input
config
units SI
time_format MET
gravity_model spherical
earth_model spherical
burn_model constant
plot2d_resolution 200
fit_max_iterations 1000
fit verbose
position
lat 23.517
lon -44.838
alt 354500
heading 137
vup -4.25
vtot 7696.0
landing_site
name KSC
burn_peg4
name Deorbit
tig 000/00:43:00.0
thetaT 130
H 65.8
c1 14992
c2 -0.6017
ops 3
output
list
position entry_interface
plot2d
file shuttle_deorbit.dat
x time
y altitude
end
Maybe I am doing something wrong ?
else if (block == "state_vector")
{
if (key == "met")
{
if (options.time_format_flag == 0)
{
options.initial_met = atof (element.c_str());
}
else if (options.time_format_flag == 1)
{
options.initial_met = converter.parse_time(element);
}
}
}
else if (block == "position")
{
if (key == "met")
{
if (options.time_format_flag == 0)
{
options.initial_met = atof (element.c_str());
}
else if (options.time_format_flag == 1)
{
options.initial_met = converter.parse_time(element);
}
}
}
I'm trying to experiment with the Leo Targeting tool, but stuck at the first hurdle. Can anyone explain in plain language how to actually run the tool
my end goal is to create PEG-4 targets for Shuttle insertion and de-orbit.
launch_site
name KSC
lat 0.0
lon 0.0
burn_peg4
name OMS2
tig APOGEE
thetaT 315
H APOGEE height wanted
c1 0.0
c2 0.0
ops 1
PEG 4 is only available and usefull for Orbit Insertion (OPS1) and Deorbit (OPS3)
The page here is quite helpful for the handling of the soft
http://www.science-and-fiction.org/science/leo_05.html
It is better to use the external soft, allowing much more iterations ( only 30 in the sim to avoid overstressing the cpu)
But if you have a good computer, I can show which line to modify to allow more in sim iterations, and avoid exporting the state vector into a config file.
For example, if you take the last dev version with iss scenario ( 2 mn before countdown for ISS window), you end up in Orbit with a very close to real parameters.
You can use those parameters for PEG 4 and a good insertion.
I played just with The Ht ( height ) paramter to have a higher targeted apsis
You see that the PEG 4solution converges and give some PEG 7 parameters, ready to be fired at next apogee.
you can try those kind of parameters for OPS 1insertion, though a good PEG prograde burn ( DVx) at the Apogee is as good.
Which gives a good insertion, ready for Rendez Vous phasing and a small out of plane burn to reduce Relative Inclination ( which will vary anyway with nodal precession)
For OPS3, same problem.
Better to be on an almost circular Orbit, deorbit burn forecasted 45 mn before Landing Site, and standard OPS 3 deorbit parameters for a 150 Nm circular Orbit
If you use those paramters for the scenario in the launcher, you should be good for a PEG 4 OPS 3 try
(Scenario that goes with the tutorial http://wiki.flightgear.org/Flying_the_Shuttle_-_Deorbit_Preparation_Advanced)
- Code: Select all
#Deorbit for KSC// one Orbit before
--aircraft=SpaceShuttle-mission
--lat=28.0
--lon=-60.0
--heading=138.0
We got some pretty decent solution
Though it is far better to do it with the LEO tool, much more accurate for reentry range and Perigee at Entry Interface ( two examples below)
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