Zeiss Ikon

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About Zeiss Ikon

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  1. Still, I, too, remember Cronkite talking about the too-shallow reentry as if it was a one-way trip to Earth escape. Fifty years later, it occurs to me that Walter was a reporter, and probably knew next to nothing about physics and orbital mechanics...
  2. Did I mention Linux and Ubuntu aren't themselves a hobby for me, never mind a job? I have no idea what llvm and debootstrap are or are good for. I use Linux mainly because it isn't Microsoft or Apple...
  3. Seems as if even upgrading to 18.04 wouldn't help me; I searched for libc++-8-dev and found it only in Ubuntu 19.04. I am NOT going to jump on the "upgrade every six months" train. Sad that the need for "useful features" pushes the entire mod out of the "Linux is just an OS, not a hobby in itself" world. Maybe, instead of upgrading Ubuntu, I need to look at Debian based rolling distros...
  4. Thanks. I was afraid of that. Clearly there's a strong bias in the Linux community in favor of those who upgrade everything at the earliest opportunity, vs. those who ride the old as long as possible to avoid having to spend their work/play time fighting bugs and learning a new system only to have it change again (figuratively) the next week. If you jumped off 16.04 in mid-2017, it had to be to 16.10, 17.04, or pre-release builds of 17.10, and as you say, it's anyone's guess whether stuff made to run on that would work on 16.04. I'll grab the binary you pointed to and see if it'll work. Thanks for the help! EDIT: Followup, not surprisingly, Principia Euclid (seemingly built under Ubuntu 16.10 or 17.04) caused my 1.6.1 RSS/RO/RP-1 game install to fail to start on Ubuntu 16.04. The library versions cited above are those for 19.04. I'd suggest that at the least, it might be more user friendly to keep support for LTS versions, at least until the next LTS comes out. At present, it appears that one must keep up to the latest non-LTS releases of Ubuntu in order to keep the most current Principia as recommended by the devs. Worth noting that the game itself seems to work in all supported versions of Ubuntu -- evidenced by the fact it works fine in 16.04, which is the oldest currently supported version. FURTHER EDIT: If I had the faintest idea how to build a complex program like this, I'd try building it myself to see if that fixes the version dependency -- but I don't know in detail how to do that.
  5. I'm a KSP Linux player, currently using Ubuntu 16.04. I recently installed RSS/RO for KSP 1.6.1 (previously I'd been playing RSS/RO 1.3.1 for several months without ever updating my Principia, then didn't play KSP for most of a year). I found I couldn't use Principia because it needs library versions that are only available in Ubuntu 18.04 and newer. Because I'm trying to hold out for Ubuntu 20.04 before I "upgrade" (because, with the amount of "tainted" software I run, it's "install clean, taking a whole weekend for each machine" instead of just running an upgrader), I seem to have two options. One, I can try to find a way to upgrade just those libraries, but that's likely to break major things in my Ubuntu and render my install non-functional (requiring me, at a minimum, to restore the old versions via command line, potentially via a Live thumb drive). Two, I can try to install an older version of Principia -- but I don't see that older binaries are available. I'm looking for the oldest version that supports 1.6.1, in the hope that it won't require libraries newer than my 16.04 Ubuntu. Three, if I can install the necessary libraries for only Principia, I'll be good to go for another several months, at least. The libraries in question are libc++ and libc++abi. I can download just the binaries for those libraries -- would Principia find them successfully if I place them inside the Principia folder?
  6. I present, I'm using 1.6.1 -- but that's with 74 mods installed for Realism Overhaul. As @VoidSquid noted, you'll probably want to check the supported versions for the mods you need/want. I don't have all the mods you want installed (i don't recognize the ASET one), but parts packs and procedural parts that support (some) sounding rockets are part of a 1.6.1 RO install, as are Deadly Reentry and RSSVE (the Real Solar System version of EVE). There may be other parts packs that would support more modern solid fuel sounding rockets. The Black Brant family are all solids, for instance, and there are/were a bunch of other sounding rockets with solid fuel motors -- RP-1 starts you with the WAC Corporal specifically because it was liquid fueled, one of the first high-flying liquid fueled rockets, and direct ancestor to engines still in use today (AJ10 series were developed from the WAC Corporal engine).
  7. Milestones. "First" anything pays better than any of those routine contracts. "First probe flyby of the Mun" or "First crewed flyby of Duna" etc. These "first" events, if you load your craft right, also tend to generate big bunches of science, which advances your careeer into improved tech that gives you access to even further milestones. More generally, with the skills and experience you have now, you ought to be able to estimate fairly well what a vessel will cost to accomplish a given contract, so don't take contracts that won't produce significant profit -- or set things up to complete multiple contracts on a single launch. Got four tourist on one contract who want to fly by the Mun, one of them wants to land, and three on another who want to land on the Mun and fly by Minmus? Launch one vessel that can both fly by Minmus and land on the Mun, and carry seven passengers plus crew, plus (assuming there are still biomes you haven't tapped out for science) science instruments. Considering that a gravity assist from Minmus to the Mun is almost free compared to just going to Minmus, the only upgrade you need compared to a minimum craft to do the Minmus flyby is enough dV to land on the Mun and get back to Munar orbit, around 1100+ m/s, plus the pittance (a couple hundred?) you'll need to capture into Mun orbit after the transfer from Minmus.
  8. Kind of an ambiguous question. I spend more total time on rockets, but I don't build or fly many aircraft. I can build a rocket, pod to clamps, in a half hour, unless I'm having to scrape for that last m/s, but I usually need several hours to get an airplane that will fly stably. Of course, this is with FAR in RO...
  9. The kerfluffle over the EM drive was based on claims that it had more thrust than could be accounted for by its radiation, i.e. It was violating conservation laws. That now appears not to be the case; instead, the inventors fooled themselves by failing to eliminate confounding factors in their tests. It's emission, BTW, is heat/IR, not microwaves, which are efficiently trapped by the truncated come enclosure.
  10. I think you forgot to divide by the square of the speed of light, a factor of about 9e16...
  11. Yes. Damned little, though. You can calculate the thrust due to light by using the mass equivalent of the emitted energy and lightspeed as your exhaust velocity. End result is you get a non-zero thrust from any light source (if it's directional), but it's very, very small.
  12. That would explain most of what you're seeing -- no orbit ellipse for Crisdon, inability to get a target lock. "Debris" might be because the game decided (s)he was below the surface and crashed, but won't actually show the craft as destroyed until you're within physics range. The "last seen on" and size class, however, are typical of an asteroid. I supposed the game getting confused with Crisdon being inside the Moon might do something weird like that, but I think it's very unlikely you'll be able to make this rescue. Mine all you like, you can't dig actual holes in the Moon (or the Mun).
  13. Now, that Bi-elliptic transfer @AHHans linked is very closely related to the cheapest way to make a large plane change: go way the heck out where your orbital velocity is very small, and you can make a 180 degree plane change for a very small amount of dV.
  14. To expand on @Signo's answer, hot staging is something you do because of ullage. It's manifestly unnecessary in the stock game -- stock engines and tanks don't care about ullage in any way. If you're playing Realism Overhaul, or pretty much anything using RealFuels and real world engine parts packs, you'll need to pay attention to ullage. "What's ullage?" Glad you asked. Ullage is the "empty space" in a propellant tank. There's always some; usually filled with some kind of pressurant (even pump-fed engines need pressure in the tanks, just not as much as pressure-fed engines). This can be bad if the pressurant winds up near the rear/bottom of the tank, where there should be propellant, when your engine needs fuel (or oxidizer). Let's say you launch a basic sounding rocket, like a WAC Corporal (1948 technology here, hang onto your hat). This is a primitive two-stage rocket, with a high thrust Tiny Tim booster (originally an air-to-ground unguided rocket from WWII). Your basic WAC Corporal stack will pull something like 30 G off the launch pad with this booster -- but the booster burns out after about 0.6 seconds, leaving you falling upward at roundly 200 m/s. If you now want to stage and ignite your (pressure fed, hypergolic liquids) upper stage sustainer, you'll find it doesn't work. EVER. Because the air drag at 200 m/s results in enough deceleration to immediately slosh all the propellants to the nose cone end of the tanks, and the nitrogen that's supposed to push the aniline/furfuryl fuel and red fuming nitric acid oxidizer into the thrust chamber instead runs straight out through the injectors. This is why ullage has to be managed. The WAC Corporal method, as of 1948, was to ignite the upper stage at the same time as the Tiny Tim, and time the staging decoupler to fire at the exact same time the Tiny Tim burned out. That gave the sustainer engine most of a second to come up to thrust, and ensured the booster wasn't hanging on creating drag that could (even with the sustainer fully ignited) lead to pressurant in the feed lines instead of propellants. Done this way, the WAC Corporal worked about 95% of the time, and would fly as high as about 120 km (less if it was carrying a payload, of course). And that's hot staging. As Signo noted, the Soviet space program used hot staging a lot -- it's the reason you see many of their rockets with open strutwork interstage structures, so that the next stage exhaust has an exit to prevent either choking the engine before it's fully ignited, or blowing out the interstage fairing with potential to lead to a structural collapse as maximum G load. By contrast, the American space program almost never used it (can't say for certain they never did, but I think that's true). Look at a Saturn V -- specifically at the base of the S-II second stage. It has (relatively) small solid propellant "ullage rockets" -- there to ensure there's a (small) positive acceleration after the staging event, so the ignition of the next stage can take place successfully. And there are no ullage rockets on the Service Module, because it was intended to fly in vacuum and needed RCS to point before a burn anyway, and RCS works just fine for ullage management. I think there are even Apollo recordings where the crew mentions the ullage burn start, several seconds before the burn to return from Lunar orbit to Earth. Ullage can be managed other ways, of course. One way (used often for things like attitude jets/RCS and long-term station keeping thrusters) is a bladder tank. This stores the fuel (usually a monopropellant, most commonly hydrazine or a derivative these days) inside a bladder, much like a water balloon inside the rigid tank structure; pressure is applied to the outside of the bladder, and the inside is carefully debubbled before launch, so that every time you open the valve, the propellant flows into the catalyst pack and turns into thrust. In the case of Voyager 2, even if the last time was thirty years ago. If you're launching from the ground (even if that "ground" is Lunar regolith), gravity (even if it's a fraction of a G) does an admirable job of managing your ullage. I don't know that it's actually been done in a rocket, but another possibility would be an aerospace version of what I learned to call a "clunk tank" when I was flying radio control models (before they were electric). This had the fuel pickup in a weight on the end of a flexible tube which would always find its way (with an audible "clunk" if you checked it on the ground with the engine stopped) to the current "bottom" of the tank. Works great when (as with an aerobatic model) you aren't sure where you local gravity will be any given moment; won't work any better than a fixed pickup in microgravity (so probably not very useful in actual rockets).
  15. A Kerbal stranded in her space suit shouldn't show as debris. Debris would normally be a spacecraft fragment, and when it's not showing an orbit ellipse, it may be "landed" on the surface of the Mun. The antenna on your ship only affects how far you can communicate back to Kerbin, it has nothing to do with targeting. Lack of targeting ability is likely due to not having upgraded your Tracking Station (or Mission Control, but I think it's Tracking Station in this case). To rendezvous with a Kerbal who likely has no EVA fuel left, without the ability to target the rescuee? You've got your work cut out for you. I don't know that I could do that, and I've done a bunch of rescue contracts in LKO and Munar orbit -- but never tried them before I had targeting ability.