-Velocity-

1996, using it from my middle school library. Though I had seen someone using it in 1994 or 1995, don't remember exactly. But of course, my parents wouldn't get internet at home until most everyone else already had it- not because they couldn't afford it but because they didn't see any "need" for it- so we didn't get 56k until 1998.

I'm pretty sure the albedo is much too high for that to be the culprit. I could be wrong, which is why I'm only pretty sure. But look to see if they've released an updated albedo estimate somewhere. It's not going to be only 40% anymore.

Well, at least they didn't blame it on US radar emissions.

Ceres is close enough for ice to sublimate that quickly? Quickly enough that even a cryovolcano could not keep it around? I doubt it. Also, I did not realize these were near-IR images. Are you sure they are not visible light? They were taken with the framing camera, but I'm not sure which filter. But as they are still approaching, why shouldn't we assume they were taken with the clear filter? It's a little too early to start looking at specific wavelengths, is it not? Also, I really doubt these are grey spots. They're saying that they're still not resolving these spots fully. Much earlier, when the spots spanned much less than one pixel, they had estimated an albedo of 40%. The spots spanned so little angular area they didn't even yet realize that there were two of them. And still, the estimated albedo was 40%! That number was clearly wrong, as the light was being spread over a large area during the earlier estimates.. They even said the spots are still not fully resolved, even now. So the albedo is very high. This appears to be some kind of white material. The scientists even are speculating ice, salt, something white.

The human urge to destroy those things that they fear and don't understand, rather than trying to understand and appreciate those things, is one of our greater evils. You should not fantasize committing acts of evil, especially the destruction of several mostly harmless and beneficial species. That is not extinction so much as it is evolution. And there's not reason to think that biological humans would not continue. I suppose if you were of the species Homo Erectus, then you'd consider that your species going extinct was something terrible, something to be feared, something to be prevented? Do you let fear control all your beliefs and desires?

A species that decides they want to completely wipe out another species just because they don't like them is far more disgusting and is a true threat to life. Maybe we should be thinking of the most environmentally friendly way to bring humans to extinction.

After about twenty-two orbits around the galaxy, it's reasonable to suppose we will never find any of Sol's sisters- not with any kind of certainty, at least. We might find some stars that are similar enough in age and composition and orbit to maybe be related. The stars born with the Sun would be spread out in a huge arc stretching possibly all the way around the galaxy by now.

Not only are volcanoes erupting silicates impossible on such a small body (with no tidal heating either!), the lava would not in fact be "brighter". It would be dark. I know that's what an article probably said, but it's wrong. Popular science articles are often full of errors. Silicate lava is dark, in general. I guess pumice is kinda white... but again, that kind of heat on Ceres is impossible. The extreme reflectivity of these spots really points to ice, I think. These are far more reflective than previously estimated at 40%. These spots are probably going to end up being like 90% reflective or more. Who knows, maybe salt like they say is a possibility, but we don't have any examples of reflective salt patches in the solar system, outside maybe Earth (and those are probably not reflective enough), but we have tons and tons of examples of highly reflective ice all over the solar system. So it's almost certainly gonna be ice. Hopefully cryovolcanoes!

It wouldn't be a problem, other than the ultraviolet light (which would rapidly give you a severe sunburn). You get around 1000 W/m^2 at sea level. As other people point out, sweat evaporates very quickly in vacuum, so you'd stay cool.

Yea, I was never a fan of SRBs- until limited funds came into effect! My small rocket designs in career mode now frequently use SRBs for the ENTIRE thrust of the first stage, and sometimes even for the second stage too. I even have one small rocket that uses SRBs for the first THREE stages (it's actually a four stage rocket, and the first stage is kinda inefficient with a low TWR, but SRBs are so cheap it doesn't matter). It makes getting into space very cheap. This is especially true for those "put a satellite in an specific orbit around _____" contracts.

You're assuming that the future will always be like today. That's silly. We can't make any assumptions about what technologies the future will bring us, except those that are explicitly against the laws of physics. And no, I'm not worried about these kinds of problems, yet. I'm worried about the day that some futurists envision where the decentralization of manufacturing makes it so anyone can make anything through technologies like 3D printing. I'm also worried about how the continuing revolution in biotechnology and genetics makes it easier and easier and easier for a person to design doomsday bacteria and viruses. These kinds of technologies, taken to their absolute conclusion, could put the capability to manufacture weapons of mass destruction in the hands of thousands or millions of people. WILL that happen? I donno. Probably not, but maybe. If it were to come to pass though, as I said, the only conceivable solution I have thought of is mass surveillance on a scale that dwarfs what the NSA was/is doing. I think this surveillance might be more practical and palpable to people if it were conducted by a massive super machine intelligence or super artificial intelligence. (I make a distinction between artificial intelligence and machine intelligence. Artificial intelligence, to me, is a machine that appears to be intelligent and aware but is actually not- it is just programmed to appear intelligent under limited circumstances. This contrasts with a general machine intelligence, which is truly sentient and sapient, and can be rightfully considered a person. There could/would be a fine line dividing the two.) A good analogy would be to steal from your "materials to make a bomb are available in stores" statement. Indeed, they are. Any reasonably intelligent person can build a bomb with today's technologies. And indeed, there are a lot of people building bombs in today's world, even in America. Here's a list I found online of bombings (and some attempted bombings) since just 1970:  April 15, 2013: Two bombs explode in the packed streets near the finish line of the Boston Marathon, killing two people and injuring more than 80.  Jan. 17, 2011: A backpack bomb is placed along a Martin Luther King Day parade route in Spokane, Wash., meant to kill and injure participants in a civil rights march, but is found and disabled before it can explode. White supremacist Kevin Harpham is convicted and sentenced to 32 years in federal prison.  May 1, 2010: Pakistani immigrant Faisal Shahzad leaves an explosives-laden SUV in New York's Times Square, hoping to detonate it on a busy night. Street vendors spot smoke coming from the vehicle and the bomb is disabled. Shahzad is arrested as he tries to leave the country and is sentenced to life in prison.  Dec. 25, 2009: The so-called "underwear bomber," Nigerian Umar Farouk Abdulmutallab, is subdued by passengers and crew after trying to blow up an airliner heading from Paris to Detroit using explosives hidden in his undergarments. He's sentenced to life in prison.  Sept. 11, 2001: Four commercial jets are hijacked by 19 al-Qaida militants and used as suicide bombs, bringing down the two towers of New York City's World Trade Center and crashing into the Pentagon. Nearly 3,000 people are killed in New York, Washington and Pennsylvania.  Jan 22, 1998: Theodore Kaczynski pleads guilty in Sacramento, Calif., to being the Unabomber in return for a sentence of life in prison without parole. He's locked up in the federal Supermax prison in Colorado for killing three people and injuring 23 during a nationwide bombing spree between 1978 and 1995.  Jan. 20, 1998: A bombing at an abortion clinic in Birmingham, Ala., kills one guard and injures a nurse. Eric Robert Rudolph is suspected in the case.  July 27, 1996: A bomb explodes at Centennial Olympic Park in Atlanta during the Summer Games, killing two people and injuring more than 100. Eric Robert Rudolph is arrested in 2003. He pleads guilty and is sentenced to life in prison.  April 19, 1995: A car bomb parked outside the Murrah Federal Building in Oklahoma City kills 168 people and injures more than 500. It is the deadliest U.S. bombing in 75 years. Timothy McVeigh and Terry Nichols are convicted. McVeigh is executed in 2001 and Nichols is sentenced to life in prison.  Feb. 26, 1993: A bomb in a van explodes in the underground World Trade Center garage in New York City, killing six people and injuring more than 1,000. Five Muslims are eventually convicted of the crime.  Nov. 7, 1983: A bomb blows a hole in a wall outside the Senate chamber at the Capitol in Washington. No one is hurt. Two leftist radicals plead guilty.  May 16, 1981: A bomb explodes in a men's bathroom at the Pan Am terminal at New York's Kennedy Airport, killing a man. A group calling itself the Puerto Rican Armed Resistance claims responsibility. No arrests are made.  Dec. 29, 1975: A bomb hidden in a locker explodes at the TWA terminal at New York's LaGuardia Airport, killing 11 people and injuring 75. Palestinian, Puerto Rican and Croatian groups are suspected, but no arrests are made.  Jan. 29, 1975: The U.S. State Department building in Washington, D.C., is bombed by the Weather Underground. No one is killed.  Jan. 24, 1975: A bomb goes off at historic Fraunces Tavern in New York City, killing four people. It was one of 49 bombings attributed to the Puerto Rican nationalist group FALN between 1974 and 1977 in New York.  Jan. 27, 1972: A bomb wrecks the New York City office of impresario Sol Hurok, who had been booking Soviet artists. One person is killed and nine are injured, Hurok among them. A caller claiming to represent Soviet Jews claims responsibility, but no arrests are made.  March 1, 1971: The Senate wing of the U.S. Capitol Building in Washington, D.C., is bombed by the Weather Underground. No one is killed.  March 6, 1970: Three members of the revolutionary Weather Underground accidentally blow themselves up in their townhouse in New York City's Greenwich Village while making bombs. Now, imagine that instead of small chemical bombs, those were nuclear bombs, or weaponized airborne ebola, or human-communicable bird flu. Civilization as we know it could not continue to survive if every few years a major city was vaporized or entire countries or regions were wiped out by bio-engineered plagues. Again, I'm not saying that I certainly believe that this will come to pass in the future. But it's been envisioned as a possibility by many people.

No, a lot would be protons, with the Sun being an especially powerful (and variable) source of potentially dangerous proton radiation. I suppose there would be alpha particles too, but not as many as protons, I would guess. Then there would also be x-rays (by the astronomical definition of x-rays/gamma rays which does not consider what the source of the photon is). And also, there would be ultraviolet, though it doesn't take much to protect against ultraviolet. I suppose there would also be small amounts of antimatter- for example, we've spotted a big cloud of positrons being ejected from the galaxy's core- but I don't know how much of those would be present in our neighborhood. Probably not a WHOLE lot, but we do know that Earth's magnetic field traps a small amount of antimatter so maybe you could have locally "high" concentrations of it. However, I would think that the effect of antimatter would be roughly equate into an increased flux of gamma rays, because antimatter particles convert to gamma rays upon interacting with regular matter. The good news is that there shouldn't be any direct neutron radiation, I think, because I believe that free neutrons have short lives, so you only get neutron radiation when something is locally producing it. But there's also another problem, a BIG problem- secondary particle showers. Basically, an extremely energetic particle hits some part of your spacecraft and creates a shower of high energy particles (kinda like a relativistic shotgun blast), and these secondary particles can be of just about any kind. - - - Updated - - - And just to be complete, really, you could get just about any element as cosmic ray. I said protons and alpha particles because they're the most common elements in the universe (hydrogen and helium), but there ought to be iron nucleus cosmic rays, oxygen cosmic rays, etc... I suppose there are even plutonium cosmic rays. Plutonium has a short half-life (20000 ish years for the longest-lived), but when it gets accelerated to 99.999...% the speed of light, time dilation should allow it to survive a trip of many billions of light-years. Actually, one of the first proofs of time dilation was the observation that unstable particles have much longer lives if they are travelling very close to the speed of light.

Cicatrix- THIS ^^. If you're building large space planes, IMO you MUST get this mod to balance intake air. The thurst assymmetry described above killed ALL my large space planes until I got the mod. This problem happens WELL before flameout. The reason your spaceplane is yawing is most likely due to this problem; all you're probably doing by setting the tail back like that is providing enough aerodynamic force to offset the thrust imbalance. Instead of putting a bandaid over the problem, FIX the problem by getting the air intake balancing mod: http://forum.kerbalspaceprogram.com/threads/104704-0-90-Intake-Build-Aid

The mods could be the problem, weren't there mods that messed with fuel balancing by transferring fuel around?

Correct, it doesn't matter. If a docking port is connected to something else in the VAB/SPH, then you will have to "decouple" it in game, regardless of what it is connected to.

This big space tanker/carrier was assembled with 4 simultaneous clampatron Sr. dockings- It wasn't actually enough to prevent significant oscillation under time compression and maximum thrust. If there's a mod that helps with simultaneous dockings like Jouni says, then I'd highly recommend it. It would sometimes take me many tries to get the two halves of this ship design correctly docked into each other.

Ok good, I hate fighting. The final stage's starting TWR on Eve is 0.93 according to Mechjeb, but it's actually going be like 0.9 when carrying two Kerbals. As I said, you were correct in pointing out this as a flaw, you were just incorrect in the severity. I'd like to think of ways to fix it, but the craft works well enough that it might not really be worth my time. Didn't the Space Shuttle also have a point in its flight were the TWR was lower than they would have liked (right after jettisoning the SRBs, maybe?) And sometimes the benefits of carrying less engine mass can outweigh the negative effects of having a lower TWR than you'd really like, as Jouni points out too.

Which is exactly why the cost of the optics is negligible, at least in this range of aperture. - - - Updated - - - He's not. He's comparing the reduction in light intensity at the sensor due to distance from the Sun with the reduction in light intensity at the sensor due to less light being reflected by the object. It's the same unit, power per unit solid angle. In SI, it's watts per steradian. He gave this comparison as distance from the Sun vs. albedo, and assumed it would be obvious to the reader that he was talking about the radiant intensity of reflected light as affected by distance from the Sun vs. albedo.

Wrong, it does not "stall", and it has a reasonable surplus of delta-V when it reaches orbit even when launched from sea level, in fact. As I said before, a previous version that was almost identical to this one flew successfully with a huge margin for error from about 50 meters ASL from Eve's surface in 0.24. And when I say "almost identical", I am not exaggerating. TWRs, engines, fuel tank sizes, were all identical. The only difference was that the final payload to orbit was slightly more in the older version, so this version actually performs better. So you're wrong, unless you're accusing me of lying. If I remember correctly, the previous version of this craft, launched from sea level, put me into something like a 600 km X 600 km orbit around Eve. I think that number is correct, but even if not, I do remember that I had a rather large margin for "error", and reaching orbit was rather easy. And again, I launched it from sea level. While you are vastly overestimating the problem of the starting TWR of the last stage, you are correct in that it's lower than I'd like. I'd really like it to be about 1.2, but I can't add fractional numbers of 48-7S engines, I have to chose 1 or 2, and if I go with 2, it's vast overkill and hugely decreases my delta-V. The reason you're wrong is because by the time that the time the last stage kicks in, the craft is into the gravity turn- even when launched from sea level. This means that the need for high TWR is already mostly removed, because you're mostly above the atmosphere, and the craft is mostly thrusting perpendicular to gravity. Anyway, if I remember correctly, the only effect of the low TWR is that at the beginning of the final stage's burn, I have to keep the craft's nose maybe 25 or 35 degrees higher than I'd otherwise like to have it- so maybe the "efficiency" is decreased to 80% of normal. It's no big deal because that problem rapidly goes away as fuel is burned anyway.

Well, when you make your Tylo lander a single stage design that can be refueled and reused many times on the same mission, it becomes much more difficult to exceed 6000 m/s dV and still carry a science payload. Oh it's possible, but you have to make the craft really big to squeeze out that last few hundred m/s. Now, if you make your lander single-use, it's different. Thanks for the tip! You've got a good point, those aerospike engines are heavy. And you know what, I'm violating my own design rules for Kerbin launches. I always make my Kerbin launchers have a starting TWR of like 1.6 or 1.7, precisely to minimize engine mass. I haven't done the math to validate this though, but it seems logical. So you think maybe I should rework my Eve lander I posted above? It would be fairly easy to modify it into a TWR of like 1.6 and increase the dV by what- 500 m/s? Even if you're right (and I think you are), I really don't think there would be any need though to modify the upper asparagus stacking though, because 48-7S engines have such a ridiculously high TWR. - - - Updated - - - Thank you so much! I'll immediately fix my posts above so that people only have to see my screenshot spam if they click the spoilers!

It is? I thought it was the opposite- a big, fast telescope, if the objective is single piece, requires A LOT of glass to be removed, because the higher the f-ratio, the closer your objective can be to having a spherical shape. So a big, fast telescope requires A LOT of polishing to get to a parabolic shape. Then again, I may be trying to extrapolate my experience with reflecting telescopes too far. Maybe this applies less to modern multi-element refracting, catadioptric, and reflecting designs that use multiple shaped mirrors (like Cassegrain or ritchey creitian or however you spell it). Regardless, I would assume that the price of the optics was pretty negligible compared to the cost of the rest of the mission. A very high quality 8" mirror only runs a few thousand dollars. Less than that, really, but if you're the USG, you'd probably end up paying like $20k to get the same thing us amateurs can get for $1k.

Actually, the chemical reaction is Si + 2X H2O -> SiO2 + 2X H2. That would make the H2O an oxidizer, unless there's more to the definition of "oxidizer" than I'm assuming. I don't know if this is an endothermic or exothermic reaction though. I, again, need to study my chemistry better, it's one of my weaknesses. I was actually considering breaking out my chemistry textbook sometime. The problem is, I find chemistry to be kinda boring... which is strange for me because I like most other technical fields/sciences. But again, yes, I agree, talking of water being an oxidizer for hydrocarbons is silly. - - - Updated - - - That's a very interesting problem I hadn't heard about. Do they really think there will enough heavy debris in the ice to cause problems? Or do we simply not know? After all, in sea ice, there isn't any debris- but sea ice on Earth is usually between a hundred to a few million times younger than ice on Europa. I doubt there would be enough meteoric debris in the ice to cause a problem. BUT we don't really know for sure what might be in the ice, do we? It would probably be safest to just assume that this problem you speak of could arise, and plan for it.

Pad test- A little after 2 minutes after launch, the second stage of asparagus staging based on 48-7S kicks in- 6 minutes and 43 seconds after launch, the last engine runs out of fuel. Velocity with respect to Kerbin is 9 km/s, altitude 1250 km- Mun's orbit crossed at 26 minutes after launch. That's what it takes to get to orbit from Eve's sea level. Pretty extreme. Why don't I launch it from Eve, you might ask- well, I tried a very similar craft to this one from Eve, and it worked fine, in 0.24. When I tried to load up that save recently, something was corrupted with it. Anyway, I'm putting together an Eve mission right now, but it will be a while still until I'm ready to use this thing.

There has been some angst about manufacturing technologies such as 3D printing and perhaps nanotechnologies (though I'm a little skeptical myself on nanotech) giving an individual person access to dangerous capabilities. We're already seeing one of the first starting to come to fruition- 3D-printed guns. What if it were to get far worse? What if a person or small group of individuals were able to make their own nuclear bomb? Or doomsday virus? Or even just a surface-to-air missile? Our ability to keep deadly weapons out of the hands of bad actors is based on how hard it is to manufacture such deadly weapons. But if individual manufacturing fully matures, then we could be a big trouble. This is where perhaps a superintelligence could come to the rescue. What if we had a superintelligence monitoring us, making sure we were not planning mass destruction or some kind of severe crime? We'd have to sacrifice our privacy, but honestly, what other choice would there be, if the alternative was nuclear, biological, chemical, or simply advanced weaponry, in the hands of thousands of psychos?!? Seriously, what other choice is there? There are thousands- probably millions- of crazies out there who, if given access to a nuclear bomb or deadly virus, would unleash it on the population without hesitation. Anyway, I donno if this might or might not come to pass. It's just something I've been thinking about for the last year, ever since the NSA scandals broke. People were very angry how their privacy "rights" had been violated, but we're already at a point in history when mass monitoring of citizens is (very) questionably justifiable. What happens if this manufacturing revolution really comes to pass? The only solution I've thought of so far is the complete loss of privacy- perhaps a superintelligence could monitor citizens and raise red flags for human law enforcement. Honestly, I'm not even sure it needs to be a superintelligence. It's just that the last year has seen so much vilification of the NSA and its intelligence gathering mechanisms, and yet, one possible future awaits us where the choice could be either the acceptance of mass surveillance, or the destruction of civilization. I'd take the mass surveillance myself if this future were to come to pass! Make a non-judgemental superintelligence do it. ANYWAY, I do not want us to discuss the NSA. I said it was questionably justifiable- which is stating the fact that some people believe it is justified, and some people do not. My discussion focuses on a future where it becomes incredibly easy to obtain extremely deadly weapons (like WMDs), and what the impact of that might be on people's attitudes about mass surveillance, and how a super-intelligence might or might not be able to fulfill that role. The NSA "scandals" were simply the inspiration for me considering this- is there in fact a future where mass surveillance becomes vital to the continuing existence of civilization? If only I had the skills of a science fiction writer, I would explore this idea.

Tylo is so much easier than Eve it's not even funny. A Tylo landing and ascent into orbit can be accomplished in a single stage (which is useful if you want to reuse your lander to make a bunch of Tylo landings on the same mission). All you need is 5500 m/s dV- IIRC, 5100 is what I found to be required, while 5500 m/s gives you somewhat of a cushion for error. The two rules I use for designing a Tylo lander (I always make them single-stage vehicles)- Starting TWR >= 1.3 Total delta-V: >= 5500 m/s. The more I exceed these numbers, the better. Here's a medium Tylo lander I made sometime last year. It should still work- For small Tylo landers, you want to use 48-7S engine, it's by far the best engine for a Tylo lander with its extremely high TWR. I didn't use it on the above pictured lander probably because the number of 48-7S engines would have been crazy huge. Also, something that will dramatically reduce the size of your single stage Tylo lander is to eliminate the crew cabin. Doing so allows you to decrease the size DRAMATICALLY. This is a "tiny Tylo lander" I made sometime last year. It caries a single Kerbal in a command chair. The Kerbals weight is counter-balanced by a goo experiment on the other side (it took a lot of testing on Kerbin to get it right). It wouldn't work right now because it's lacking reaction wheels (the probe core I used no longer has reaction wheels), but that could be easily rectified. I'd probably sacrifice some of the RCS. It's powered by 8X 48-7S engines. So Tylo is easy to make a lander for, but difficult to fly it, actually. You have to time your deorbit burns just right. But that's what quicksave and quickload are for, right? EVE, OTOH is far more difficult. You need like 11,500+ delta-V to make it to orbit from sea level, AND a TWR of around 2 for all the lower stages- and that's an EVE TWR of 2, so like 32, 33 m/s acceleration. My early Eve landers worked but were mounstrous; the first I made was 700 tons and couldn't even make it from sea level to orbit, it had to be launched from like 2000 meters elevation at least. The second generation I made was better, but still 400 tons, IIRC. Finally, I dumped the requirement for a crew cabin and science experiments; my Eve-bound Kerbals simply live and work in a big habitat that lands separately, and use a rover to drive them over to the Eve ascent vehicle (which I landed somewhere nearby) when they are ready to depart. This allows me to create an Eve ascent vehicle ("EAV") that solely is devoted to getting to orbit. So my Kerbals sit protected by a "wind screen" in command chairs. My current design only has seats for 2, but I could expand its seating to 4 if I wanted, I think. But it would be wasted weight when I'm only planning on two-man Kerbal Eve surface missions. Including the orbital maneuvering engines- which are jettisoned during landing- the entire thing weighs just 162 tons (the actual ascent vehicle part of it weighs 135 tons). Earlier designs of my EAVs had the parachutes jettison on takeoff, but with these newer designs that have a lower center of gravity, that only saved a few m/s delta-V so I judged it overkill. Anyway, it uses two separate stages of asparagus staging. The first set of asparagus staging uses aerospike engines to get through the lower atmosphere. Stacked on top of this asparagus assembly is a second, smaller asparagus staged assembly that is based on 48-7S engines. My "EAV Mk6", including orbital maneuvering engine and docking port- This is just the ascent stages. The first ascent stages are a big asparagus stack based off of the aerospike engine- This is the second asparagus stack, based on the 48-7S (thirteen of them), that rides on top of the first one- This is the final stage, the only part of all that mess that actually makes it back up to orbit- So yea, Eve is incomparably harder than Tylo. One final note- you must TEST TEST TEST TEST your lander on Kerbin first. An Eve ascent vessel especially moreso than a Tylo one, but the Tylo one will still need testing. Not only should you test to make sure the rockets work correctly, you have to test to make sure that your Kerbals can actually use the ladders to get to where they need to sit!!! Both Eve and Tylo have too high of gravity for your Kerbals to fly using EVA packs!!! The ladders MUST work!