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photogineer

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    Rocketry Enthusiast
  1. So, I'm back after a long hiatus and v1.0 and all that good stuff. I'm trying career mode and I am getting burned (pun intended) on the new aerodynamic and heat effects. I am trying to do a test contract for the RT-10 booster firing between 40km and 45km and a certain speed window, I did this by stacking three RT-10s with tweaked thrust limiters so the third one ignites while coasting in the target window. Contract satisfied, but then I can't get the capsule safely to splash down because the chutes keep failing. I've tried deploying them as early as possible but it seems like nothing I do will get them to open until 5km altitude and by the time my capsule + heatshield is that low, it's screaming along at nearly 1km/sec and the chutes tear right off. I'm not sure how to slow my capsule down enough to use the chutes safely without being able to deploy them earlier. Thoughts? Thanks!
  2. So.... why did the camera lens ice up during the deorbit burn? Matt
  3. So, I was reading up on the RS-25 engines that flew on the shuttle and are slated for SLS and I read in multiple places that they were deliberately shutdown before fuel exhaustion because if they were left to run dry they would be destroyed. I am curious why this is though? In my reading I've come up with two theories: 1) The sudden loss of fluid pressure inside one or both of the turbopumps would cause cavitation that could damage or destroy the pumps or 2) Since the cryogenic fuels were circulated through multiple heat exchangers to heat the fuel and cool the engine, before reaching combustion, that a sudden loss of fuel would result in abrupt loss of cooling while the combustion was still occurring, thus damaging or destroying the uncooled components. Are either of these even close to being true? Is it another reason? Enlighten me please Matt
  4. Alright, that clears that up, thanks everyone! I'm learning new tricks all the time... I'm not sure that the burning required to actually do the slingshot around Mun was any cheaper than just burning way out and changing orbit directions at the Ap, but eh, this was more fun! Matt
  5. So, I (finally) put my satellite in orbit around Duna, it went pretty well actually! I used a little ship I built dubbed the ITV-1 (Interplanetary Transfer Vehicle-1) to put it there. Pleased with myself, and with the amount of propellant left in the ITV-1, I sent it home when the next Duna->Kerbin window opened up. Transfer went great, I came in inclined and hot, but it was no problem to insert in to orbit. I then used my high apoapsis to rotate the orbit to be equatorial, and burn my periapsis down to 120km to intersect my station orbit. Perfection! I started to really feel smug at this point, I played with the maneuver nodes and got it set up so I would burn most of the way down to a circular 120km orbit, and then one orbit later intercept the station. So chortling away like the genius I was, I did the burn and then warped around to closest encounter.... .....at which point my space station whipped by at 2x the orbital speed! Yep, all that clever interplanetary piloting and I was going the wrong way round Kerbin. Krap! At this point I was low on fuel too, so I sent up another ITV ship (the ITV-2) in to retrograde orbit and docked with ITV-1. Together the ships burned in to a Mun encounter, at the Mun Pe I did a retro burn, but not enough to insert in to orbit, just enough to whip around and escape Mun going the other way. This dropped me in to a pretty huge Kerbin orbit, but in the right direction. This time I was able to rendezvous with and dock to my station, hooray! So, I was wondering, that maneuver I pulled whipping around Mun to change my orbit direction, is that considered a gravity assist? I wonder only because that is a wicked amount of dV I got out of it, considering it totally reversed my orbit direction. Admittedly I was in a much higher orbit after, so it wasn't a 2x orbital velocity change, but still... not bad! Just curious what I should call it when I describe it to my non-KSP playing friends (who really don't care... but I will tell them anyway! ) Matt
  6. I was testing my Duna Surveyor series satellite prototype, I put it on a launch vehicle and successfully launched it in to a 500km x 100km orbit. At Apokee I did a short retro burn to lower the perikee to about 25km so I could ditch the last launch vehicle stage to Kerbin and jettisoned it. The seperatrons on it did their job and hurled it away from the satellite. I fired up the satellite's stationkeeping motor to circularize the 500km orbit.... and promptly plowed in to my deorbiting launch vehicle. Cue big boom! I now have a pile of debris on a helpful reentry trajectory so it will clean itself up. Oops. Well, at least I know she probably would have made it to the destination orbit intact... Matt
  7. Hey all, I have a nice Saitek X52 Pro flight stick with throttle quadrant I'd love to use for KSP, along with the accompanying rudder set. The only hiccup is that my flight stick lost a button at some point and it makes me really twitchy and OCD-like to see it like that, which makes it hard to use. Yes, I'm crazy The missing button So, does anyone know where I can get a replacement button short of replacing the entire system? As far as I know everything else works perfectly fine, so it's a shame if I can't fix this. Matt
  8. I will give this a shot! You're right, I'm on Mac. I can hear my PC friends laughing at me...! Matt
  9. Well, here's a fun problem, I am using 0.23.5 with ARM parts to try and build my next generation space station. When I launch my rocket it climbs to about 10km before the SRBs burn out and I ditch them. Then the 4x engine cluster runs out of fuel and I stage to ditch that.... and KSP hangs. Every time. No idea why, I've got a screenshot of the craft here, does anyone know what might be the problem? Thanks, Matt
  10. Everytime I've tried to do that I usually end up pitched all the way over burning without getting a higher apoapsis, and then scrubbing the launch, I am not sure what I'm doing wrong? Very cool, I didn't know about that, thanks! Again, cool, thanks. Is this really that super difficult to do? Is it more difficult when your rocket isn't designed for one payload to one specific orbit? Is it worth the trouble? It sounds like a fun challenge, but not if it won't really net me anything Thanks, Matt
  11. Actually, before I (stupidly) moved my station in to an inclined higher orbit, this was pretty easy with practice. My method makes a few assumptions: 1. You're flying a consistent launch vehicle, I was always using the same lifter or crew transport rocket. 2. Your station/target is in a circular equatorial orbit Do some practice launches, get it to the point where you're consistently flying the same launch profile and circularizing on your target orbit so you're always ending up in the same orbit, in the same amount of time (this can be done if the rocket is stable and you practice). Take this time, and calculate/guesstimate how far your station travels along it's orbit arc in that time. Launch when it's that far from KSC. Unfortunately I never thought to take video, but I've done multiple launches where my circularization burn was done using the target retrograde marker with the station selected. I shut down at 0.0m/s relative velocity and I was in a matched orbit ~400m from the station reliably. Then RCS to dock. It's worth the practice, it is really fun, and saves time and fuel. Matt
  12. Do any parts besides KW Rocketry parts appear in the VAB? I once (accidentally) replaced the parts folders with a plugins parts instead of merging them, and it deleted all the stock parts so nothing worked. If the regular parts aren't showing up in the VAB, that's probably what happened. Otherwise I don't know, but I'd bet it was something to do with the way you installed the mod making the parts not usable somehow. Matt
  13. Hey all, Another question for you, I am just full of them lately. I am getting pretty decent at getting my rockets in to orbit. I can more or less hit the orbit I want every time now, with my light and heavy launch vehicles, My ascent profile is pretty straightforward: 1. Launch, burn out first stage boosters and liquid engines, stage them 2. Around 8km to 10km, depending on payload, pitch over to 45 degree gravity turn on launch azimuth. 3. Hold that attitude until second stage burnout, then move to track prograde marker as soon as Navball switches to orbit 4. Follow prograde burn until apoapsis is just about 1-2km above target and kill engines, if that stage isn't enough for insertion burn (almost always the case), ditch it while it's still suborbital. 5. Wait until coast brings me high enough that apoapsis stops dropping, usually settles right on my target, jump to map view and plan a maneuver node for my final orbit (circular, intercept phasing, etc, whatever the mission needs) 6. Coast to apoapsis and fire insertion burn Also, on recent launches I've been experimenting with modulating the throttle to keep atmospheric efficiency (as measured by Kerbal Engineer) near 100%, until I'm high enough that I saturate at full thrust then I stop fiddling with it. It doesn't seem to be helping my dV budget that much, though it does make early launch a bit less tedious This is working pretty well, but it makes me wonder, is the coast really necessary? Do real spacecraft do that? I was always under the impression that most craft burned solid from launch to parking orbit. I realize many craft will restart the engines later from their parking orbit for target orbits, and other operations, but is there usually a coast between liftoff and parking? If not, why is it that way in KSP? Is it just easier? Would a single burn to parking be more efficient or more challenging? Thanks, Matt
  14. Well, thanks everyone, I just managed to put the first long term crew on to my KSS. I was able to predict about when the orbit would be aligned with the launch site based on the 1 minute per degree figure and some Kerbal Engineer readouts on the station while in orbit. I then timewarped ahead to that time, and launched a crew rocket up, in to a nice 350km x 300km phasing orbit. Took a little playing with the engine but I successfully rendezvoused and transferred my crew. Next step, precision landing! Thanks all, Matt
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