Maneuver Test Object Definitions

Conversations pertaining to the testing of GMAT

Maneuver Test Object Definitions

Spacecraft Definitions

ScA is the Baseline spacecraft with the following definition
Sc.CentralBody = Planet;

'//State information';
'Sc.Epoch = 21545.000000000;'

'//Physical Information';
'Sc.VehicleDryMass = 850;'
'Sc.Cd = 2.2;'
'Sc.Cr = 1.8;'
'Sc.DragArea = 15;'
'Sc.SRPArea = 1;'
'//Attitude';
'Sc.AttitudeRefFrame = ''MJ2000Eq'';'
'Sc.Q1 = 0;'
'Sc.Q2 = 0;'
'Sc.Q3 = 0;'
'Sc.Q4 = 1;'

ScB has drymass increased to 1000kg
ScC has a lower Cd value and should not change the script in any way because drag is not modeled
ScD has a lower Cr and should also not affect the output of the scripts due to not being modeled
ScE has a higher drag area and should not affect the output due to not being modeled
ScF has Sc.Q1 as the main direction of the attitude
ScG has Sc.Q2
ScH has Sc.Q3
ScI has higher SRP area and should never affect the outcome of the results
JTichy

Posts: 26
Joined: Tue May 12, 2009 9:02 pm

Re: Maneuver Test Object Definitions

Tank Definitions

TankA being the baseline tank with the following values

'// Tank A Baseline Tank';
'TankA.TankMass = 725;'
'TankA.TankPressure = 1200;'
'TankA.TankTemperature = 20;'
'TankA.TankRefTemperature= 12;'
'TankA.TankVolume = 0.8;'
'TankA.TankFuelDensity = 1029;'
'TankA.TankPressureControl = 1;'

TankB has the tank filled at Maximum Capacity for the given parameters where Tank Mass = 820
TankC has ultra high pressure of 2500
TankD has lower pressure of 725
TankE has extremely high temp of 200
TankF has a low temperature of 2
TankG has a high ref temp of 100
TankH has a low ref temp of 2
TankI has a large tank Volume = 80
TankJ has a low fuel density and altered tank volume to compensate
TankK has extremely high fuel density 2500
L - V are same as above except with Blowdown modeled for pressure regulation
JTichy

Posts: 26
Joined: Tue May 12, 2009 9:02 pm

Re: Maneuver Test Object Definitions

Thruster Definitions

Thruster A is the chosen baseline thruster and has the following definition
ThrusterA.CoordinateSystem = ',CoordSys,'
ThrusterA.Origin = ',Planet,'
ThrusterA.Axes = 'AxesCode'
ThrusterA.Element1 = 1
ThrusterA.Element2 = 0
ThrusterA.Element3 = 0
ThrusterA.DutyCycle = 1
ThrusterA.ThrustScaleFactor = 1
ThrusterA.DecrementMass = true
ThrusterA.Tank = {'tanksin'}
ThrusterA.GravitationalAccel = 9.81
ThrusterA.C1 = 10
ThrusterA.C2 = 0.25
ThrusterA.C3 = 0.25
ThrusterA.C4 = 0
ThrusterA.C5 = 0
ThrusterA.C6 = 0
ThrusterA.C7 = 0
ThrusterA.C8 = 0
ThrusterA.C9 = 0
ThrusterA.C10 = 0
ThrusterA.C11 = 0
ThrusterA.C12 = 0
ThrusterA.C13 = 0
ThrusterA.C14 = 0
ThrusterA.C15 = 0
ThrusterA.C16 = 0
ThrusterA.K1 = 300
ThrusterA.K2 = 0.25
ThrusterA.K3 = 0.25
ThrusterA.K4 = 0
ThrusterA.K5 = 0
ThrusterA.K6 = 0
ThrusterA.K7 = 0
ThrusterA.K8 = 0
ThrusterA.K9 = 0
ThrusterA.K10 = 0
ThrusterA.K11 = 0
ThrusterA.K12 = 0
ThrusterA.K13 = 0
ThrusterA.K14 = 0
ThrusterA.K15 = 0
ThrusterA.K16 = 0

Thruster B has its direction equally spaced in all directions of the coordinate system where X = Y = Z = 0.5774
Thruster C has a low duty cycle of 0.1
Thruster D has a low thrust scale factor of 0.1
Thruster E has an alternate g_accel of 12.14
Thruster F has a loaded thruster polynomial which evaluates to 10 Newtons when coupled with Tank A
Thruster G has a loaded Isp polynomial which evaluates to 300 seconds when coupled with Tank A
Thruster H has decrement mass turned off
JTichy

Posts: 26
Joined: Tue May 12, 2009 9:02 pm

Re: Maneuver Test Object Definitions

Coordinate Systems

CS0 is Mean of J2000 Equatorial
CS1 is VNB
CS2 is LVLH where X_GMAT = Z_FreeFlyer; Y_GMAT = Y_FreeFlyer; Z_GMAT = -X_FreeFlyer
CS3 is Spacecraft Body Coordinate System
CS4 is a custom defined VNB frame and compared against FreeFlyers regular VNB for accuracy (CS1 and CS4 scripts should produce the same output)
JTichy

Posts: 26
Joined: Tue May 12, 2009 9:02 pm 