- Joined
- Apr 28, 2008
- Messages
- 32
- Reaction score
- 0
- Points
- 6
- Location
- Kapolei, HI
- Website
- www.kluempers.org
I downloaded the James Cook & James Cook HLV spacecraft with the needed prequistes. I fired up the Lunar Base scenario and engaged the Prograde Auto-Pilot. It took quite awhile for the spacecraft to settle down and get oriented to the Prograde velocity vector. I understand it is a large ship with a great deal of mass so it will respond slower than a DGIV.
I fired up IMFD and plotted a course to the moon using Target Intercept and it dutifully plotted my course for me. When I use Auto Burn the RCS cannot seem to keep the velocity vector on track. As soon as it engages the main engines the bow of the ship swings heavily to the left (towards earth and soon the main engine cuts off and it take several minutes for the ship to reorient itself to the burn velocity vector and re-engage the main engines.
I found a thread that discusses the AB RCS Threshhold and AB Throttle Down values in the IFMD Configuration. I did not find any documentation on them but I could have missed it. I tried bumping them around remembering to keep AB RCS Threshhold below AB Throttle Down as suggested in the thread but had no luck. I am wondering if the spacecraft configuration needs to be changed to allow the RCS to have bit more power to allow IMFD to work properly. If so what parameters would I need to change. Here is the the current info on the James Cook (Just the first part):
[CONFIG]
MESHNAME="jamescook"
SIZE=100
CAMERA=(0,0,100)
EMPTY_MASS=350000
FUEL_MASS=2400000
MAIN_THRUST=18000000
RETRO_THRUST=12.3e4
ATTITUDE_THRUST=64e5
ISP=150000
TRIM=0.05
PMI=(15.5,22.1,7.7)
CW_Z_POS=0.09
CW_Z_NEG=0.09
CW_X=2.
CW_Y=1.4
CROSS_SECTION=(422,398,148)
COG=2.5
PITCH_MOMENT_SCALE=0.00005
BANK_MOMENT_SCALE=0.00005
ROT_DRAG=(0.43,0.43,0.29)
Thanks for any help you might be able to offer me on this. Orbiter has a steep learning curve and I have a great deal to learn.
DaveK
I fired up IMFD and plotted a course to the moon using Target Intercept and it dutifully plotted my course for me. When I use Auto Burn the RCS cannot seem to keep the velocity vector on track. As soon as it engages the main engines the bow of the ship swings heavily to the left (towards earth and soon the main engine cuts off and it take several minutes for the ship to reorient itself to the burn velocity vector and re-engage the main engines.
I found a thread that discusses the AB RCS Threshhold and AB Throttle Down values in the IFMD Configuration. I did not find any documentation on them but I could have missed it. I tried bumping them around remembering to keep AB RCS Threshhold below AB Throttle Down as suggested in the thread but had no luck. I am wondering if the spacecraft configuration needs to be changed to allow the RCS to have bit more power to allow IMFD to work properly. If so what parameters would I need to change. Here is the the current info on the James Cook (Just the first part):
[CONFIG]
MESHNAME="jamescook"
SIZE=100
CAMERA=(0,0,100)
EMPTY_MASS=350000
FUEL_MASS=2400000
MAIN_THRUST=18000000
RETRO_THRUST=12.3e4
ATTITUDE_THRUST=64e5
ISP=150000
TRIM=0.05
PMI=(15.5,22.1,7.7)
CW_Z_POS=0.09
CW_Z_NEG=0.09
CW_X=2.
CW_Y=1.4
CROSS_SECTION=(422,398,148)
COG=2.5
PITCH_MOMENT_SCALE=0.00005
BANK_MOMENT_SCALE=0.00005
ROT_DRAG=(0.43,0.43,0.29)
Thanks for any help you might be able to offer me on this. Orbiter has a steep learning curve and I have a great deal to learn.
DaveK