Predict air brakes about ksptrajectories

[fat-lobyte]

Question to the community: Is this even relevant, or should I close this?

The thing is, air brakes are not useful for reentry anymore because they will burn right off in the flaming ball of plasma when deployed.

I think the "support" for air brakes should be limited to them being calculated correctly in the state that they are currently in (or rather that the aerodynamic model is based on), and not on a future deploying point.

[PiezPiedPy]

Maybe an airbrake deploy altitude value that can be set by the user in the Gui Descent Profile would be useful.

[fat-lobyte]

Maybe an airbrake deploy altitude value that can be set by the user in the Gui Descent Profile would be useful.

I guess, but that's again a change of the vessel state in the future that we can't yet simulate. Right now we take the vessel as-is, and simulate all the forces on it from all kinds of directions and speeds.

Doing changes of the vessel state in the future requires some changes in the way that we request forces in the future. That's kind of also the reason why we can't predict with parachute deployments and staging.

[PiezPiedPy]

Thanks for explaining, I've not looked at any of the simulation code yet, so I didn't really have a clue if it would work or not, ahh well

[fat-lobyte]

According to a forum user, Current state of air brakes is not used for drag calculations.

I will need to test, and then figure out why they are not considered.

[fat-lobyte]

Turns out the code in StockAeroUtil.SimAeroForce() that is supposed to handle wings and such doesn't do much when it comes to Airbrakes.

I will take a look at that at some point.

[PiezPiedPy]

I might be able to do something about this issue if the Multithreading #123 gets finished.

Since a lot of data is cached for thread safety, including the drag cubes as well as the math for aero calculations it should be possible to swap drag cubes etc as needed.

A simple list that can be changed on the GUI or a widget on a parts info panel should be sufficient for deployment altitude etc.

[mwerle]

Maybe show the impact point with and without air brakes deployed.. since the mod can't know when they will be deployed, by showing impact markers for both situations, the pilot can guestimate where they will land since it will be between the two points depending on when the brakes are deployed?

As for me, my air brakes (Kerbin orbital velocity reentry) don't burn off during reentry.. I deploy them after my reentry burn before hitting any atmosphere.