Zeiss Ikon

I've done a Duna flyby with single launch, using a single Mk. 1 Command Pod and a transfer stage consisting of two orange tanks and a Mainsail. I don't recall what I had for a launcher under this, but I'm pretty sure it was a Mammoth engine -- possibly with some boosters added -- and did the job without an orbit insertion stage. The problem with a flyby with intent to return the crew is that you're guaranteed to have a bad transfer window, either from Kerbin or from Duna, so you need to be prepared for a multi-year mission duration (if you play stock, that's not a big deal, but a life support mod will really complicate this) -- and this ship barely had the dV to use a gravity assist from Duna to get back to Kerbin (and was fortunate that Ike stayed out of the way). I'd consider it pretty much the minimum crewed Duna mission. In my case, the mission duration was around four years before reentry (of course, minimum even if you have the dV to capture and wait at Duna for a good window is close to three, so one extra year wasn't that bad).

There's a game setting (under "settings" on the first menu after startup, on the right side), for "max persistent debris" -- you can choose how many "debris" objects the game will keep. Once full, the oldest ones will despawn (I think). Now, this still won't keep "parts of parts" -- if a solar array was a single part when you built the vessel, when it's destroyed (by reentry heating, or an impact, for instance), it's gone -- but if the core of a spacecraft is destroyed, pieces attached to it will fly loose and become debris. With this setting high enough, that'll let you have a nice Kessler infestation before you've finished out your tech tree.

Okay, what this setup should do is let you run the outboard tanks dry and finish with the center tank full (though it won't show that way on the bars in the staging display until you stage off the side boosters). If it's not doing that, something may have accidentally gotten changed in your flow priority settings -- or you may have a bug in your KSP (either the stock or one of your mods might do it, especially if your KSP got upgraded to 1.3 and you have a mod that's not fully compatible with that version).

I'm not a user of Deadly Reentry (not sure it's really needed with the post-1.2 stock reentry code, I find reentry plenty deadly if you don't do it right). However: 1.2.2 was out long enough I'm sure others would have noticed if there were a big issue with Deadly Reentry in this KSP version. What were you doing when the kerbals went EVA and exploded? LKO, higher orbit, deep space, or suborbital? If you're below 70 km, I wouldn't expect a Kerbal to last long at orbital velocity with more heating than the stock game...

The fuel pipes are one-way devices. You know that, right? They'll transfer from the first tank you attached to, to the second one, but not the other way. I'm not sure what you're trying to do with running three engines from two tanks, however -- can you post a screen shot of the vessel?

Not to mention that, to me at least, it seems much more reasonable to expect a probe core to bring a parachute recovery down, than to land a spaceplane on flat ground (first finding the flat ground) or a runway (first finding the runway). Career KSP may consider a no-stars pilot to be inferior to a top end probe core, but I don't see them as such, especially for things like recognizing terrain that won't destroy your expensive orbiter if you happen to miss the Space Center.

Oh. Then you'd have to install a few drogues to open on staging, to slow the stage enough for the mains to deploy with "deploy when safe". Otherwise, nose first, it might not slow down enough, soon enough. With a water landing, you'd still avoid damage to the fins once you get the parachute quantity/distribution sorted out.

Look at my entries in the Mass Fraction Challenge reboot. I built an SSTO rocket that could launch around 16% payload to orbit, then added landing legs on one side and parachutes on the other (plus a probe core and a couple fuel cells), and had a recoverable booster that could land successfully on either land (as long as it was reasonably flat) or sea with zero damage, with very little mass fraction penalty (above 12% still with recovery). The recovery part of this ought to work for any spent booster, and if you can be sure of water landing (as with a first staging launching from KSC) you could leave off the landing legs. If you stage the parachutes to arm at staging you could leave off the probe core (and its power source) as well; the booster will stabilize engines first (assuming no fins), and will slow enough for parachute deployment well before impact. As I recall, it took six parachutes aft, and two forward, to lower a Twin Boar with orange tank attached at a reasonable tilt angle -- you may need to experiment with this. No, parachutes don't have the cachet of wings -- but they're cheaper, carry far less mass penalty, and they work.

It usually isn't the tool that has this problem; you're grinding that convex anyway, so the edge has an obtuse angle. The concave surface of the mirrror, where it meets the edge, is the potential problem. It doesn't take a large bevel to prevent trouble, just enough to take the "sharp" off the ground edge.

You're getting to the point where you have to watch for the mirror and tool sticking together if you let them stand still in contact (especially near the end of a wet) for even a minute or two. Evaporation of water from the abrasive mud will create a partial vacuum between the two pieces, and make them almost impossible to separate (a tile tool like the one I used doesn't do this, but a glass tool surely will). If this should occur, gently plunk the whole thing into a tub of room temperature water, wait a few minutes or longer as needed, and then slide the mirror off the tool (or vice versa). Don't try to wedge them apart (you'll chip the now-sharp edge of the mirror); don't try to force them to slide without soaking (you might succeed -- and propel one piece or the other across the shop to its doom), and most especially don't strike either piece with anything -- you'll injure your hand, and anything sturdier may injure one or both pieces of glass. Speaking of now-sharp mirror edge; this is about the point, also, where for the first time you might want to take a carborundum sharpening stone (grinding wheel, wet-dry sandpaper, etc.) and grind a bevel at the edge of the mirror. Don't worry about losing light gathering area; most amateur made mirrors (especially first mirrors) gain image quality by having the outer edge (rule of thumb is 10% of radius) masked off, even though they gather a bit less light that way (polishing tends to "turn down" that edge, and it's quite hard to prevent that if you do all your polishing with a pitch lap). But putting a bevel out there reduces the likelihood of having a conchoidal chip knocked out of the edge of the mirror, taking a much deeper bite out of the reflecting surface to be.

Even if you have an underground "space gun" launcher you'll still be unable to launch in (for instance) a tornado. Payload carrier comes out of the gun at 10+ km/s, and spends a large fraction of a second exposed to a 150 m/s crosswind -- and doesn't go where it's intended. Anything slower would just be torn apart by the wind shear (zero to 150 m/s over a few meters), and any launch vehicle at all would be vulnerable to impacts from windborne debris.

It's tempting (for this one who doesn't built airplanes or spaceplanes) to suggest that if your craft isn't capable of surviving the load on the runway, it's very unlikely to be able to land intact...

May the Kraken not even roll in his sleep.

No denying, the V-1 was a cruise missile (though not the first one -- that honor goes to a propeller powered flying bomb built by the US Army in the 1920s. It was also one of the earliest radio controlled aircraft). However, most modern cruise missiles are also jet powered (there are a few that have rocket engines as primary propulsion; they're typically the supersonic sort used against moving targets like ships). The American Tomahawk uses a small turbofan engine and cruises not much faster than the V-1 (around 150+ m/s) -- but like the short-launcher version of the V-1, the surface and submarine versions are launched by a rocket engine (it virtually stands on its tail until it builds up some horizontal speed, and doesn't extend the wings until the booster has burned out). And to me, the V-1 doesn't look at bit like a rocket. It looks like an airplane designed by a 3rd grader.

Like other elements of planets and moons, I would expect gravity to be "on rails" -- that is, it'll emanate from a fixed point, and even if you added enough parts to make a non-trivial addition to the total mass of the Gilly-and-ring system, the gravity won't change either magnitude or point of origin. I don't know why you'd want or need to claw anything to Gilly, however -- it's got gravity (albeit not much), so claws aren't needed to keep the ring in contact. There is enough flex in parts that imperfections in the ring will even out -- and plain solid support pillars will take up considerable variation in ground height (your pillars will need to be close to the correct height, but won't need to be perfect). Now, whether BD Armory can extend the physics calculation distance enough to allow the ring to "fly", may not be relevant, either. As a "vessel" or "debris", as long as persistence is turned on in settings, it should stay where you put it, and the only trouble you might get into would be if you move the piece you're building onto enough that flex can't take up the strain before the connections go out of physics range.

You do, however, need to get the tool ground all the way to the center. If your sagitta is already deep enough (f/6 is close, it'll come in some as you fine grind and polish, then a bit more as you figure), you can switch to a W stroke, with no more than 25% overhang at the ends of the center stroke and much shorter strokes toward the sides (which should also not exceed 25% overhang). This will keep the mirror from getting too much deeper as you get the tool fully ground and will bring both surfaces closer to spherical, which they'll need to be before you finish the 220, at the finest.

Wow, I didn't know they sold pregenerated blanks in the 1960s. Still, that's going to save you several hours of grinding and a lot of coarse grit (though not as much as it would if they'd provided a preground tool as well -- or did they?) Worth noting, I recall reading about people going from flat blanks (water jet cut from thick plate glass, as I recall) to polished mirrors in a single weekend -- but those were 4" diameter, f/8 to f/10, and left spherical (which is optically adequate at those dimensions).

Well, yes and no -- but if it forgets ethics, it has fallen.

Very important: be sure you're grinding the center of the mirror almost over the edge of the tool while hogging out the depth of the sagitta. And don't be afraid to lean on the mirror while roughing. Heavy pressure and lots of overhang will cut down the center fast and make best use of your coarsest grit. Wets should be pretty short before the grit breaks down to mud. I recall turning the mirror in my hands every couple strokes, and stepping around the work stand (a 55 gallon barrel with two bags of play sand in the bottom) the same direction every 3-4 times I turned the mirror -- and I was leaning so hard on the mirror that when the room was dim I'd see sparks through the glass (I was never sure if they were heat from fracturing carborundum grains, or triboluminescence like what happens when you bite a wintergreen Lifesaver). Don't expect anything resembling a spherical surface during hogging out -- you're just after getting the sagitta to the right depth. You'll convert that depth to a spherical shape in the 120 and finer grits, and it won't take long (because it doesn't have to remove much glass) -- but when you hog out for an f/5 on a 6" mirror, you'll taking out something like half a pound of glass, and the faster you get it done, the less likely you are to have to buy more roughing grit or change your plan to a longer focal length. Edit: BTW, if you haven't already got them, it's worth trying to find copies of Richard Berry's Build Your Own Telescope and Neale Howard's Standard Handbook for Telescope Making. Texereau's How to Make a Telescope is another standard in this field; if you can only get one, get Texereau (I seem to recall it even had an appendix on silvering your own mirror -- aluminizing service most likely isn't any easier to find than it was when I made mine).

I think the fellow who built a monorail that ran from KSP to the island runway is likely to know this answer...

On the level of nit-picking -- the V-1 was NOT a rocket plane; it was powered by a pulse-jet engine that burned gasoline with air. The piloted version was modified, with a cockpit just below the jet intake, and was to have the warhead replaced by a launcher holding an array of small rockets (the unguided kind that aircraft would fire in clusters at ground targets). Some V-1s (including the manned version, which had a different model designation that I don't recall at the moment) were launched from a short rail with a peroxide monopropellant rocket when space didn't permit a much longer steam catapult. Hannah Reitsch was a hero who did what she had to do to be able to fly, and served her country even when it tried to punish her for it. The fact that her country was pedant Germany is barely relevant, IMO. If you want to run down female pilots based on who they flew for, you should note that the Soviet Union for which Valentina Tereshkova flew treated her no better than pedant Germany treated Hannah Reitsch -- and treated their other citizens no better, either. Doesn't make the first woman in space any less of a hero. Edit: apparently the word filter changes the abbreviation of "National Socialist" to pedant -- carry on.

I'm still playing 1.2.2 and I have Ap and Pe nodes showing for the vessel I'm flying and whatever body or vessel is set as a target.

(Science game) Maltrey and Magcella (engineer) reached and successfully latched onto captured asteroid Valentina 1, rechristening the combined vessel as "Fuel Station Valentina Alpha). As previously noted, the drill/converter vessel, which was rather hurriedly modified from a Far Traveler transfer stage, was a bit of a pig to maneuver -- the center of mass was displaced, both laterally and fore and aft, leading to a high load on either pilot or SAS module for any precision maneuvering. The lander can, however, did have enough torque to keep things lined up for burns (though multiple small corrections were required to get a close encounter). Valentina 1 was in a four-day orbit, well inside Mun (and inclined around 25 degrees), so there wasn't a long wait after the transfer burn to get to their intercept. Maltrey armed the claws well ahead. Use of claws on asteroids has been demonstrated on two prior missions, but this is the first that's intended to remain docked indefinitely, and three claws were specified to ensure a completely rigid connection (in case a later ship needs to push the rock, it need only have a compatible docking clamp). The drill is mounted between the claws; the converter and most of the ore tankage are in the other two between tank spaces. Eventually, the asteroid got close enough to show on radar. Then naked eye. In another innovation, Maltrey verified a technique that came down directly from Werner, of using the nav ball display to accomplish most of the final orbit matching with the main engines, rather than RCS. This makes less difference with this vessel, which has the new Vernor RCS units that run on Lf/O, but will be very useful in future asteroid rendezvous and other sun-orbit docking missions, to reduce the amount of RCS fuel required and/or save fuel in general (interplanetary transfer engines are far more efficient than even Vernors). Eventually, after three attempts (due to the drill having limited extension range, thus requiring connecting with flat or convex surface between the claws to reach rock) Maltrey got docked to the fuel resource space rock in a position that allowed ore harvesting and conversion to take place. Calculations were correct; the fuel cell capacity was sufficient to operate the converter (though not the converter and drill simultaneously), and the abundance of ore allowed drilling and conversion to slowly get ahead of consumption by the fuel cells: Fuel Station Valentina Alpha was open for business. With fuel cell power for the drill and converter, orientation of the asteroid relative to the sun is irrelevant, and the fuel cells consume a minuscule amount of fuel compared to what the converter produces, with the supervision of a skilled engineer and the high ore content of the asteroid. Even so, resource conversion takes time, so Maltrey and Magcella will be kept busy converting fuel for a while before they're ready to refuel an interplanetary ship. They may even need to be rotated home to Kerbin first, given that the upcoming Duna mission(s) will require little if any more dV than the ones to Gilly did -- but once Kerbalkind is ready to reach for Dres, they'll be able to launch a much larger ship with only partially filled tanks, and refuel here before burning for the outer system.

Enjoy the process, and don't be so sure your "beginner skills" won't produce a better mirror than the common ones you can afford to buy. Twenty years ago, I built my 8" f/6.8 (on a Dobson mount) completely from scratch, had never built a scope or ground a mirror -- the only finished telescope parts I bought were the diagonal flat and the focuser. I ground the mirror starting from a miscellaneous Pyrex blank I got from Surplus Shed, and a tool made with field tile (fully vitrified tile made into a mat with silicone dots between tiles, sold to go over the drain in a shower) and cast plaster of Paris; I bought my roughing grit at a lapidary supply, and got a "grit kit" for the rest of the grades from the (Seattle) local telescope makers' club. I wound up with better than 1/5 wave accuracy on the mirror, and an 8" Newtonian that, side by side at a star party, performs about the same (in terms of what and how well I can see) as a commercial 10" Schmidt-Cassegrain. Mine is a little more work to point at a specific object and keep tracking, of course, but it was about 1/8 the money. In the end, by buying a lot of my "telescope parts" at the local Lowe's Home Improvement (for instance, I used a 9" diameter furnace duct for the tube, 8" and 9" duct caps and some bits and pieces became the mirror cell, I bought guitar machine heads to tension the wire spider, which is made from .010" diameter guitar strings, and I fabricated the diagonal mount from PVC plumbing parts), I spent a total of $500 -- which, at the time, was about $100 less than a commercial 8" Dobsonian (and I spent a total of around 120 hours which, as hobby time, I don't count against the cost). Hold yourself to the standard of "if it's not right, keep at it until it is," and you can make a telescope that will do anything a comparable size commercial scope can. And when you're done, you can spend the rest of your life saying "I made that!" Edit to add: I'm sure you'll find you want at least twice the amount of roughing grit in that kit you bought -- drop by a shop that sells lapidary supplies and grab a couple pounds of their 60-80 carborundum, and switch to the kit grit when you're at the required depth, before making the jump to 120 or 180.

One might think it was my recent dual Gilly landing mission -- but one would be wrong. So far, my proudest moment was when Val (with a scientist and engineer whose names I've forgotten) made the very first (in my science game) venture outside Kerbin's SOI to intercept and then capture an asteroid -- and managed, with chemical rockets only, to capture the rock into Kerbin orbit. The 960 t rock. Bonus: the rock reads as 83% ore.