sndrtj

I launched the core network of my Kerbin Positioning System today. It consists of 8 satellites (KPS2-9, KPS1 was a test) launched at different angles to a low circular orbit of 70-75km using a minimal launch system. This launch system leaves no debris in orbit, thus minimizing Kessler syndrome. All sats have more than enough oomph left to deorbit safely if so required. An extended KPS system (eXKPS) consisting of an additional 6-8 satellites is currently being studied. The minimal launch system A sat in orbit LKO overview

That the technology exists doesn't mean it's practical. A SpaceTram would have to be launched out of a mountain at least 7km high. AFAIK, those only exist in the himalayas. Most certainly not in Europe. Try getting a mega-engineering project to work in the highly politically unstable himalayas. On top of that, the tube must be at least a 100 km in length, unless one utilizes truly extreme acceleration rates (which will then soupify any normal space probe designs).

Ah, thanks for the tips! This ship was doomed for a wrong orientation then. Only one command node. But I'll keep it in mind for later reference. Many thanks :-).

I managed to finally land properly on the Mun. I know it's a small step for you guys, but for me it's a giant leap ;-) Small problem tho: mr Kerman launched himself into bizarre orbit around Kerbin after leaving the Mun. And is now without fuel. A rescue vessel is now required to get him safely back to Kerbin. (Note on that: how do I turn the navball upside down, so to speak? The lander has its engines on the opposite site, but blue maneuver markers stay on the original launcher side).

While it is true that males are more likely to die young because of a generally more risky life style, this alone cannot explain why women live longer. Even at older ages - where lifestyles of males and females are pretty much the same - females still outlive males. From an evolutionary standpoint, it sure makes sense for females to live longer. Men are not "required" to live long, because they can spread their genes on much shorter time spans than females (a man can impregnate many women in a single year. A woman can only be pregnant once every 9 months). Furthermore, unlike more simpler forms of life where juveniles are pretty much independent from birth, mammalian infants require copious amounts of care from parents to survive. For humans, this effect is even enhanced. Compared to other mammals, humans are born very immature. A giraffe baby can stand up in its first few hours. A human baby can't even see properly the first few months. Human juveniles can't survive independently for about 15 years after birth. This means that it is evolutionary advantageous to have at least one parent survive at least 15 years after childbirth. Furthermore, "natural" human relationships are estimated to be on the order of 4-5 years, enough for the offspring to reach toddler age, but not long enough for full independence. This burden thus becomes primarily the job of the mother. Hence, women need to live longer than men. (Note: yes, nearly all cultures have the notion of livelong marriages. Where and how this fits in the evolutionary picture is somewhat unclear. Perhaps the concept of marriage is too recent to have an evolutionary effect?) It has been shown that childless women live longer than child-bearing women. This makes sense from an evolutionary standpoint, as the body must be kept "fresh" for the time when childbirth finally happens. This does, indeed, suggest some connection with hormonal balance. For men, this relation doesn't exist, as there as no way for the male body to know when it has produced offspring.

Mach 26 is a speed, not an acceleration. To reach escape velocity (7.5 km/s, Mach 25.5), 12 minutes of acceleration at 1G will be enough. However, for that acceleration, you need a tube of 52,000 km to reach escape velocity. Since that's larger than the circumference of Earth, that's unpractical. For greater acceleration you need an ever smaller tube. At 5G, you need "only" 2250km. At 15G you need just 250km, and at 25G you only need 90km. Perhaps one can shorten the route further by applying short ms bursts of super acceleration (~100G) at intervals.

Not yet. Current spectroscopes are not sensitive enough to detect the faint light from an Earth-like exoplanet (most exoplanets are discovered by the gravitational or obscuring effect they have on their parent star, not by direct measurement) required for such experiments. However, performing spectrography on an exoplanet has been done, and oxygen has been detected (just not in vast quantities indicative of life) on planet HD209458b (https://en.wikipedia.org/wiki/HD_209458_b). This planet is both large (bigger than Jupiter) and VERY close to its star, which means that much star light falls through its atmosphere, facilitating atmospheric analyses. But we will get there soon enough for Earth-like planets. If I could place my bet on it, I suspect we will find an oxygen-rich Earth-like exoplanet in the next 10 years. With any luck, a planet in the Kepler dataset might already fit the bill. It would be a huge discovery thing for exobiology.

Biologist here! . I'd like to point out that the chance of life parameter is measurable. At least a low estimate is possible. The crux here is measuring atmospheric oxygen on exoplanets. Sure, there are physical processes that can produce atmospheric oxygen, but they are few. Oxygen is a very reactive chemical, of which the vast majority of oxygen in an atmosphere will react to form minerals in geologically short time spans. Unless it is replenished continuously. By life. This is what is happens on Earth. If all life on the planet were to wiped out today, there would be very little oxygen left a few million years from now. Measuring the chemical makeup of exoplanets' atmospheres is possible by way of spectroscopy. An exoplanet with an oxygen-rich atmosphere is very likely to harbour life. Measuring the rate of oxygen-rich exoplanets can thus be a measure of the chance of life appearing on planets. However, estimates by this measure would be on low side of things. Life on Earth has evolved to produce oxygen, but this doesn't have be true for alien life. Already on Earth we find the most bizarre chemical processes that life can utilize. What is, I think the most difficult parameter in the drake equation is the chance of evolving intelligent life. There is not really a known way to measure this. And even here on Earth, we don't even have a decent description of what 'intelligent' even means! Cetaceans are super smart animals, but would we consider them "intelligent"? Or does the definition of intelligence include heavy tool use? A cetacean might be very smart, but it can make less use of its capacity as it simply doesn't have the dexterity to handle tools. And so on. I would be inclined to say that the emergence of intelligence is somewhat of an evolutionary outcome on very long time scales. Humans are not the only smart species on the planet. Our deceased cousins, the Neanderthals, for instance, made heavy tool use and had art. One can teach a gorilla or bonobo to understand and respond to human language. Cetaceans have highly developed brains, and show features of having distinct cultures. It was very recently discovered that the framework of it all - neural systems - has likely already evolved independently at least twice on Earth alone (see: http://www.nature.com/news/jelly-genome-mystery-1.15264 ). Who knows what a few tens of million years of extra evolution would have accomplished. A world ruled by dolphins?

Hi there, I am an avid fan of Alastair Reynold's books, and I'm wondering what the properties of a Reynolds-style Chibesa engine would be. For those who have no clue what Chibesa engines are (I suspect that that is the majority): Chibesa engines are fictional engines which are a result of "chibesa physics", some fictional type of physics mankind discovered around the year 2200. The details of Chibesa engines are quite scant. From his latest book, On the Steel Breeze, these are some speeds and descriptions: 1) A "slow" Chibesa-equipped ship takes 3 days to go from low Earth orbit to low Venus orbit under "somewhat favorable" conditions. 2) During this trip, the engines delivered thrust up to 1g for at least 12 hours straight. 3) The maximum speed attainable with a practical/standard Chibesa engine seems to be on the order of 13% of light speed. 4) They have a significantly better lsp than VASIMR engines. Lets say that "most favorable" conditions for a 3-day trip to Venus means that Sun, Venus, and Earth are nearly at sygyzy (i.e., Venus is at closest approach to Earth). If one would then fly straight "up" from an equatorial Earth orbit towards an Earth escape orbit, while heading directly towards Venus, how much dV would then be required to travel that distance? Here's a schematic of the situation at hand (planets orbit counter-clockwise): I've done some simple calculations, assuming a direct straight line, and after accelerating for 12 hours straight at a constant 1g, one would already have traveled be 0.19 AU (28735945482 m). Since the minimum distance between Earth and Venus is 0.28 AU (4.159e+10 m), one would already be over the half-way point! That means to arrive at Venus one would have to slow down with more than 1g for a shorter time (probably something like 8-10 hours at 1.5g)! By that mark, the author's descriptions are plausible (the book mentioned "somewhat" favorable conditions, not maximally favorable conditions ). However, I feel like this is way too simplistic an idea. How do I _properly_ calculate this situation? R code used to calculate stuff: Note: I'm obviously considering Newtonian physics. These speeds are way too slow for relativistic effect to show up, so I won't go to the hassle of calculating stuff at the relativistic level ;-) > g <- 9.81 # 1g is roughly 9.81m/s^2 > twelveh <- 12*24*60 # 12 in seconds > speed_at_12h <- g*twelveh # speed after 12 hours of constant acceleration > distance_at_12h <- speed_at_12h^2 # distance is the integral value of speed. for speed = ax --> distance = ax^2 > venus_orbit <- 108e9 # value from wikipedia. 108 million km. This here is in meters > earth_orbit <- 149.59e9 # again from wikipedia. 149.59 million km. This here is in meters again > distance_to_cross <- earth_orbit - venus_orbit # distance Earth<-->Venus at sygyzy > distance_left_12h <- distance_to_cross - distance_at_12h > print(distance_at_12h) # in m [1] 28735945482 > print(distance_to_cross) # in m [1] 4.159e+10 > print(speed_at_12h) # in m/s [1] 169516.8

I send my Munar Orbital Habitation Module (MOHM) in orbit around the Mun. Nearly ran out of fuel, but just made it to a nice orbit at the edge of the Mun's SOI. MOHM is going to be a part of a bigger Munar space station. After that, I send a robotic flyby mission to Mimmus in anticipation of some bigger missions. The Mimmus Flyby and Return Mission (MiFaRM) managed to make a flyby of the Mun as well on the return trip, before plunging back to Kerbin. Earlier this week I relieved Bob from his 6-year duty circling around Kerbin in a highly inclined orbit. It was becoming a bit boring for him, and his request for de-orbit was granted. After that, he became a test pilot for the space plane program. Sadly, he got killed doing this job. RIP Bob Kerman.

For the first time, I docked some modules to my space station I launched yesterday. My first attempt was a very small unmanned probe. The second module was a science lab. Both were successful on first try! The unmanned probe approaching Almost there! There we are! My science lab en route It's bigger than the entire station lol Tadaaaa!

I launched my first station module today! I know it's not much of an achievement, but it's something! Now I'm attempting to dock another module.

Ah, that sounds exactly what I'm looking for! Awesome! Thanks! :-)

I get that, but how do I calculate when the launch window gets nearby? I assume orbits of planets are rather fixed, so couldn't one calculate when (and at what angle) Hohmann transfer orbit-style launch windows appear? Or is this wishful thinking on my behalf?

Hello! Hailing from Netherlands, Europe, Earth, Solar System, Galaxy, Local Group, Virgo Supercluster! I've recently bought KSP and I absolutely love it! Best game purchase ever.... I have one question though: how I do plan efficient interplanetary trips? I have successfully landed at Duna, but it took me 2.5 years to get there. That seems a bit redundantly long (especially considering Earth-Mars trips take about 6-18 months, and Mars is far further from Earth than Duna is from Kerbin). I know this is probably a rather basic question, so sorry in advance when this has already been answered countless times! Thanks a lot, and happy to meet y'all! Sndrtj.