thrusters.go

package smd

// EPThruster defines a EPThruster interface.
type EPThruster interface {
	// Returns the minimum power and voltage requirements for this EPThruster.
	Min() (voltage, power uint)
	// Returns the max power and voltage requirements for this EPThruster.
	Max() (voltage, power uint)
	// Returns the thrust in Newtons and isp consumed in seconds.
	Thrust(voltage, power uint) (thrust, isp float64)
}

/* Available EPThrusters */

// PPS1350 is the Snecma EPThruster used on SMART-1.
type PPS1350 struct{}

// Min implements the EPThruster interface.
func (t *PPS1350) Min() (voltage, power uint) {
	return t.Max()
}

// Max implements the EPThruster interface.
func (t *PPS1350) Max() (voltage, power uint) {
	return 350, 2500
}

// Thrust implements the EPThruster interface.
func (t *PPS1350) Thrust(voltage, power uint) (thrust, isp float64) {
	if voltage == 350 && power == 2500 {
		return 89e-3, 1650
	}
	panic("unsupported voltage or power provided")
}

// PPS5000 is the latest Snecma EPThruster.
type PPS5000 struct{}

// Min implements the EPThruster interface.
func (t *PPS5000) Min() (voltage, power uint) {
	return t.Max()
}

// Max implements the EPThruster interface.
func (t *PPS5000) Max() (voltage, power uint) {
	return 350, 2500 // From 1350, not the actual values!
}

// Thrust implements the EPThruster interface.
func (t *PPS5000) Thrust(voltage, power uint) (thrust, isp float64) {
	if voltage == 350 && power == 2500 {
		return 310e-3, 1800
	}
	panic("unsupported voltage or power provided")
}

// BHT1500 is a Busek 1500 EPThruster.
// Below is the high thrust mode
type BHT1500 struct{}

// Min implements the EPThruster interface.
func (t *BHT1500) Min() (voltage, power uint) {
	return t.Max()
}

// Max implements the EPThruster interface.
func (t *BHT1500) Max() (voltage, power uint) {
	return 1, 2700 // Didn't find the voltage
}

// Thrust implements the EPThruster interface.
func (t *BHT1500) Thrust(voltage, power uint) (thrust, isp float64) {
	return 179e-3, 1865
}

// BHT8000 is a Busek 1500 EPThruster.
// Below is the high thrust mode
type BHT8000 struct{}

// Min implements the EPThruster interface.
func (t *BHT8000) Min() (voltage, power uint) {
	return t.Max()
}

// Max implements the EPThruster interface.
func (t *BHT8000) Max() (voltage, power uint) {
	return 400, 8e3 // From datasheet
}

// Thrust implements the EPThruster interface.
func (t *BHT8000) Thrust(voltage, power uint) (thrust, isp float64) {
	return 449e-3, 2210
}

// VX200 is a VASIMR 200 kW EPThruster.
// Data from http://www.adastrarocket.com/Jared_IEPC11-154.pdf
type VX200 struct{}

// Min implements the EPThruster interface.
func (t *VX200) Min() (voltage, power uint) {
	return t.Max()
}

// Max implements the EPThruster interface.
func (t *VX200) Max() (voltage, power uint) {
	return 1, 200e3 // Incorrect voltage
}

// Thrust implements the EPThruster interface.
func (t *VX200) Thrust(voltage, power uint) (thrust, isp float64) {
	return 5.8, 4900
}

// HERMeS is based on the NASA & Rocketdyne 12.5kW demo
type HERMeS struct{}

// Min implements the EPThruster interface.
func (t *HERMeS) Min() (voltage, power uint) {
	return t.Max()
}

// Max implements the EPThruster interface.
func (t *HERMeS) Max() (voltage, power uint) {
	return 800, 12500
}

// Thrust implements the EPThruster interface.
func (t *HERMeS) Thrust(voltage, power uint) (thrust, isp float64) {
	if voltage == 800 && power == 12500 {
		return 0.680, 2960
	}
	panic("unsupported voltage or power provided")
}

// GenericEP is a generic EP EPThruster.
type GenericEP struct {
	thrust float64
	isp    float64
}

// Min implements the EPThruster interface.
func (t *GenericEP) Min() (voltage, power uint) {
	return 0, 0
}

// Max implements the EPThruster interface.
func (t *GenericEP) Max() (voltage, power uint) {
	return 0, 0
}

// Thrust implements the EPThruster interface.
func (t *GenericEP) Thrust(voltage, power uint) (thrust, isp float64) {
	return t.thrust, t.isp
}

// NewGenericEP returns a generic electric prop EPThruster.
func NewGenericEP(thrust, isp float64) *GenericEP {
	return &GenericEP{thrust, isp}
}