Hoverslam Controller EPIC

[lamont-granquist]

Near term goal: multi-stage airless RF/RO landing

• ullage time into stage stats.
• ullage integration with burn simulation + executor.
• spoolup variables into stage stats.
• spoolup integration with burn simulation (actually simulate the curve).
• consider the comments around throttle authority and how it affects the simulation.
• should be able to take a multistage lander requiring ullage and spoolup in RF and hit a button and have it work.

Middle term goal: aerodynamics

• add CdAref drag cube calcs into stage stats.
• use atmosphere model and bottom-end CdAref in the sim for drag (will support FAR changes to atm model, but not to aerodynamics)
• should be able to do multistage powered landings on Kerbin or even Earth with RF spoolup/ullage.

Middle term goal: targeting position

• add a simple optimizer to adjust an impulsive maneuver to adjust the landing position
• consider finding an optimal deorbit burn to target a position
• probably need some boundary controls over the time of maneuver, don't want it too soon, don't want it too late
• have the controller execute the planned impulse
• pick a target by clicking on the map, or select a waypoint
• should be able to land very close to a designated spot

Late term goal: aerodynamics polish

• add parachutes like the ReentrySim
• look at adding aerobrakes (OPTIONAL)
• gridfins? (OPTIONAL)
• figure out what the aerocapture burn feature is

Final goal: anything else required to replace the ReentrySim/LandingController

• using rcs + rcs-balancer to translatron over to more precisely hit the landing site?
• delete the existing ReentrySim/LandingController and make the HoverslamController the LandingController?

Out of scope, at least for now:

• precision adjustment of landing site during descent
• (no precise landing back on a launchpad or "catching" of the rocket)
• "biome hopping"
• automatically selecting flat surfaces
• passing off to "hover"
• passing off to "surface normal attitude"
• optimality and all kinds of non-gravity-turn steering controls.
• excessively RF caveman (deorbit stage should really have 2 ignitions, descent stage should be throttleable or have a few relights)
• sequential engine shutdown.