Ydoow Posted February 10, 2012 Share Posted February 10, 2012 This is part a 'How do I do this?' and part experiment to find the best approach thread (if one isn\'t already out there).I\'ve tried a couple times so far. What I do is watch the KSC retrograde pink marker fall across the Navball. I do a retro burn at various angles and reducing to varies speeds, all at ~100k orbits (standard deviation around 4k)So far I\'ve tried:30 degreeretro-burn => 1587 m/s -- Overshot KSC45 degreeretro-burn => 2100m/s -- Overshot KSC40 degreeretro-burn => 2058m/s -- Overshot KSC, but pretty close.I couldn\'t find any equations online, but I did find real shuttles come in at around 40-45 degrees. Because of real atmospheric conditions, this changes and it\'s all automated.I\'m thinking at 40 degrees, and retro-burning to about 2020m/s should be real close. Perhaps 2000m/sI understand this varies given shuttle mass. I\'ve been using the shuttle I\'ve linked.it has much more fuel than needed. I eject the second stage once I\'ve made a steady, circular 100k orbit. And eject the third stage as I\'m entering the atmosphere.Here are the mods used in this craft.Down Under Aerospace & Party Supplies:http://kerbalspaceprogram.com/forum/index.php?topic=3362.0C7 Flight Pack:http://kerbalspaceprogram.com/forum/index.php?topic=1172.0 Link to comment Share on other sites More sharing options...
Guest Flixxbeatz Posted February 10, 2012 Share Posted February 10, 2012 close enough Link to comment Share on other sites More sharing options...
Ydoow Posted February 10, 2012 Author Share Posted February 10, 2012 Ah, but I\'m trying for somewhat of a 'free return'.Meaning I burn to drop out of orbit, and then atmosphere slows me down to land at KSP. No further burns while in the atmosphere Link to comment Share on other sites More sharing options...
foamyesque Posted February 10, 2012 Share Posted February 10, 2012 Use the map and wings. Link to comment Share on other sites More sharing options...
Ydoow Posted February 11, 2012 Author Share Posted February 11, 2012 That\'s not the point here :lI don\'t use wings on my upper stages to conserve fuel, and plus they\'re pretty darn useless on the Mun.Of course I could just glide any old thing in, but my goal is to make a controlled crash landing, with a parachute to bring things to a safe fall speed.This isn\'t entirely a 'help me' thread. It\'s meant for people to pitch ideas around until a solution is found Link to comment Share on other sites More sharing options...
foamyesque Posted February 11, 2012 Share Posted February 11, 2012 I use winglets all the time on my upper stages to conserve MORE fuel. That way you can get away without having to lug a chute/decoupler around.That said, the map is still your best option. Do your deorbit burn while watching it and allow some overshoot. The shallower your entry the more overshoot you should allow, and the worse your glide ratio the more you should allow. Link to comment Share on other sites More sharing options...
Splendid Posted February 11, 2012 Share Posted February 11, 2012 If using a shuttle:Start burning at the ____________________________Make sure your Periapsis is going through kerbin at the little square point, when it\'s there cut off engines and glide your way towards the runway. Link to comment Share on other sites More sharing options...
Ydoow Posted February 11, 2012 Author Share Posted February 11, 2012 If using a shuttle:Start burning at the ____________________________Make sure your Periapsis is going through kerbin at the little square point, when it\'s there cut off engines and glide your way towards the runway.That changes based on your height though, so we can\'t really use that as a 100% accurate guide. Link to comment Share on other sites More sharing options...
White Owl Posted February 11, 2012 Share Posted February 11, 2012 If you\'re determined to glide in, and not burn at all after re-entry, then you\'re limited to atmospheric maneuvers to adjust your gliding distance. So deliberately overshoot KSC by a little bit, and make s-turns as needed to shed airspeed and altitude. Link to comment Share on other sites More sharing options...
Tim_Barrett Posted February 11, 2012 Share Posted February 11, 2012 Yea... I remember when this was attempted WITHOUT the map/acceleration...Then again, Kerbin rotates now. Link to comment Share on other sites More sharing options...
Ydoow Posted February 11, 2012 Author Share Posted February 11, 2012 If you\'re determined to glide in, and not burn at all after re-entry, then you\'re limited to atmospheric maneuvers to adjust your gliding distance. So deliberately overshoot KSC by a little bit, and make s-turns as needed to shed airspeed and altitude.Not even having aeronautical control. My reentry is just the command capsule. Much like the very early space missions where they come in and deploy chutes.I think it\'s just going to take more tries Link to comment Share on other sites More sharing options...
Splendid Posted February 11, 2012 Share Posted February 11, 2012 Your height doesnt matter if using a shuttle, by that point, even if you\'re coming in from 500km, you\'ll still be able to glide towards the runway. Link to comment Share on other sites More sharing options...
Cepheus Posted February 11, 2012 Share Posted February 11, 2012 This is an interesting thought. I\'ve built a rocket that is reliable, and can be likened to the Saturn IB (I could have just used my Gemini rocket, but I was planning to do this anyway. I have work to do now, but I shall return with some test results. Link to comment Share on other sites More sharing options...
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