ElectricTank

Field	Description
AllowNegativeFuelMass	This field allows the ElectricTank to have negative fuel mass which can be useful in optimization and targeting sequences before convergence has occurred. This field cannot be modified in the Mission Sequence. Data Type Boolean Allowed Values true, false Access set Default Value false Units N/A Interfaces GUI, script
FuelMass	The mass of fuel in the tank. Data Type Real Allowed Values Real > 0 Access set, get Default Value 756 Units kg Interfaces GUI, script

Use of ElectricTank Resource in Conjunction with Maneuvers

An ElectricTank is used in conjunction with finite maneuvers. To implement a finite maneuver, you must first create both an ElectricThruster and a FiniteBurn resource. You must also associate the ElectricTank with the ElectricThruster resource and you must associate the ElectricThruster with the FiniteBurn resource. The finite maneuver is implemented using the BeginFiniteBurn/EndFiniteBurn commands. See the BeginFiniteBurn/EndFiniteBurn command documentation for worked examples on how the ElectricTank resource is used in conjunction with finite maneuvers.

For a complete descripton of how to configure all Resources required for electric propulsion modelling, see the Tutorial named Chapter 12, Electric Propulsion

Behavior When Configuring Tank and Attached Tank Properties

Create a default ElectricTank and attach it to a Spacecraft and ElectricThruster.

%  Create the ElectricTank Resource
Create ElectricTank aTank
aTank.AllowNegativeFuelMass = false
aTank.FuelMass = 756

%  Create an ElectricThruster and assign it a ElectricTank
Create ElectricThruster aThruster
aThruster.Tank = {aTank}

%  Add the ElectricTank and Thruster to a Spacecraft
Create Spacecraft aSpacecraft
aSpacecraft.Tanks = {aTank}
aSpacecraft.Thrusters = {aThruster}    

As exhibited below, there are some subtleties associated with setting and getting parent vs. cloned resources. In the example above, aTank is the parent ElectricTank resource and the field aSpacecraft.Tanks is populated with a cloned copy of aTank.

Create a second spacecraft and attach a fuel tank using the same procedure used in the previous example. Set the FuelMass in the parent resource, aTank, to 900 kg.

%  Add the ElectricTank and ElectricThruster to a second Spacecraft
Create Spacecraft bSpacecraft
bSpacecraft.Tanks = {aTank}
bSpacecraft.Thrusters = {aThruster}
aTank.FuelMass = 900    %Can be performed in both resource and 
                        %command modes

Note that in the example above, setting the value of the parent resource, aTank, changes the fuel mass value in both cloned fuel tank resources. More specifically, the value of both aSpacecraft.aTank.FuelMass and bSpacecraft.aTank.FuelMass are both now equal to the new value of 900 kg. We note that the assignment command for the parent resource, aTank.FuelMass, can be performed in both resource and command modes.

To change the value of the fuel mass in only the first created spacecraft, aSpacecraft, we do the following.

%  Create the Fuel Tank Resource
BeginMissionSequence
aTank.FuelMass = 756   %Fuel tank mass in both s/c set back to default
aSpacecraft.aTank.FuelMass = 1000 %Can only be performed in command mode.      

As a result of the commands in the previous example, the value of aSpacecraft.aTank.FuelMass is 1000 kg and the value of bSpacecraft.aTank.FuelMass is 756 kg. We note that the assignment command for the cloned resource, aSpacecraft.aTank.FuelMass, can only be performed in command mode.

Create a default ElectricTank and attach it to a Spacecraft and ElectricThruster.

%  Create the ElectricTank Resource
Create ElectricTank aTank
aTank.AllowNegativeFuelMass = false
aTank.FuelMass = 756

%  Create an ElectricThruster and assign it a ElectricTank
Create ElectricThruster aThruster
aThruster.Tank = {aTank}

%  Add the ElectricTank and ElectricThruster to a Spacecraft
Create Spacecraft aSpacecraft
aSpacecraft.Tanks = {aTank}
aSpacecraft.Thrusters = {aThruster}   

BeginMissionSequence