Stage#

class Stage#

A single stage of a vessel. Obtain activation (burn) stages from Vessel.Stages / Vessel.StageAt, and decouple stages from Vessel.DecoupleStages / Vessel.DecoupleStageAt.

Note

Delta-v, thrust, TWR, specific impulse, burn time and mass members are only available on activation stages. On decouple stages those members throw InvalidOperationException because stock delta-v data does not apply. Thrust is reported in newtons and masses in kilograms (stock values are converted from kilonewtons and tonnes).

int32_t number()#: The stage number (activation stage for burn stages, decouple stage otherwise).

std::vector<Part> parts()#: The parts that belong to this stage.

Resources resources(bool cumulative = true)#

Returns a Stage::resources() object for this stage.

Parameters:

cumulative – When false, only resources assigned to this stage. When true, resources for this stage and all later activation or decouple stage numbers are included. On activation stages, unstaged resource containers (for example fuel tanks) are grouped with the first higher activation stage before they are detached.

Note

This is an RPC method: call resources() (optional cumulative argument). For activation stages, unstaged resource containers (for example fuel tanks) are grouped with the first higher activation stage before they detach, matching the C# Resources() documentation.

float delta_v()#: Delta-v for this stage in the current situation, in m/s.

Note

Delta-v is only defined for activation stages (decouple is false). Calling this on a decouple stage raises an error.

float vacuum_delta_v()#: Vacuum delta-v for this stage, in m/s.

float sea_level_delta_v()#: Sea-level delta-v for this stage, in m/s.

float thrust()#: Thrust in the current situation, in newtons.

float vacuum_thrust()#: Vacuum thrust, in newtons.

float sea_level_thrust()#: Sea-level thrust, in newtons.

float twr()#: Thrust-to-weight ratio in the current situation.

float vacuum_twr()#: Vacuum thrust-to-weight ratio.

float sea_level_twr()#: Sea-level thrust-to-weight ratio.

float specific_impulse()#: Specific impulse in the current situation, in seconds.

float vacuum_specific_impulse()#: Vacuum specific impulse, in seconds.

float sea_level_specific_impulse()#: Sea-level specific impulse, in seconds.

float burn_time()#: Burn time for this stage, in seconds.

float start_mass()#: The mass of the vessel after the stage activates, in kg.

float end_mass()#: The mass of the vessel when the stage burns out, in kg.

float dry_mass()#: The dry mass of the vessel after the stage activates, in kg.

Note

Includes the parts of all later stages.

float fuel_mass()#: The fuel mass of the vessel when the stage activates, in kg.

Note

Includes the fuel of all later stages, and the fuel left in the parts the stage decouples. The stage burns Stage::start_mass() minus Stage::end_mass().