KSK

Thanks! Next chapter is about 50-60% done I think, but Real Life has been getting in the way of writing, so it's all been a bit slower than I would have liked. I'm on holiday next week though, so hoping to get the time to get it finished up. This might provide a bit of inspiration too! On the off-chance that anybody else is planning to be there next week, if you spot an older, long-haired, slightly tubby guy in a Gagarin t-shirt*, he's always happy to find somewhere to have a coffee. * because I'm sure that'll narrow the field right down.

Great news - grats Jim! A well deserved sticky if ever there was one!

Delta IV would seem to be a better comparison and there was still a two year gap between first flight of the Delta IV Medium and the Delta IV Heavy. But again, it's a largely pointless comparison since we're talking about different sized companies with different agendas, customers and business models.

C'mon - that's not exactly fair. OK, Falcon Heavy is 'just' three F9 cores strapped together but F9 itself is pretty darn new as boosters go. The failure last summer will have delayed things, as CatastrophicFailure pointed out. I'm also wondering (and this is pure speculation) whether there's been any redesign work needed to strap three significantly upgraded F9 cores together. I think I remember hearing that F9 was designed to be modular from the outset (so that it could be used in a Falcon Heavy type design) but I don't know whether that's also true of the much taller F9 1.1. You would hope so but neither is it difficult to imagine that the taller core has necessitated a rethink or two. SpaceX have also recovered relatively well from last summer. Compared to Orbital Sciences who are still waiting for their return-to-flight. Or Virgin Galactic, who have taken way longer than expected to move beyond SpaceShipOne. Different companies with very different hardware and business models so a direct comparison isn't fair, but they do serve as reminder that it's easy to over-promise in spaceflight and all too easy for schedules to slip, regardless of which company you're talking about.

And on a high G world you definitely do not toss a dwarf.

Genuine question but how tolerant of normal LOX would an engine developed to use sub-cooled LOX be? I can imagine (quite probably wrongly) that a turbopump that's set up to work with a particular propellant density might have problems with suddenly being fed a lower density propellant mid-flight. Would this 'just' result in reduced thrust (which itself might be enough to scrub the mission), or could it result in a damaged/broken pump? Put another way, is sub-cooled LOX an all or nothing thing, or would F9-FT still be able to launch with warmer LOX if SpaceX were prepared to just forego any landing attempt for the sake of meeting customer demands?

Interesting questions. As a quick aside to begin with, I don't think we need unobtanium, just a habitable world that's bigger than Earth but with comparable density. But that wasn't really the point of the thread so I'll move on. 1). It would certainly be tough, especially at the start. In general, the human body is pretty economical with its resources. If you're living in zero-g, your system adapts to the reduced loads by losing surplus (for the current environment) bone strength and muscle tone. The human body can adapt back to 1g conditions (regain muscle tone and bone strength) after extended periods in 0g but it's not easy, as any astronaut returning from the ISS will tell you. I have no idea how well that works the other way. Weightlifters and other 'extreme strength' athletes can do some pretty crazy things, so I'm guessing that your skeletomuscular system can adapt to higher gravity given time and could probably be helped along the way with steroids and the kind of drugs that are used to treat osteoporosis. However, the rest of the squishy bag of water that you call your body ( ) might not be able to adapt as easily. Your heart might not cope well with pumping heavier blood day in, day out? Your lymphatic system (that drains excess intracellular fluid from your tissues) essentially relies on 'passive pumping' caused by normal movements to work - that might not work so well either in higher gravity. Even little things like your eyeballs distorting under higher gravity might lead to complications later on. 2. It would probably depend on the sport. Not all muscle fibres are the same, so muscles adapted for living in high G might not be whatt you want in a sprinter for example. My best 'pulled out of thin air' guess, is that our astronaut might be competitive at weightlifting and jumping, probably less so at running. 3. Possibly, although it would be highly dependent on how much the fetus could adapt in utero. If it is possible, the poor newborn would probably have a really rough time of it, and all the normal bumps and falls associated with learning to walk are going to be nasty in high G. You would probably be better off delivering by c-section too - being delicate about it, giving birth naturally with muscles adapted to high-G living might not be a great plan.

They tried parachutes and they didn't work. If I remember rightly, aerodynamic stresses caused the booster stages to break up in mid air.

We, the KSPers, are very good at assuming that we were the first to discuss something. Take a look at this list of speculative biochemistries that have been proposed - ammonia appears right at the top of the list of non-water solvents that have been considered.

Or how about we stop running around like headless chickens worrying that the sky is falling on our heads because *shock* a rocket launch is delayed because of technical issues, stop proposing overcomplicated solutions to a problem that may or may not even exist and see how subcooled LOX works over the next few flights before jumping to any conclusions? Besides, if I remember rightly, Raptor was also going to take advantage of subcooled propellants. This isn't a one-off boondoggle for Falcon. Like propulsive landing, if SpaceX can get this to work properly, it'll have a knock-on effect for everything else they do in future.

It might count as shipping or possibly roleplay too. Best be careful. Snarks aside, I too am not quite sure how to have an interplanetary relations thread that doesn't involve politics.

"At any rate," Gene finally said, "that capsule pre-dates the KSA. It even predates the Kleptogart space program. It was the first craft to return living things from space. Well, technically. That poor squirrel was never the same. Or the rat. Or the fish. And then they got loose and--" Dun...dun...dunnnnnnn. "With no other obvious course of action, Valentina did as he said, crawling on her hands and knees past demolished furniture and brawling Kerbals. The sound system was thumping out something about a barroom blitz. Or maybe it was ballroom. She couldn't tell over the din around her. " I see what you did there.

We'll see how well the SuperDracos work at the next abort test. For now, I'm betting that if a bunch of armchair rocket scientists can spot the potential issues, then the actual rocket engineers at SpaceX have probably thought of them too. Regarding reduced costs, I have no idea what working conditions in the US are like in general and at SpaceX in particular. So far as I'm aware, most of the cost reduction has come about through good engineering, commonality of components, doing most of their manufacturing in-house and generally setting themselves up as if they hope to actually make a profit on what they're doing. Quality - yes they had problems with Falcon 1. Off the top of my head though, Falcon 9 has only had a couple of visible issues - and they've flown quite a few of them now in various iterations. I can think of one engine explosion - which didn't result in a loss of vehicle, and one loss of vehicle which was traced to a faulty strut sourced from an outside company. I'm sure there have been other problems along the way - launches don't just scrub themselves - but so far the ethos seems to have been 'scrub rather than 'splode.' TL: DR, I'm not seeing any obvious signs of poor quality control or corner cutting with flight operations.

We're kerbals. Safety is our watchword.

Getting out of the atmosphere requires five parts (parachute, pod, decoupler, FL-T400 tank, LV-T30 engine). Getting to orbit is very doable with 30 parts, although the weight limit might be more of a problem, depending on how good your design is. By the time you've completed the contract to get to orbit, you should have plenty of funds to upgrade your VAB. Problem solved.

Because fixing the shaken-to-bits-by-loud-noise launchpad after every launch gets really boring.

Yeah - I don't think the psychologists were too impressed with that one.

Given the choice between persevering with a known technology (subcooled LOX isn't exactly a new thing, just new for them) or developing an entirely new rocket complete with new tooling, new engines and a new fuel, not to mention new infrastructure to support it, I can't imagine why SpaceX opted to stick with the known technology for the moment. It's not like they're short of other ongoing projects either. Or that subcooled LOX isn't going to give a performance upgrade to any LOX/CH4 they decide to build in future.

Ooooh - lyrics! Can I play too? Will delete em if they don't fit the thread. To the tune of 'Rock the Night' by Europe...

Ooof - this powerpointillism (or keynotism in my case) stuff is tough, especially with no dialogue to work with. Deep respect to all the graphic novelists out there - and give me plain ol' words any day of the week! Getting all the characters in the same place at the same time, trying to get that launch shot (the first several attempts were... not dramatic) and then the cropping and layout. Best part of an evening's work all told and even then I think it lacks a certain oomph. With prose, I can describe sound, smell, vibration, all the visceral stuff that conveys the ground-shaking power of a rocket launch. With a graphic novel I only have sight to work with, which requires a rather different approach I'm thinking, especially in stock KSP where things like engine plumes aren't terribly dramatic to begin with. It was certainly an interesting exercise though - thanks for suggesting it Kuzzter!

Graphic novel challenge accepted...

15 was cool but didn't all of the last three Apollo's include rovers?

I think Apollo 12 was my favourite too. I always liked the story about how Pete Conrad (not Shepard - he was commander for Apollo 14 if I recall correctly), gave Bean a turn at flying the ascent module back up from the Moon, just because it seemed right that he (Bean) should get a go at the flying too. When Bean wasn't sure whether Mission Control would go for it, Conrad pointed out that there was nothing they could do about it, being as they were out of radio contact at the time.

Well, I'd have a tapered hatch, such that the higher pressure inside your hab forces it into its frame. I'd also go with a tubular gasket - just extrude your synthetic rubber through a circular die and melt the ends together to give you a continuous loop. Stick loop to hatch frame, done. But your point still stands - manufacturing stuff off-world is going to be difficult and everything that you need to import from Earth, makes you that bit less self-sufficient. Like I said - I think a truly self-sufficient colony is a very long way off, even in the context of OP's thought experiment. You're absolutely right about Stardust. On the other hand, I would think that any crewed mission to Mars will probably involve going into orbit around Mars and then descending to the surface from orbit, rather than re-entry from interplanetary speeds. The g-loading would be more survivable that way. Apparently the Apollo capsules would be peaking at around 7g on re-entry, so we do have some data on low g reentry. For radiation studies, I would use an unmanned probe. Basically a collection of boxes with radiation detectors in, wrapped in whatever shielding you want to try. Measure the radiation dose inside your box and see if it's low enough that the risk to crewed flights is acceptable. I'm honestly not sure how much use any biological models would be. For growing crops, to be honest, I'd go straight to Mars and make that the first priority and go/no-go point for the colony. Assume that your colony is going to start off entirely supplied from Earth. Their first task is to grow food. If they can't then you bring them home (because the colony is never going to be viable), or just commit to regular supply runs from Earth. If you really wanted to do some studies ahead of time, go for an Elon's Greenhouse approach and do those studies on Mars.

I'm sure you did intend to be helpful but I think you also missed the point of the thread, which was set up to be a thought experiment. OP was presuming we can get to Mars with enough equipment for survival. The question is - what next? What do we need to survive on Mars in the long term. What do we need to establish a colony? How can we make that colony more self-sustaining? (Accepting that full independence isn't going to happen for a long time.) Also with respect, a lot of your so-called necessary research doesn't actually tell us anything useful or new. They will start to develop Bion https://en.wikipedia.org/wiki/Bion-M_No.1 like proves, for sending to free return trajectories when available or little dv to return ones, because if not he launch windows will be very limited, to Mars and Venus. This will evaluate long space travel effects in animals, also can double as a test for an interplanetary re-entry capsule. Interplanetary reentry capsules we can do. See Stardust, or the Mars Polar Lander. Sure, the MPL crash-landed but as far as we know, it survived reentry from interplanetary speeds just fine. Long term space travel effects in animals - we don't have any shortage of data from the ISS nor data from radiation exposure studies on Earth. Besides, trying to extrapolate from animal studies to effects in humans isn't necessarily going to work very well. The first ones goes pretty bad (reasonable assumption being the first) but it has data from almost half of the travel to venus (first we star with venus, less Dv requirements, and more frequently available launch windows, so a delay in development isn't that bad), like the animals food consumption rates in free fall and interplanetary radiation levels. Biology basic data. Interplanetary radiation levels we can get with a robotic probe (assuming we don't have the data already). Why do we need animal food consumption rates in free-fall when we've had humans living in free-fall for months at a time on the ISS? At the same time as the animals probes, they start developing plants proves, starting a research about plants growing in low gravity, for that mission they start looking at the moon. A little lander lands in the moon, with some short-life plants, they grow erratically but some survives the 14 day day of the moons. They all die in the night (by design), they try to regrowth again in the next moon day but it doesn't work. We've grown plenty of plants in space. If we can grow them in space with no gravity to provide their normal growth cues, they're probably going to grow just fine on Mars, where there is gravity. Growing them for 14 days on the Moon and letting them die by design (why are we doing that anyway?) isn't going to tell us much. I will concede that growing them for longer on the Moon might tell us something but if we're going to be sending people to Mars anyway, why bother? Just do the experiments on Mars. It's not like we need to be growing food from Day 1 on Mars anyway. The second animal probe survives the travel to venus but not the re-entry to earth, proving basic life support and food storage technologies for space travel. It also gets valuable data about the animals. How basic are we talking about here? Again, apart from radiation shielding, we have ample data on basic life support and food storage (seriously?) from the ISS. A series of landers get more and more valuable data from low g growth in the moon, looks like some plants adapt to the moon, but they are not as healthy. They keep trying new plant types. Some even regrowth after the moon night. See previous comments. The third animal probe takes the same destination, this is an experiment looking how different foods affect the long term exposure of radiation or microgravity, if some of them helps to mitigate some of the effects. Maybe it also test some chems for that purpose. The prove re-enters in earth without killing everything in it. The fourth animal probe goes to Mars, testing longer exposure in interplanetary environment, it survives all the travel, even the re-entry but it goes bad for lots of the animals. They get valuable data and start researching improvements of the design. This might be useful but again I'd be very wary about extrapolating results in animals to useful effects in humans. The next series of landers in the moon tries to growth plants, and release a laboratory mice (obviously until this moment it had other food source) when they grow enough to eat. The mice survives until the moon night. Results looks promising. See previous comments. With regard to your comment about airlock doors - a gasket hardly qualifies as high tech. Manufacturing suitable materials is a bit more high tech but a Mars colony is going to need some kind of chemical industry anyway. There's a lot you can make starting from CO2 and water, including some synthetic rubbers which should make you a nice gasket for your airlock. The real trick is going to be making chemical reactors that are rugged and portable enough to send to Mars. ROFL. If we threw out all the sci-fi threads in this forum, we'd have virtually nothing left.