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John Doe

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  1. John Doe
    By top heavy, I mean that it wants to pitch so much that I'm going straight along the z axis, which happens just after I go into the second burn at around 40,000 m, pointed at 45 degrees to the right. SAS will bring me back vertical and then the next thing I know I get a nasty pitch. (and thats assuming I clear the tower in one piece due to much the same problem ) Here are the flight results.
  2. John Doe
    No, I'm not using anything but the tri-coupler with a decoupler sitting on top of it to seperate the whole tri-coupled section as a single stage, with the ability to decouple the SRBs once they burn out to decrease drag. The only major structures below the tri-coupler are the three (relatively large) fuel tank / engine assemblies with two sets of symmetrical winglets , symmetrically placed radial decouplers attached to these tanks upon which the SRB's are placed symmetrically as low as feasible on the stack, and the pyrotechnic stabilizers ( which are attached to the stack just above the 3 SRB's) to hold the rocket to the pad until both the SRBs AND the first-stage liquid engines are both fired up at full throttle. My aim is to make the 10,000 m mark with 2 minutes into the mission. A cross section of this looks much like a triangle with the apex of the triangle facing away from the tower. I've included screenshots of the stack without the launch stability enhancers attached.
  3. John Doe
    but, wait even if a orbit is circular, you can still have Ap and Pe. Consider the following orbit, as viewed approximate from the pole. (Ap is 229,450 m and Pe is 182,971 m.) . As we see, however, this orbital path looks nothing like an ellipse. (though I would assume that for an orbit to be truly circular Ap = Pe?? ). I'm really trying to understand obrital paths here a bit beyond what the tutorial really gets at (i.e. how to raise/lower Ap and Pe, and how to tilt an orbit.), I'm trying to figure out how I inserted an engine and fuel tank assembly into an orbit by decoupling it after doing a antegrade burn to deorbit. When I decoupled I was under the assumption that I would fling the the dead engine / tank out into space, or if lucky, into the moon or something.
  4. John Doe
    I'm thinking it might be a center of mass issue. My basic design is using a tri-coupler to construct a relatively Heavy and massive portion as a first stage, much like the first stage of the sat 5 rocket, (three large tanks each with their own engine firing at once AND three SRBs , one attached to each tank, which is the only real odd thing about the stack, mind you removing the SRBs does not seem to make too much of a difference in flight. ) which makes up a little more than the total height of the the rocket. I've kept everything else as slim as possible, looking loser to the top most stages of an saturn II-B (in its late form) with my center of mass just a bit below the tri-coupler. The center of thrust is a bit lower but vertically in line with the center of mass. It seems that I am unable shift my center of mass upwards to account for the total length of the parts. The logs are showing that the SRBs are firing and then the main engines firing, just before i decouple the stability enhancers. most the time once I get up off the pad and have SAS on, the rocket once to pitch pointing the engines directly At me to where I'm travelling horizontally on the z axis as opposed to travelling vertically on the x axis. The resulting stack looks something like a Saturn II-B mounted to the massive bottom stage of the Saturn V. Its behaving as though its top-heavy, but yet my center of mass is quite low on the stack as a whole.
  5. John Doe
    The problem I seem to be having is that when I attempt to modify the stock model (The Kerbal 5) in a very simple way, by adding an extra fuel tank / engine assembly / winglets as its own stage in the rocket, (which I am adding just below the command module in the stack) Once I get it out to the pad, I get an apollo-1 situation in the sense of going BOOM right there on the pad, the second I light the first stage, OR i get the challenger effect- (i.e. going BOOM at less than a minute after liiftoff ) usually as a consequence of hitting the ground because the whole stack wants to to pitch / yaw so much that the direction of velocity ends up being horizontal and then DOWN. I wouldn't think that adding one extra stage (adding about 20m or less to the original 85m high stack) would change the center of mass, etc.
  6. John Doe
    But, your assuming the orbit is actually elliptical, in the first place. In the situation of a circular orbit, while the same general concept holds true, it also demonstrates that the concept is not necessarily confined to an elliptical shape, but rather apply to an orbit of any shape, If I'm understanding it right. But from what I read somewhere, I'd heard that the terms were always interchangeable and the shorter terms substituted due to NASA's need to simplify the procedure manuals, and that they had started to do this late in the Apollo program and early in the STS program.
  7. John Doe
    What are the basic principles of rocket design, as to be able to accomplish orbit, etc. and, more importantly to avoid an Apollo 1 situation (i.e. blowing up on the pad), or a challenger situation (i.e. blowing up less than a minute after liftoff)? I also find that when I add an extra fuel tank / engine toward the top of the stack, immediately below the command module, that I have these sorts of problems, despite adding winglets to the extra fuel tank. (note that I'm running an early demo version of the program).
  8. John Doe
    Well, I have found two things about Kerbin that are different than earth. Apparently, Kerbin's gravity is greater than earth, given the fact that the Kerbal 5, which is around an 85m stack, doesn't accelerate anywhere near as fast as it should, using the figures for earth's gravity. Second thing I've found is that Kerbin's day appears to be at just over two hours or so.
  9. John Doe
    But for the fact that we attempt to keep orbits as circular as possible, generally speaking? and kerbin is practically synonymous with the earth in the context of the game, correct?
  10. John Doe
    Actually the term Apogee (Pronounced A' Poe' Gee) is synonymous with Apoapsis, and the term Perigee (Pronounced Peri'Gee) is synonoymous with Periapsis. The difference between the two terms is that Apogee /Perigee became the less formal, but more commonly used terms, particularly during the Apollo and STS missions. The latter terms are the more formal terms found in the study of astrophysics within the classroom context. The fact that the game elects to use the more formal terms is unusual given the context of manned flight missions.
  11. John Doe
    Actually the way I pulled it off was to stay near vertical up until 10,000 and then adjusting to around 50 to give me a wider initial suborbital path, with apogee about two and a half to three minutes away, and then of course raising the apogee to around 227,369. This renders the periapsis at around 124,827, a fairly circular orbit. Problem is that this leaves me with barely enough fuel to lower the periapsis enough for re-entry, after all is said and done. I've tried adding an extra stage with a simple fuel/engine combo, and the necessary aerodynamic components, but this will either end up exploding on me in true Apollo 1 style (though occasionally it will go challenger style at around 1:30 seconds or so into the mission) but even when I manage to get ready to manurer to my prograde vector, I find that it likes to swing back and forth like a chimp on a rope, and that's with heavy use of sass in attempt to stabilize, so by the time I manage to get my prograde worked out, I'm already so far into the decent that firing prograde does nothing but expend fuel to engine cut off. And I'm running the demo version through the Linux Steam application. (which apparently wasn't updated.)
  12. John Doe
    Well, I have managed to do it- to successfully launch to an orbit just a bit higher than a LEO, and pull of a successful re-entry manurer. Interesting thing was when I decoupled the command capsule from the last fuel tank / rocket (which I executed immediately upon doing an exahustive antegrade burn) I managed to inadvertently insert the fuel tank / engine assembly into a satellite orbit.
  13. John Doe
    By the Kerbal 5... This screenshot is what I mean... http://tinypic.com/r/wiu8p1/9
  14. John Doe
    Anyone have any idea how to raise paraphasis enough to get into orbit from a suborbital flight path using the stock Kerbal 5? I've tried thrusting prograde upon reaching the apogee (Apostasis) in order to attempt to raise the periphasis high enough to constitute an orbit, but either I always seem to run out of fuel before the periphasis raises enough, despite adding an extra fuel tank to the engine and then proceeding with attaching the stack decoupler to the tri-coupler. (and even thin this added tank likes to explode on me half the time at around 8,000 meters or so into the launch.
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