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Mad_Maelstrom

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Everything posted by Mad_Maelstrom

  1. The heat from aerobraking is a discrete amount of heat, the Sun will be a constant flow of heat. I suspect once a heat shields starts ablating it is only going to last a few minutes, so I think your best bet for getting close to the Sun is to use parts with high temperature limits.
  2. That is an awesome KSP version of the Juno Spacecraft. If you're interested in re-creating the Juno mission in KSP, I have a tutorial on how to do a fly-by of Kerbin to get a gravity assist to Jool. It can save 400 m/s and it's not as hard as doing fly-by gravity assist by other planets. The link to it is below. Juno style Kerbin fly-by to Jool
  3. The twin-boar uses two KR-1 engines. I'm pretty sure these are a reference to the F1-B rocket engines being used by Dynetics to develop an advanced booster for NASA's SLS. The F1-B will be a modern version of the old F-1 rocket engines used on the Saturn V moon rockets.
  4. The "RAPIER" is a reference to the SABER, an engine being developed by the UK for the Skylon launch vehicle. The "Nerv" is a reference to the NERVA rocket program, a program that produced nuclear thermal rockets designed and tested by NASA and the Atomic Energy Commission. The development of these engines required the most powerful nuclear reactors ever built. The "Aerospike" is a real type of rocket engine that automatically compensates for changes in altitude (ambient pressure).
  5. I think you are going to have to send a rescue mission for Jeb. If your spacecraft doesn't have docking ports you are not going to be able to refuel it. Assuming Jeb can EVA, an empty capsule controlled by a probe can rescue him. Jeb can collect all of the science on your spacecraft by flying to the instruments in EVA, right-clicking on them, and selecting "collect data" (or something like that). Also, if you have not rendezvoused in space yet you should check out some tutorials on it, it can be very anti-intuitive. Scott Manley is a great resource. Below is a good video on rendezvous, it's an oldy but a goody. https://youtu.be/AHkY3FusJIQ
  6. What is Juno? Juno is a spacecraft enroute to Jupiter. The unique trajectory Juno is taking to Jupiter requires less delta-v than a direct (Hohmann transfer) route. After a single orbit of ~2 years, Juno returned and flew by Earth to get a gravitational assist to Jupiter. Because the assist came from Earth, Juno could launch whenever the phase angle between Earth and Jupiter was right and didn't have to wait for other bodies (like Mars) to be in the right spot. Who cares? This method can be used to reduce the delta-v required to get to Jool by over 400 m/s! For some perspective, saving 400 m/s will reduce a chemical spacecraft's mass by more than 12% or a nuclear spacecraft's mass by 5.7%. The penalty for using this is one extra maneuver in space, one extra encounter with Kerbin, and ~2 extra Kerbin years of flight time. How is it done? Getting into an orbit with a period of approximately two Kerbin years will put a spacecraft on an encounter with Kerbin. The apoapsis of this initial orbit around the Sun (Kerbol) is important and sensitive to errors. The apoapsis determines where and how fast Kerbin will be encountered and how good the gravitational assist will be. A small retrograde burn is performed at apoapsis to put the spacecraft on an encounter with Kerbin. The approach speed will be greater than the speed the spacecraft originally departed Kerbin. Passing as close to Kerbin as possible (without impacting the atmosphere) will cause the greatest change in velocity and provide the greatest gravitational assist. Below is a graph providing the required delta-v (retrograde burn @ initial apoapsis) and expected final apoapsis after the Kerbin fly-by for a given initial apoapsis around the Sun. Getting to Jool! Before any interplanetary mission, the spacecraft cannot leave Kerbin until the planets are properly positioned. To get an encounter with Jool using this Kerbin fly-by maneuver Jool should be ~60 degrees ahead of Kerbin. A final apoapsis of ~70 billion meters should work well for an encountering with Jool. Based on the graph above, an initial apoapsis of 30.4 billion meters and a retrograde burn of 175 m/s will be enough to get to Jool. Click on the "spoiler" under the graph for guidance on how to use the graph. Getting into the right initial orbit will cost about 1340 m/s of delta-V if leaving Kerbin from a 75 km orbit. Perform the retrograde burn at apoapsis; it should only require ~175 m/s but perform the burn as necessary to encounter Kerbin. The encounter with Kerbin also provides a good opportunity to adjust the inclination of the trajectory to Jool. Below is a screenshot taken shortly after reaching interplanetary space, with a small maneuver node at the apoapsis of the initial orbit the spacecraft will fly-by Kerbin and reach Jool in under 4 Kerbin years. Please share your experiences (good or bad) with trying this method to get to Jool.
  7. The homemade rocket parts are awesome! What mod are these parts from?
  8. I got it, the trick definitely was getting the ascent right.
  9. Between 13 and 15 percent sounds pretty good to me, especially if it is reliable.
  10. OhioBob, The design of your rocket is pretty efficient but I'm having some trouble getting it into orbit. Below is an image of what I built based on your design. I'm running KSP stock and I can almost get it into orbit but I run out of fuel in the 2nd stage before I can get the periapsis out of the atmosphere. The payload is 19.9T and includes SAS and everything above it. What does your launch profile typically look like?
  11. I would love it if eclipes actually cast shadows on other bodies.
  12. None of the planets or moons have different rotational tilts. In the stock game there are no clouds, weather, or wind.
  13. I'm curious about what approach people take to designing their launch vehicles. I personally have 3 criterion I like to constrain. 1) 2-stage to orbit design (this is personal preference, primarily for simplicity) 2) Delta V to orbit of >=4500 m/s (this is based on what I have found online and experience. This assumes SL Isp for the 1st stage and the avg between SL and vac Isp for the 2nd stage) 3) A TWR between 1.5 and 2 at the firing of each stage (A TWR of 2 is almost perfect because it balances gravity loss and air drag losses. I like to start a little lower than 2 because the TWR will rise as the vehicle burns fuel) In addition, I use a spreadsheet to try to pinch-pennies when I'm in career mode. The spreadsheet allows me to consider many different designs of 2-stage launch vehicles rapidly. The spreadsheet only works for liquid fueled rockets and only handles parallel staging with fuel lines (onion staging) or series staging. A link to the excel spreadsheet is here. Let me know what you think of the spreadsheet and what approach you take when designing a launch vehicle.
  14. KSP Version: v0.90.0.705 Beta Windows 8.1 64-bit What Happens: Craft randomly exploded after taking off from Pol Mods / Add-Ons: All Stock Steps to Replicate: http://youtu.be/kNhya-DE7ZA?t=2m30s Result: Craft randomly exploded after taking off from Pol Fixes/Workarounds: ??? Other Notes/Pictures/Log Files: This is my first post. I didn't manage to get the persistent file after it happened. I doubt it matters but here was the craft file at launch. Also please let me know if reporting this issue was worth your time and if there is anything else I should be doing.
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