons due to gravitational interactions with Miranda and tidal heating. It has pockets of ammonia-rich water in its ice layer, similar to pockets of water underneath the ice of Antarctica. These, however, appear to be sterile- one theory is that these lakes were once frozen over, but when Miranda and Ariel went into orbital resonance, these pockets reheated, but devoid of life. [0.0161 G] MOON (0.3°) {18.3 AU-20.1 AU} Umbriel: (0.015x Moons Mass) Same as in OTL. Umbriel, like Ariel and Miranda, has canyons, but has an otherwise old surface dominated by craters. It has a very low albedo of 10%, and has a slightly blueish color. Like most of the other major Uranian moons, it is composed of equal parts ice and rock. [0.0142 G] MOON (0.13°) {18.3 AU-20.1 AU} Titania: (0.0496x Moons Mass) Same as in OTL. Titania has an extremely thin CO2 Atmosphere, which often freezes into dry ice frost. This is from out-gassing of CO2 from its 50 km thick, ammonia-rich ocean. As this water is located very deep, between its core and mantle, along with the moon's distance, means it is not known if it contains life. This is unlikely, however, as it is likely too cold to allow for earth-like life sustaining processes. It has large rifts and scarps formed by the expansion of its interior during its evolution. [0.0248 G] MOON (0.34°) {18.3 AU-20.1 AU} Oberon: (0.04x Moons Mass) Same as OTL. Oberon is a typical Uranian moon, with canyons and rifts (formed by expansion of the planet in its later phases) and is about half ice and rock. It has dark patches similar to marina on the OTL Moon, but formed by cryovolcanic liquids (primarily water) filling the craters, rather than lava. Of course, these liquids quickly froze and evaporated when exposed to the vacuum of space. [0.0332 G] MOON (0.06°) {18.3 AU-20.1 AU} Neptune: (17.15x Earths Mass) Same as OTL. An ice giant somewhat larger than Uranus, the deep-blue Neptune has the strongest sustained winds in the solar system (more than even Jupiter). [1.14 G] PLANET (1.78°) {29.8 AU-30.3 AU} Triton: (0.291x Moons Mass) Neptune's only large moon, Triton is a captured dwarf planet orbiting retrograde to Neptune. It is 2x larger than in OTL, and has a surface covered in frozen nitrogen and methane, and a crust made of water and ammonia ices (which make up 30% of its mass). It has a young surface dotted with nitrogen cryovolcanoes (which can spew plumes up to 8km high), and cut with icy valleys and ridges. Like in OTL, it has ice caps of nitrogen- along with flat, nitrogen-ice plains and “cantaloupe terrain” formed from cryovolcanism. Triton also has an orbit (but still inclined and retrograde) slightly closer to Neptune- the increased mass of Triton, along with greater tidal heating from a closer orbit means that more of its nitrogen ices have sublimated than in OTL. Therefore, Triton has a much thicker nitrogen atmosphere at a pressure of 57 Pa- 30 x than in OTL (but still very thin- it's about as thin as Mars' in OTL at Olympus Mons). This atmosphere also gives Triton a slight haze, due to its content of hydrocarbons and nitriles in the lower atmosphere, forming from sublimated methane (which also helps heat up the moon). Triton also has a subsurface ocean holding multiple ecosystems, including multi-celled life- though its biosphere lacks the complexity seen in other moons found closer to the Sun. The first lander sent here, MANN, returned overly optimistic information about Triton and its habitability for life. [0.0582 G] MOON (156.89°) {29.8 AU-30.3 AU} Pluto: (0.65x Earths Mass) A planet orbiting in a highly eccentric and inclined orbit after being shot out by Neptune/Aether during the formation of the solar system. It has a hazy, thick nitrogen-methane atmosphere (of 3 atm pressure at sea level) from sublimated nitrogen ice, along with methane-based cryovolcanism, thanks to internal and some tidal heating from Charon. Like in OTL, it is extremely contrastive, has an extreme axial tilt of 120°, and has 5 moons- the largest being Charon. However, unlike in OTL, Pluto is not in a binary system, as Charon is much smaller than Pluto. Pluto's surface is mainly water ice, covered with a layer of methane, including methane seas (like Titan, but deeper, as the Sun does not break apart methane molecules out here) with a variety of landforms. There are also a variety of lifeforms here, centring around underwater cryovolcanic vents (but also lacks significant complexity.) Interestingly, the planet's internal heating is higher than expected, and it was only very recently that the cause was found: An astonishing 0.01% of the planet is made of some kind of radioactive material. The specific elements and isotopes in question don't appear anywhere else in nature other than Charon, suggesting that, in the words of the HAE Space Agency's science director, "sometime within the last 10,000 years, some serious **** went down in the Pluto system." Pluto was discovered in 1999, as its relatively high infrared signature gave it away to infrared telescopes (despite its insane distance). It was later found to be responsible for the orbits of Sednoids, along as being the explanation for a sudden drop-off in the Kuiper Belt at 48 AU- the Kuiper Cliff- caused by Pluto “clearing its orbit”. Pluto also has a thin, unstable ring system- thought to be caused by an asteroid-sized moon that got too close to Pluto (this moon was almost certainly a small, captured moon captured much later than Charon's formation.) [0.401 G] PLANET (3°) {101 AU-197 AU} Charon: (0.7x Moons Mass) The only major moon of Pluto, Charon is about half the size of Titan in OTL. Charon, which formed from a collision on Pluto- has a similar composition as Pluto. Though lifeless, Charon has a strangely young surface dominated by water ice and ammonia (and some hydrocarbons forming an icy inch-thick crust on top of the water ad ammonia ices), along with cryogeysers spewing these ices. As there is a lack of Sun, volatiles do not form reddish tholins here, making it colourless. Like the Moon in OTL, Charon is slowly moving away from Pluto, something that caused the destabilization of the orbits of Pluto's other moons. The volcanism is a complete mystery- it's thought the differentiated Charonian interior (and possibly also Pluto's interior) contains much more radioactive material than originally thought. [0.2 G] MOON (0°) {101 AU-197 AU} Persephone: (10.0x Earths Mass) Once thought to be the outermost planet in the solar system, Persephone was discovered due to strange observations in the orbits of tiny dwarf planet-like objects around the sun. From the way the orbits are all oriented it was found that a large object was in that part of space. Later observations proved the object’s existence and showed it to be an ice giant like Uranus and Neptune. Persephone’s large size, combined with the discovery of Tyche, lead to the IAU reclassification of what a ‘planet’ was in 2017. [0.31 G] PLANET (30°) {200 AU-805 AU} Europa: (0.65x Moons Mass) Europa is the closest moon to Persephone, and is very similar to its version in OTL. Europa has a thick water-ice crust, with a liquid water ocean underneath its surface. Its surface is shaped by cryovolcanoes (though smaller than those on Enceladus, they are located at Europa's poles) and 'cryo-plate tectonics'. As a result, Europa has few craters on its surface, and has deposits of salt coating parts of its surface (created when the salty water brought from below rose to the surface during eruptions- similar to lava on Earth.) However, due to Europa's intensely close orbit to Persephone (which is also somewhat elliptical), it also orbits somewhat faster than its parent planet's rotation. Both these factors lead to greater tidal heating, liquefying its underwater ocean. However, like Triton's retrograde orbit, Europa's super-synchronous orbit dooms the moon to an eventual break-up over Persephone. This, however, means the moon supports life, even without gravitational resonances providing significant heating. This life is relatively complex, and is clustered around hydrothermic vents and other geological underwater heat sources- though bacteria do live elsewhere in the ocean (along with the underside of the water-ice crust, and in pockets of water inside the crust). Many of these consume hydrogen peroxide, tholins, and other minerals from the surface of Europa. If it wasn’t destined to break apart, it is very likely Europa could be the one place in the solar system whose microbial inhabitants survive the sun’s red giant and planetary nebula phases. [0.134 G] MOON (1.5°) {200 AU-805 AU} Mimas: (0.042x Ceres Mass) Similar to its version IRL, Mimas is a very heavily cratered moon of Persephone. Mimas is known for its enormous, crater 'Hershel' that makes it look like the Death Star (alas, Kerbals have made numerous proposals to hollow out Mimas into a Death Star- none of which materialized, thankfully). This impact shaped Mimas, and nearly shattered the moon apart. It is also a 'trojan moon' to Europa, and is situated at its trailing L5 Lagrange Point. It is composed mostly of water ice and, despite sharing an orbit so close to Persephone, has a liquid water ocean only very deep in- and is only home to simple life forms. [0.0065 G] (TROJAN) MOON (1.5°) {200 AU-805 AU} Tyche: (18.2x Earths Mass) Discovered in 2016 by WISE, Tyche is a large ice giant, known to have a large system of moons and rings. It is also responsible for the orbits of some Sednoids (which had previously been unaccounted for- as Pluto and Persephone alone could not be responsible for their orbits.) Its far distance from the Sun, relatively small size, and lack of seasons (due to its solar distance) means that it lacks much of the winds of most other gas giants- appearing similar to Uranus. Tyche is in a halo orbit around the Sun, in a near-circular, inclined orbit. Its discovery contributed to the redefinition of what a ‘planet’ was in 2017. Tyche is likely to be the hypothetical “fifth giant planet” responsible for creating the current solar system. [0.92 G] PLANET (83°) {1485 AU-1590 AU} Hyperion: (0.0059x Ceres Mass) Hyperion- the same as its version in IRL (other than its different orbit), is a small, irregular moon noted for its sponge-like appearance- which formed due to the moon being very porous and its very low density. Hyperion is darkened due to material from nearby moons, and is somewhat reddish. It is mostly composed of water ice, with very little rock. [0.0021 G] MOON (0.43°) {1485 AU-1590 AU} Dione: (1.17x Ceres Mass) Dione is an outer, rounded moon of Persephone composed of mostly of water ice (with a small fraction of rock), and is in resonance with Tethys, Hyperion, and Rhea. Being very similar to its version IRL, Rhea and Dione are 'twins', with many of the same features, such as dissimilar leading and trailing hemispheres. However, unlike Rhea, Dione has enormous fractures and ice cliffs dominating its trailing hemisphere, formed by tectonic fracturing in the distant past. It also lacks an internal ocean, unlike its twin moon- though small pockets of heated water are thought to exist in its interior. [0.024 G] MOON (0°) {1485 AU-1590 AU} Tethys: (0.66x Ceres Mass) Tethys, an outer, rounded moon of Persephone composed mostly of water ice, and is somewhat different from its version in OTL- however, it is much darker than in OTL, due to not being sandblasted by ring particles. Tethys' ice has a large porosity, and is contaminated in many places by compounds like haematites, ammonia, carbon dioxide, and organics. Tethys also lacks the slight discolorations of its OTL counterpart, due to Persephone having a much less powerful magnetosphere, and Tethys' distance from its parent body. Tethys also is in orbital resonance with Dione and Rhea, and has some chasms and a large impact crater- Odysseus, 2/5s of the moon's diameter. Tethys, despite its resonance, also lacks an internal ocean, like in OTL- though small pockets of heated water are thought to exist in its interior. [0.015 G] MOON (1.12°) {1485 AU-1590 AU} Rhea: (2.46x Ceres Mass) Rhea, the 2nd largest moon of Persephone, Rhea is similar to its version in OTL. Rhea is an undifferentiated body (ice and rock is spread throughout, therefore lacking a core) with an internal liquid water ocean produced by its gravitational resonance with Tethys and Dione, along with its internal radioactive heating. This liquid water ocean is home to some halophilic bacteria (the internal ocean is very salty) Rhea is a twin moon of Dione, and thus both are similar to each other (for example, both have fractures and ice cliffs). Rhea has a thin exosphere composed of carbon dioxide from oxidation of organics on its surface, which is white, but heavily cratered. However, Rhea is mainly notable for having a tenuous ring system- the only moon yet known to have a ring system of its own. These particles are 'shepherded' by tiny moonlets that orbit within the ring system, and was formed from an impact 150 million years ago. [0.027 G] MOON (0.35°) {1485 AU-1590 AU} Fredinnus: (3.4x Earths Mass) Discovered by the decrypting of the Phobos and Deimos Monoliths. A rouge planet on an escape trajectory from Sol, it is currently near its apoapsis to the Sun. It could be a good refuelling stop for interstellar missions, and seems to show that rouge planets are quite common in the Milky Way (estimations range from 2 to 100,000x more rouge planets than stars). Aside from being a frozen-over carbon planet, little else is known about it. All information on this object has been obtained from the monoliths, which have questionable reliability. Fredinnus was the name given to this object by the archiving civilization. [1.67 G] ROUGE PLANET (11°) {Currently 0.9 Ly from the Sun} Crisplance: (2.1x Jupiter Masses) Discovered by the decrypting of the Phobos and Deimos Monoliths. A rouge planet on an escape trajectory from Sol, it is currently far from its apospsis to the Sun. It could be a good refuelling stop for interstellar missions, and seems to show that rouge planets are quite common in the Milky Way (estimations range from 2 to 100,000x more rouge planets than stars). Aside from being an enormous gas giant, little else is known about it. All information on this object has been obtained from the monoliths, which have questionable reliability. Crisplance was the name given to this object by the archiving civilization. [5.42 G] ROUGE PLANET (5°) {Currently 1.2 Ly from the Sun} Silverstrivler: (0.75x Earths Mass) Discovered by the decrypting of the Phobos and Deimos Monoliths. A rouge planet on an escape trajectory from Sol, it is currently approaching its apoapsis to the Sun. It could be a good refuelling stop for interstellar missions, and seems to show that rouge planets are quite common in the Milky Way (estimations range from 2 to 100,000x more rouge planets than stars). Aside from being a coreless water-ice planet, little else is known about it. All information on this object has been obtained from the monoliths, which have questionable reliability. Fredinnus was the name given to this object by the archiving civilization. [0.563 G] ROUGE PLANET (8°) {Currently 1.4 Ly from the Sun} Nibiru System: (0.12 Sol Mass) <Not going to be complete for a while> {Currently 1.02 ly from Sun} So, with all that said, do you think this solar system is possible? If not, what would I need to change? (Note that it doesn't have to be perfectly stable, just long enough for the alternate timeline to take place)