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About MPDerksen

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    Spacecraft Engineer

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  1. Oh yeah, last thing: you ask how you know if you are getting closer to, or further from, your target? If the NavBall is in Target mode, the Retrograde marker REDUCES THE RELATIVE SPEED BETWEEN THEM. If you were flying towards your target, Retrograde would slow your approach. If you are flying away from your target, Retrograde will slow your path away from it. In other words, it won't matter. Your NavBall will read your relative velocity in m/s. This number goes down when you burn Retrograde. Once the rate <1.0, the marker disappears and you are left with just SAS. then you have to find the pink circle to point your ship at/from your target. Is that helpful?
  2. I would only consider myself an Intermediate player. Nothing like some of the pros here. But I do seem to have no issues docking anymore, and have a few additional tips: 1. I don't use RCS at all. I don't even put them on the ship. Get close, burn retrograde to the target (making sure the navball is in that mode) until I hit 0.0. Then flip around, and burn at the target (pink circle) slightly and the prograde marker will appear on top of the target marker. Repeat with smaller and smaller changes in velocity. 2. Once you are within 2km, you can switch back and forth between the 2 vessels. You want to make sure the target points it's docking port at the incoming vessel. Right click on the incoming docking port and select as target. Then, back to the other, and re align that one. Back and forth. SLOWLY. this is why approaching at just a few meters/second is wise. 3. Right click on the engine of the craft you are flying towards the target, and lower the thrust from 100 down to as little as you need (5?). Then, when you thrust forward, you don't go zooming along. However, you still need enough that you can kill your relative velocity when you go retrograde. I tend to use around 20%. Hitting "Z" still gives me a nice push, but a single "Shift" is a very gentle nudge. 4. If you have it unlocked, try using the advanced grabber unit. You can "stick" it onto the side of a target's fuel tank, and has a wider cone to connect. 5. Similar to #3 above, I tend to get my encounter arrows close, but then not use a maneuver node to fine tune at all. I turn my thrust way down, and make small thrusts while watching the distance in Map view. I'll watch it close, for example, from 10km down to 2km, then start to rise again, and I hit "X" and stop. Once you do get close, if your relative velocity is pretty high, you will want your engine back at 100% to get to 0.0m/s as quickly as possible (this happens when you cross paths, but your orbits are vastly different. I suddenly was able to do this when I realized I needed to stop looking at my orbit once I got the target in view and ONLY look at the navball in Target mode to adjust from there.
  3. Turns out I got them home with the onboard fuel, but this is great to know for the future! Thanks. I'm going to give myself a test, and post the results here. Making up a mission, I'm going to deploy a science lab on Ike. The dV map says I need 5,280 just to get there (I think I can improve that will some aerobraking around Duna on the way in...). I'm still not super clear how to read the map in reverse. But if I got back from Duna with 2,775, I bet I can do it from Ike with 1,800, plus ~500 for the landing, so 2,300 total in the lander? I'll try out the Nerv to get from Kerbin to Ike orbit. I'll give the design a go, and talk through my choices here to see if I really understood all the great information.
  4. This is SUPER helpful, so thanks for the detailed response. Let me look at a specific example from the Wiki. Let's compare a Reliant vs. a Swivel. I've typically just used the Swivel so I have the gimbal control at launch. Seems I give up about 18% of the Thrust (atm) for that. But right next to that, there are columns for T/W ratio for atm and vac. How is that even helpful? So do 4 Vectors = 1 Mammoth? And can someone explain the Atomic/Nuclear option? It has a vac thrust of only 60, but an Isp of 800??? A terrier also has a vac thrust of 60, but an Isp of only 325. Still vague on the difference between them. I did get my Duna Lander home. Cost me 1,300 dV to get to a 52K Duna Orbit, 775 to get my Kerbin capture, and another 300 to lower the Pe to about 30km for a nice firework display of my fuel tanks. I came home with multiple missions accomplished, earned about $800K and 1,000 science points. Plus all 3 member of the crew are now 3 stars. All that time allowed my Mun Science Station to build up another 500 science too. Next, I want to put a rover down on Duna for a scanning contract.
  5. Dang it. That would have been good to know before Jeb and Co. were in Duna orbit. See what I mean about missing some basics? And here I was so proud of my first aerobraking success.... So I'll get them down and back, then maybe we need a rescue. Too bad I didnt add a docking port or I could send a refueller. Can I transfer fuel with the grabber unit? Could be a fun mission right there... Right, so I either grossly overbuild or fail completely. My lander being TWR of 3+ means I could select smaller than the poodle for this? Next it would be appreciated if someone clarified the benefits of using the nuclear and ion engines.
  6. Lander: 20.9Tons TWR 3.85 (for Duna) ISP 332s dV 2776 I'm guessing I want a TWR >1? I just put it in Duna orbit at 55K. I used aerobraking (setting my Pe at 15K and crossing my fingers). I have about 700 dV left in the transfer stage. My contract calls for NE Basin, Northern Shelf or East Canyon to find "Blueberries"? and bring them home. I can only find the Shelf in the biome map I can see online, so I think I'll do some low orbit EVAs first. Like mentioned above, I have 2776 dV in the lander, and that has to count for a gentle touchdown too. Probably going to go just fine. But I still am puzzled if just TWR is the key number, and use that with the dV map?
  7. I was just getting my Duna skills when Breaking Ground launched and I had to start a fresh Career. Now I have the tech tree done (just from Kerbin, Mun and Minmus), I have a small station, I have a relay network, I have multiple Sentinels and got my fly-by science of Duna done (and about $10M in the bank). All that for the second time, but I STILL have no idea what ISP actually is.... I'm just tired of copying someone else's design from a video to get missions done. Making my own stuff is part of the fun, right? Michael
  8. background: I can do interplanetary transfers. I can land in a teacup. I can dock. I can EVA. But now I'm faced with actually LEARNING. My Career has progressed to Duna and Eve. Instead of just copying ships from various YouTube videos, I want to actually understand how to build something intelligently, rather than just trial and error. We can use leaving Duna as the example, since that is actually what my next mission will need. But this time I want to better understand the design. On to the specific question: I have designed a lander. I know it will sit on Duna. I know what it weighs. In the dV map, I see that I need 1,450 to achieve orbit, and another 740 to get back to Kerbin. I know that I'm a terrible pilot, so I will plan on an additional 20%. So I need enough fuel, and an engine that creates 2,628 dV. This is what I need to see once it's landed. So far, am I basically correct? Fancy things, like refueling in orbit, leaving the Science Jr. behind etc. help, but at this point, let's stay basic. How do I select an engine (or set of engines) that are appropriate for a given gravity and sufficient to lift what I want back up? I think, if I can better understand this, I will make ALL my rockets better. Sometimes I put together a lifter that seems fine, but then takes FOREVER and burns WAY more fuel than it should to get going off the launchpad. I might not be asking this correctly, but I think there is more than just the thrust to consider from the engine description in the VAB (and atmosphere vs. vacuum). Start with small words to match my small brain Michael
  9. Mission accomplished. I made a 4-pack of little probes. Antennae, QBE core, tiny reaction wheel, small battery, Oscar tank and a twitch engine. Total package was 0.4tons full, and 0.2tons empty for each one. I carried it to Minmus easy enough connected to individual couplers around a small girder above my HECS2 core. Once I got 90 degrees from the target, I would launch 1 of them, go retrograde at a steep angle to drop on the target. Once I was sure I was over the last mountain, I would burn prograde at the site. I hit 200-2000 meters from it and cleared the contract with my little smart bombs in 3 impacts. I still have 1 left as well as the carrier probe. Too bad I didn’t stick a thermometer on there, since I could get $40K for “science around Minmus) that I forgot I had in the queue. The total ship cost about $30,000, and I got 10x that for the contract. I would post a pic, but TinyPic site is gone, and I’m not sure where to host my images.
  10. Typical contract. I need 50% data from the deployable seismic experiment that's sitting on Minmus. Already easily deployed with control, solar, comm station. I'm ready to rig up a probe and go pounding the nearby surface. How close, and how much mass do I need to throw at it? It would be more fun to have like 4 small probes and hit it in sequence. But too small and it will take dozens. A single, mammoth probe could be pretty too. What are the rules to get this done without excessive trips?
  11. I used almost all my dV to get out this far (3rd contract), so I'm not going anywhere from here... lol I'll mark as completed, since I do feel I fulfilled it as given. I didn't know how to access the menu, so thanks for that. my only mod is KAC. Highly unlikely that could effect a science contract. thanks for the help.
  12. Reading right off the contract: Ap - 29,042,109,229, Pe - 26,006, 582,174, inclination - 0.1 Since Duna is roughly 20B meters out, I am completely too high, but that's what the contract calls for. SO...... the contract is broken? I should simply cancel it, take the loss, and move on?
  13. I apologize for putting this in the incorrect forum (I do know better and wasn't thinking before coffee). So I just tested again. Went into my save, Purple target orbit was there. I navigated the Sentinel Probe prograde a touch, and it went away, and I got the green checks in the Contracts menu. Back to KSC, no green checks, back to probe, green checks. Hmm. Okay. Perhaps it just doesn't register? Save the game, exit, reload. Purple target orbit is back, and no green checks. But I'm at the right place in the orbit (the AN). Adjust again. Exit, reload, same thing. Right clicking on the probe I get: "Telescope: Misaligned with Dres" The contract is: "Map 20 asteroids passing near Duna's orbit with a SENTINEL Infrared Telescope." Down in the contract menu it states "Map 20 asteroids around Duna with an inclination greater than 38". Even though my target ORBIT inclination is only 0.1% I first can't understand why I get the right orbit, then don't. But second, once I do have it, and don't leave, nothing maps. I have an HG-55 that has connection for the entire orbit, unless Kerbol is between the probe and Kerbin.
  14. launched the Sentinel, got all 16 asteroids. Got a second contract, moved the probe to the new orbit. Got all 11. Got a THIRD contract, barely getting to it with remaining dV, but make it. The purple target orbit goes away, leaving me with only my current Blue one. I check the little contracts window, and I have the green check for being in the right place, with the right sensor. However, I go back to the KSC, and check the contracts, and it does NOT have a green check. SO I go into the tracking station, and yep, the purple target orbit is back. As soon as I select to "fly" my Sentinel, it goes away again. Back and forth. I even backed up 1 quicksave and moved back out a second time, with the same result. Just to check, once I had it in the right place, I stayed focused on the probe and did a complete Kerbal rotation (4 years) and never got a message that it identified a single asteroid. Am I missing something? It's got an HG-55 and connection to KSC, and it's the same probe that has worked successfully twice already. Michael
  15. I had to read it a few times to grasp it, but YES, this makes complete sense, once the lightbulb went on. Thanks.