SimpleKSPOrbitalOperations0.001

-- SimpleKSPOrbitalOperations is a purely calculation based lua library, with some constants hardcoded for Kerbal Space Program
-- v0.001
-- to use, put
-- require "SimpleKSPOrbitalOperations"
-- in your lua script, or run it with
-- dofile("SimpleKSPOrbitalOperations")
-- Original Work Copyright 2012, Nadrek, insofar as any elements that aren't obvious, trivial, or mathematics are concerned (none of which are copyrightable)
-- licensed under your choice of GPLv2, GPLv3, or Creative Commons Attribution-ShareAlike 3.0 Unported (CC BY-SA 3.0)  http://www.gnu.org/licenses/gpl-2.0.html  or  http://www.gnu.org/licenses/gpl.html  or  http://creativecommons.org/licenses/by-sa/3.0/
-- KSP specific functions will have KSP in the name; other functions will not, and can be used for real life calculations as well.

-- This script requires SimpleKSPOrbitalMechanics to do the math, which in turn requires SimpleOrbitalMechanics to do the heavy mathematical lifting.
-- This script contains KSP specific functions and calls useful to and reliant on Kerbal Space Program, MechJeb, and MechJeb's Autom8 module.


require "SimpleKSPOrbitalMechanics"



local function launchSkooFromApPeInc(Ap, Pe, Inclination)
  -- Ap is the Apoapsis in meters
  -- Pe is the Periapsis in meters
  -- Inclination is the desired orbital inclination in degrees
  -- FUTURE include wait(time) or warp(time), but right now do print(vessel.time) wait(2) print(vessel.time) end    freezes the game for 2 seconds and then displays two identical times.

  -- REQUIRES globalSomMainBodyReset to have been called properly
  --   the simple way is to run globalSkomKSPMainBodyResetBasedOnGuessing() first!

  -- First, let's reset our main body; perhaps we've switch orbits recently!
  globalSkomKSPMainBodyResetBasedOnGuessing()

  -- Check to see if the Ap and Pe is obviously bad
  if Ap == (-1) or Pe == (-1) then
    print("ERROR: Ap or Pe is -1, which indicates an inability to get a prior calculation to come out right when orbiting " .. globalSomMainBodyName)
    return
  end


  print("Launching to a Periapsis of " .. Pe .. " meters with Inclination " .. Inclination .. " degrees at " .. vessel.time)
  mechjeb.launchTo(Pe, Inclination)
  wait(mechjeb.free)
  mechjeb.autoStageActivate()
  local StartTime = vessel.time -- in seconds, with a massive offset.  Maybe for use later.
  print("Followon launch circularization at " .. StartTime)
  mechjeb.circularize()
  wait(mechjeb.free)
  print("Changing Apoapsis to " .. Ap .. " meters starting at " .. vessel.time)
  mechjeb.changeAp(Ap)
  wait(mechjeb.free)
  print("Tweaking orbit Pe starting at " .. vessel.time)
  mechjeb.changePe(Pe)
  wait(mechjeb.free)
  print("Tweaking orbit Ap starting at " .. vessel.time)
  mechjeb.changeAp(Ap)
  wait(mechjeb.free)
  mechjeb.autoStageDeactivate()
  print("Launch complete at " .. vessel.time)
  printSkomKSPCurrentOrbitalElements()
end


local function launchSkooMolniyaFromIncMoe(Inclination, MarginOfError)
  -- Inclination is the desired orbital inclination in degrees, and should be 63.4, -63.4, 116.6, or -116.6 degrees
  --   to correctly counteract the gravitational effect of an oblate body, like Earth's fat equatorial bulge
  -- MarginOfError 0.001 means allow 0.1% for a "safety zone" above the minimum stable altitude, or below the Hill sphere of influence.
  --   Do this if you want to just barely scrape by!
  --   2 means allow a 200% "safety zone" above the minimum stable altitude, or below the Hill sphere of influence.
  --   Do this if you want to have a much less eccentric orbit - perhaps you want to keep certain orbits clear for other uses!
  --   If in doubt, try setting MarginOfError to 0.1
  -- REQUIRES globalSomMainBodyReset to have been called properly
  --   the simple way is to run globalSkomKSPMainBodyResetBasedOnGuessing() first!


    -- First, let's reset our main body; perhaps we've switch orbits recently!
  globalSkomKSPMainBodyResetBasedOnGuessing()

  -- Now, did we get a good Inclination?  If not, give a polite warning.
  if Inclination ~= (63.4) and Inclination ~= (-63.4) and Inclination ~= (116.6) and Inclination ~= (-116.6) then
    print "WARNING: Classic Molniya orbits must have an inclination of 63.4, -63.4, 116.6, or -116.6 degrees"
    print "   to correctly counteract the gravitational effect of an oblate body, like Earth's fat equatorial bulge"
    print "   Continuing to try anyway.  You have been politely warned!"
  end

    -- Now, calculate a Molniya orbit.
  local localAp, localPe = calcSkomMolniyaApPeFromMainBodyCurrentlyBeingOrbitedFromMoe(MarginOfError)

    -- Did we get one?  If we got -1 back, we didn't.
  if localAp == (-1) or localPe == (-1) then
    print("ERROR: Cannot calculate a stable Molniya orbit with this MarginOfError around " .. globalSomMainBodyName)
    return
  end


  launchSkooFromApPeInc(localAp, localPe, Inclination)
end

function colaunchSkooFromApPeInc(Ap, Pe, Inclination)
    local coToLaunchWith = coroutine.create(launchSkooFromApPeInc)
    coroutine.resume(coToLaunchWith, Ap, Pe, Inclination)
end


function colaunchSkooMolniyaFromIncMoe(Inclination, MarginOfError)
    local coToLaunchWith = coroutine.create(launchSkooMolniyaFromIncMoe)
    coroutine.resume(coToLaunchWith, Inclination, MarginOfError)
end

print "Usage: colaunchSkooMolniyaFromIncMoe(Inclination, MarginOfError)"
print "   If you're currently landed in launch position, this will either launch you into a Molniya orbit, or"
print "   give you a message stating that no stable Molniya orbit exists for this body and Margin of Error."
print "   Inclination should be 63.4, -63.4, 116.6, or -116.6 degrees"
print "   Inclination is the desired orbital inclination in degrees, and should be 63.4, -63.4, 116.6, or -116.6 degrees"
print "     to correctly counteract the gravitational effect of an oblate body, like Earth's fat equatorial bulge"
print "   MarginOfError 0.001 means allow 0.1% for a \"safety zone\" above the minimum stable altitude, or below the Hill sphere of influence."
print "     Do this if you want to just barely scrape by!"
print "     2 means allow a 200% \"safety zone\" above the minimum stable altitude, or below the Hill sphere of influence."
print "     Do this if you want to have a much less eccentric orbit - perhaps you want to keep certain orbits clear for other uses!"
print "     If in doubt, try setting MarginOfError to 0.1"
print "   Ex: "
print "     colaunchSkooMolniyaFromIncMoe(-63.4, 0.01)"
print "   REQUIRES globalSomMainBodyReset to have been called properly"
print "     the simple way is to run globalSkomKSPMainBodyResetBasedOnGuessing() first!"
print "Usage: colaunchSkooFromApPeInc(Ap, Pe, Inclination)"
print "   Ap is the Apoapsis in meters"
print "   Pe is the Periapsis in meters"
print "   Inclination is the desired orbital inclination in degrees"
print "   Ex: 125km circular orbit, 0 degree inclination"
print "     colaunchSkooFromApPeInc(125000, 125000, 0)"
print "   REQUIRES globalSomMainBodyReset to have been called properly"
print "     the simple way is to run globalSkomKSPMainBodyResetBasedOnGuessing() first!"