Lexif

Asmi, I wish your mother all the best. And I wish you the strength to keep up with keeping your real life stuff going while supporting her. Silly computer games just have to take the back seat in life situations like that. Thanks for telling us that you take a hiatus.

The datum is where you want it to be, that's how it works. For planets with interconnected oceans, it's kind of obvious, but even then it's not so simple in the real world. The earth's sea levels are at different distances from the earth's center as the earth is not spherical and does not have a homogenous density profile... (Plus other effects, like tides, currents, etc...) Even on earth, different countries use different datums. For example, they built a bridge over the Rhine between Switzerland and Germany, and both countries use different datums for their altimetry data. A contractor made a mistake like confusing a sign when converting between the datums, and the bridge heads were off by a meter or so because of that...an expansive mistake. If I remember it right, the germans use a datum based on mean sea level at some north sea port, while the swiss use the exit of Lac Leman at Geneva, but which is in practise linked by measurements to mean sea levels in the adriatic sea or something like that...

R4inator, doesn't matter in my opinion. Seeing Saturn's rings kind of hang there in the void of space through a telescope is one of the most magical things I ever saw, except for that total eclipse, maybe... It really can't be captured in a picture in my opinion. XIRA, that's a nice picture. I really like the atmosphere it conveys with the chimney etc... Chickenplucker, great pictures, especially that shot of Jupiter! Funny, on the same evening, I saw the moon and Jupiter quite close together and thought I might try and capture Jupiter's moons and our Moon in the same shot. There was more haze that what I could see with the naked eye... Also, I couldn't resolve Io and Callisto. I don't know if you can see the moons in the small resolution...click on the picture for the full resolution. (100 mm, f/6,3, 1 s, ISO 800) I also got quite a nice shot of the moon at 250 mm (100% crop).

I don't think it's a practical proposal. That way, you would never be able to see the stars. Either you look at the lit side of your vessel, or in the general direction of the sun. And yes, the dynamic range of photographs is much smaller than what your eyes can see.

If we are talking about sustained g-forces, shock absorbers are useless. You can try everything that's indistinguishable from a micro meteorit impact or maybe a collision with space debris. But the problem is that everyone will see that you maneuvered your vehicle to get close to the target. If there's a way to get it done without being detected, then you can just use a simple, high-dv satellite with something very similar to a shotgun instead of an X-37. And if you don't care if they detect you (WW III just broke out), you just do the same. I think deorbiting an X-37 somewhere specific on short notice still takes too long for the scenario you describe. There's no way you can deliver anything from a specific orbit to some random place on earth in less then an hour. Also, again, why spaceplane? To nuke something, wouldn't we just use the reentry vehicles we have? Those are certainly precise enough.

Yes, I hate this problem almost as much as I like this mod.

I think this is the most likely use for the X-37, it's basically the only thing that can't be done by other systems cheaper or better. I would have guessed it's just a scaled-down test vehicle, but it seems to me they are using it for something, or why would the leave it up there for so long? I'm very curious what it is they are manufacturing or testing, I hope we will find out some day. Unless, of course, they are just toying around with it because they have a lot of money to burn that they can't direct back into non-secret projects.

My house rules are that LV-Ns are not to be crashed into bodies with an atmosphere. I use Deadly Reentry, so aerocapture is generally not considered. That means I often need to inject my interplanetary transfer stages into an orbit around the target body anyway, so that's where they generally end up. (Unless it makes sense to plan a seperate stage for injection around the target body.) Stages using the LV-N are always equiped with a docking port, so that I can reuse them or depose them if I want to. As I use Remote Tech too, I often give those stages a probe core and some antennas, so that they can be repurposed as a communication satellite for future missions. I still have to do a manned interplanetary mission, but I think those that use the nukes will return them into a Kerbin-orbit if enough fuel is left, so that they can be reused. But if the reserves have to be used, they will end up in a solar orbit and never be seen again.

Omicron, great picture of Jupiter! I caught the new moon setting yesterday evening. (EF-S 55-250 mm 1:4-5,6 IS @ 250 mm, cropped 50%) (EF-S 55-250 mm 1:4-5,6 IS @ 145 mm) Nice pictures, chickenplucker. Is this the 28/2.8 you got? http://www.pentaxforums.com/userreviews/osawa-28mm-f2-8-m42.html I think I've got a relative of that lens, branded Exakta. It looks very similar, but the font is green instead of yellow, and my lens is dubbed Macro now and focusses to 20 cm instead of 30.

Guys, this kind of statistics is totally meaningless, just stop it. There is just not enough data to do meaningfull statistics on. It's the same bull as with aircraft accident statistics. Just like how Concorde was the safest passenger airliner in existance, and the next day, it was the most dangerous one. This just tells us the statistics are useless. Also, don't the Afhanistan troop numbers include staff in supporting roles? Then why are we not counting launch pad crews etc. as well for space programs? See, you can spin this any way you want, because the dataset is too sparse.

Only with FAR, I think.

The EF 50/1.8 is a flimsy bucket of plastic held together by only two screws, and the focus motor sounds like an electric screwdriver. But the optics are good and it is a lot sharper than the kit lens that comes with the EOS 600D. And it's really lightweight at 100 g and very compact, so I never find an excuse to leave it at home. I really recommend it as a start if you want to try out if you like non-zoom lenses. I replaced my kit lens with a 10-24 mm ultra wide angle zoom and the 50/1.8 for most use cases. I find I rarely use the range between about 28 and 50 mm on my kit lens anyway. (I mostly photograph landscapes.) I also have the EF-S 55-250, which often joins in on hinking trips etc. because it's very lightweight.

Ah, thanks Lordhermann. I like your picture of the moon! So I guess it's one of those 650-1300 mm f/8-f/16 sold under brands like Wallimex or Opteka here in Germany. If you look for a good and cheap lens for astro stuff, I guess this is not the way to go. Astrophotography seems to be unforgiving and demanding. A quick google search seems to show a lot of complaints about colourfull fringes and lack of sharpness for this lens. Astrophotography has hard contrasts and those problems will show up a lot. Sadly, you get what you pay for when it comes to lenses for (D)SLRs. Also, the aperture (f/8-f/16, depending on the focal length) is just horrific. In general, a smaller number (= larger aperture opening) collects more light in the same time, so you will be able to get more light on the sensor before the time gets too long and the earth's rotation blurs your image. For "normal" photography with such a lens, your exposure times will be very long, and you will very likely be unable to take pictures without a tripod even in bright daylight. If you want to get somthing "tele" to use in astrophotography and want to go cheap, I would rather buy an old, used 135 mm f/2.8 (larger aperture, smaller aperture number) off ebay, with an M42 adapter to screw it on your camera and experiment a little. Those go for 30-50€. Much longer focal lengths won't get you more stars on your pictures if you don't have a mounting that can correct for the earth's rotation, and a 135 mm lens is still quite usefull for everyday pictures in my opinion. I personally use the cheapest lens Canon offers, the EF 50/1.8, for my pictures. It's "only" about 100€, and it's got some problems near the edges as you can see in my photos. But it's a real winner for the price, very sharp in the center of the frame. I also find a lot of use for it for nice portraits in low light, where you can use it without the flash unlike the default 18-55 3.5-5.6 because it lets more light in. PS: It thought about my advice for a 135 mm for astrophotos, and I now think that's neither here nor there -- it won't be able to get you any "interesting" pics of the moon or the planets (I tried on Jupiter and you can see the moons, but no details on the planet), and it's about the longest focal length I would try without any kind of guidance, I think. So if you want to go and get something cheap for your camera, I would try and stick with star field photography with 80 mm or less, that should be rewarding and might teach you a lot. But I don't have much experience myself when it comes to astro photography...

I guess there's a case of confusion between tele and zoom? I hear people say zoom a lot when they mean tele. And the Plejades shot looks to me like the framing a 135 mm would give on a crop 2 DSLR, so maybe an extra zero made it's way into the post by accident. A 1300 mm could just about fit the Plejades in on a 36 mm sensor DSLR. PS: Also, a 100-400 mm zoom, a 2x teleconverter and a 1.6 crop DSLR would give you the same frame as a 1300 mm tele on a 36 mm sensor (full frame) DSLR, and you would be able to take that Plejades shot, too, if you ditch the teleconverter. But I guess the resulting effective apperture because of the teleconverter (f/8 for a f/4 telezoom, right?) would make it worthless for astro shots for anything fainter than the moon.

I discovered stacking multiple images and some reprocessing methods that can tickle a lot more details out of relatively mundane images. I had two large image series of Orion back from 2011, and reprocessed them again this january. I took 86 images with my Canon EOS 1000D and a 50mm/1.8 lens on two dates, and a few dozen darkframes. Not exactly in a dark place, but out of the window of my german city appartent. Exposure times are 3.6 and 5 seconds, for a total time of about seven minutes. I stacked them (with DeepSkyStacker) and ran them through a HDR program and did some processing steps with FITSworks and Photoshop CS2. Besides the Orion nebula, you can see the flame nebula and the horsehead nebula. Here is a single shot without stacking, by the way: http://i.imgur.com/ufy68Hj.jpg This year, I tried my ultra wide angle lens on astrophotography. In this picture, you see Jupiter on top competing with Sirius in the lower left corner, and of course Orion is there, too. You can also see several open star clusters in the milky way below Jupiter. At 11 mm and f/4, four pictures with 30 s exposure time (for a total two minutes) were processed in a similar way. I also managed to get a shot of comet Lovejoy this december. The sky was still quite bright and the moon was up, and as I was standing on the sidewalk of my street, I couldn't even see a single star in this frame. You can just about see Lovejoy's trail above the antenna, and M 13, a globular cluster in Hercules is the blurry spot above and to the right of the middle of the image. 29 images with about 3 s exposure each, 50/1.8 at f/2.8. PS: The antenna in the photo of Lovejoy is imaged twice (and of blurred) because the shot is a composite of two different series of pictures. I had to wait a few minutes because my neighbours were coming home and their cars lit everything up. I guess they must suspect I'm some kind of pervert, standing on the sidewalk with my camera on a tripod, taking pictures of the sky above my house. Anyway, the blurryness comes from the earth's rotation, as the comet was setting in the west. The stacking program then identified and aligned the stars.

I can recommend this, but I edited out the rescaling as I think the larger parts look more convincing for a long range hab module or a station. I'm thinking about adding the scaled down parts back in, but with a matching lower capacity.

I once built something like this and would leave the landing leg grabbers out the next time. They tend to snap off, and it's just better to remember to keep some slight forward thrust on while rotating with debris in the bucket. Edit: The challenging part is to get rotating debris into the bucket. You could always cheat and use time warp to stop the rotation.

I like this mod a lot, the concept is very good in principle. Clean and just the needed elements and interface. But I agree that some problems are turning me off. - I can't terminate debris in the tracking station - I experience some of the UI lockups Motokid600 mentions. I use RT, though, might it have to do with that? But the interface sometimes locks up in the VAB, too. (If you need more data, I'll try to reproduce it.) - I experienced the leaving-a-Kerbal-on-EVA-issue now, and took a series of screenshots. I noticed that the number of Kerbals seems to multiply in each screenshot, at least by counting the helmets visible. Might Nutt's bolded comment about a Kerbal in EVA having a crew of five have something to do with it? Please don't give up, I'm sure if you can make this work, this will be my choice for a life support mod. Take your time.

You can change a runway landing into an off-runway landing pretty quickly if you manage to miss the runway or run off the side... Civil Airliners manage to do that from time to time, and they have similar arangements, of course without the explosives to remove the hatch. All transport category aircraft have a way for the crew to egress from the cockpit through a window with a rope as a secondary escape route. The 747 even has a hatch in a similar position on the roof. (It is sometimes used to clean the cockpit windows from above,too...) It's because if you get into a crash landing, the fuselage and with it the cockpit door might be warped and will not open, or there might be a fire in the cabin behind. And they have been used quite a few times. I guess the reasoning behind the installation on the shuttle might be similar. More escape routes are always better, and the roof is the area least likely to be damaged in a rough landing. Edit: Found a picture of the 747 roof hatch used to clean the windscreen: http://www.airliners.net/photo/Qantas/Boeing-747-438/0968767/L/

I think I also saw a reference to the solid stage having thrust vectoring capability, but I can't find the page now. So that just might be what it's for. I guess that provides steering in only one axis, though? Or do they internally inject the stuff into different ports in the nozzle depending on the steering impulse needed?

It's a mockup of the Manned Orbital Laboratory (MOL), reusing the Gemini 2 capsule that was flown unmanned for a suborbital test flight and recovered. https://en.wikipedia.org/wiki/Manned_Orbiting_Laboratory

As the title says, I looked at photographs of the Titan IIIC, which has solid fuel boosters as its first stage. There's a tank visible on the side of one of one booster in each picture, it's painted orange near the top in this picture: (Click for full resolution) I guess the other booster has one on the far side as well. It seems to feed into the nozzle of the engine on the booster. I wonder what it's for? Thanks in advance!

I guess they did the math and found out that the mechanism to move the wings would be so heavy that it eats up all the benefits. Also, safety considerations might have been important in the design decision. What if the wings fail to extend after the ascend?

I would use scansat as it has some awesome features, but the dealbreaker for me is that the scan width apparently doesn't depend on the orbit altitude. I like how you have to decide between speed and resolution with ISAmapsat, and the challenge of setting up a good mapping orbit.

All my display maps (so far for Kerbin and the Mun) are only 8x8 pixel in size. Meanwhile, the Biome maps are working fine, but have the smaller format of the old verstion. I'm using the X2r4-version from the blog. I think it worked fine with the older dev build. Is this a known problem with a solution? I set the textures to half size in the KSP settings as my machine is not up to the task otherwise, if that might be a factor. I tried to search the thread, but it's kind of hard to find good search terms for this problem.