Thaniel

*sigh* those aren´t problems per se, those are "design requirements",needing a process often called "engineering", wich are what usualy goes on when designing a purpose built craft of most any kind. No surprise there. As for examples that it has been done before, there is a company called Virgin Galactic who have proven that it is possible to build purpose built crafts that can both fly, carry other vehicles, drop said vehicles in mid-air, and those vehicles are able to handle both the stress of being carried under a wing, and being propeled by a rocket engine. Using hybrid rocket tech btw. solid/liquid fuel. Wich when stored, is not considered an explosive compared to solids, and much more stable and predictable than pure liquid setups. Using liquid oxidizer for such horizontaly launched vehicles is known to work just fine btw. Well, if using any form of liquid fuel, that is not poisonous, or even just an oxidizer, it is possible to dump it over board. And by purpose building the carrier plane, it is possible to make it with overdimensioned undercarriage able to handle such a landing just fine. It´s been done before, for decades. I challange you to cough up atleast some rough estimates of the difference for this. Sure, the benefit is limited, but consider the WK2, if all goes to plan, it will be used for launcing both satelites and people. Building something able to launch to orbit, cheaper than ordinary vertical launced boosters, will have orders queing up. The benefit of being able to launch from different locations, more or less by will, will also be apreciated for the more "exotic" orbits. So no, so far, from what I´ve seen around, the benefits of such a profile, both economic and flexibility wise and safety-wise does seem intriguing. It all boils down to the engineering compromises they will have to make contra the benefits of using modern materials and knowledge. Give VG a few years of first hand experience, and who knows what new plans they might hatch.

Let me rephrase then: "And there´s no real reason why a MANNED(or womaned) horizontaly launched rocket can´t be launched to LEO." I realy hoped that was the intended payload here. I dug around a bit, and some very rough calculations/guestimates gave me a probable capacity for WK3 would only need to be a bit more than a 100 tons. ( I came to 105.ish) if using hybrid engines atleast for the main booster. Would cost a pretty penny to develope that generation of planes, would be by far the largest hybrid launched from aircraft in history, and quite possibly pose new challenges.

Been digging a bit, found some tinteresting numbers around. Like, the AN 255 can lift as much as 247 tons of cargo. The Titan 2 ICBM used to launch the mercury capsules weight fully fueled some 154 tons, and the gemini capsule with a crew of 2 weight in at just below 4 tons. So, if lifted by aircraft to above the thickest part of the atmosphere, a rocket that could be able to lift something along the lines of a gemini capsue size/weight into LEO should be possible. So designing WK 3 with a capacity of some 150 tons is a reasonable goal. And there is no real reason why a rocket launched horizontaly, with a throttled engine, couldn´t be used to get to LEO.Guaranteed, VG have poked their nose into the idea, or they´d be stupid.

I believe I wrote something awfully similar to that, just with more words, and not mentioning the economic benefit of being able to use the WK2 for two different purposes (something wich should be obvious), in the post you just replied to, XD Hence the notation of not being able to upscale the LauncherOne to 10-20-50 times it´s current capacity, wich would allow for humans into space. The problem would ofcourse be to upscale the WK2 to the same capacity. Wich I don´t see happening any time soon.

Well, Vg is currently working on an orbital launcher from their existing WhiteKnight 2 that is intended for launching the Spaceship 2. It´s the LauncherOne ( Is it only me? Or do these names somewhat resemble IKEA furniture naming?) http://www.virgingalactic.com/launcherone But agreed, if they intend to launch humans, or significant cargo into orbit, then upscaling WhiteKnight2 by 10-20-50 times won´t get that much more into orbit.

When reading this (http://en.wikipedia.org/wiki/Atrophy) on atrophy, it also clearly mentions at the bottom that atrophy can be severily limited using drugs. While the currently known ones aren´t necesarily advisable at the moment (unwanted sideeffects), spending some money into further research on this topic as well may bring forth fruits that can help make hibernation a very interesting option indeed.

So instead of figuring out if we can do this, sucessfully, we should rather just forget about it and focus on something completely different instead of expanding our possibilities? That's rather naive I say.http://www.ncbi.nlm.nih.gov/pubmed/23561945. Just a little something about using electricity to counter muscle atrophy, wich showed descent results.Another thing, what about plastics? If someone thought "Naaw, this will just be flamable, we can't use that for anythingusefull, let's not research this and spend all our money on cast iron instead". The net result? Any goernment support in developing the material would have come from private research, wich could take forever. So what if induced hibernation won't make it into spaceflight within 20 years, chances are that it would prove a valuable tool for other areas of society, and quite possibly help to get more funding into space-related research in the future. Investing into space-related hibernation for humans now may very well be returned a hundred-fold in 20 years into other more direct projects. Expanding the base of knowledge, finding options and possibilities early on is worth much more than adding half a percent to a couple of propulsion developement projects.

Absolutely interesting. While this kind of idea, with slowed metabolic rates have been suggested before, I believe this is the first time it´s being done some serious science on the topic intended for space application. With this, building a small donut-shaped protected centrifuge with space for 15-20 astronauts, and a couple of inflatable hab units for when they arrive at the red planet, sounds plausible. While a base with that many astronauts would probably need a decent amount of supplies, such things can be launched in advance on very slow trajectories anyway. And having a relatively large crew like that would significantly lower while at mars, since there can be multiple specialists on key topics. For instance, two doctors instead of just one increases the likelyhood that an incident won´t rob the expedition of one of them. Another possibilitiy here, is the possible significantly lower prise per person to ship to faraway places.Another thing, if they can manage to work this out, and make it available in a modulised form, it might be an option if for some reason, supplies run low, and it´s months until the next possibility for resuply is at hand. A stranded or based crew could enter hibernation to conserve supplies. It´s another option for some cases atleast.Exciting anyway you look at it, if this fans out.

Nice thought. One problem many of us face with this is our governments who think that private people should not be allowed to build and launch model rockets, since they can so easily be turned into ICBM's (or something just as devastating). So my question for you is: have you though of what kind of fuel to go for? Solid? Hybrid? Liquid?And secondly, you mention suborbital, I atleast think of a rocket that is able to go beyond the Karman line, but not reach orbit proper. Or did you mean just "realy realy high"?I know that if you just want to reach well past the 100km mark with a rather small payload, it's quite possible to do using solids, and relatively cheap materials. After all, sounding rockets used by universities here and there aren't realy too large or advanced, but they still reach high altitudes. When I say "cheap" and "simple", it's a relative term.Anyway, I wish you luck, even if it ends up being just a small one (or ten) reaching just a few km up. The fun is (as I see it) in learning, building, then, if possible, launching. Or just run a hot test on the ground, and build the next one a bit better.

Agreed. Such an experimental "station" for a few years would be able to give a lot of new information on the topic. I assume one or possibly two launches of a SLS heavy would be able to place a large enough habitat module with a built in bunker of sorts, and a counter weight. Should get several decks in such a place. Spin it up, get different gravities, monitor crew at something like moon gravity, mars gravity, and 0.5 g over atleast a year at a time. With only short stops for resuply, if needed. Could possibly be made with a rotating docking port at it's mass center and an inflatable tube to get there. Only used for visits and suplys.

Oh, you mean something like the suggestion you just snipped away from my post there? And rewrote yourself? That asside, there realy isn´t need for anything super light and super strong and magical. We allready have materials able to do this job fairly light and easy. Kevlar and titanium to mention some. In this case, aluminium will also get to play a part without trouble. As for size, Why so large? Ofcourse, the larger the ring, the slower it can rotate, but a diameter of around a 100 meter as I proposed means a circumference of a little more than 300 meter, (you could place the ISS in the hub of the wheel, the outer tips of the solar panels would be around the wheel´s rim), is a decent and viable small size to aim for. But double that then, to a 200 meter in diameter. The wheel itself launched in 30-32 launches, using todays tech and variations over modules being developed today. Add in wire support to a hub, a couple of inflatable shafts to the center, a hub-module or two, giving 0.5 g at 2 rpm. That´s significant. Now here comes a few sad numbers, if about 50% of the space shuttle´s ET´s could have been salvaged for a station, out of the 135 launches, say we could utilize some 67 of them. That could give a wheel-station either 46 meter wide, ca 90 meter radius (560 meter circumference). Used side by side like that, it would give the benefit of each piece of straight floor to have very little deviation from the wheel´s normal, hence, the percieved gravity would be nice and uniform. Spinning this up to 2.2 rpm would give a nice and toasty 0.5 g at the rather large floorspace. Easily several decks actualy. Now, if placed end to end, the wheel would be considerably larger. The problem with this setup is that atleast for smaller wheels, the vector of the gravity in each module will be significantly different depending on where in the module you would be. But, 67 tanks, each some 47 meters long, gives a wheel with a circumference of roughly 3.14 km. That means a diameter of around 1 km. Giving a radius of say, 500 meter. Spinning this up to 0.3 rpm is all it´d take. That is less than a third of a revolution per minute, to produce 0.5 g. The problem with using the ET´s for this is that they would need some external support, and they would have had been redesigned a little from the begining. But something along those lines where actualy proposed. In wich case, we would already have launched a lot of the hardware for a pretty large station with artificial gravity. These numbers are sad, because the Orbiter is now retired, and atleast for the foreseeable future, no such large tanks will be launched into orbit is such an abundance. At this point, I´m guessing you still yell on about needing superstrong materials and such. If that´s the case, then please, read up on what materials we have available today. Because this is ONLY a question of engineering with what we have now (politics and economy asside). I´d still prefer the first wheel station to be made up of inflatable modules like I first suggested though, as that would be simpler, cheaper, and be a nice proof of concept. And if it for some reason failed as a concept, atleast the modules could be salvaged into a more traditional configuration. And we didn´t have to build a time machine first Edit: Thanks Mr. Shifty

No, because such a "system", asuming that at the very least some kind of surgery is needed, at the most, it´s actualy equipment connected to the body, would not only have to be produced in the billions, and some kind of servicing would allways be needed. Or else it would fall into disrepair, and grind to a halt after a few years. The logistics for this to be a species killer would be insane. For all practical reasons, it would only be an option, and when considering the possible result of people not wanting to go back, it would most likely be outlawed and forbidden, on basis that it would possibly affect national/global economy.

My favorite is the last listed item in the related comentary.

Well, you´re teacher is part right, and part wrong. Check this out for reference: http://www2.jpl.nasa.gov/basics/bsf10-1.php It has some basic info about telecomunication in interplanetary space. Under coherence dopler is mentioned, and how it´s measured and compensated for, among other disturbances in the force.... signal. But like Bunsen says, the wider the channel width, the less the equipment cares about dopler.

SETI for instance compensate for the dopler created by the movement of earth in it´s orbit around the sun to confirm/rule out terrestial signals. I.e. if there is no shift, it´s not of celestial origin.