Fuzzy Dunlop

The rear RCS system is built into the orbital manuvering system pods on each side of the shuttle, these are also detachable.

I thought the paint was to protect the foam against UV, then they discovered it wasn't really a problem and stopped doing it to save weight. But I can't remember if I acctually learnt this or am just making this up.

Thats actually kind of how yo-yo despin mechanisms work

It's worth noting that if you can maintain air presssure to the lungs, humans are suprisingly well adapted for space. Skin is extremely airtight and comes with its own thermal control system, it's also easily strong enough to stop you exploding. The only problem is that without air pressure fluid would pool in all the places where the skin folds and stretches to allow for movement - which would be very debilitating. But if you had were wearing a tightfitting elastic webbing, kind of like a fishnet bodystocking (which sounds horrifying now that I think about it) you should be OK.

No they don't, marsupials don't have a placenta but they do give live bearth. Monotremes are mammals that lay eggs, but they are no more related to marsupials than placental mammals (despite both being largley confined to australia in modern times). Mammals aren't really a fuzzy clasification, at least among non-extinct species (and classifying extinct species is always fuzzy if you go back far enough). Monotremes seem to have split off from the rest of mammals about 200 million years ago, in the late Triassic (or possibly early Jurassic). However synapsids, the reptiles which mammals are descended from, split off from diapsids (ancestors of lizards, crocodiles, birds, dinosaurs and probably turtles) at least 320 million years ago.

It's always seemed quite simple, the air follows the trailing edge, which is angled towards the ground - hence upwards lift. The interesting part for me is persuading the air to flow over the wing without slowing it down too much.

One main way you can see a common relationship is skulls. All mammals have one hole in the sides of their heads - the temporal fenestra. All reptiles have two (except turtles, but turtles are complicated)

Jool has moons, you can use them to flip the inclination of an orbit 180 degrees for very little delta-V

The mun is just too small to provide a significant delta-V boost. Kerbin, Eve, Jool and some of it's moons are the only objects big enough to make gravity assist worthwhile. That said, slingshots from virtually any body are awesome for changing inclination. Like when you realise that your Kerbin return vessel is in retrograde Duna orbit, and you've launched into prograde.

Uranium would significantly increase the thrust, but it would also make the boosters much heavier. So specific impulse will be much lower, and thrust to weight may or may not increase.

Lies! Concorde! Also the Lockheed Constellation was utterly gorgeous.

It wasn't based on the R-7, it was an R-7, Sputnik was effectivley the second long range ballistic missile test (less than 2 months after the first). My point was that the Soviets, who had vitually zero prior experience with rocketry, went from a captured V2 in 1945 to an operational launch vehicle in 1957. Moreover, this first effort has proven more successful than any subsequent design from any other organisation - no matter how much more experienced or well funded. What I was trying to argue was that organisations don't acctually get much better at managing major projects as they get bigger and older, thus the new guys are no more likely muck it up than the old experinced heads.

Reaction engines have man-millenia, thats really not that much, Boeing probably have man-eons. That said experience is terrible predictor of project success, SpaceX is flying to the ISS from a standing start about a decade ago (compare that to Lockheed or Boeing). The Soyuz rocket is in many ways identical to the first orbital vehicle ever flown - which Korolev designed less than a decade after the Soviet's captured their first V2. I think there is still an impression that reaction engines in still 3 guys in a shed, that may have been the case 10 years ago but today the're a fairly significant entity. They recently appointed a new CEO from Morgan Crucible (a turnover ~ £1 billion, FTSE 250 engineering company)

Defense procurement is a complete mess the world over, the eurofighter is nothing compared the F-35. A lot of goverment funded projects show the same issues where poorly managed projects consume all the cash avliable and then more, but the millitary is generally worse. Boeing and Airbus (at least their civil divisions) are comparatively efficient. the A380 cost $15 billion to develop, thats probably the very minimum you could expect to budget for SKYLON.

More than a little harsh, what they have done is build and successfully test what is by most measures the highest performing heat exchanger ever designed. Reusable SSTO's are basically physically impossible, we can't push engine ISP much higher (a least not with feasable chemical propellents) and current materials science wont allow us to push the fuel fraction of tanks much higher. Plug this into the rocket equation and your payload is only just enough to cover your heat shield. So either you need voodoo chemistry or voodoo super-strong materials. Or you cheat the rocket equation and gather some of your propellent in flight. Problem is the only way to do this is to scoop up air at mach 5, and it's hard to burn it at that speed. This is what a scramjet is, unfortunatly their thrust to weight ratio is so aweful that they'll end up eating all your payload fraction and then some. Or you could slow the air down and then burn it, like normal jets and ramjets do. Thing is, this makes the air hot, and when you're slowing it down from mach 5 it makes it too hot to burn effeciently (also it might melt everything). Could you cool it down? Well yeah you could, in fact given how much cryogenic liquid hydrogen you've got on tap you could easily chill down enough air. Only snag is that you'd need a cooler so big that you couldn't carry anything else to orbit, also it would probably chill all the water out of the air and freeze over. Unless you have some fancy voodoo heat exchanger that is... wait you do? The point about Skylon is that it is the only proposal for a reusable SSTO that doesn't depend upon a single piece of technology that has never been tested before. Yeah, there are so many ways it could fail; the SABRE engines are unique and horrificallycomplex, SKYLON itself is a huge aircraft that can't afford to be even a couple of tonnes overweight. It will stuggle to get the funding it needs and even then there's no guarantee it will ever fly - But at least we know that it can work. We're not even certain any other proposal is physically possible.

If you take energy out of the earth's rotation (slow it down) the moon has to gain some, because you have to conserve angular momentum. Edit: you're not acctually extracting energy from the tidal bulge, the earth rotates faster than the bulge, so by increasing the friction between the two, you're adding energy to the bulge, which ends up in the moon.

I thought it worked like this By using tidal power you increase the friction on the ocean, effectively dragging the tidal bulge east of where it should be. That mean rotation slows down more and the moon drifts out faster. Interestingly it appears that the moon has receded at very different speeds over the earth history (it can't have always been receding at the present rate because that would mean 4 billion years ago it would be too close the earth to even form). Basically when all the continents are jammed together in one supercontinent (i.e. pangea) there's not much to stop the ocean just running around the planet without losing any energy, so the earth doesn't slow down much and the moon recedes slowley. When all the land is spread out with lots of little nooks and cranies, like today, you have a high friction system and the moon recedes relativly rapidly.

This is why my anti-tidal power campaign is called "Keep The Moon"

SSTO isn't that hard: Atlas style ballon tanks, and NK-33 engines should do it nicely (In fact a Titan II first stage could probably get itself to orbit). A SSTO with a useful payload fraction is much much more difficult. And becuase the payload fraction is always going to be small compared to staged rockets then the only real way to compete is with reusablility.

I'm not sure this is the case. I think you might have overlooked the kinetic energy of the planet. If you ascend vertically you will drag the planet after you more than if you gravity turn.

It wouldn't require any extra pumps, rocket engines suck fuel pretty effectivley.

I'm always cautious about the validity of any of the space radation studies. Some types of radiation are more dangerous than others. On earth we only have to deal with Alpha, Beta, Gamma and occasionly Neutron radiation. In space there are a lot of Protons and Heavy Ions. Basics studies show that the protons are twice as dangerous as gamma rays (per unit of absorbed energy), heavy ions are about 20 times worse. But thats just killing cells in a petri dish - we have no real idea of the relative cancer risk.

If you want to do this stock there may be a way. Place pairs of the small radial engines pointing a right angles to the main engines, then tie the pair to actions groups, when the shuttle starts tipping over fire the pair that points in the opposite direction. You'll have to keep toggling it all the way up but it is possible.

Depends on the situation, it has a pretty poor thrust to weight ratio, so not great for launching/landing in high gravity enviroments. For very low gravity the nuclear engine is generally a lot better. I often use the poodle in upper stages (to get from about 1000 m/s to LKO). It also has the best gimbal range of any engine.

All the engines have a value called "ISP" or Specific Impulse. This is a measure of the amount of thrust produced per unit of fuel. Acctually the ISP changes depending on how thick the atmosphere is, so you have ISP - vacuum and ISP - sea level. Often the highest ISP engine is the best, but sometimes thrust to weight can matter more.