Zeiss Ikon

Are you sure that's not a Dalek?

Yesterday, Jeb took VIP tourist Lugard to land on the Mun. Yes, it was only the second landing ever (in that career), and the first flight of the newly redesigned lander (which still had far too much descent stage fuel), but Lugard waved so much prestige and so many funds under Gene's nose, it was hard to say no. The flight was pretty routine, though the lander is still too tall, with the hazard of tipping it over. But you have to say this for Jeb. Only he could leave the descent stage upside down at the landing site. BTW, I don't know how to display it, but the plaque on this flag reads "if you don't see a descent stage somewhere around here, please notify the authorities." Would have been funnier if I'd done a biome hop.

The D-21 drone was essentially a baby SR-71 mounted on top of the aircraft -- it had a single central engine similar to (albeit smaller than) the J-57 turbo-ramjets that powered the SR-71. The drone launch was intended to have the D-21 start its engine and bring it to full thrust before decoupling and climbing away from the parent aircraft. Doing this inside a supersonic shock structure is inherently dangerous, no question -- it'd be like launching a Space Shuttle from the back of a 747 by starting the main engines (we'll assume tankage inside the payload bay), and look how well that worked in Moonraker. Based on the account I've read, the D-21 was unstable when it decoupled, likely due to shock wave interactions between its nose or wing and the top deck of the SR-71. Launching essentially a missile, even from a dorsal hardpoint like the one the D-21 used, is far safer. All you do is put the SR-71 into a mild negative G maneuver, and hit the launch switch, which decouples the rocket and starts a time delay (during which the rocket will pass out of the SR-71's shock wave structure), after which the engine ignites. There's enough air at 22 km to support the SR-71, so there ought to be enough for the rocket's fins to stabilize it at Mach 3. If you use a belly hardpoint (no, the SR-71 never had one, but we'd probably have to build a few new ones to make launching from them a going concern), like a conventional missile launcher, it's better still -- the missile falls away from the hardpoint, then ignites, just like a Phoenix or AAMRAM. My understanding is that there is no Russian aircraft that's "almost as fast" as the SR-71. The fastest one I'm aware of is roundly 2/3 the Blackbird's top speed, at a couple kilometers lower level flight ceiling.

If you could launch a rocket in that class from an SR-71 flying at near maximum altitude and speed, it might have a chance of reaching a once-around orbit (Pe would dip back into atmosphere, without some means to circularize). Then again, a once-around is all the Japanese brewery wants from this; they're after "space traveled" yeast to brew with. Assuming the SR-71 flies at 1.1 km/s above 97% of the atmosphere (published operational altitude appr. 22 km), you're 13% of the way to orbit and have almost no air drag to deal with. You essentially just need a dV of about 6.9 to 7.2 km/s in your vehicle. Additionally, you can launch with a nozzle optimized for .03 bar and get much better Isp than launching with a sea level nozzle. Too bad the SR-71s are all in museums, now.

Based on the photos of the parts and description of the cycle, that appears to be a uniflow type hot gas expander running on the hydrazine decomposition gas. The engine itself would (with suitable changes in seal materials) run on compressed air, steam, external combustion of fuel and oxidizer, or any monopropellant you like. Hydrazine has the advantage of being long-term storable (disadvantages are short catalyst operating life, high toxicity, and only so-so energy content -- peroxide would be a better choice, but it decomposes in storage over long periods, such as a Mars transfer). Uniflow engines are simple (the piston directly actuates the inlet valve, exhaust is through a port similar to a 2-stroke gasoline engine), light, and powerful compared to conventional valved single- and double-acting steam engines. In terms of familiar devices, this engine operated the same way as the air engine from an Airhogs toy aircraft, or one of the "two stroke to steam engine" conversions you can find all over YouTube. Such an engine is not self-starting, and the test operation must have involved hazmat suits, because the person starting the engine would have been exposed to hydrazine vapors (unless they used an onboard starter that I missed in quick-scanning the article).

This goes back to the jet engine on Titan using an oxidizer in the fuel tanks. Yes, if and only if the atmosphere is a reducing one, that is, hydrogen or hydrocarbon vapor, at least in significant fraction. Compress this, inject your oxidizer, add a little spark, and use a turbine to extract enough energy to run the compressor (and a bypass fan if you want still more efficiency at mostly subsonic speeds). if you mean a bipropellant engine, then no way, no how. The best "efficiency" you can possibly get from a bipropellant rocket would require an exotic fuel/oxidizer compound (I don't recall if it's flourine/hydrogen, or oxygen triflouride/acetylene -- the latter is surely hotter burning, but requires unobtainium containment and plumbing since chemical glassware will spontaneously ignite in oxygen triflouride, and the combustion temperature is prone to melting the combustion chamber). However, no exotic is enough better than hydrolox to be worth the trouble, and in terms of system efficiency (which is the real measure for things like what it costs to launch a payload, and what it costs per kilometer for a winged cargo carrier), it's very hard to beat kerosene/LOX, or if you need better storability, kerosene/nitrous oxide or kerosene/HTP (high test peroxide). None of those bipropellant systems has an Isp that even approaches the efficiency of a no-bypass turbojet, which is just about the least efficient form of gas turbine propulsion. The peak of chemical bipropellant systems is below 400 seconds, while it's pretty easy to build a turbofan that will exceed 10,000 seconds (by ignoring the mass of oxidizer/remass it takes from the atmosphere, and calculating using only the fuel).

There are also a couple tricks you can apply earlier in the process (though if you do an excellent job of setting up your intercept as @Kosmo-not demonstrated, you may not need this). When you're tens of kilometers from target and have closing velocity up to tens of meters per seconds, but your velocity vector isn't quite aligned with the target, you can use the nav ball to determine the direction you need to burn to correct your closing vector -- and then use the main engines for these relatively large burns to save your monopropellant. You need to remember that when your velocity display is in target mode, the prograde marker is your "toward target" velocity vector (and retrograde, of course, is "away from target" velocity vector). You also have the pink markers, indicating actual direction to and away from target. If the yellow prograde and pink "to target" markers are aligned, you're closing directly; if not, you're going to pass by at some distance. You can only fly these when you're close enough that orbital mechanics have little effect, but tens of kilometers is about right in LKO. The technique, as I learned it (from Scott Manley, IIRC) is to offset your heading from the "to target" marker, opposite direction from the prograde marker if you want to burn toward the target and improve your close approach, or offset your heading from the retrograde marker opposite the "from target" marker make a braking burn while also correcting your approach. Try it in flight, it's very easy to do once you have the idea.

He appears to have fallen out of the headline cycle. He may or may not be back when he has the necessary permissions in hand to actually launch -- or he may have gotten what he wanted (attention) and crawled back into his hole limo.

I started just over a year ago by downloading the demo, which has, um, pretty limited parts choices. Liquid fuel engine, a Swivel, as I recall; FL-T200 tanks only. I Google a bit for how to get to orbit in Demo -- followed directions. Three engines on launch, staged down to one after a bit, go vertical until 15 km then turn 45 degrees east (had to figure out that was D for yaw, rather than S or W for pitch -- which, IMO, would have and still would make more sense), then follow prograde after it comes down to the heading marker; boost until your Pe lifts out of the atmosphere. Demo has pre-1.0 atmosphere, it seems. After flying that, I bought the game. Now, with low tech starting parts, it's a Jumping Flea (though in my current career I had to design my own from ground up -- i turned off the prebuilt craft when I set it up, not fully intentional but it worked out pretty well). Flea booster with three basic fins, Mk. 1 pod, Mk. 16 parachute, and as much science as I can strap on. A quick turn eastward off the pad (don't do it quick, you won't do it at all; even three basic fins will totally overcome your reaction wheel by the time you're up to 100 m/s, which happens PDQ) ensures a water landing, so the high-ish descent speed doesn't break stuff.

One might say the same of some human chess grandmasters. Especially the part involving friends, pictures, and guitars...

A while back (in this thread, I think) I calculated that a 10 mm round would push 100 kg of shooter and space suit around .05 m/s. Coincidentally, the 7.62x39 round has a similar momentum -- instead of a 180 grain bullet at 1600 ft/s, it's a 100 grain bullet at around 2300 ft/s. You'll get a little more rocket effect from the gas with the AK (due to higher pressure when the bullet leaves the bore) than with the 10 mm pistol, but that's hard to quantify. So, you, rifle, and office chair mass (not surprisingly) close to 100 kg. You fire one round, and get pushed to a speed of 2-3 inches (.05 to .08 m) per second, and if the floor is very smooth and level, and the chair's casters in exceptionally good condition, you'll move a few inches. Of course, if you unload a whole 20 round magazine as rapidly as the (USA minimum hassle) semi-auto mechanism will function, you ought to be able to get up to around 1.5 m/s -- about average walking speed -- and that would let you coast (very roughly) five or ten meters before friction brings you to a stop. Edit: I'm not a Kalashnikov expert. If it's a 30 round magazine, you'll get 50% more velocity. Hope those casters are in good shape and that floor's clean -- if a caster hits a piece of junk that acts like a wheel chock while you're rolling at 2+ m/s, you might take a tumble. Fortunately, the rifle you're carrying will have an empty magazine by that time.

That (including bringing enough fuel to direct or park thousands of tonnes of rock) is exactly what you're doing if you intercept an asteroid that's blundered into Kerbin's SOI. Unless it's temporarily captured by a Mun encounter, any asteroid that comes from outside Kerbin's SOI is on an escape trajectory (though the game sometimes incorrectly reports them as "orbiting Kerbin" with an apoapsis above the SOI limit).

There's an understatement. In my science game (which I haven't opened in a while), I captured a 998 T asteroid, parked it in Kerbin orbit (eccentric and inclined, but inside the Mun's orbit), launched a drill/refinery and some tanks to it -- and sucked it dry in about 100 days, without even filling the empty tanks I'd sent to it (four oranges and a couple adapter tanks). Not sure whether that was because the drill and fuel converter were running on fuel cells at first (the fuel I obtained provided the energy to mine and convert the ore, as well as filling the tanks), or 83% ore in under 1000 T is just that little...

Oh, great. Something else to shop for. Please, at least tell me KSP has setup options to use a joystick for, say, pitch and roll. I can handle throttle the way KSP does it, and to be honest I don't use rudder much except when taxiing (unless you're trying to keep from making the back seat passengers airsick, it's far simpler to bank more and pull elevator to keep the nose close to the horizon than to try to coordinate a turn when you don't have a turn-and-bank).

Sigh. Observer bias sucks. In fact, there was never an improvement in the game performance, other than flying the Aeris A4 in an otherwise clean sandbox, with no flights in progress and no (or almost no) debris in orbit. And after a seeming misstep on Friday evening, attempting to switch between hybrid graphics software (bumblebee to nVidia Prime and back), I managed to do something to my Ubuntu that killed both mouse and keyboard response at the login screen. I spent most of the weekend reinstalling Ubuntu (took a half hour) and getting all my customization back in place (took most of two days). No data lost; my /home folder was untouched and once I had all the applications reinstalled I was actually able to rename the old user home (which I'd renamed, so as to reuse the same login) back to my login name and get the last few details straight. Unfortunately, it appears I have a relative rarity -- a Thinkpad T430 that was sold with an i7 processor, but only 320 GB hard disk and no dedicated GPU (someone needed CPU, but when cheap on graphics and HDD space). So, whatever I'm getting for performance now is what I'm going to get. It's not bad; in fact, even with only the Intel graphics, it's still similar, if not slightly better than what I get with my desktop machine, which has an nVidia GTx750 (and similar clock speed, but in a Core2Quad instead of i7). A little bit of a letdown, though, after reading the page that showed the only i7 model as having the nVidia GPU. I guess I'll have to wait until I can upgrade the MB/CPU/RAM in my desktop machine to really see improved performance. I'm hoping I can afford an i5 or i7 with a clock speed above 3.5 GHz. That and at least 16 GB RAM, with the GTx750 and my SSD, should help a good bit...

I must have gotten this game on exactly the right day -- I paid $13.95 direct from the KSP web page (no Steam involved, thank you). I was deeply gratified that it's native in Linux (I don't have to use Wine to make it mostly run), and it's the only game I've ever seen that makes a playable game out of orbital mechanics and spacecraft design. I have very limited play time per week, these days (an hour each way commute, driving myself, doesn't contribute to playing anything a lot), but the only other game I've got more hours into is an MMO that I've been playing for fourteen years, called There -- and much of that time, I've been paying $10/mo plus an occasional outlay for in-world money to spend on virtual doodads and pay rent on my virtual house. I've easy dropped over $1000 in There over the years -- and the software was a free download back in 2004. And in There, I can't set up a transfer orbit, I just get to drive a dune buggy or pilot a hoverboat... Neither one of which works as well since I switched to Linux; it's a Windows client only, and it only almost fully works under Wine.

Wire recording was, of necessity, monaural. There was never a way to keep a wire aligned so as to put two audio tracks on it, and a dual-wire system would be impractical (twists and desynchronization as the wires stretched or broke and were spliced). As a result, it was also possible to accidentally play a wire backward, as there was no simple way to tell the beginning from the end (there was a generic takeup spool on the machines, but if you have a wire on the same kind of spool, you have no way to know if it just didn't get rewound). Some of these issues would be solved by emulating the earliest video recording technology, which used a metal ribbon (very hazardous to be around -- the fast-moving ribbon would slice like a razor blade if it came off the spools or slots, and moved fast enough that unspooling was a real issue). Aside from loss of stereo separation (most like you'd mix everything down to mono during re-recording), you'd wind up with an LP or CD replaced by a wire spool about the size of a large roll of electrical tape. That was the one hour size, though some older LPs would fit on a half hour spool, and a few maximum length CDs wouldn't quite fit on the one hour size. A "single," needing only about five minutes of wire, would fit on a spool hardly bigger than an old style silver dollar (roughly twice the diameter and half again as thick as a modern golden dollar), if a little thicker. The wire was somewhat fragile (because very thin and made of soft steel, so it would accept magnetization easily); it could break during either recording or playback. Splicing was tricky, and produced a very audible "bump" in the recording, as the twisted splice ran over the playback head and the magnetized wire got closer and further from the head as the splice passed. Both record and playback heads were subject to significant wear as the steel wire slid over the head surface -- I don't know what their working life was, but it can't have been comparable to that of a magnetic tape recorder/player, where there's a very thin, very smooth overcoat protecting the heads from the metal oxide (or, in a few ultra-premium tapes, sputtered metal) recording material. An afternoon in the sun, on a car dashboard or similar, wouldn't harm a wire recording at all (unlike vinyl records, plastic cassette shells, or CD cases and disks; wire spools were usually stored in card stock boxes), but one would have to take care to store them in dry conditions, so the wire wouldn't rust. Rust on the wire wouldn't have much immediate effect on the recorded sound (the rust is magnetic, too, and should pick up the field from the parent metal as it forms), but iron oxide is abrasive, so would further accelerate wear on the recording and playback heads.

Given that those (huge) lava tubes have the same kind of conditions that have led to ice accumulation in the sunless craters of the south polar region (i.e. never seen the sun since the rock solidified), they have similar likelihood of having collected ice. I'd say that makes them target number one -- check for ice, verify conditions in which we might build a base or colony inside one (radiation and meteorite shielding already constructed for us, if it has ice as well, it's got most of the hard work already done).

This trio of changes to the way I fly, combined with designs that match what I already knew from building model airplanes, have done wonders for my own spaceplane flying, too. Now I just need to get more science, so I can research better engines (Panthers and Whiplash, if not R.A.P.I.E.R.). I flew the Aeris A4 from the stock game's prebuilt library, and it was like it *wanted* to go into orbit. Just climb gently until the Whiplashes start to lose thrust, then ignite the Dart aerospike, and after the Whiplashes flame out (around 20-25 km) fly it just like a vertical-launch rocket -- follow prograde to get apogee above atmosphere, shut down, and set up a circularizing maneuver. Easy peasy!

Now that "billion years" Elon spoke of makes a lot more sense. His car is going to wind up on an orbit that avoids the main Asteroid Belt, crosses the orbits of Earth and Mars -- and if it doesn't wind up with too close an encounter with one or the other (possible, after the Mars encounter), and doesn't collide with some random rock, it might still be not just recoverable, but restorable whenever someone finds it worth his time and delta-V to go retrieve it.

I can assure you, I have it in both of my sandbox games (1.2.2 and 1.3.0). It's in the "hypersonic flight" node, about 1/3 of the way down from the top, at the next to last science cost level. The icon looks like a top view of a Space Shuttle.

As I recall, the actual music on the Voyager disks was analog, and video data encoded in analog form. The package even included a phonograph cartridge, to ensure the aliens would have a suitable reproduction device (turning the record at the correct angular rate, encoded on the package, and electronic processing of the signal output from the cartridge was left as an exercise). I wonder if there was any thought given to correct pre-amp characteristics? Some years ago, I hooked up my magnetic-cartridge turntable directly to the microphone jack on my sound card (because, with no pre-amp in the turntable, the signal wasn't strong enough for line-in), and the resulting music was extremely tinny. Turns out vinyl disks (at least in the post-1970 stereo era) were equalized to compensate for pre-amp response curves that heavily favored bass. I was later able to apply a digital filter to weaken the high frequencies, in emulation of a suitable pre-amp, but that music was painful to listen to before then.

All the world's computers combined? Well, let's see -- equivalent to a fast Core2Duo, say 2+ GHz, or (as noted previously) around 27,000 mips. Honestly, there was probably more mainframe capacity than that in just the United States before 1980. Banks had gone heavily into computers starting as early as the 1970s. Of course, there were the mainframes at NASA, NOAA, and heaven only knows what the CIA and NSA had then -- but I'd bet it was at least equal to NASA. Every university of consequence had a mainframe or two. When I took Fortran in 1979-1980, we had an IBM 360 and there was an Amdahl 470 at the neighboring school eight miles (13 km) away -- and I was at University of Idaho. So, even if we ignore the mini-computers and early micros (there were never that many of the latter anyway), US installed mainframes alone likely exceeded the required mips count and RAM size for minimum KSP by 1980.

I found some instructions on how to enable the nVidia GPU in my laptop, and it seems to make a big difference. I opened my sandbox save, picked an Aeris A4 out of the prebuilt craft, and launched it to orbit with not much yellow clock and much less intrusive freezes (I'm now more sure those are garbage collection). Still working on getting things optimized with either Prime or Bumblebee (Ubuntu 16.04 isn't fully up to speed with hybrid graphics, it seems), but this seems likely to help a great deal.

I'm virtually certain my T430 doesn' t have Thunderbolt 3. It does have USB 3.0, and an ExpressCard 34. However, I was just looking at the specs, and the i7 version of the T430 is supposed to have nVidia graphics with Optimus. Now I have to go find out how to determine if that's actually the case -- as I understand it, if Optimus has the nVidia turned off, it looks like there isn't one (which is what I'm seeing with the commands I know to check hardware).