Jump to content


  • Posts

  • Joined

  • Last visited


91 Excellent

Profile Information

  • About me
    Sr. Spacecraft Engineer
  1. For the thrust versus pressure graph, should all the engines but the rapier drop to 0 thrust instead of 1 in vacuum?
  2. Was it PreciseNode plus changing the focus or conics mode to view the trajectory?
  3. Hard to say for sure without pictures. Larger rockets are easier to control because all the stacks help keep the rocket stable in the direction of the airflow. If you are using multiple stacked tanks in you LFO rockets, then the top tanks use fuel first. This causes your center of mass to get lower over time. When you CoM goes behind your center of pressure, then your rocket want to flip. However solids use one big tank, so they don't have the shifting CoM.
  4. My lifter spaceplane ascents to LKO go like this: - Lift off - 10-20* pitch up until speed above 270 m/s - Raise pitch to maintain speed below 290 m/s (high drag above this speed) - At 10-14km, pitch down to 0-5* and accelerate until 500 m/s closer to 10km for only turbojets and to 14km for only rapiers - Slowly raise pitch to 15* while building speed 5* pitch up per 50 m/s speed increase above 500 m/s seems to work well - Grab the last bit of airbreathing speed by pitching back down to 5-10* upslope Do this around 17km for turbos and 20km for rapiers - As soon as your speed indicator stops going up, punch the rockets and/or switch modes on the rapiers - Get out of dodge by aiming at 20* upslope until 32km - After 32km follow the top of prograde marker until your at 5-6* pitch - Cruise until your desired apoapsis - Cruise out of atmospshere to apoapsis and circularize You don't have to do all that exactly, but its what I do when efficiency is more important than lackadaisical piloting.
  5. Yes, you need to be going the same direction of the dots. To swap directions optimally you will need around you perapsis velocity in dv remaining. Swapping orbit directions: - At peri, burn prograde to raise your apo to right before the SOI edge - At apo, burn retrograde for 2x you apo velocity to swap your orbit direction - At peri, burn retrograde to lower your apo back to its original value Next time set up the polar, prograde, or retrograde orbit before you enter Mun's SOI or at the latest just after you enter its SOI.
  6. Well 25km was just a guess as it generally depends on your speed and heat characteristics. After it loses all ablator the heatshield is just another part, but by that point you were going slow enough that a normal part with that thermal mass and heat tolerance would survive just fine. Basically, you were lucky... this time. However, if you can find ways to increase your drag, you don't even really need a heatshield at all for Kerbin re-entry from something like Mun or Minmus.
  7. Another launch window planner with porkchop plots is here: http://alexmoon.github.io/ksp/ You are coming in too hot, which is typical for your first interplanetary transfers. The move you are doing is referred to as the insertion burn in that planner. If you leave at the first window of the game on day 231, and perform an optimal Hohmann transfer where your apoapsis just barely arrives at the planets orbit at same time the planet arrives there, then the planner says the insertion burn should only cost you 640-650 m/s dv. However as Empiro points out, if you can take the heat then you can reduce the dV require down to <100 m/s by aerobraking in Duna's mid-to-upper atmosphere.
  8. You are not alone. This spinning thing is something we all initially had trouble with in the new 1.0+ aero until we learned to engineer and fly new rockets. Spinning out of control essentially comes down to a contest between drag and control. When the drag overcomes your control authority, you go for a spin. You can decrease drag by staying closer to prograde and building a more aerodynamic rocket. You can increase control using engine gimbals, stabilizer wheels, and control fins (like AV-R8). Also note that drag increases significantly right around mach one (340 m/s), so you should stay pointed as prograde as possible at speeds around 290-400 m/s. On a rocket, any control fins should be as low and outside as possible. If you are using control fins on more than one stage, the CoL needs to stay below the CoM at all times, even as the tanks empty.
  9. If you had lost all ablator by 25km then you likely would have been toast. Craft lose heat from radiation and in atmosphere also from convection. You can watch the process yourself by right-clicking a part, after you turn on the thermal details in the action menu using Alt-F12 -> physics -> temperature -> action menu.
  10. Fairing closing can be annoying to me as well. Some things I noticed are that once it goes orange it tends to stay orange, even when it would have been green if it never went orange first. Another is that sections need to be some minimum size or you can't seem to close them. Still, I spent 5 minutes once trying to get a fairing to close again at the same place it closed before after I changed something minor. After that is when I decided to test if they were even worth adding for Kerbin ascent (not really).
  11. I suggest you roll over so that the side of your rocket that usually faces east will be facing north (Q or E keys). That will also spin your nav-ball so north is where east would usually be on it. After that, you can just do what you usually would do going east, only now you just happen to be going north.
  12. I think Claw has fixed the airbrakes and action groups problem in his Stock Bug Fixes mod, if that would help you.
  13. I have seen some severe and abnormal overheating with some science instruments placed on the back face of a mk2 cargo bay. Technically that means they were attached to the part behind the bay, but they still should have been protected. I'm not sure whats going on, but at one point I had the thought that it seemed like they got incoming heat flux like they were outside the bay, but outgoing heat flux like they were inside of it. I need to do more testing, but I don't recall having the same problems with the front edge of the cargo bay.
  14. So far (*oOo*) in stock I have not been able to eject a fairing below 30km without the pieces causing rapid unplanned disassembly of the lifter. I do favor high TWR rocket designs, so they are going at a good clip by that point.
  15. Yeah, but not using oxidizer is also a stealth reduction in effectiveness unless you switch to Mk2 or Mk3 liquid fuel only tanks, which have a better dry mass ratio that normal tanks with no oxidizer. The reduction comes because the engines still use the same mass of total fuel per second, but now it all is LF instead of LF/Ox.
  • Create New...