Module metrics 

What a flight comes to: its peaks, its apogee, its stability margins, the ejection delay that would fire at apogee, and where each body landed (the flight-metrics milestone and its decision record; the guide’s Flight metrics page).

• FlightMetrics is an Observer: fly a Simulation with it, then ask it for a FlightSummary. It finds each peak on the integrator’s dense output, not in a recorded table, so a peak between two rows is not missed (Loft lesson L34).
• stability gives the static margin and the margin at the flight’s Mach number at one instant, and margin the margin of any flow. A margin that would be a ratio of nearly cancelling slopes is None, with the pitch-moment slope beside it (L33).
• optimum_delays flies the rocket with its charges held and gives, for each motor, the delay from its burnout to that apogee, so it doesn’t depend on the delay flown (L94).
• Anything that did not happen is None, never a zero, and every height names its datum (L35).

Heights. A height here is the center of mass’s ellipsoidal height above the launch site’s, Sample::height_above_ground_m. The center of mass starts above the site (the rocket stands on the rail), at FlightSummary::launch_height_m; Apogee::gain_m counts from there, as OpenRocket’s altitude does.

Structs

Apogee

The apogee of the flight’s center of mass.

FlightMetrics

Watches a flight and keeps its peaks, and its stability from the rail exit to apogee or the first deployment.

FlightSummary

The metrics of one flight. Every field that may not have happened is an Option.

Landing

Where something landed: the center of mass as it reached the launch site’s ellipsoidal height.

Margin

The stability margin of one flow.

OptimumDelay

The ejection delay that would fire a motor’s charge at apogee.

Peak

A peak over the flight, with where and when it came.

Stability

The rocket’s stability at one instant.

Constants

MARGIN_CONDITION_LIMIT

The largest ratio κ = Σ |C_Nα,i| / C_Nα at which a margin is given: √10.

STATIC_MARGIN_MACH

The Mach number of the static margin: the air at rest, as RocketPy’s static_margin takes it.

Functions

margin

The margin of aero in flow with the center of mass at cg_station_m (m aft of the nose tip). See Margin and MARGIN_CONDITION_LIMIT for when it is None.

optimum_delays

The optimum ejection delay of each motor that burns out before apogee: the time from its burnout to the apogee of the same flight with every recovery charge held, so that the answer is a property of the rocket, its motors and its air, and not of the delay flown (Loft lesson L94).

stability

The static margin and the flight margin of aero at time_s, with the center of mass height_above_ground_m above the launch site and at cg_station_m on the airframe, and the flight’s air at Mach mach pressing with dynamic_pressure_pa.

weakest_margin

The least margin of aero at Mach mach, the air along the axis, over the direction it crosses the rocket, with the center of mass at cg_station_m: margin in the weakest plane, whose direction it gives (Margin::roll_rad); or a plane where no margin can be given, if there is one (#329).