Zeiss Ikon

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About Zeiss Ikon

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    Spacecraft Engineer
  1. I didn't find rendezvous "in orbit around the sun" any harder than rendezvous in LKO, just a lot slower (and I've done it a total of once, if you don't count a Duna flyby with gravity assist return). Took almost a quarter year to meet the asteroid I was hunting, and I got a low-velocity intersection on the first orbit -- IOW, it could have been MUCH longer. The problem is, if you accidentally gravity assisted of Mun into interplanetary space, the ship that went out probably had a pretty high velocity -- that means you need an even higher velocity to catch up quickly (or a lower intersecting orbit if you're willing to wait years), then something like twice that velocity in dV to get home again. This isn't hard, at least if you can rendezvous and dock in Kerbin orbit -- it just takes a lot of game time, and requires a ship with very long legs.
  2. That's not hibernation. They consume the same resources as if they were bouncing and zooming around the house, they just do it quietly.
  3. Permeability was mentioned above. Recall that graphene(s) are basically chicken wire made from carbon -- there's a hole in each hexagon big enough to pass, not just hydrogen, but water molecules (it's been proposed as an osmotic filter with no modifications). So, you have to come up with a way to plug the holes, else your hydrogen will permeate the graphene (and this is almost certainly bad for graphene, as thermal energy will tend to allow conversion into various chain lengths of alkane hydrocarbons -- i.e. your tank liner will tend to "magically" transform into gasoline or kerosene).
  4. I modified my previous "Rocket-only" entry for the Stock Payload Fraction Challenge, and flew an SSTO in "Rocket-only Recovery" -- which requires recovering all parts of the rocket other than payload. Spam parachutes and provide landing legs (in case of dry land recovery), add a probe core and a big enough battery to keep it running until after parachute and landing leg deployment, and the same booster can launch the same payload (for a slightly lower payload fraction, because the recovery parts add mass to the booster). Note: only works if the original SSTO was arriving in orbit with at least a little fuel left -- some to account for the added mass of recovery parts, and some to deorbit (though a 40 km periapsis from a 100 km orbit doesn't take much of a burn). As it turns out, deorbit only used about half the fuel seen here, leaving a little burst of thrust for use during reentry if/as needed.
  5. Well, given that my previous (SSTO) rocket-only entry had a little fuel left in the booster when it reached orbit, I reasoned that it ought to be possible to add the parts needed to recover the booster and still launch the same payload. Only one way to be sure, right? I used the exact same payload -- 1.25 m tanks to hold 2000 units of LF/O, inline Clamp-o-Tron, 1.25 m inline monopropellant tank, 1.25 m probe core, 2 fuel cells, 1.25 m decoupler, heat shield, Mk. 1 Command Pod, Mk. 16 parachute -- but I removed two RCS quads from the command pod, bringing the total to ten. The only changes I made to the booster were addition of (after several reduced fuel test flights) nine Mk. 2 Radial Parachutes, six on the Twin Boar's integral tank, and three on the forward tank and fuel adapter, and three pairs of the medium size landing legs, plus another 1.25 m probe core and a battery to keep the probe core operating after decoupling from the payload (and its fuel cells). The parachutes and landing legs were set up to land the booster horizontally. Here's the .craft file. Payload weight changed little if at all: The booster (hence GLOW) gained a little -- parachutes and landing legs aren't massless, more's the pity. Don't forget to subtract the weight of the launch clamps, which won't be leaving the pad. As previously, Jeb was selected to fly this mission; the expected optimum launch profile was virtually identical to that of the original entry, and he'd flown that. Here's the vessel on the pad. And here it's coasting toward apoapsis and the circularizing burn. Circularizing wasn't perfect, the vessel wound up with apo just above 105 km, and peri just below 100, but tweaking the final orbit with RCS on the payload is within the rules, so Jeb didn't burn more LF/O to improve the orbit. The correction maneuver required only 10 units of monopropellant (around 6 m/s). And here we see the final payload orbit, well within tolerance after correction. With the payload in the required orbit, it's time to think about recovering the booster (no other parts to worry about for the moment). Even after the payload's orbit correction, the booster is still pretty nearby. One nice thing about reentering from a low orbit -- if you pick a fairly high peri, the heat load isn't too high; engine bells can take it easily and the weight of the engines keeps the rest of the craft in the heat shadow well enough. Ground control burned the last whisper of fuel trying to get a landing on the desert continent (having failed to adquately compensate for Kerbin's rotation in setting the deorbit burn, hence reentering too far west to be close to KSC), but overshot and the booster landed in the sea. The landing legs weren't needed, so weren't extended. Nothing fell off, broke up, or exploded on splashdown (previous low altitude test flights had shown that this booster lands without damage on reasonably level land, so I wasn't much concerned about a water landing). And this was, of course, the only stage to recover from an SSTO launch. Here's the payload, still in its designated orbit. Eventually, Jeb detached the command pod, deorbited (using only about 60% of the pod's RCS fuel for the 56 m/s burn), and returned to Kerbin, leaving the fuel tank in orbit, ready to refuel a future mission Payload mass was 14.59 t; GLOW was 117.315 t (minus .2 t for the launch clamps), for a presumed score of 8.03 (rounded, exact is 8.0271) in rocket-only recovery. Not huge, but there's no SSTO rocket category...
  6. First sentence of the linked Wikipedia article: "Clathrate hydrates, or gas clathrates, gas hydrates, clathrates, hydrates, etc., are crystalline water-based solids physically resembling ice, in which small non-polar molecules (typically gases) or polar molecules with large hydrophobic moieties are trapped inside "cages" of hydrogen bonded, frozen water molecules." That's a solid, not a gas. And unless the trapped gas molecules increase the density significantly above that of ice, it'll float, not sink.
  7. I've done bi-elliptic reversals around Minmus -- orbital velocity is so low it's easy. Pretty small burn to raise apoapsis near the edge of the SOI, then a pretty small burn to reverse the orbit, and another pretty small burn to circularize. I've also done it with Kerbin orbit, when I was trying to intercept an asteroid during the rock's encounter -- again, with a highly eccentric orbit that peaks beyond Minmus, the velocity is so low at apoapsis that it takes little dV to reverse the orbit. Others have explained pretty well that the upper limit for the dV you can get from a planet gravity assist is no more than twice the planet's escape velocity; in practice, you can't get even that much. Now, if you were to add an Oberth-enhanced maneuver at a very low periapsis, your combined dV total could be close to twice escape velocity plus several times the actual maneuver dV, but possible ejection angles from this kind of maneuver rule out the 180 degree turn the OP illustration seems to be looking for.
  8. As far as I know, there's no gas that's denser than liquid water at any pressure (not even supercritical CO2 -- though you might see if you can find a phase diagram with densities that covers supercritical radon). There are "pools" at the bottom of Earth's ocean, in many locations, formed of water with increased density due to something dissolved (either hypersaline, or sea water with hydrogen sulfide, generally). Even if you had a "gas" in pools below an ocean, it would behave like a liquid -- the density would mean you'd float in it, even more so than in water, and while its compressibility might cause some odd behaviors, you'd be at the limits of pressure tolerance for even remotely piloted machines to explore it...
  9. Worth noting that some Chromebooks are 32-bit hardware, even as recently as a couple years ago -- perfectly capable of running minimal KSP (most of those have 2 GB RAM and some are expandable to 4 GB), but 32-bit controller chipsets even if the CPU is 64-bit capable.
  10. As I understand it, there were serious bug issues with the 64-bit Windows version until 1.2.2 came out -- which might make Windows users a little wary of the 64-bit version.
  11. Unless, like this Linux player, you see no reason to even bother with the 32-bit version.
  12. My proudest moment has to have been Val's last asteroid mission. After three attempts to rendezvous with an asteroid during its Kerbin encounter, she (I) decided to venture out of Kerbin's Sphere of Influence (only my second time since I downloaded KSP). Rendezvoused with the (more or less randomly chosen) asteroid in Kerbol orbit -- and found it massed 968 t. Even so, flying with chemical rockets only, she pushed it into a Kerbin encounter, then successfully captured it into Kerbin orbit (high, pretty eccentric, but stable as long as someone gave it a little polish before it could encounter Mun -- there's only so much dV in 3 1/2 orange tanks). Not only did I (Val) successfully redirect and capture an asteroid on the first successful rendezvous, but the asteroid seems to be about 83% ore; it will soon become Fuel Station Valentina, and serve as a jumping off point for missions to Duna, Eve, and Dres, at a minimum. I still need to get the science to research drills and converters, but that's just a matter of more missions to more places.
  13. Another version of Jebediah has managed to fly all the way from Gilly back to Kerbin on just his EVA jets. Of course, that was when you could still reenter a Kerbal in his space suit, and they just had to land on their heads to bounce instead of exploding...
  14. Hence the linear accelerator launcher. Of course, if you're going to build one of those, a pretty small upgrade in G limits would let you launch direct to LEO, at least, needing only a circularizing motor (a few hundred m/s?) along with the payload. Payload fraction (as launched) 80%? Run the rail from Cartagena to a suitable peak in the northern Andes, and you could launch at less than 5 G even direct to orbit (possibly as low as 3 G). You could probably run the thing on hydro and wind power, without even the need for a fission power plant. Think of it as Musk's Hyperloop with a set of partial pressure doors at one end. Doors, say a couple dozen a couple miles apart, open sequentially as the vehicle approaches, but never enough open at once to significantly repressurize the tube, and you'd use a conventional two-gate airlock to load the vehicle at the bottom end.
  15. I do the same -- but there's not a docking port on the command pod here, so the only thing you'll be doing after staging the pod off the tank is deorbiting; there's not enough fuel here to get a much higher orbit (sure, you could probably kick it up another 100 km with the RCS on the tank, not to mention the whisper of LF/O left in the booster, but why would you bother unless you're on a rescue mission?). Beside, go much higher and you'll have a hard time getting the pod back without burning up.