-Velocity-

Yea, water is not oxidizer. Generally, it's a product that you frequently get from oxidation. Water and CO2 is what you get from burning methane, in fact. So it's silly to talk about as an oxidizer in this case. Though to be technically precise, while rust is a product of oxidation, it can be in fact be an oxidizer in certain situations. It is the oxidizer in thermite (a high temperature incendiary explosive), for example. The key is that the oxygen in the iron oxide has an even lower chemical energy state it can go to by bonding with the aluminum "fuel". At least I think that's how it works. I only had a single college level chemistry class; they don't require much chemistry for electrical engineers. Another example, water can in fact be an oxidizer too under the right conditions. If I want to grow a thick layer of silicon dioxide on a silicon wafer, then I flow a mixture of about 3 parts oxygen and 5.9 parts hydrogen into our oxidation oven at 1000C; I run it oxygen rich so that we don't run the risk of a hydrogen buildup on the ceiling of the lab (yea, that could be bad). Anyway, it makes water vapor inside the furnace, which for some reason I don't understand, actually grows an oxide layer on the silicon faster than if I just flow pure oxygen. Go figure.

I doubt you could survive very long in space with just a face mask. You have other holes in your body- your ears, your butt, your eyes- and those need to be plugged too. The sphincter isn't going to be able to hold back the vacuum of space when it can barely even hold back a large burrito. Additionally, you might have a difficult time exhaling- because your chest is exposed to vacuum. When you load it up with air, that will be a lot of lbs per square inch pushing it outward. However, let's say that you had just your arms and legs directly exposed to vacuum. You could probably survive like that for a fairly long time, if you could get a fairly airtight seal around them and replace any air leaking out. It probably wouldn't be very comfortable though. I believe there was an account of someone who got their entire hand exposed to vacuum for a pretty long time and suffered no ill effects at all. Your body, except for where it has holes, is reasonably well sealed. For a more reasonable depiction of human exposure to vacuum, see 2001: A Space Odyssey. There are a few inaccuracies with that scene however; for one, the gasses released from the hatch expand too slowly; secondly, there would be some "sound" when the gasses expanding from the blown hatch hit the microphone; microphones register pressure changes generally, so if there is an expanding cloud of gas in space a microphone will pick up a "noise". I say "noise" because it's not truly acoustic sound because the medium is actually dispersing and the physical movement of that medium is what causes the "sound"; true sound is a wave phenomenon involving no gross transport of the medium.

I doubt it. I think the main reason they go for aperture is resolution; the closest New Horizons gets to Pluto is 12,500 km according to Wikipedia; at that range, you'll need a big telescope to see small details on the surface. Additionally, aperture and light gathering power does not work the way most people think it does. Surface brightness- the amount of light per unit of angular area of an image of an extended object- does not increase with aperture. If you've matched your focal plane array pixel size to some some small multiplier (like 1.0) of the size of a point source on the image plane- which you do if you want to squeeze the maximum amount of resolving power out of your system- then surface brightness of extended objects does not increase. In other words, as long as you match the pixel size to the some fixed constant of the size of a point source, then when you look at an extended object- like a planet, a nebula, a galaxy, etc.- then the number of photons falling on each pixel is the same, regardless of whether you're hooked up to 20 mm telescope or a 2000 mm telescope. However, if you're willing to use pixels that are not fixed in size with regards to the angular resolution of the telescope, then you CAN increase the number of photons hitting each pixel by going with a short (small) f-ratio. This is what is meant by "fast" telescopes- they have short focal lengths and have low power (for their aperture size). "Fast" originated from the world of photography; you could take images of faint objects faster with "fast", small f-ratio telescopes, because they concentrated more light per unit area on the film. HOWEVER, their resolution suffers because of this. That said, it is important to understand that how "fast" an imaging system is has nothing to do with its aperture; it is solely dependent on the f-ratio. It's a similar situation as to what occurs in visual astronomy, which I've been doing for over 20 years now. The pupil of the human eye cannot open wider than about 7 mm. This means that if the cone of light entering your eye is wider than 7 mm, you are wasting light from your telescope. The diameter of the light cone as it enters your eye is known as the "exit pupil". To calculate it, you just need to divide the telescope's aperture by the magnification. Say I've got a 200 mm telescope operating at a 7 mm exit pupil. That's 28.6X. Let's compare that to a 400 mm telescope operating at a 7 mm exit pupil- 57X. Let's say we're looking at the Orion nebula. The 400 mm telescope gathers 4X more light, but must be operated at TWICE the magnification. This means that the light that is gathered is spread over 4X more area. So, while the bigger telescope gathers more light, it spreads that light over proportionally more area. The surface brightness- the amount of light per unit area of the image- does not change. The Orion nebula appears larger and more detailed in the bigger telescope, because the larger a low surface brightness object is, the easier it is for a human eye to see it. Sometimes, this is perceived as the object being brighter, because in truth, the total brightness of the magnified object has increased by 4X because it's area is 4X larger. But the brightness per unit area has not changed. This is actually a "law" in optics- that optics cannot increase surface brightness- and I've read about it elsewhere. I forgot the name of it though. I think there was even a Wikipedia page on it, but I can't find it right now.

Supposedly its relative radial velocity is something like 80 km/s. It's changed many, many times over, and we're probably somewhat lucky to be here at all. There's a reason they call it "spaceship Earth" sometimes. Since its birth, the Earth has made about 20 full trips around the galaxy.

Incorrect. Scientists have not stated that this is the closest that any star has ever come to the solar system its entire 4.6 billion years of existence. In fact, there are probably hundreds of stars out there that have come closer to the solar system than this star did. Even the Wikipedia article on Scholz's star says that stellar encounters this close (0.8 light-years) or closer should come every 9 million years, pretty frequently astronomically speaking.

This is only one wall of the crater, and the screenshots don't do it justice. I think the other side is even higher, and almost as steep of an angle. It's on Mun at 69 50'N 115 25'W.

I am not a botonist or biologist, but right off the top of my head, I can say no with high confidence. For one, the atmospheric pressure is far too low, and only in extremely low elevations on Mars can liquid water exist- and only then in a very narrow temperature range. The plant will dry out and die quickly. You could mix in antifreezes I suppose and extend that range, but I doubt the plant can live off of them. Also, the ultraviolet light and surface radiation environment would probably kill it. What other things might kill it? I'm not sure. The Martian soil is probably toxic for it too. Underground, things might be different, I wouldn't be surprised if there are some Earth microbes that could survive there, especially if the recurring slope lineae we see coming down some crater walls are in fact flowing water streaks bubbling up from underground. But plants? Plants need sunlight. - - - Updated - - - Anyway, supposedly, if we could melt the ice caps, composed of carbon dioxide, we could increase the surface pressure to like 0.3 bar. But I donno how plants would take that. That's a VERY high partial pressure of CO2, for all I know, they could get CO2 poisoning- sorta like drowning them in water. I'm not a biologist/botonist, as I said, maybe I should keep my mouth shut Few a few thousand dollars you could get a vacuum pump, a pressure vessel, and a CO2 tank and find out for yourself. It could be fun. You could even get some UV lamps to simulate the lack of any kind of ozone. Maybe set it in your garage beside your operating Farsworth fusor fusing deuterium to help simulate the high radiation environment The good news is that plants are not susceptible to cancer death because they don't have vital organs and high cellular mobility to allow cancer to spread... but radiation can still kill them. - - - Updated - - - Oh yea, and the overnight low is gonna kill your plants too. It is not uncommon for the daytime high and nighttime low to be more than 100 degrees C in difference. There is very little atmosphere, so the temperature drops like a rock when the Sun goes down.

Anyone know if we'll ever get a "return a Kerbal from the surface of" type contract? Because it's blatantly missing in the game, and it's one of the big goals in real life space exploration. And it especially adds gameplay value for Eve. Right now, you don't technically have to return Kerbals from the surface to fulfill any contract you get on Eve.

Umm... I think that one is a mockup... it looks like the monkey head was created by an unskilled taxidermist. The first photo looked real though.

Yea. As soon as a guy actually goes inside the capsule and launches, I'll be hoping he comes back alive and unharmed. But I wish they wouldn't try at all. If Iran wasn't pursuing nuclear technology, sponsoring terrorism, and making threatening statements towards other countries, I'd feel entirely different about their space exploration efforts. Once Iran has the missile technology it desires, they will suddenly find their space exploration program to be "too expensive" or something like that.

No probably not. You can guarantee that Sol has had much closer encounters with other stars in the past. Also, this star whipped past us really fast, so its gravity had very little time to act on the solar system. The star could have perturbed some comets our way (though the chances of them hitting Earth are slim). Wikipedia claims that it would take about 2 million years for perturbed comets to reach the planets/Sun. I verified this by plugging a 0.4 light-year semi-major axis length into the formula for orbital period- it gives 4 million years. Divide that by two to get the amount of time it takes a comet to fall into the Sun from 0.8 light-years away - 2 million years. I suppose some comets could have gotten a boost and could arrive a bit sooner, but probably not a lot. It's too bad that this encounter happened 70,000 years in the past instead of 70,000 years in the future. It would have been a perfect chance for interstellar travel if civilization were still on Earth.

No need to argue, and thank you for the correction. I was confused about what the term Oberth effect meant, and where it was supposed to apply. I thought the term was defined to apply ONLY around a gravitating body- in which case, the gravity determines the velocity (and how much kinetic energy you keep from the encounter- or your gravitational potential energy at your apoapsis- increases the faster you "run away" from the gravitating body, as Lost Oblivion said). However, I looked up the official definition and it looks like the Oberth effect is actually defined more generally, simply stating the obvious that you get a larger increase in energy per unit delta-V when you are moving faster (assuming your apply the delta-V in the direction of or against your motion)! And obviously, work = force*distance works in deep space, not just around a gravitating body

No Slashy, Lost Oblivion's interpretation is perfectly correct, and you are very off track when you say that gravity has no effect. Gravity is CENTRAL to the Olberth effect, because it's what defines your point of maximum efficiency- your closest approach to a gravitating body! However your mathematical statements are correct, as they are essentially based the equivalent of Work = Force*Distance. The gravity of a body makes you move faster the closer you are to it, and so when you apply an amount of force with your engine, it is applied over a further distance due to the increased velocity, resulting in more energy (work) added. Anyway, I personally find Lost Oblivion's interpretation to be the most intuitive, but you can keep your interpretation if it seems more intuitive to you; mathematically, they are equivalent.

I use rovers a lot. Most of my landers are in fact rovers, because why put landing legs when you can just put wheels? It makes it real easy to visit closely spaced things for contracts. The longest drive I've done with a rover so far before taking off and flying somewhere else was about 150 km, on Duna to fulfill a contract for accelerometer measurements. After that drive, I flew the rover back into orbit, refueled it, and landed it somewhere else and drove another long distance to get multiple measurements for some other contract (but it was only like 75 km total the second time). BTW, Mechjeb rover autopilot was used for this. I do like how this contracts system forces us to drive long distances on the surface now. Before 0.9, my longest drive was only like 35 km, round-trip, on Eve (and yes, seeing as it was EVE, that rover was strictly a rover ).

I found an extremely steep and tall cliff on the Mun, sorta near the north pole (maybe 70 degrees north?) in one of the Highland Craters. It was much more extreme than the cliff pictured above.

Yea, I also want to see a closer screenshot. Did you implement a self-destruct mode? That would be spectacular. On my biggest rocket, I set up a self-destruct on "Abort", but triggering a bunch of sepatrons to fire into several key root parts, causing them to explode and the rocket to disintegrate (lighting up the second stage engines simultaneously as well helps to make the fireball even more spectacular). I'd love to see your rocket go boom!

That's correct.

I'm confused, and not sure what you are referring to. Are you referring to the fact that if you complete your burn to a distant planet within Kerbin's SOI- the closer the better- you save delta-V from the Olberth effect? If THAT is what you are referring to, yea, you can't split that up, and the higher the TWR, the better. But I personally have trouble planning maneuvers to other planets when in another planet's SOI, because in my experience I can't see my path around the Sun until I've made a burn that puts me past escape velocity, so I'll always make a transfer burn to another planet after I leave Kerbin's SOI. Hmm... maybe if I plan a second burn it will allow me to see my solar orbit?

Incorrect, you did not interpret my post correctly. See my above screenshot. One place I can think of where you CAN'T break down your maneuvers into separate parts for maximal efficiency is of course capture burns. I remember one time I was approaching Eeloo with a big nuclear-ion manned ship, and I had to start my orbital insertion maneuver before I even entered Eeloo's SOI, or I would have just flown right on past it. I think that the Dawn spacecraft may be doing something similar right now as it approaches Ceres, just based on how it's taking it over a month just to fly a distance less than that from the Earth to the Moon. - - - Updated - - - I was only considering the question of going from Kerbin to the Mun. So you mean doing your ENTIRE burn to some distant planet from low Kerbin orbit?! You need some kind of transfer window planner for that, if that would even work. Your orbital path around the Sun doesn't even appear to you for the first time until you're on a path to leave Kerbin's SOI (though I think MAYBE I've gotten it to appear for me before, but I don't know how), so I wouldn't have a clue how to do everything in just a single burn; it's impossible to target something beyond Kerbin if you don't even know where a maneuver is going to take you.

Here- here's a three-part Hohman transfer to the Mun, broken down into 3 equal parts that are like 280 m/s each- So, like I said, even with a very low TWR, you can still make many of your burns at the optimal point in your orbit.

Say I need 750 m/s to get to the Mun, and I want to split it into roughly two. I create a manuever node where I think I will make my final burn, and make it a 300 m/s-400 m/s maneuver. This creates a dotted line that I can make a SECOND manuever node on, that I will execute on the orbit AFTER I make the first maneuver, and this second node will also be placed at the same point (which will be periapsis of the orbit after the first maneuver has been done) as the first node. Now, on this second node, I create whatever delta-V maneuver is necessary to reach the Mun. It's really simple, but it can be harder to time, because you're thinking two orbits ahead instead of just one. I'll make an example and show you a screenshot. You can also think THREE or more orbits ahead and split your maneuver into three or more parts, which I have done on occasion for some ion-powered spacecraft with extremely low TWRs. Basically, it becomes simply a matter of thrusting at your periapsis and only at your periapsis over and over again, slowlying increasing your orbital eccentricity till your apoapsis is just outside the torroidal zone defined by the path of the Mun's SOI around Kerbin, then waiting for a random alignment with the Mun so that an additional small thrust at Kerbin periapsis will butt you into the Mun's SOI on an encounter with the characteristics you desire. There is no loss of efficiency when doing this either.

No thanks. I'll take my slow rocket ship instead. At light speed, time runs infinitely fast in the external universe, and all lengths in the direction of your motion are contracted to zero. So if you could ride a photon through the solar system, you would instantaneously find yourself in the death throes of the universe- assuming there is an end- and trillions of light-years away from Sol or probably further, assuming you weren't "lucky" enough to strike something like a star or planet or interstellar dust grain hundreds, thousands, millions, or billions of light-years from Earth first. At least you would have a very high probability of being absorbed by interstellar dust if you left in a direction aligned with the galactic plane- though that depends on what kind of photon you wanna be. If you're a radio photon, you've pretty much got a guaranteed instantaneous one-way-ticket to the end of the universe. That's not something I wish to see

Nice... do you have any other dyslexic tendencies?

Most of the time you can plan ahead and break your nodes into multiple separate burns that all occur at the optimal point (especially if it's a Hohman transfer) and this no longer applies. Though I think that the people who never put more than like two NTRs on their interplanetary ships are causing themselves a lot of hassle for very minimal gain. You don't lose a lot of delta-V by adding more, and you greatly reduce the tedium of very long burns. I've built interplanetary ships that weigh in excess of 1000 tons before, do you really want a ship that accelerates at only 12 cm/s^2?!

No parts have docking ports built in. In general, in stock, for most space stations, orbital or surface, the crewed areas are going to be built with 2.5 m command pods- http://wiki.kerbalspaceprogram.com/wiki/Mk1-2_Command_Pod http://wiki.kerbalspaceprogram.com/wiki/PPD-12_Cupola_Module http://wiki.kerbalspaceprogram.com/wiki/Mk2_Lander-can the Hitchhiker storage container- http://wiki.kerbalspaceprogram.com/wiki/PPD-10_Hitchhiker_Storage_Container and/or the Mobile Processing Lab http://wiki.kerbalspaceprogram.com/wiki/Laboratory Other than that, "long whitish tubes" describes a lot of stuff in KSP, so I can't help you, sorry. The structural fuselage http://wiki.kerbalspaceprogram.com/wiki/Structural_Fuselage is a long white tube that does absolutely nothing, if that's what you're looking for.